During the past five decades, dramatic progress has been made in the development of curative therapies for pediatric malignancies. More than 80% of children with cancer who have access to contemporary therapies are expected to survive into adulthood.[1] The therapies responsible for this survival can also produce adverse, long-term, health-related outcomes, referred to as late effects, which appear months to years after completion of cancer treatment.
Many approaches have been used to study the very long-term morbidity associated with childhood cancer and its contribution to early mortality. These initiatives have used a spectrum of resources, including data from the following:
High-quality data is needed to establish the occurrence of and risk profiles for late cancer treatment–related toxicity. The highest quality data typically comes from studies that report outcomes in survivors who have undergone medical assessments that provide well-characterized clinical statuses, treatment exposures, and specific late effects. Regardless of study methodology, it is important to consider selection and participation bias of the cohort studies in the context of the findings.
Late effects are common in adults who have survived childhood cancer. Their prevalence increases as time from cancer diagnosis elapses. Multi-institutional and population-based studies have shown excess risk of hospital-related morbidity among childhood and young adult cancer survivors compared with age- and sex-matched controls, with some evidence that this risk is disproportionately high among survivors of racial and ethnic minority populations.[3,9-13]
Among adults who were treated for cancer during childhood, late effects contribute to a high burden of morbidity. Research has shown the following:[4,7,14-18]
The St. Jude Life (SJLIFE) cohort study aimed to describe the cumulative burden of cancer therapy using the cumulative burden metric, which incorporates multiple health conditions and recurrent events into a single metric that takes into account competing risks. By age 50 years, survivors in this cohort experienced an average of 17.1 chronic health conditions, 4.7 of which were severe/disabling, life threatening, or fatal.[16] This finding contrasts with the cumulative burden in matched community controls, who experienced 9.2 chronic health conditions, 2.3 of which were severe/disabling, life threatening, or fatal (see Figure 1).[16]
SJLIFE cohort study investigators compared the cumulative burden of chronic health conditions among 4,612 adolescent and young adult survivors at the ages of 18 years (the time of transition from pediatric to adult health care systems) and 26 years (the time of transition from family to individual health insurance plans) with that of 625 controls.[20]
The variability in prevalence is related to differences in the following:
Childhood Cancer Survivor Study (CCSS) investigators demonstrated that the elevated risk of morbidity and mortality among aging survivors in the cohort increases beyond the fourth decade of life. By age 50 years, the cumulative incidence of a self-reported severe, disabling, life-threatening, or fatal health condition was 53.6% among survivors, compared with 19.8% among a sibling control group. Among survivors who reached age 35 years without a previous severe, disabling, life-threatening, or fatal health condition, 25.9% experienced a new grade 3 to grade 5 health condition within 10 years, compared with 6.0% of healthy siblings.[4]
The presence of serious, disabling, and life-threatening chronic health conditions adversely affects the health status of aging survivors. The greatest impact is on functional impairment and activity limitations. Predictably, chronic health conditions have been reported to contribute to a higher prevalence of emotional distress symptoms in adult survivors than in population controls.[21] Female survivors demonstrate a steeper trajectory of age-dependent decline in health status than do male survivors.[22] The even-higher prevalence of late effects among cohorts evaluated by clinical assessments is related to the subclinical and undiagnosed conditions detected by screening and surveillance measures.[7]
CCSS investigators also evaluated the impact of race and ethnicity on late outcomes. The study compared late mortality, subsequent neoplasms, and chronic health conditions in Hispanic (n = 750) and non-Hispanic Black (n = 694) participants with those in non-Hispanic White participants (n = 12,397).[23] The following results were observed:
Recognition of late effects, concurrent with advances in cancer biology, radiological sciences, and supportive care, has resulted in a change in the prevalence and spectrum of treatment effects. In an effort to reduce and prevent late effects, contemporary therapy for most pediatric malignancies has evolved to a risk-adapted approach that is assigned on the basis of a variety of clinical, biological, and sometimes genetic factors.
The CCSS reported that with decreased cumulative dose and frequency of therapeutic radiation from 1970 to 1999, survivors have experienced a significant decrease in risk of subsequent neoplasms.[25]
A CCSS investigation examined temporal patterns in the cumulative incidence of severe to fatal chronic health conditions among survivors treated from 1970 to 1999.[26]
Late effects also contribute to an excess risk of premature death among long-term survivors of childhood cancer, as observed in the following studies:
Despite high premature morbidity rates, overall mortality has decreased over time.[28,30,31,35,36]
CCSS investigators evaluated all-cause and health-related late mortality (including late effects of cancer therapy), SMNs, chronic health conditions, and neurocognitive outcomes among 6,148 survivors of childhood acute lymphoblastic leukemia (median age, 27.9 years; range, 5.9–61.9 years) diagnosed between 1970 and 1999.[37]
The risk of late mortality and serious chronic health conditions have decreased over time among survivors of acute myeloid leukemia (AML). CCSS investigators evaluated the long-term morbidity, mortality, and health status of more than 800 5-year survivors of childhood AML based on treatment and treatment era. Survivors were compared by treatment group (hematopoietic stem cell transplant [HSCT]); chemotherapy with cranial radiation [CRT]; chemotherapy only) and decade of diagnosis.[38]
Population-based data from a state cancer registry was used to evaluate differences in survival and long-term outcomes by race and ethnicity among 4,222 children diagnosed with cancer between 1987 and 2012.[12]
An SJLIFE cohort study explored associations between modifiable chronic health conditions and late mortality within the context of social determinants of health.[39]
The CCSS and an SJLIFE cohort study investigated the contribution of cancer-predisposing variants to the risk of SMN-related late mortality (5 years or more after diagnosis).[40]
Little information is available on late mortality among survivors of AYA cancer.[41-43]
Recognition of both acute and late modality–specific toxicity has motivated investigations evaluating the pathophysiology and prognostic factors for cancer treatment–related effects. Consequently, the results of late effects research have played an important role in the following areas:
The common late effects of pediatric cancer encompass several broad domains, including the following:
Late sequelae of therapy for childhood cancer can be anticipated based on therapeutic exposures, but the magnitude of risk and the manifestations in an individual patient are influenced by numerous factors. Multiple factors should be considered in the risk assessment for a given late effect (see Figure 3).[48]
Cancer-related factors:
Treatment-related factors:
Host-related factors:
The need for long-term follow-up of childhood cancer survivors is supported by the American Society of Pediatric Hematology/Oncology, the International Society of Pediatric Oncology, the American Academy of Pediatrics, the Children’s Oncology Group (COG), and the Institute of Medicine. A risk-based medical follow-up is recommended, which includes a systematic plan for lifelong screening, surveillance, and prevention that incorporates risk estimates based on the following:[48]
Part of long-term follow-up also focuses on appropriate screening of educational and vocational progress. Specific treatments for childhood cancer, especially those that directly impact nervous system structures, may result in sensory, motor, and neurocognitive deficits that may have adverse effects on functional status, educational attainment, and future vocational opportunities. In support of this, a CCSS investigation observed the following:[49]
These data emphasize the importance of facilitating survivor access to individualized education services, which has been demonstrated to have a positive impact on education achievement.[50] These services may in turn enhance vocational opportunities.
In addition to risk-based screening for medical late effects, the impact of health behaviors on cancer-related health risks is also emphasized. Health-promoting behaviors are stressed for survivors of childhood cancer. Educational efforts focused on healthy lifestyle behaviors include the following:
Proactively addressing unhealthy and risky behaviors is pertinent because several research investigations confirm that long-term survivors use tobacco and alcohol and have inactive lifestyles despite their increased risk of cardiac, pulmonary, and metabolic late effects.[54-56]
Most childhood cancer survivors do not receive recommended risk-based care. The CCSS observed the following:
Access to health insurance appears to play an important role in risk-based survivor care.[61,62] Lack of access to health insurance affects the following:
Overall, lack of health insurance—related to health issues, unemployment, and other societal factors—remains a significant concern for survivors of childhood cancer.[65,66] Legislation, including the Health Insurance Portability and Accountability Act (HIPAA),[67,68] has improved access and retention of health insurance among survivors, although the quality and limitations associated with these policies have not been well studied.
Transition of care from the pediatric to adult health care setting is necessary for most childhood cancer survivors in the United States.
When available, multidisciplinary long-term follow-up programs in the pediatric cancer center work collaboratively with community physicians to provide care for childhood cancer survivors. This type of shared care has been proposed as the optimal model to facilitate coordination between the cancer center oncology team and community physician groups providing survivor care.[69]
An essential service of long-term follow-up programs is the organization of an individualized survivorship care plan that includes the following:
A CCSS investigation that evaluated perceptions of future health and cancer risk highlighted the importance of continuing education of survivors during long-term follow-up evaluations. A substantial subgroup of adult survivors reported a lack of concern about future health (24%) and subsequent cancer risks (35%), even after exposure to treatments associated with increased risks. These findings present concerns that survivors may be less likely to engage in beneficial screenings and risk-reduction activities.[70]
The CCSS evaluated the surveillance and screening practices of 11,337 childhood cancer survivors. They found that fewer than half of high-risk survivors at increased risk of developing SMNs or cardiac dysfunction received the recommended surveillance, which likely exposes them to preventable morbidity and mortality.[58]
For survivors who have not been provided with this information, the COG offers a template that can be used by survivors to organize a personal treatment summary. For more information, see the COG Survivorship Guidelines, Appendix 1.
To facilitate survivor and provider access to succinct information to guide risk-based care, COG investigators have organized a compendium of exposure- and risk-based health surveillance recommendations, with the goal of standardizing the care of childhood cancer survivors.[71]
The compendium of resources includes the following:
Information concerning late effects is summarized in tables throughout this summary.
Several groups have undertaken research to evaluate the yield from risk-based screening as recommended by the COG and other pediatric oncology cooperative groups.[7,73,74] Pertinent considerations in interpreting the results of these studies include the following:
Collectively, these studies demonstrate that screening identifies a substantial proportion of individuals with previously unrecognized, treatment-related health complications of varying degrees of severity. Study results have also identified low-yield evaluations that have encouraged revisions of screening recommendations. Ongoing research is evaluating the cost effectiveness of screening in the context of consideration of benefits, risks, and harms.
Subsequent neoplasms (SNs) are defined as histologically distinct neoplasms developing at least 2 months after completion of treatment for the primary malignancy. SNs may be benign or malignant. Childhood cancer survivors have increased risks of developing SNs that are multifactorial in etiology and vary according to the following:
SNs are the leading cause of nonrelapse late mortality (standardized mortality ratio, 15.2; 95% confidence interval [CI], 13.9–16.6).[1] The Childhood Cancer Survivor Study (CCSS) reported the following 30-year cumulative incidence rates:[2]
This represents a sixfold increased risk of SNs among cancer survivors, compared with the general population.[2]
Several studies have described the excess risk of SNs.[3,4]
Evidence (excess risk of SNs):
Prolonged follow-up has established that multiple SNs are common among aging childhood cancer survivors.[7,8]
The incidence and type of SNs depend on the following:
Unique associations with specific therapeutic exposures have resulted in the classification of SNs into the following two distinct groups:
Subsequent primary leukemias have been reported in survivors of Hodgkin lymphoma, leukemia, sarcoma, CNS tumors, non-Hodgkin lymphoma, neuroblastoma, and Wilms tumor. In a cohort of nearly 70,000 5-year childhood cancer survivors, survivors had a fourfold increased risk (SIR, 3.7) of developing a leukemia, with an absolute excess risk of 7.5. Specifically, a sixfold relative risk of developing a myeloid leukemia (SIR, 5.8) was reported.[15]
A pooled analysis examined all published studies with detailed treatment data for children with cancer diagnosed between 1930 and 2000. Treatment data included estimated radiation doses to the active bone marrow and doses of specific chemotherapy agents. In this report, 147 cases of second primary leukemia (69% of cases were AML) were matched to 522 controls.[16]
Characteristics of MDS-pCT and AML-pCT include the following:[17,18]
Based on the updated definitions from the World Health Organization, MDS-pCT and AML-pCT are clonal disorders, which arise in patients previously exposed to cytotoxic therapy, either chemotherapy or large-field radiation therapy, for an unrelated neoplasm.[19] The following two types of MDS-pCT and AML-pCT are the most frequently observed among survivors:
The risk of alkylating agent–related MDS or AML is dose dependent, with a latency of 3 to 5 years after exposure; it is associated with abnormalities involving chromosomes 5 (-5/del(5q)) and 7 (-7/del(7q)).[20]
Most of the translocations observed in patients exposed to topoisomerase II inhibitors disrupt a breakpoint cluster region between exons 5 and 11 of the band 11q23 and fuse KMT2A with a partner gene.[20] Topoisomerase II inhibitor–related AML presents as overt leukemia after a latency of 6 months to 3 years and is associated with balanced translocations involving chromosome bands 11q23 or 21q22.[21]
For more information, see the Therapy-Related AML and Therapy-Related Myelodysplastic Neoplasms section in Childhood Acute Myeloid Leukemia Treatment.
Therapy-related solid SNs represent 80% of all SNs, demonstrate a strong relationship with radiation exposure, and are characterized by a latency that exceeds 10 years. The risk of solid SNs continues to increase with longer follow-up. The risk of solid SNs is highest when the following occur:[4,13]
The histological subtypes of solid SNs encompass a neoplastic spectrum ranging from benign and low-grade malignant lesions (e.g., NMSC, meningiomas) to high-grade malignancies (e.g., breast cancers, glioblastomas) (see Figure 4).[4,13,22,23]
Solid SNs in childhood cancer survivors most commonly involve the following:[4,13,22,24-27]
With longer follow-up of adult survivors of childhood cancer cohorts, epithelial neoplasms have been observed in the following:[13,28]
Benign and low-grade SNs, including NMSCs and meningiomas, have also been observed with increasing prevalence in survivors who were treated with radiation therapy for childhood cancer.[4,10,29]
Recipients of HSCT are treated with high-dose chemotherapy and, often, TBI, which makes their risk of SNs unique from that of the general oncology population.
Some well-established solid SNs are described in the following sections.
Female survivors of childhood, adolescent, and young adult cancer treated with radiation therapy to fields including the chest are at increased risk of developing breast cancer.
Evidence (excess risk of breast cancer):
Breast cancer risk varies among childhood cancer survivors who are treated with chest radiation therapy, and the risk is based on multiple clinical factors. The first personalized breast cancer risk prediction model was developed and validated using multinational cohorts of female 5-year cancer survivors who were diagnosed at younger than 21 years and treated with chest irradiation (n = 2,147). The model includes current age, chest radiation field, whether chest radiation was delivered within 1 year of menarche, anthracycline exposure, age of menopause, and history of a first-degree relative with breast cancer. The model is available as an online risk calculator.[46]
Several studies have investigated the clinical characteristics of subsequent breast cancers arising in women treated with radiation therapy for childhood cancer.[47-51]
In a study of female participants in the CCSS who were subsequently diagnosed with breast cancer (n = 274) and matched to a control group of women (n = 1,095) with de novo breast cancer, the following was observed:[53]
Although current evidence does not show a survival benefit from the initiation of breast cancer surveillance in women treated with radiation therapy to the chest for childhood cancer, interventions to promote detection of small and early-stage tumors may improve prognosis. Those with more limited treatment options because of previous exposure to radiation or anthracyclines may especially benefit.
In support of surveillance, SJLIFE investigators observed that breast cancers detected by imaging and/or prophylactic mastectomy were more likely to be in situ carcinomas, be smaller masses (3.3 cm mean tumor size detected by physical examination vs. 1.1 cm detected by imaging), have no lymph node involvement, and be treated without chemotherapy, compared with breast cancers detected by physical findings.[24]
Investigators used data from the CCSS and two Cancer Intervention and Surveillance Modeling Network breast cancer simulation models to estimate the clinical benefits, harms, and cost-effectiveness of breast cancer screening among childhood cancer survivors who were previously treated with chest radiation.[54]
Another CCSS investigation quantified the association between temporal changes in cancer treatment over three decades and subsequent breast cancer risk.[35]
Thyroid cancer is observed after the following:[12,23,55,56]
The 25-year cumulative incidence of thyroid cancer among survivors of childhood cancer is 0.5%.[13] The risk of thyroid cancer among childhood cancer survivors is more than tenfold higher than that of the general population (SIR, 10.5; 95% CI, 9.1–12).[4] Significant modifiers of the radiation-related risk of thyroid cancer include the following:[27,57]
In a Dutch case-control study, childhood cancer survivors with subsequent thyroid cancer were more likely to present with smaller tumors and bilateral tumors than the general population. Treatment outcomes were similar between subsequent and sporadic thyroid cancers.[59]
For information about detecting thyroid nodules and thyroid cancer, see the Thyroid nodules section.
Subsequent CNS tumors represent a spectrum of histological subtypes, from high-grade gliomas to benign meningiomas. A comprehensive Pediatric Normal Tissue Effects in the Clinic (PENTEC) review analyzed the risk of SNs. The study reported a 10-year median latency period for the development of a malignant CNS neoplasm and a 21-year median latency period for the development of a meningioma.[60] Accurate assessment of the prevalence of low-grade and benign lesions is challenging because of the variable opinions and practices related to neuroimaging versus symptom surveillance in long-term survivors treated with cranial irradiation. Therefore, the prevalence of these tumors is likely higher than proven.
Brain tumors develop after cranial irradiation for histologically distinct brain tumors or for management of disease among ALL or non-Hodgkin lymphoma patients.[61] SIRs reported for subsequent CNS neoplasms after treatment for childhood cancer range from 8.1 to 52.3 across studies.[23]
The risk of subsequent brain tumors demonstrates a linear relationship with radiation dose.[25,60,62]
The Dutch Long-Term Effects after Childhood Cancer (LATER) investigators have described the clinical characteristics of childhood cancer survivors who developed histologically confirmed meningiomas.[11]
The European PanCare Childhood and Adolescent Cancer Survivor Care and Follow-Up Studies (PanCareSurFup) investigators described findings in childhood cancer survivors who developed meningiomas or gliomas:[66]
A PENTEC analysis of CNS SNs included 32 published studies of 1,035 subsequent meningiomas after previous radiation therapy in childhood cancer survivors.[60]
Neurological sequelae associated with meningiomas can include seizures, auditory-vestibular-visual deficits, focal neurological dysfunction, and severe headaches.[9] Despite the well-established increased risk of subsequent CNS neoplasms among childhood cancer survivors treated with cranial irradiation and the growing recognition of associated morbidity, the current literature is insufficient to evaluate the potential harms and benefits of routine screening for these lesions.[67] The decision to initiate surveillance should be shared by the cancer survivor and health care provider after carefully considering the potential harms and benefits of surveillance for CNS neoplasms, such as meningioma.
Proton radiation therapy for pediatric medulloblastoma is associated with low rates of brain stem injury and secondary malignancies. The long-term effects were reported in 178 pediatric patients with medulloblastoma who were treated with surgery, proton radiation therapy, and chemotherapy between 2002 and 2016 (median follow-up, 9.3 years).[68]
Survivors of hereditary retinoblastoma, Ewing sarcoma, and other malignant bone tumors are at a particularly increased risk of developing subsequent bone and soft tissue tumors.[69-73]
Evidence (excess risk of bone and soft tissue tumors):
Nonmelanoma skin cancers (NMSCs) are one of the most common SNs among childhood cancer survivors and show a strong association with radiation therapy.[4,81] Adherence to sun protection behaviors can reduce exposure to UV radiation that may exacerbate risk.
The CCSS performed a randomized, controlled, comparative effectiveness trial to test methods to improve early detection of skin cancer among survivors of childhood cancer at high risk after radiation therapy exposure. Participants were randomly assigned to the experimental arm, which included print materials in combination with mHealth strategies (text messages and use of the Advancing Survivors’ Knowledge website), or the control arm. Screening rates improved by 1.5-fold in the experimental arm. Rates of physician skin examination increased from baseline to 12 months, and rates of self-examination increased from baseline to 18 months in all three intervention groups. However, the increase in rates did not differ between the intervention groups.[82]
Evidence (excess risk of NMSCs):
Malignant melanoma has also been reported as an SN in childhood cancer survivor cohorts, although at a much lower incidence than NMSCs.
Risk factors for malignant melanoma identified among these studies include the following:[84]
Evidence (excess risk of melanoma):
The incidence of melanoma and NMSC was evaluated in a cohort of 1,851 long-term, White survivors of retinoblastoma (1,020 hereditary and 831 nonhereditary) who were diagnosed from 1914 to 2006 and monitored through 2016.[86]
Among childhood cancer survivor cohorts, lung cancer represents a relatively uncommon SN. A PENTEC systematic review reported a median latency period of 25 years (range, 19–29 years) between the childhood cancer diagnosis and the development of a lung SN.[60] The ERR/Gy was 0.068, compared with background cumulative risks. After 20 Gy, the excess absolute risk was predicted to be 0.27% at 50 years. After 50 Gy, the excess absolute risk was predicted to be 0.7% at 50 years.[60]
Evidence (excess risk of lung cancer):
There is substantial evidence that childhood cancer survivors develop GI malignancies more frequently and at a younger age than the general population. This evidence supports the need for early initiation of colorectal carcinoma surveillance.[89-91]
Evidence (excess risk of GI cancer):
The PanCareSurFup consortium reported on risks of oral second primary neoplasms (validated through pathology reports) in a cohort of 69,460 5-year childhood cancer survivors in Europe.[97]
Development of subsequent primary urogenital cancers in childhood and adolescent cancer survivors is rare.
Using SEER data of 43,991 patients (aged <20 years) diagnosed with a first primary cancer from 1975 to 2016, the risk of urinary system cancer was higher for both females (SIR, 5.18; 95% CI, 3.65–7.14) and males (SIR, 2.80; 95% CI, 1.94–3.92), compared with the general population.[98]
Consistent with reports among survivors of adult-onset cancer, an increased risk of renal carcinoma has been observed in survivors of childhood cancer.[28,99,100] Underlying genetic predisposition may also play a role in the risk of developing renal carcinomas because rare cases of renal carcinoma have been observed in children with tuberous sclerosis.[99] Cases of secondary renal carcinoma associated with Xp11.2 translocations and TFE3 gene fusions have also been reported and suggest that cytotoxic chemotherapy may contribute to renal carcinogenesis.[101-103]
Evidence (excess risk of renal carcinoma):
Evidence (HPV-associated SMNs):
Outcome after the diagnosis of an SN is variable, as treatment for some histological subtypes may be compromised if childhood cancer therapy included cumulative doses of agents and modalities at the threshold of tissue tolerance.
Using data from the SEER Program, individuals younger than 60 years with first primary malignancies (n = 1,332,203) were compared with childhood cancer survivors (n = 1,409) who had a second primary malignancy.[107]
In a study of female participants in the CCSS who were subsequently diagnosed with breast cancer (n = 274) and matched to a control group of women (n = 1,095) with de novo breast cancer, survivors of childhood cancer were found to have elevated mortality rates (HR, 2.2; 95% CI, 1.7–3.0) even after adjusting for breast cancer treatment.[53]
Literature clearly supports the role of chemotherapy and radiation therapy in the development of SNs. However, interindividual variability exists, suggesting that genetic variation has a role in susceptibility to genotoxic exposures, or that genetic susceptibility syndromes confer an increased risk of cancer, such as Li-Fraumeni syndrome.[108,109] In a population-based Swiss Childhood Cancer Survivor Study, cancer predisposition syndromes were associated with a high risk of second primary neoplasms before the age of 21 years and represented the most important risk factor (HR, 7.8; 95% CI, 4.8–12.7) for developing a second primary cancer.[110]
Previous studies have demonstrated that childhood cancer survivors with a family history of Li-Fraumeni syndrome in particular, or a family history of cancer, carry an increased risk of developing an SN.[111,112] A prospective registry followed 480 individuals with pathogenic or likely pathogenic germline TP53 variants.[113] Individuals who developed a first cancer were monitored for the development of a second malignant neoplasm. Among individuals who were younger than 17 years at the time of diagnosis of their first cancer, 50% developed a second cancer within 20 years.
The risk of SNs could potentially be modified by variants in high-penetrance genes that lead to these serious genetic diseases (e.g., Li-Fraumeni syndrome).[112] However, the attributable risk is expected to be very small because of the extremely low prevalence of variants in high-penetrance genes.
Likewise, children with neurofibromatosis type 1 (NF1) who develop a primary tumor are at an increased risk of SNs compared with childhood cancer survivors without NF1. Treatment with radiation, but not alkylating agents, increases the risk of SNs in survivors with NF1.[114] SNs represent a major contributor to excess mortality in adult survivors of childhood glioma with NF1.[115] These survivors developed late-onset (>5 years from diagnosis) SMNs at four times the rate of glioma survivors without NF1 (4.02; range, 2.12–7.62). The 30-year, all-cause late mortality rate was 46.3% (95% CI, 23.9%–62.2%) in glioma survivors with NF1, compared with 18% (95% CI, 16.1%–20.0%) in glioma survivors without NF1. The most common causes of death among survivors with NF1 and glioma were SNs.
Table 1 summarizes the spectrum of neoplasms, affected genes, and Mendelian mode of inheritance of selected syndromes of inherited cancer predisposition.
Syndrome | Major Tumor Types | Affected Gene | Mode of Inheritance |
---|---|---|---|
AML = acute myeloid leukemia; MDS = myelodysplastic syndromes; WAGR = Wilms tumor, aniridia, genitourinary abnormalities, and range of developmental delays. | |||
aAdapted from Strahm et al.[116] | |||
bDominant in a fraction of patients, spontaneous variants can occur. | |||
Adenomatous polyposis of the colon | Colon, hepatoblastoma, intestinal cancers, stomach, thyroid cancer | APC | Dominant |
Ataxia-telangiectasia | Leukemia, lymphoma | ATM | Recessive |
Beckwith-Wiedemann syndrome | Adrenal carcinoma, hepatoblastoma, rhabdomyosarcoma, Wilms tumor | CDKN1C, NSD1 | Dominant |
Bloom syndrome | Leukemia, lymphoma, skin cancer | BLM | Recessive |
Diamond-Blackfan anemia | Colon cancer, osteogenic sarcoma, AML/MDS | RPS19 and other RP genes | Dominant, spontaneousb |
Fanconi anemia | Gynecological tumors, leukemia, squamous cell carcinoma | FANCA, FANCB, FANCC, FANCD2, FANCE, FANCF, FANCG | Recessive |
Juvenile polyposis syndrome | Gastrointestinal tumors | SMAD4 | Dominant |
Li-Fraumeni syndrome | Adrenocortical carcinoma, brain tumor, breast carcinoma, leukemia, osteosarcoma, soft tissue sarcoma | TP53 | Dominant |
Multiple endocrine neoplasia 1 | Pancreatic islet cell tumor, parathyroid adenoma, pituitary adenoma | MEN1 | Dominant |
Multiple endocrine neoplasia 2 | Medullary thyroid carcinoma, pheochromocytoma | RET | Dominant |
Neurofibromatosis type 1 | Neurofibroma, optic pathway glioma, peripheral nerve sheath tumor | NF1 | Dominant |
Neurofibromatosis type 2 | Vestibular schwannoma | NF2 | Dominant |
Nevoid basal cell carcinoma syndrome | Basal cell carcinoma, medulloblastoma | PTCH | Dominant |
Peutz-Jeghers syndrome | Intestinal cancers, ovarian carcinoma, pancreatic carcinoma | STK11 | Dominant |
Retinoblastoma | Osteosarcoma, retinoblastoma | RB1 | Dominant |
Tuberous sclerosis | Hamartoma, renal angiomyolipoma, renal cell carcinoma | TSC1, TSC2 | Dominant |
von Hippel-Lindau syndrome | Hemangioblastoma, pheochromocytoma, renal cell carcinoma, retinal and central nervous system tumors | VHL | Dominant |
WAGR syndrome | Gonadoblastoma, Wilms tumor | WT1 | Dominant |
Wilms tumor syndrome | Wilms tumor | WT1 | Dominant |
Xeroderma pigmentosum | Leukemia, melanoma | XPA, XPB, XPC, XPD, XPE, XPF, XPG, POLH | Recessive |
The McGill Interactive Pediatric OncoGenetic Guidelines (MIPOGG) tool identifies children with cancer who have an increased likelihood of having a cancer predisposition syndrome. This tool guides clinicians through a series of yes or no questions, and it generates a recommendation for or against genetic evaluation.[117,118]
The interindividual variability in risk of SNs is more likely related to common polymorphisms in low-penetrance genes that regulate the availability of active drug metabolites or are responsible for DNA repair. Gene-environment interactions may magnify subtle functional differences resulting from genetic variations.
In related research, SJLIFE investigators evaluated cancer treatments and pathogenic germline variants in 127 genes from six major DNA repair pathways to identify childhood cancer survivors at an increased risk of SNs.[119]
The following three groups were identified to have an elevated risk of SNs:
Metabolism of genotoxic agents occurs in two phases.
The balance between the two sets of enzymes is critical to the cellular response to xenobiotics; for example, high activity of a phase I enzyme and low activity of a phase II enzyme can result in DNA damage.
DNA repair mechanisms protect somatic cells from variants in tumor suppressor genes and oncogenes that can lead to cancer initiation and progression. An individual’s DNA repair capacity appears to be genetically determined.[120] A number of DNA repair genes contain polymorphic variants, resulting in large interindividual variations in DNA repair capacity.[120] Evaluation of the contribution of polymorphisms influencing DNA repair to the risk of SN represents an active area of research.
Survivors of childhood cancer are at an increased risk of subsequent cancers attributable to the late effects of radiation therapy and other treatment exposures. To better understand the impact of genetic predisposition on this risk, several studies have examined radiation-related cancers and chemotherapy only–related cancers.
Investigators combined genotype data for 11,220 5-year survivors from the CCSS and SJLIFE cohort study. They conducted a comprehensive investigation of general population, cancer-specific polygenic risk scores (PRS) derived from genome-wide association study findings. The study aimed to identify whether the PRS were associated with subsequent cancer risk among survivors of childhood cancer, after controlling for treatment exposure and nongenetic risk factors. They also quantified joint associations between radiation therapy and PRS to understand the potential interplay between genetic and treatment risk factors.[121]
With the decreased use of radiation therapy, it has become important to define the role of genetic susceptibility in chemotherapy-related SMNs. SJLIFE cohort study investigators evaluated treatment-related SMNs among long-term survivors of childhood cancer. An externally validated 179-variant PRS associated with risks of common adult-onset cancers in the general population was calculated for each survivor.[122]
Vigilant screening is important for childhood cancer survivors at risk.[123] Because of the relatively small size of the pediatric cancer survivor population and the prevalence and time to onset of therapy-related complications, undertaking clinical studies to assess the impact of screening recommendations on the morbidity and mortality associated with the late effect is not feasible.
Well-conducted studies of large populations of childhood cancer survivors have provided compelling evidence linking specific therapeutic exposures and late effects. This evidence has been used by several national and international cooperative groups (Scottish Collegiate Guidelines Network, Children’s Cancer and Leukaemia Group, Children's Oncology Group [COG], DCOG) to develop consensus-based clinical practice guidelines to increase awareness and standardize the immediate care needs of medically vulnerable childhood cancer survivors.[124]
All pediatric cancer survivor health screening guidelines employ a hybrid approach that is both evidence-based (using established associations between therapeutic exposures and late effects to identify high-risk categories) and grounded in the collective clinical experience of experts (matching the magnitude of the risk with the intensity of the screening recommendations). The screening recommendations in these guidelines represent a statement of consensus from a panel of experts in the late effects of pediatric cancer treatment.[123,124]
The COG Guidelines for malignant SNs indicate that certain high-risk populations of childhood cancer survivors merit heightened surveillance because of predisposing host, behavioral, or therapeutic factors.[123]
Specific comments about screening for more common radiation-associated SNs are as follows:
Mammography, the most widely accepted screening tool for breast cancer in the general population, may not be the ideal screening tool by itself for radiation-related breast cancers occurring in relatively young women with dense breasts. On the basis of research among young women with inherited susceptibility to breast cancer, dual-imaging modalities may enhance early detection related to the higher sensitivity of MRI in detecting lesions in premenopausal dense breasts and the superiority of mammography in identifying ductal carcinoma in situ;[126-128] therefore, the American Cancer Society recommends including adjunct screening with MRI.[129] The high sensitivity and specificity in detecting early-stage lesions with dual-imaging surveillance is offset by a substantial rate of additional investigations attributable to false-positive results.[128]
Many clinicians are concerned about potential harms related to radiation exposure associated with annual mammography in these young women. In this regard, it is important to consider that the estimated mean breast dose with contemporary standard two-view screening mammograms is about 3.85 mGy to 4.5 mGy.[130-132] Thus, 15 additional surveillance mammograms from age 25 to 39 years would increase the total radiation exposure in a woman treated with 20 Gy of chest radiation to 20.05775 Gy. The benefits of detection of early breast cancer lesions in high-risk women must be balanced by the risk predisposed by a 0.3% additional radiation exposure.
To keep young women engaged in breast health surveillance, the COG Guideline recommends the following for females who received a radiation dose of 10 Gy or higher to the mantle, mediastinal, whole lung, and axillary fields:
The risk of breast cancer in patients who received less than 10 Gy of radiation with potential impact to the breast is of a lower magnitude compared with those who received 10 Gy or higher. Monitoring of patients treated with less than 10 Gy of radiation with potential impact to the breast is determined on an individual basis after a discussion with the provider regarding the benefits and risk/harms of screening. If a decision is made to screen, the recommendations for women exposed to 10 Gy or higher are used.
Cardiovascular disease, after recurrence of the original cancer and development of second primary cancers, has been reported to be the leading cause of premature mortality among long-term childhood cancer survivors.[1-3]
Evidence (excess risk of premature cardiovascular mortality):
The specific late effects covered in this section include the following:
This section will also briefly discuss the influence of related conditions such as hypertension, dyslipidemia, and diabetes. However, this section will not provide a detailed review of those conditions as a consequence of childhood cancer treatment. A comprehensive review of long-term cardiovascular toxicity in childhood and young adult survivors of cancer has been published.[7]
Evidence (selected cohort studies describing cardiovascular outcomes):
Chemotherapy (in particular, anthracyclines and anthraquinones) and radiation therapy, both independently and in combination, increase the risk of cardiovascular disease in survivors of childhood cancer and are considered to be the most important risk factors contributing to premature cardiovascular disease in this population.[3,10,17,28]
Anthracyclines (e.g., doxorubicin, daunorubicin, idarubicin, and epirubicin) and anthraquinones (e.g., mitoxantrone) are known to directly injure cardiomyocytes through inhibition of topoisomerase 2-beta in cardiomyocytes and formation of reactive oxygen species, resulting in activation of cell-death pathways and inhibition of mitochondrial apoptosis.[29,30] The downstream results of cell death are changes in heart structure, including wall thinning, which leads to ventricular overload and pathological remodeling that, over time, leads to dysfunction and eventual clinical heart failure.[31,32]
Risk factors for anthracycline-related cardiomyopathy include the following:[19,33]
Traditionally, anthracycline dose equivalence has largely been based on acute hematologic toxicity equivalence rather than late cardiac toxicity.
Cardioprotective strategies that have been explored include the following:
While anthracyclines directly damage cardiomyocytes, radiation therapy primarily affects the fine vasculature of affected organs.[7]
Late effects of radiation therapy to the heart specifically include the following:
These cardiac late effects are related to the following:
Patients who were exposed to both radiation therapy affecting the cardiovascular system and cardiotoxic chemotherapy agents are at even greater risk of late cardiovascular outcomes.[10,19] This risk may be decreasing based on Children's Oncology Group (COG) Hodgkin lymphoma clinical trials spanning from 2002 to 2022.[53]
Cerebrovascular disease after radiation therapy exposure is another potential late effect observed in survivors.
Evidence (selected studies describing prevalence of and risk factors for cerebrovascular accident [CVA]/vascular disease):
Children with cancer have an excess risk of venous thromboembolism within the first 5 years after diagnosis. However, the long-term risk of venous thromboembolism among childhood cancer survivors has not been well studied.[67]
CCSS investigators evaluated self-reported late-onset (5 or more years after cancer diagnosis) venous thromboembolism among cohort members (median follow-up, 21.3 years).[68]
Long-term survivors of childhood, adolescent, and young adult malignancies with past exposure to potentially cardiotoxic treatments are at risk of peripartum cardiac dysfunction.
In the general population, peripartum cardiomyopathy (PPCM) is a rare condition characterized by heart failure during pregnancy (usually the last trimester or <5 months postpartum). The estimated incidence in the general population is 1 case per 3,000 live births.[82]
There are limited data available about the prevalence in survivors of pediatric, adolescent, and young adult malignancies who have received cardiotoxic therapies.
Based on available evidence about peripartum cardiomyopathy, the International Guideline Harmonization Group assessed that cardiomyopathy surveillance is reasonable before pregnancy or in the first trimester for female survivors of childhood, adolescent, and young adult cancer who are at moderate and high risk because they were treated with anthracyclines or chest radiation therapy.[33]
Survivors of childhood cancer represent a population at high risk of mortality after major cardiovascular events. Investigators estimated the cumulative incidence of all-cause and cardiovascular cause–specific mortality among survivors from the CCSS who had experienced a major cardiovascular event and compared them to siblings. They also compared the outcomes from the CCSS cancer survivors with a population-based cohort of racially diverse adults from the Coronary Artery Risk Development in Young Adults (CARDIA) study.[86]
Data about the prevalence and outcomes of survivors with heart failure requiring heart transplant are limited.
While much knowledge has been gained over the past 20 years in better understanding the long-term burden and risk factors for cardiovascular disease among childhood cancer survivors, many areas of inquiry remain, and include the following:
The International Guideline Harmonization Group has worked collaboratively to harmonize evidence-based cardiac surveillance recommendations and have identified knowledge deficits to help guide future studies.[33,72] Risk groups defined by cumulative exposures of anthracycline and chest-directed radiation therapy as well as cardiomyopathy surveillance recommendations are summarized in Table 2.
Risk Group | Anthracycline (mg/m2) | Chest-Directed Radiation Therapy (Gy) | Anthracycline (mg/m2) + Chest-Directed Radiation Therapy (Gy) | Is Screening Recommended? | At What Interval? |
---|---|---|---|---|---|
NA = not applicable. | |||||
aAdapted from Ehrhardt et al.[33] | |||||
High risk | ≥250 | ≥30 | ≥100 and ≥15 | Yes | 2 years |
Moderate risk | 100 to <250 | 15 to <30 | NA | Maybe | 5 years |
Low risk | >0 to <100 | >0 to <15 | NA | No | No screening |
Predisposing Therapy | Potential Cardiovascular Effects | Health Screening |
---|---|---|
aThe Children's Oncology Group (COG) guidelines also cover other conditions that may influence cardiovascular risk, such as obesity and diabetes mellitus/impaired glucose metabolism. | ||
bAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Any anthracycline and/or any radiation exposing the heart | Cardiac toxicity (arrhythmia, cardiomyopathy/heart failure, pericardial disease, valve disease, ischemic heart disease) | Yearly medical history and physical examination |
Electrocardiography at entry into long-term follow-up | ||
Echocardiography at entry into long-term follow-up, periodically repeat based on previous exposures and other risk factors | ||
Radiation exposing the neck and base of skull (especially ≥40 Gy) | Carotid and/or subclavian artery disease | Yearly medical history and physical examination; consider Doppler ultrasonography 10 years after exposure |
Radiation exposing the brain/cranium (especially ≥18 Gy) | Cerebrovascular disease (cavernomas, moyamoya, occlusive cerebral vasculopathy, stroke) | Yearly medical history and physical examination |
Radiation exposing the abdomen | Diabetes | Diabetes screening every 2 years |
Total-body irradiation (usually <14 Gy) | Dyslipidemia; diabetes | Fasting lipid profile and diabetes screening every 2 years |
Heavy metals (carboplatin, cisplatin), and ifosfamide exposure; radiation exposing the kidneys; HSCT; nephrectomy | Hypertension (from renal toxicity) | Yearly blood pressure test; renal function laboratory studies at entry into long-term follow-up and repeat as clinically indicated |
HSCT = hematopoietic stem cell transplant. |
Neurocognitive late effects are commonly observed after treatment of malignancies that require central nervous system (CNS)–directed therapies, including the following:
Children with CNS tumors or acute lymphoblastic leukemia (ALL) are most likely to be affected. Risk factors for the development of neurocognitive late effects include the following:[3-7]
Cognitive phenotypes observed in childhood survivors of ALL and CNS tumors may differ from traditional developmental disorders. For example, the phenotype of attention problems in ALL and brain tumor survivors appears to differ from developmental attention-deficit/hyperactivity disorder (ADHD) in that few survivors demonstrate significant hyperactivity/impulsivity, but instead have associated difficulties with processing speed and executive function.[8,9]
A Pediatric Normal Tissue Effects in the Clinic (PENTEC) comprehensive review was performed to develop models to facilitate the identification of dose constraints for radiation-associated CNS morbidities.[10]
In addition to the direct effects of neurotoxic therapies like cranial radiation, Childhood Cancer Survivor Study (CCSS) investigators observed that chronic health conditions resulting from non-neurotoxic treatment exposures (e.g., thoracic radiation) can adversely impact neurocognitive function presumably mediated by chronic cardiopulmonary and endocrine dysfunction.[11] In addition, some sequelae of neurotoxic therapy (e.g., severe hearing loss) have been associated with neurocognitive deficits independent of the neurotoxic treatment received.[12]
A related investigation from the CCSS evaluated longitudinal associations between physical activity and neurocognitive problems in adult survivors of childhood cancer.[13]
A subsequent systematic review and meta-analysis compared the effects of physical activity or exercise interventions on cognitive function among individuals diagnosed with cancer (aged 0–19 years) with that of controls. Twenty-two unique studies (16 randomized controlled trials) were found with data on 12,767 individuals.[14] The median age at the start of the study was 12 years (interquartile range [IQR], 11–14 years), the median time from the end of cancer treatment was 2.5 years (IQR, 1.1–3.0 years), and the median intervention period was 12 weeks (IQR, 10–24 weeks).
Childhood cancer survivors may be at risk for cognitive decline throughout their lives (even if not present in the first 10 years after therapy). In a study of 2,375 adult survivors of childhood ALL, Hodgkin lymphoma, or CNS tumors (mean age at evaluation, 31.8 years) and their sibling controls, new onset memory impairment emerged more often in survivors, decades after cancer diagnosis and treatment.[15]
Long-term cognitive effects caused by illness and associated treatments are well-established morbidities in survivors of childhood and adolescent brain tumors. Risk factors for adverse neurocognitive effects in this group include the following:
The negative impact of radiation treatment has been characterized by changes in IQ scores, which have been noted to drop about 2 to 5 years after diagnosis.[24-26]
Evidence (predictors of cognitive decline among survivors of CNS tumors):
Longitudinal cohort studies have provided insight into the trajectory and predictors of cognitive decline among survivors of CNS tumors.
Evidence (predictors of cognitive decline among long-term survivors of CNS tumors):
Although adverse neurocognitive outcomes observed 5 to 10 years after treatment are presumed to be pervasive, and potentially worsen over time, few empirical data are available regarding the neurocognitive functioning in very long-term survivors of CNS tumors.
The neurocognitive consequences of CNS disease and treatment may have a considerable impact on functional outcomes for brain tumor survivors.
Data are emerging regarding cognitive outcomes after proton radiation to the CNS.[50-52] However, these studies have been limited by retrospective analysis of cognitive outcomes among relatively small clinically heterogenous pediatric brain tumor cohorts and the use of historically treated photon patients or population standards as comparison groups.
Considering the relatively brief follow-up time from radiation, longitudinal follow-up is important to determine whether proton radiation provides a clinically meaningful benefit in sparing cognitive function compared with photon radiation. In addition, more targeted radiation treatment volumes with photons may diminish potential differences.
To minimize the risk of late cognitive sequelae, contemporary therapy for ALL uses a risk-stratified approach that reserves cranial irradiation for children who are considered at high risk of CNS relapse.
In survivors of ALL, cranial radiation therapy may result in clinical and radiographic neurological late sequelae, including the following:
Because of its penetrance into the CNS, systemic methotrexate has been used in a variety of low-dose and high-dose regimens for leukemia CNS prophylaxis.
Evidence (neurocognitive functioning in large pediatric cancer survivor cohorts):
The type of steroid used for ALL systemic treatment may affect cognitive functioning.
Neurocognitive abnormalities have been reported in other groups of cancer survivors. A study of adult survivors of childhood non-CNS cancers (including ALL, n = 5,937) reported the following:[57]
Emerging data suggest that the development of chronic health conditions in adulthood may contribute to cognitive deficits in long-term survivors of non-CNS cancers.
An SJLIFE cohort study evaluated whether children who experienced CNS injury were at higher risk of neurocognitive impairment associated with subsequent late-onset chronic health conditions. A total of 2,859 survivors who were aged 18 years or older and at least 10 years from diagnosis completed a neurocognitive battery and clinical examination. Of these patients, 1,598 had received CNS-directed therapy, including cranial radiation, intrathecal methotrexate, or neurosurgery.[75]
Neurocognitive abnormalities have been reported for the following cancers:
SJLIFE study investigators evaluated neurocognitive function and health status through objective clinical assessments in 150 survivors of childhood soft tissue sarcoma (median age, 33 years; median time from diagnosis, 24 years).[79]
A study of very long-term adult survivors, who were on average 33 years postdiagnosis, demonstrated largely average cognitive functioning across domains of intelligence, memory, attention, and executive function.[83]
Cognitive and academic consequences of HSCT in children have also been evaluated and include, but are not limited to, the following:
Risk of neurological complications may be predisposed by the following:
In children with CNS tumors, mass effect, tumor infiltration, and increased intracranial pressure may result in motor or sensory deficits, cerebellar dysfunction, and secondary effects such as seizures and cerebrovascular complications.[89]
Numerous reports describe abnormalities of CNS integrity and function, but such studies are typically limited by small sample size, cohort selection and participation bias, cross-sectional ascertainment of outcomes, and variable time of assessment from treatment exposures. In contrast, relatively few studies comprehensively or systematically ascertain outcomes related to peripheral nervous system function.
CNS tumor survivors remain at higher risk of new-onset adverse neurological events across their lifetimes than siblings. No plateau has been reached for new adverse sequelae, even 30 years from diagnosis, according to a longitudinal study of 1,876 5-year survivors of CNS tumors from the CCSS. The median time from diagnosis was 23 years, and the median age of the patients studied was 30.3 years.[90]
Neurological complications that may occur in survivors of childhood cancer include the following:
The development of seizures may occur secondary to tumor mass effect within the CNS and/or from neurotoxic CNS-directed therapies.
Vinca alkaloid agents (vincristine and vinblastine) and heavy metals (cisplatin and carboplatin) may cause peripheral neuropathy.[93-95]
Table 4 summarizes CNS late effects and the related health screenings.
Predisposing Therapy | Neurological Effects | Health Screening |
---|---|---|
IQ = intelligence quotient; IT = intrathecal; IV = intravenous. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Heavy metals (carboplatin, cisplatin) | Peripheral sensory neuropathy | Neurological examination |
Vinca alkaloid agents (vinblastine, vincristine) | Peripheral sensory or motor neuropathy (areflexia, weakness, foot drop, paresthesias) | Neurological examination |
Methotrexate (high dose IV or IT); cytarabine (high dose IV or IT); radiation exposing the brain | Clinical leukoencephalopathy (spasticity, ataxia, dysarthria, dysphagia, hemiparesis, seizures); headaches; seizures; sensory deficits | History: cognitive, motor, and/or sensory deficits, seizures |
Neurological examination | ||
Radiation exposing cerebrovascular structures | Cerebrovascular complications (stroke, Moyamoya disease, occlusive cerebral vasculopathy) | History: transient/permanent neurological events |
Blood pressure test | ||
Neurological examination | ||
Neurosurgery–brain | Motor and/or sensory deficits (paralysis, movement disorders, ataxia, eye problems [ocular nerve palsy, gaze paresis, nystagmus, papilledema, optic atrophy]); seizures | Neurological examination |
Neurology evaluation | ||
Neurosurgery–brain | Hydrocephalus; shunt malfunction | Abdominal x-ray |
Neurosurgery evaluation | ||
Neurosurgery–spine | Neurogenic bladder; urinary incontinence | History: hematuria, urinary urgency/frequency, urinary incontinence/retention, dysuria, nocturia, abnormal urinary stream |
Neurosurgery–spine | Neurogenic bowel; fecal incontinence | History: chronic constipation, fecal soiling |
Rectal examination | ||
Predisposing Therapy | Neurocognitive Effects | Health Screening |
Methotrexate (high-dose IV or IT); cytarabine (high-dose IV or IT); radiation exposing the brain; neurosurgery–brain | Neurocognitive deficits (executive function, memory, attention, processing speed, etc.); learning deficits; diminished IQ; behavioral change | Assessment of educational and vocational progress |
Formal neuropsychological evaluation |
Many childhood cancer survivors report reduced quality of life, impaired health status, or other adverse psychosocial outcomes, compared with siblings or noncancer population groups.[115,116] Vulnerable groups have been identified related to sociodemographic factors (e.g., female sex), specific cancer diagnoses (e.g., CNS tumor), cancer treatments (e.g., cranial radiation therapy), health behaviors (e.g., smoking), and type/cumulative burden of chronic health conditions. The diagnosis of childhood cancer may also affect psychosocial outcomes and the expected attainment of functional and social independence in adulthood. Several investigations have demonstrated that survivors of pediatric CNS tumors are particularly vulnerable.[49,117]
Evidence for adverse psychosocial adjustment after childhood cancer has been derived from sources, ranging from patient-reported or proxy-reported outcomes to data from population-based registries. The former may be limited by small sample size, cohort selection and participation bias, and variable methods and venues (clinical vs. distance-based survey) of assessments. The latter is often not well correlated with clinical and treatment characteristics that permit the identification of survivors at high risk of psychosocial deficits.
Survivors with neurocognitive deficits are particularly vulnerable to deficits in achievement of expected social outcomes during adulthood.
Childhood cancer survivors are also at risk of developing symptoms of psychological distress and suicidality.[124]
The presence of chronic health conditions can also impact aspects of psychological health.
Incorporation of psychological screening into clinical visits for childhood cancer survivors may be valuable. However, limiting such evaluations to those returning to long-term follow-up clinics may result in a biased subsample of survivors with more difficulties, and precise prevalence rates may be difficult to establish.
For more information about psychological distress, depression, and cancer patients, see Adjustment to Cancer: Anxiety and Distress and Depression.
A population-based study from Taiwan compared the prevalence of serious mental illnesses in 5,121 childhood and adolescent cancer survivors with that of population controls.[132]
A population-based study linked individuals with a history of six common cancers diagnosed at age 15 to 21 years to provincial health care data to compare rates of outpatient (family physician and psychiatrist) visits for psychiatric indications and time to severe psychiatric events (emergency room visit, hospitalization, and suicide). The study included 2,208 AYA cancer patients and 10,457 matched controls.[133]
Despite the many stresses associated with the diagnosis of cancer and its treatment, studies have generally shown low levels of post-traumatic stress symptoms and PTSD in children with cancer, typically no higher than those in healthy comparison children.[134]
Most research on late effects after cancer has focused on individuals with a cancer diagnosis during childhood. Little is known about the specific impact of a cancer diagnosis with an onset in adolescence or the impact of childhood cancer on AYA psychosocial outcomes.
Evidence (psychosocial outcomes in AYA cancer survivors):
Overall results support that behavioral, emotional, and social symptoms frequently co-occur and are associated with treatment exposures (cranial radiation, corticosteroids, and methotrexate) and late effects (obesity, cancer-related pain, and sensory impairments) in adolescent survivors diagnosed between 1970 and 1986.
Evidence (functional and social independence):
Chemotherapy, radiation therapy, and surgery can result in cosmetic and functional abnormalities of the oral cavity and dentition. The quality of current evidence regarding this outcome is limited by retrospective data collection, small sample size, cohort selection and participation bias, and heterogeneity in treatment approach, time since treatment, and method of ascertainment.
Oral and dental complications reported in childhood cancer survivors include the following:
Abnormalities of dental development reported in childhood cancer survivors include the following:[1-12]
The prevalence of hypodontia has varied widely in series depending on age at diagnosis, treatment modality, and method of ascertainment.
Cancer treatments that have been associated with dental maldevelopment include the following:[3,10]
Children younger than 5 years are at greatest risk of dental anomalies, including root agenesis, delayed eruption, enamel defects, and/or excessive caries related to disruption of ameloblast (enamel producing) and odontoblast (dentin producing) activity early in life.[3]
Key findings related to cancer treatment effect on tooth development include the following:
Xerostomia, the sensation of dry mouth, is a potential side effect after head and neck irradiation or HSCT that can severely impact quality of life.[18]
Key findings related to cancer treatment effect on salivary gland function include the following:
For more information about oral complications in cancer patients, see Oral Complications of Cancer Therapies.
Table 5 summarizes oral and dental late effects and the related health screenings.
Predisposing Therapy | Oral/Dental Effects | Health Screening/Interventions |
---|---|---|
CT = computed tomography; GVHD = graft-versus-host disease; HSCT = hematopoietic stem cell transplant; MRI = magnetic resonance imaging. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Any chemotherapy; radiation exposing oral cavity | Dental developmental abnormalities; tooth/root agenesis; microdontia; root thinning/shortening; enamel dysplasia | Dental evaluation and cleaning every 6 months |
Regular dental care including fluoride applications | ||
Consultation with orthodontist experienced in management of irradiated childhood cancer survivors | ||
Baseline Panorex x-ray before dental procedures to evaluate root development | ||
Radiation exposing oral cavity | Malocclusion; temporomandibular joint dysfunction | Dental evaluation and cleaning every 6 months |
Regular dental care including fluoride applications | ||
Consultation with orthodontist experienced in management of irradiated childhood cancer survivors | ||
Baseline Panorex x-ray before dental procedures to evaluate root development | ||
Referral to otolaryngologist for assistive devices for jaw opening | ||
Radiation exposing oral cavity; HSCT with history of chronic GVHD | Xerostomia/salivary gland dysfunction; periodontal disease; dental caries; oral cancer (squamous cell carcinoma) | Dental evaluation and cleaning every 6 months |
Supportive care with saliva substitutes, moistening agents, and sialogogues (pilocarpine) | ||
Regular dental care including fluoride applications | ||
Referral for biopsy of suspicious lesions | ||
Radiation exposing oral cavity (≥40 Gy) | Osteoradionecrosis | History: impaired or delayed healing after dental work |
Examination: persistent jaw pain, swelling or trismus | ||
Imaging studies (x-ray, CT scan and/or MRI) may assist in making diagnosis | ||
Surgical biopsy may be needed to confirm diagnosis | ||
Consider hyperbaric oxygen treatments |
The gastrointestinal (GI) tract is sensitive to the acute toxicities of chemotherapy, radiation therapy, and surgery. These important treatment modalities can also result in some long-term issues in a treatment- and dose-dependent manner.
Reports published about long-term GI tract outcomes are limited by retrospective data collection, small sample size, cohort selection and participation bias, heterogeneity in treatment approach, time since treatment, and method of ascertainment.
Treatment-related late effects include the following:
Digestive tract–related late effects include the following:
The abdomen is a relatively common location for several pediatric malignancies, including rhabdomyosarcoma, Wilms tumor, lymphoma, germ cell tumors, and neuroblastoma.
Intra-abdominal tumors often require multimodal therapy, occasionally necessitating resection of bowel, bowel-injuring chemotherapy, and/or radiation therapy. Thus, these tumors would be expected to be particularly prone to long-term digestive tract issues.
Evidence (GI outcomes from selected cohort studies):
Factors predicting higher risk of specific GI complications include the following:
A limited number of reports describe GI complications in pediatric patients with genitourinary solid tumors treated with radiation therapy:
Table 6 summarizes digestive tract late effects and the related health screenings.
Predisposing Therapy | Gastrointestinal Effects | Health Screening/Interventions |
---|---|---|
GVHD = graft-versus-host disease; HSCT = hematopoietic stem cell transplant; KUB = kidneys, ureter, bladder (plain abdominal radiograph). | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Radiation exposing esophagus; HSCT with any history of chronic GVHD | Gastroesophageal reflux; esophageal dysmotility; esophageal stricture | History: dysphagia, heart burn |
Esophageal dilation, medical management, antireflux surgery | ||
Radiation exposing bowel | Chronic enterocolitis; fistula; strictures | History: nausea, vomiting, abdominal pain, diarrhea |
Serum protein and albumin levels yearly in patients with chronic diarrhea or fistula; gastroenterology consultation | ||
Surgical and/or gastroenterology consultation for symptomatic patients | ||
Radiation exposing bowel; laparotomy | Bowel obstruction | History: abdominal pain, distention, vomiting, constipation |
Examination: tenderness, abdominal guarding, distension (acute episode) | ||
Clinical evaluation in patients with symptoms of obstruction | ||
Surgical consultation in patients unresponsive to medical management | ||
Pelvic surgery; cystectomy | Fecal incontinence | History: chronic constipation, fecal soiling |
Rectal examination |
Hepatic complications resulting from childhood cancer therapy are observed primarily as acute treatment toxicities.[41] Because many chemotherapy agents and radiation are hepatotoxic, transient liver function anomalies are common during therapy. Severe acute hepatic complications rarely occur. Survivors of childhood cancer can occasionally exhibit long-standing hepatic injury.[42]
Some general concepts regarding hepatotoxicity related to childhood cancer include the following:
Certain factors, including the type of chemotherapy, the dose and extent of radiation exposure, the influence of surgical interventions, and the evolving impact of viral hepatitis and/or other infectious complication, need additional attention in future studies.
Asymptomatic elevation of liver enzymes is the most common hepatobiliary complication.
Less commonly reported hepatobiliary complications include the following:[45]
The type and intensity of previous therapy influences risk for late-occurring hepatobiliary effects. In addition to the risk of treatment-related toxicity, recipients of HSCT frequently experience chronic liver dysfunction related to microvascular, immunologic, infectious, metabolic, and other toxic etiologies.
Key findings related to cancer treatment effect on hepatobiliary complications include the following:
Viral hepatitis B and C may complicate the treatment course of childhood cancer and result in chronic hepatic dysfunction.
Survivors with liver dysfunction should be counseled regarding risk-reduction methods to prevent hepatic injury.
Table 7 summarizes hepatobiliary late effects and the related health screenings.
Predisposing Therapy | Hepatic Effects | Health Screening/Interventions |
---|---|---|
ALT = alanine aminotransferase; AST = aspartate aminotransferase; HSCT = hematopoietic stem cell transplant. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Methotrexate; mercaptopurine/thioguanine; HSCT | Hepatic dysfunction | Laboratory tests: ALT, AST, bilirubin levels |
Ferritin in those treated with HSCT | ||
Mercaptopurine/thioguanine; HSCT | Veno-occlusive disease/sinusoidal obstructive syndrome | Examination: scleral icterus, jaundice, ascites, hepatomegaly, splenomegaly |
Laboratory tests: ALT, AST, bilirubin, platelet levels | ||
Ferritin in those treated with HSCT | ||
Radiation exposing liver/biliary tract; HSCT | Hepatic fibrosis/cirrhosis; focal nodular hyperplasia | Examination: jaundice, spider angiomas, palmar erythema, xanthomata, hepatomegaly, splenomegaly |
Laboratory tests: ALT, AST, bilirubin levels | ||
Ferritin in those treated with HSCT | ||
Prothrombin time for evaluation of hepatic synthetic function in patients with abnormal liver screening tests | ||
Screen for viral hepatitis in patients with persistently abnormal liver function or any patient transfused before 1993 | ||
Gastroenterology/hepatology consultation in patients with persistent liver dysfunction | ||
Hepatitis A and B immunizations in patients lacking immunity | ||
Consider phlebotomy and chelation therapy for iron overload | ||
Radiation exposing liver/biliary tract | Cholelithiasis | History: colicky abdominal pain related to fatty food intake, excessive flatulence |
Examination: right upper quadrant or epigastric tenderness (acute episode) | ||
Consider gallbladder ultrasonography in patients with chronic abdominal pain |
The pancreas has been thought to be relatively radioresistant because of a paucity of information about late pancreatic-related effects. However, children and young adults treated with TBI or abdominal irradiation are known to have an increased risk of insulin resistance and diabetes mellitus.[83-85]
While corticosteroids and asparaginase are associated with acute toxicity to the pancreas, late sequelae in the form of exocrine or endocrine pancreatic function for those who sustain acute injury have not been reported.
Evidence (risk of diabetes mellitus):
For digestive system late effects information, including risk factors, evaluation, and health counseling, see the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers.
Endocrine dysfunction is common among survivors of childhood cancer, especially in those who were treated with surgery or radiation therapy that involved hormone-producing organs and those who received alkylating agent chemotherapy.
The prevalence of specific endocrine disorders is affected by the following:[1-4]
Endocrinologic late effects can be broadly categorized as those resulting from hypothalamic-pituitary injury or from peripheral glandular compromise.[1-4] The former are most common after treatment for central nervous system (CNS) tumors. The prevalence of these late effects was 24.8% in a nationwide cohort study of 718 survivors who lived longer than 2 years and all hypothalamic-pituitary axes were affected.[3]
The following sections summarize research that characterizes the clinical features of survivors at risk of endocrine dysfunction that impacts pituitary, thyroid, adrenal, and gonadal function.
Thyroid radiation therapy. An increased risk of hypothyroidism has been reported among childhood cancer survivors treated with head and neck radiation exposing the thyroid gland, especially among survivors of Hodgkin lymphoma.[1-4] Among survivors of head and neck tumors treated with radiation therapy potentially exposing the hypothalamic-pituitary region and the thyroid gland, hypothyroidism may result from thyrotropin-releasing hormone (TRH) and/or thyroid-stimulating hormone (TSH) deficiency (central hypothyroidism), thyroid gland dysfunction (primary hypothyroidism), or a combination of central and primary causes.
Iodine I 131-metaiodobenzylguanidine (131I-MIBG).
Thyroidectomy. As observed in the general, noncancer population, partial or obviously subtotal surgical resection of the thyroid is a risk factor for subsequent hypothyroidism.[11-13]
Evidence (prevalence of and risk factors for hypothyroidism):
Mean Thyroid Dose | Risk of Hypothyroidismb | |||
---|---|---|---|---|
Age <14 yc | Age >15 yc | |||
Female | Male | Female | Male | |
aAdapted from Milano et al.[19] | ||||
bAny hypothyroidism (i.e., compensated or uncompensated). | ||||
cAge 14 to 15 y was used as a cutoff because the two studies that analyzed age used different cut-points. Presumably, the risks of hypothyroidism in patients irradiated at ages 14 to 15 y would be intermediate to those shown for ages <14 y and >15 y. | ||||
10 Gy | 10% | 6% | 14% | 8% |
20 Gy | 22% | 13% | 29% | 17% |
30 Gy | 39% | 23% | 53% | 31% |
40 Gy | 59% | 35% | 79% | 47% |
While less common than hypothyroidism, childhood cancer survivors also experience an increased risk of hyperthyroidism.[2,16,22,23]
Evidence (prevalence of and risk factors for hyperthyroidism):
The clinical manifestation of thyroid neoplasia among childhood cancer survivors ranges from asymptomatic, small, solitary nodules to large, intrathoracic goiters that compress adjacent structures.
The following factors are linked to an increased risk of thyroid nodule development:
For information about subsequent thyroid cancers, see the Subsequent Neoplasms section.
Survivors of pediatric hematopoietic stem cell transplant (HSCT) are at increased risk of thyroid dysfunction.[38,39]
TSH deficiency (central hypothyroidism) is discussed with late effects that affect the pituitary gland.
Table 9 summarizes thyroid late effects and the related health screenings.
Predisposing Therapy | Endocrine/Metabolic Effects | Health Screening |
---|---|---|
131I-MIBG = Iodine I 131-metaiodobenzylguanidine; T4 = thyroxine; TSH = thyroid-stimulating hormone. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Radiation exposing thyroid gland; thyroidectomy | Primary hypothyroidism | TSH level |
Radiation exposing thyroid gland | Hyperthyroidism | Free T4 level |
TSH level | ||
Radiation exposing thyroid gland, including 131I-MIBG | Thyroid nodules | Thyroid examination |
Thyroid ultrasonography |
Survivors of childhood cancer are at risk of developing a spectrum of neuroendocrine abnormalities, primarily because of the effect of radiation therapy on the hypothalamus.
The quality of the literature regarding pituitary endocrinopathy among childhood cancer survivors is often limited by retrospective data collection, small sample size, cohort selection and participation bias, heterogeneity in treatment approach, time since treatment, and method of ascertainment. However, the evidence linking this outcome with radiation therapy, surgery, and tumor infiltration is compelling because affected individuals typically present with metabolic and developmental abnormalities early in follow-up.
The risk of hypothalamus-pituitary dysfunction increases with higher doses of radiation therapy. When the radiation therapy dose exceeds 30 Gy, there is a higher risk of developing hypothalamus-pituitary disorders, including adrenocorticotropic hormone (ACTH) deficiency, luteinizing hormone (LH)/follicle-stimulating hormone (FSH) deficiency, and TSH deficiency.[40]
Central diabetes insipidus may herald the diagnosis of craniopharyngioma, suprasellar germ cell tumor, or Langerhans cell histiocytosis.[44-46]
Deficiencies of anterior pituitary hormones and major hypothalamic regulatory factors are common late effects among survivors treated with cranial irradiation.[43]
Evidence (prevalence of anterior pituitary hormone deficiency):
The International Late Effects of Childhood Cancer Guideline Harmonization Group (IGHG) consisting of 42 interdisciplinary international experts performed a systematic literature search on hypothalamic-pituitary axis surveillance in childhood cancer survivors.[40]
The six anterior pituitary hormones and their major hypothalamic regulatory factors are outlined in Table 10.
Pituitary Hormone | Hypothalamic Factor | Hypothalamic Regulation of the Pituitary Hormone |
---|---|---|
(–) = inhibitory; (+) = stimulatory. | ||
Growth hormone (GH) | GH-releasing hormone | + |
Somatostatin | – | |
Prolactin | Dopamine | – |
Luteinizing hormone (LH) | Gonadotropin-releasing hormone | + |
Follicle-stimulating hormone (FSH) | Gonadotropin-releasing hormone | + |
Thyroid-stimulating hormone (TSH) | Thyroid-releasing hormone | + |
Somatostatin | – | |
Adrenocorticotropic hormone (ACTH) | Corticotropin-releasing hormone | + |
Vasopressin | + |
Growth hormone deficiency is the most common and often the first anterior pituitary deficit to occur after cranial radiation therapy. In childhood survivors of CNS tumors, the overall prevalence of growth hormone deficiency is 12.5%.[3]
Evidence (radiation-dose response relationship of growth hormone deficiency in childhood brain tumor survivors):
Evidence (risk of growth deficits in childhood cancer survivors):
Evidence (growth hormone deficiency in childhood HSCT survivors):
Evidence (subsequent neoplasm risk after growth hormone deficiency replacement therapy):
In general, the data addressing subsequent malignancies among childhood cancer survivors treated with growth hormone therapy should be interpreted with caution given the small number of events.[43,56,73-75,79,80]
As outlined in a consensus statement by the Growth Hormone Research Society, areas of uncertainty include the safety of growth hormone in children with cancer-predisposing conditions, its use in growth hormone–deficient children who are receiving maintenance therapy, and the overall benefit-risk ratio in adult survivors.[81]
TSH deficiency (also referred to as central hypothyroidism) in survivors of childhood cancer can have profound clinical consequences and be underappreciated. Among survivors of head and neck tumors treated with radiation therapy potentially exposing the hypothalamic-pituitary region and the thyroid gland, hypothyroidism may result from TRH and/or TSH deficiency (central hypothyroidism), thyroid gland dysfunction (primary hypothyroidism), or a combination of central and primary causes.
Table 11 summarizes pituitary gland late effects and the related health screenings.
Predisposing Therapy | Endocrine/Metabolic Effects | Health Screening |
---|---|---|
BMI = body mass index; FSH = follicle-stimulating hormone; LH = luteinizing hormone; T4 = thyroxine; TSH = thyroid-stimulating hormone. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
bTesticular volume measurements are not reliable in the assessment of pubertal development in boys exposed to chemotherapy or direct radiation to the testes. | ||
cAppropriate only at diagnosis. TSH levels are not useful for follow-up during replacement therapy. | ||
Tumor or surgery affecting hypothalamus/pituitary. Radiation exposing hypothalamic-pituitary axis. | Growth hormone deficiency | Assessment of nutritional status |
Height, weight, BMI, Tanner stageb | ||
Tumor or surgery affecting hypothalamus/pituitary or optic pathways; hydrocephalus. Radiation exposing hypothalamic-pituitary axis. | Precocious puberty | Height, weight, BMI, Tanner stageb |
FSH, LH, estradiol, or testosterone levels | ||
Tumor or surgery affecting hypothalamus/pituitary. Radiation exposing hypothalamic-pituitary axis. | Gonadotropin deficiency | History: puberty, sexual function |
Examination: Tanner stageb | ||
FSH, LH, estradiol or testosterone levels | ||
Tumor or surgery affecting hypothalamus/pituitary. Radiation exposing hypothalamic-pituitary axis. | Central adrenal insufficiency | History: failure to thrive, anorexia, episodic dehydration, hypoglycemia, lethargy, unexplained hypotension |
Endocrine consultation for those with radiation dose ≥30 Gy | ||
Radiation exposing hypothalamic-pituitary axis. | Hyperprolactinemia | History/examination: galactorrhea |
Prolactin level | ||
Radiation exposing hypothalamic-pituitary axis. | Overweight/obesity | Height, weight, BMI |
Blood pressure test | ||
Components of metabolic syndrome (abdominal obesity, hypertension, dyslipidemia, impaired glucose metabolism) | Fasting blood glucose level and lipid profile | |
Tumor or surgery affecting hypothalamus/pituitary. Radiation exposing hypothalamic-pituitary axis. | Central hypothyroidism | TSHc free thyroxine (free T4) level |
Testicular and ovarian hormonal functions are discussed in the Late Effects of the Reproductive System section of this summary.
An increased risk of metabolic syndrome or its components has been observed among survivors of childhood cancer. The evidence for this outcome ranges from clinically manifested conditions that are self-reported by survivors to retrospectively assessed data in medical records and hospital registries to systematic clinical evaluations of clinically well-characterized cohorts. Studies have been limited by cohort selection and participation bias, heterogeneity in treatment approach, time since treatment, and method of ascertainment. Despite these limitations, compelling evidence indicates that metabolic syndrome is highly associated with cardiovascular events and mortality.
Definitions of metabolic syndrome are evolving but generally include a combination of central (abdominal) obesity with at least two of the following features:[101]
Evidence (prevalence of and risk factors for metabolic syndrome in childhood cancer survivors):
Evidence (lifestyle modifications to reduce cardiovascular risk in childhood cancer survivors):
For individuals treated at a young age (age <11 years), abdominal radiation therapy and TBI are increasingly recognized as independent risk factors for diabetes mellitus in childhood cancer survivors.[2,109-113]
Evidence (risk factors for diabetes mellitus in childhood cancer survivors):
Table 12 summarizes metabolic syndrome late effects and the related health screenings.
Predisposing Therapy | Potential Late Effects | Health Screening |
---|---|---|
BMI = body mass index. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Abdominal irradiation; total-body irradiation. | Components of metabolic syndrome (abdominal obesity, hypertension, dyslipidemia, impaired glucose metabolism) | Height, weight, BMI, blood pressure test |
Laboratory tests: Fasting glucose and lipids |
Evidence (risk factors for overweight/obesity):
Evidence (risk factors for body composition alterations):
Evidence (body composition changes in adult survivors of childhood ALL):
Variable outcomes across studies likely relate to the use of BMI as the metric for abnormal body composition, which does not adequately assess visceral adiposity that can contribute to metabolic risk in this population.[142]
Among brain tumor survivors treated with higher doses of cranial radiation therapy, the highest risk of developing obesity has been observed in females treated at a younger age.[143]
Survivors of craniopharyngioma have a substantially increased risk of developing extreme obesity because of the tumor location and the hypothalamic damage resulting from surgical resection.[144-147]
A cohort of 661 childhood survivors of brain tumors (mean follow-up time, 7.3 years) was evaluated for weight gain associated with hypothalamic-pituitary dysfunction. This cohort excluded survivors who had craniopharyngiomas or pituitary tumors.[148]
Young adult survivors of childhood cancer have a higher-than-expected prevalence of frailty, a phenotype characterized by low muscle mass, self-reported exhaustion, low energy expenditure, slow walking speed, and weakness.[154]
Table 13 summarizes body composition late effects and the related health screenings.
Predisposing Therapy | Potential Late Effects | Health Screening |
---|---|---|
BMI = body mass index. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Cranial radiation therapy | Overweight/obesity | Height, weight, BMI, blood pressure test |
Laboratory tests: Fasting glucose and lipids |
For endocrine and metabolic syndrome late effects information, including risk factors, evaluation, and health counseling, see the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers.
Late effects of the immune system have not been well studied, especially in survivors treated with contemporary therapies. Reports published about long-term immune system outcomes are limited by retrospective data collection, small sample size, cohort selection and participation bias, heterogeneity in treatment approach, time since treatment, and method of ascertainment.
Surgical or functional splenectomy increases the risk of life-threatening invasive bacterial infection:[1]
Individuals with asplenia, regardless of the reason for the asplenic state, have an increased risk of fulminant bacteremia, especially associated with encapsulated bacteria, which is associated with a high mortality rate.[8]
The risk of bacteremia is higher in younger children than in older children, and this risk may be higher during the years immediately after splenectomy. Fulminant septicemia, however, has been reported in adults up to 25 years after splenectomy.
Bacteremia may be caused by the following organisms in asplenic survivors:
Individuals with functional or surgical asplenia are also at increased risk of fatal malaria and severe babesiosis.[9]
Daily antimicrobial prophylaxis against pneumococcal infections is recommended for young children with asplenia, regardless of their immunization status.
Table 14 summarizes spleen late effects and the related health screenings.
Predisposing Therapy | Immunologic Effects | Health Screening/Interventions |
---|---|---|
GVHD = graft-versus-host disease; HSCT = hematopoietic stem cell transplant; IgA = immunoglobulin A; T = temperature. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Radiation exposing spleen; splenectomy; HSCT with currently active GVHD | Asplenia/hyposplenia; overwhelming post-splenectomy sepsis | Blood cultures during febrile episodes (T >38.5°C); empiric antibiotics |
Immunization for encapsulated organisms (pneumococcal, Haemophilus influenzae type b, and meningococcal vaccines) | ||
HSCT with any history of chronic GVHD | Immunologic complications (secretory IgA deficiency, hypogammaglobulinemia, decreased B cells, T cell dysfunction, chronic infections [e.g., conjunctivitis, sinusitis, and bronchitis associated with chronic GVHD]) | History: chronic conjunctivitis, chronic sinusitis, chronic bronchitis, recurrent or unusual infections, sepsis |
Examination: attention to eyes, nose/sinuses, and lungs |
For more information about posttransplant immunization, see the Centers for Disease Control and Prevention (CDC) Guidelines for Preventing Opportunistic Infections Among Hematopoietic Stem Cell Transplant Recipients.
Although the immune system appears to recover from the effects of active chemotherapy and radiation therapy, its effect on immune function into survivorship has not been well studied. Most studies have evaluated children treated for acute lymphoblastic leukemia (ALL), which in the disease itself, involves impaired lymphocyte maturation of either T or B cells in addition to lymphotoxic therapy.[16] Small studies suggest that protective titers against vaccine-preventable illnesses can be affected for months to years after non-HSCT childhood cancer therapy. There are no universal standards for the timing of serological evaluations or whether boosters and revaccinations should be given to every survivor.[16]
While there is a paucity of data regarding the benefits of administering active immunizations in this population, reimmunization is necessary to provide protective antibodies. The recommended reimmunization schedule will depend on previously received vaccinations and on the intensity of therapy.[16]
Immune status is also compromised after HSCT, particularly in association with GVHD.[21]
The major North American and European transplant groups, the CDC, and the Infectious Diseases Society of America have published follow-up recommendations for transplant recipients.[23-25] The American Society for Transplantation and Cellular Therapy has provided recommendations for preventing measles in patients who received HSCT or chimeric antigen receptor (CAR) T-cell therapy.[26]
Late effects after CD19-targeted CAR T-cell therapy for patients with relapsed or refractory ALL are largely unknown. Many patients will undergo an HSCT after CAR-T cell therapy, which complicates assessment of late effects. The most frequent late effect (as defined as >90 days post CAR T-cell therapy) is hypogammaglobulinemia.
Preexisting humoral immunity to vaccine-related antigens can persist in patients despite marked B-cell aplasia after CD19-targeted T-cell immunotherapy. Studies have shown that a population of plasma cells lacking CD19 expression survives long-term after CD19 CAR T-cell immunotherapy.[29]
Infectious complications resulting in hospitalization occur in excess rates among long-term childhood cancer survivors.[30]
For immune system late effects information, including risk factors, evaluation, and health counseling, see the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers.
The musculoskeletal system of growing children and adolescents is vulnerable to the cytotoxic effects of cancer therapies, including surgery, chemotherapy, and radiation therapy. Documented late effects include the following:
While these late effects are discussed individually, it is important to remember that the components of the musculoskeletal system are interrelated. For example, hypoplasia of a muscle group can negatively affect the function of the long bones and the resultant dysfunction can subsequently lead to disuse and osteoporosis.
The major strength of the published literature documenting musculoskeletal late effects among children and adolescents treated for cancer is that most studies have clearly defined outcomes and exposures. However, many studies are observational and cross-sectional or retrospective in design. Single-institution studies are common, and for some outcomes, only small convenience cohorts have been described. Thus, it is possible that studies either excluded patients with the most severe musculoskeletal effects because of death or inability to participate in follow-up testing, or they oversampled those with the most severe musculoskeletal late effects because these patients were accessible as they returned for complication-related follow-up. Additionally, some of the results reported in adult survivors of childhood cancer may not be relevant to patients currently being treated because the anticancer treatment and delivery of anticancer modalities, particularly radiation therapy, have changed over the years in response to documented toxicities.
The effect of radiation on bone growth depends on the sites irradiated, as follows:
In an age- and dose-dependent fashion, radiation can inhibit normal bone and muscle maturation and development.
Cranial radiation therapy damages the hypothalamic-pituitary axis in an age- and dose-response fashion and can result in growth hormone deficiency.[6,7] If the growth hormone deficiency is not treated during the growing years and, sometimes, even with appropriate treatment, it leads to a substantially lower final height. Patients with a central nervous system (CNS) tumor [8,9] or acute lymphoblastic leukemia (ALL) [10,11] treated with 18 Gy or higher of cranial radiation therapy are at highest risk. Patients treated with single-fraction total-body irradiation (TBI),[12-14] and those treated with cranial radiation for non-CNS solid tumors [15] are also at risk of growth hormone deficiency. If the spine is also irradiated (e.g., craniospinal radiation therapy for medulloblastoma or early ALL therapies in the 1960s), growth can be affected by two separate mechanisms—growth hormone deficiency and direct damage to the spine.
Radiation therapy can also directly affect the growth of the spine and long bones (and associated muscle groups) and can cause premature closure of the epiphyses, leading to the following:[16-18]
Orthovoltage radiation therapy, commonly used before 1970, delivered high doses of radiation to bone and was commonly associated with subsequent abnormalities in bone growth.
However, even with contemporary radiation therapy, if a solid tumor is located near an epiphysis or the spine, alterations in normal bone development can be difficult to avoid.
The effects of radiation therapy administered to the spine on survivors of CNS tumors and Wilms tumor have been assessed.
Evidence (effect of radiation therapy on the spine and long bones):
Although increased rates of fracture are not reported among long-term survivors of childhood cancer,[23] maximal peak bone mass is an important factor influencing the risk of osteoporosis and fracture among older patients. Treatment-related factors that affect bone mineral loss include the following:
Most of our knowledge about cancer and treatment effects on bone mineralization has been derived from studies of children with ALL.
Clinical assessment of bone mineral density in adults treated for childhood ALL indicates that most bone mineral deficits normalize over time after discontinuing osteotoxic therapy.[32]
Evidence (low bone mineral density):
Data from the St. Jude Life (SJLIFE) cohort study (development) and Erasmus Medical Center (validation) in the Netherlands were used to develop and validate prediction models for low and very low bone mineral density on the basis of clinical and treatment characteristics that identify adult survivors of childhood cancer who require screening by dual-energy x-ray absorptiometry.[40]
Osteonecrosis (also known as aseptic or avascular necrosis) is a rare, but well-recognized skeletal complication observed predominantly in survivors of pediatric hematological malignancies treated with corticosteroids.[41] The condition is characterized by death of one or more segments of bone that most often affects weight-bearing joints, especially the hips and knees.
Factors that increase the risk of osteonecrosis include the following:
Chronic comorbidities were assessed in a cohort of 6,778 2-year survivors of AYA cancer (defined as diagnosed with cancer between the ages of 15 and 39 years), with a median follow-up of 5.1 years after cancer diagnosis. The risk of developing chronic comorbidities was compared with matched individuals without a history of cancer. The incidence rate ratio (IRR) for all comorbidities was highest for osteonecrosis (IRR, 8.3), followed by osteoporosis (IRR, 5.75), and joint replacement (IRR, 3.89). The use of methotrexate (IRR, 21.6 for any dose) and corticosteroids (IRR, 5.4 for any dose) was significantly associated with osteonecrosis.[65]
Evidence (risk of osteochondroma):
Amputation and limb-sparing surgery prevent local recurrence of bone tumors by removal of all gross and microscopic disease. If optimally executed, both procedures accomplish an en bloc excision of tumor with a margin of normal uninvolved tissue.
A number of studies have compared functional outcomes after amputation and limb-sparing surgery, but results have been limited by inconsistent methods of functional assessment and small cohort sizes.
CCSS investigators evaluated risk factors for and outcomes of late amputation in survivors treated for lower extremity sarcomas.[80]
The incidence of late major surgical interventions among childhood cancer survivors was examined through data from the CCSS. In the report, survivors of Ewing sarcoma and osteosarcoma had the highest cumulative burden of late, major surgical interventions among all solid tumor survivors (mean cumulative counts of late surgical interventions was 322.9 per 100 survivors of Ewing sarcoma and 269.6 per 100 survivors of osteosarcoma). A large component of this burden is related to the increased rate of additional late musculoskeletal surgeries, such as arthroplasty, amputation, prosthetic revision caused by an infection, device failure, or associated fractures. Locoregional surgery or radiation therapy cancer treatments were associated with undergoing late surgical intervention in the same body region or organ system.[81]
HSCT with any history of chronic GVHD is associated with joint contractures.[82,83]
Table 15 summarizes bone and joint late effects and the related health screenings.
Predisposing Therapy | Musculoskeletal Effects | Health Screening |
---|---|---|
CT = computed tomography; DXA = dual-energy x-ray absorptiometry; GVHD = graft-versus-host disease; HSCT = hematopoietic stem cell transplant. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Radiation exposing musculoskeletal system | Hypoplasia; fibrosis; reduced/uneven growth (scoliosis, kyphosis); limb length discrepancy | Examination: bones and soft tissues in radiation fields |
Radiation exposing head and neck | Craniofacial abnormalities | History: psychosocial assessment, with attention to educational and/or vocational progress, depression, anxiety, posttraumatic stress, social withdrawal |
Head and neck examination | ||
Radiation exposing musculoskeletal system | Radiation-induced fracture | Examination of affected bone |
Methotrexate; corticosteroids (dexamethasone, prednisone); radiation exposing skeletal structures; HSCT | Reduced bone mineral density | Bone mineral density test (DXA or quantitative CT) |
Corticosteroids (dexamethasone, prednisone) | Osteonecrosis | History: joint pain, swelling, immobility, limited range of motion |
Musculoskeletal examination | ||
Radiation with exposure to oral cavity | Osteoradionecrosis | History/oral examination: impaired or delayed healing after dental work, persistent jaw pain or swelling, trismus |
Amputation | Amputation-related complications (impaired cosmesis, functional/activity limitations, residual limb integrity, chronic pain, increased energy expenditure) | History: pain, functional/activity limitations |
Examination: residual limb integrity | ||
Prosthetic evaluation | ||
Limb-sparing surgery | Limb-sparing surgical complications (functional/activity limitations, fibrosis, contractures, chronic infection, chronic pain, limb length discrepancy, increased energy expenditure, prosthetic malfunction [loosening, nonunion, fracture]) | History: pain, functional/activity limitations |
Examination: residual limb integrity | ||
Radiograph of affected limb | ||
Orthopedic evaluation | ||
HSCT with any history of chronic GVHD | Joint contracture | Musculoskeletal examination |
For musculoskeletal system late effects information, including risk factors, evaluation, and health counseling, see the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers.
Reproductive outcomes in childhood cancer survivors may be compromised by surgery, radiation therapy, or chemotherapy that negatively affects any component of the hypothalamic-pituitary axis or gonads. Evidence for this outcome in childhood cancer survivors is limited by studies characterized by small sample size, cohort selection and participation bias, cross-sectional assessment, heterogeneity in treatment approach, time since treatment, and method of ascertainment. In particular, the literature is deficient regarding hard outcomes of reproductive potential (e.g., semen analysis in men, primordial follicle count in women) and outcomes after contemporary risk-adapted treatment approaches.[1,2]
The risk of infertility is generally related to the tissues or organs involved by the cancer and the specific type, dose, and combination of cytotoxic therapy.
Earlier studies used the alkylating agent dose to define dose levels associated with the risk of gonadal toxicity within a specific study cohort. Childhood Cancer Survivor Study (CCSS) investigators developed the cyclophosphamide equivalent dose, which is a metric for normalization of the cumulative doses of various alkylating agents that is independent of the study population. The alkylating agent dose and cyclophosphamide equivalent dose perform similarly when used in several models for different survivor outcomes that include treatment exposures, but only the cyclophosphamide equivalent dose permits comparison across variably treated cohorts. Investigations that evaluate risk factors for gonadal toxicity vary in the use of cumulative doses based on individual alkylating agents, the alkylating agent dose, and the cyclophosphamide equivalent dose.[3]
The St. Jude Children's Research Hospital reported the cumulative risk of hypogonadism and infertility in a cohort of 156 pediatric patients with medulloblastomas who were treated with surgery, risk-adapted craniospinal irradiation, and dose-intensive chemotherapy in the SJMB03 study (2003–2013).[4]
In addition to anticancer therapy, age at treatment, and sex, it is likely that genetic factors influence the risk of permanent infertility. Pediatric cancer treatment protocols often prescribe combined-modality therapy; thus, the additive effects of gonadotoxic exposures may need to be considered in assessing reproductive potential. Detailed information about the specific cancer treatment modalities, including specific surgical procedures, the type and cumulative doses of chemotherapeutic agents, and radiation treatment volumes and doses, are needed to estimate risks for gonadal dysfunction and infertility.
The treatment-indicated risk of infertility does not simply translate into adult fertility status. This is particularly important for patients who were unable to participate in sperm/oocyte preservation because of their young age when diagnosed and treated for cancer.
Cancer treatments that may impair testicular and reproductive function include the following:
Among men who were treated for childhood cancer, gonadal injury may have occurred if radiation treatment fields included the pelvis, gonads, or total body.
Radiation injury to Leydig cells is related to the dose delivered and age at treatment.
Cumulative alkylating agent (e.g., cyclophosphamide, mechlorethamine, dacarbazine) dose is an important factor in estimating the risk of testicular germ cell injury. However, limited data are available that correlate results of semen analyses in clinically well-characterized cohorts.[16]
Studies of testicular germ cell injury, as evidenced by oligospermia or azoospermia, after alkylating agent administration with or without radiation therapy have reported the following:
The risk of gonadal dysfunction and infertility related to conditioning with total-body irradiation (TBI), high-dose alkylating agent chemotherapy, or both is substantial.[37] Because patients with relapsed or refractory cancer often undergo HSCT, previous treatment with alkylating agent chemotherapy or hypothalamic-pituitary axis or gonadal radiation therapy may confer additional risks.
Recovery of germ cell function after cytotoxic chemotherapy and radiation therapy is possible. However, evidence based on hard outcomes like sperm count is limited. Most studies use hormonal biomarkers like inhibin B and FSH levels to estimate the presence of spermatogenesis. However, limitations in the specificity and positive predictive value of these tests have been reported.[42,43] Male survivors should be advised that semen analysis is the most accurate assessment of adequacy of spermatogenesis.
Leydig cell function in childhood cancer survivors has not been well studied.
In a population-based study that used the National Quality Registry for Childhood Cancer in Sweden, 1,212 male childhood cancer survivors aged 19 to 40 years (median age at diagnosis, 7 years; median age at study, 29 years; treated 1981–2017) participated in a self-reported survey about hormonal treatments and the ability to father a biological child.[38]
SJLIFE study investigators evaluated the prevalence of and risk factors for Leydig cell failure and Leydig cell dysfunction in 1,516 men (median age, 30.8 years; median time from diagnosis, 22 years).[44]
Cancer treatments that may impair ovarian function/reserve include the following:
The main challenge for the pediatric surgeon in the management of ovarian tumors is finding the right balance between optimal tumor resection and maximal fertility preservation. Oophorectomy performed for the management of germ cell tumors may reduce ovarian reserve. Contemporary treatments use fertility-sparing surgical procedures combined with systemic chemotherapy to reduce this risk.[45]
In women treated for childhood cancer, primary gonadal injury may have occurred if treatment fields involved the lumbosacral spine, abdomen, pelvis, or total body. The frequency of ovarian failure after abdominal radiation therapy is related to both the age of the patient at the time of irradiation and the radiation therapy dose received by the ovaries. The ovaries of younger individuals are more resistant to radiation damage than those of older women because of their greater complement of primordial follicles.
Whole-abdomen irradiation at doses of 20 Gy or higher is associated with the greatest risk of ovarian dysfunction. Seventy-one percent of patients in one series failed to enter puberty, and 26% of women experienced premature menopause after receiving whole-abdominal radiation therapy doses of 20 Gy to 30 Gy.[46] Other studies reported similar results in women treated with whole-abdomen irradiation [47] or craniospinal irradiation [48,49] during childhood.
Ovarian function may be impaired after treatment with combination chemotherapy that includes an alkylating agent and procarbazine. In general, girls maintain gonadal function at higher cumulative alkylating agent doses than do boys. Most female childhood cancer survivors who are treated with risk-adapted combination chemotherapy retain or recover ovarian function. However, the risk of acute ovarian failure and premature menopause is substantial if treatment includes combined-modality therapy with alkylating agent chemotherapy and abdominal or pelvic radiation therapy or dose-intensive alkylating agents for myeloablative conditioning before HSCT.[50-55]
Premature ovarian failure is well documented in childhood cancer survivors, especially in women treated with both an alkylating agent and abdominal radiation therapy.[50,54-57]
Studies have associated the following factors with an increased rate of premature ovarian insufficiency (acute ovarian failure and premature menopause):
The presence of apparently normal ovarian function at the completion of chemotherapy should not be interpreted as evidence that no ovarian injury has occurred.
Evidence (excess risk of premature ovarian insufficiency after chemotherapy and radiation):
The preservation of ovarian function among women treated with HSCT is related to age at treatment, receipt of pretransplant alkylating agent chemotherapy and abdominal-pelvic radiation therapy, and transplant conditioning regimen.[52,61]
Evidence (excess risk of premature ovarian insufficiency after HSCT):
Infertility remains one of the most common life-altering treatment effects experienced by long-term survivors of childhood cancer. Pediatric cancer cohort studies have demonstrated the impact of cytotoxic therapy on reproductive outcomes. CCSS investigations have elucidated factors contributing to subfertility among childhood cancer survivors.[66,67]
No abnormalities in fertility (reproductive characteristics and AMH levels as compared with controls) were identified in a series of 56 long-term female survivors of childhood differentiated thyroid cancer who received iodine I 131 (131I) for treatment. The median follow-up was 15.4 years (range, 8.3–24.7 years), and the median cumulative dose of 131I was 7.4 GBq/200.0 mCi. None of the survivors reported premature menopause.[68]
Evidence (excess risk of impaired fertility):
Cyclophosphamide Equivalent Dose by Tertile | Male | Female | ||
---|---|---|---|---|
HR (95% CI) | P Value | HR (95% CI) | P Value | |
CI = confidence interval; HR = hazard ratio. | ||||
Lower (<4,897 mg/m2) | 1.14 (1.00–1.30) | .045 | 0.97 (0.86–1.08) | .55 |
Middle (4,897–9,638 mg/m2) | 0.79 (0.68–0.91) | .0010 | 0.98 (0.87–1.11) | .76 |
Upper (≥9,639 mg/m2) | 0.55 (0.47–0.64) | <.0001 | 0.90 (0.79–1.01) | .07 |
The psychosexual health of adults who were treated for cancer during childhood, adolescence, and young adulthood has not been well studied.
An SJLIFE study estimated the prevalence of and risk factors for sexual dysfunction among 936 adult female survivors of childhood cancer. The study also evaluated associations between sexual dysfunction and psychological symptoms/quality of life.[70]
In a prospective cohort study (Project REACH), 249 adult childhood cancer survivors (aged 18–65 years) completed measures for physical activity and mental health, including sexual dysfunction. Thirty-two percent of survivors experienced clinically significant sexual dysfunction. Physical and mental health concerns such as fatigue, poor sleep, pain, poor physical health, poor mental health, and depression were associated with sexual dysfunction and a history of a CNS tumor.[71]
Progress in reproductive endocrinology has resulted in the availability of several options for preserving or permitting fertility in patients about to receive potentially toxic chemotherapy or radiation therapy.[72-75]
For survivors who maintain fertility, numerous investigations have evaluated the prevalence of and risk factors for pregnancy complications in adults treated for cancer during childhood. Pregnancy complications such as hypertension, fetal malposition, fetal loss/spontaneous abortion, preterm labor, and low birth weight have been observed in association with specific diagnostic and treatment groups.[88-93]
Evidence (excess risk of pregnancy complications):
The largest study to comprehensively investigate birth rates and obstetric complications in female survivors of AYA cancer and report a wide spectrum of obstetric outcomes for specific types of cancer was conducted using the Teenage Young Adult Cancer Survivor Study (TYACSS). The study included over 200,945 5-year survivors of cancer, diagnosed at age 15 to 39 years, from England and Wales. Investigators quantified deficits in birth rates and risks of obstetric complications for female survivors (n = 13,886) of 17 specific types of AYA cancer.[93]
For childhood cancer survivors who have offspring, there is concern about congenital anomalies, genetic disease, or risk of cancer in the offspring. Children of cancer survivors are not at significantly increased risk of congenital anomalies stemming from their parents' exposure to mutagenic cancer treatments.
Evidence (children of cancer survivors not at significantly increased risk of congenital anomalies):
Table 17 summarizes reproductive late effects and the related health screenings.
Predisposing Therapy | Reproductive Late Effects | Health Screening |
---|---|---|
AMH = antimüllerian hormone; FSH = follicle-stimulating hormone; LH = luteinizing hormone. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Alkylating agents; radiation exposing the gonads | Testicular hormonal dysfunction: Testosterone deficiency/insufficiency; delayed/arrested puberty | Tanner stage |
Morning testosterone | ||
LH | ||
Impaired spermatogenesis: Reduced fertility; oligospermia; azoospermia; infertility | Semen analysis | |
FSH | ||
Inhibin B | ||
Ovarian hormone deficiencies: Delayed/arrested puberty; premature ovarian insufficiency/premature menopause. Reduced ovarian follicular pool: Diminished ovarian reserve; infertility. | Tanner stage | |
Menstrual cycle history | ||
Estradiol | ||
FSH | ||
LH | ||
AMH | ||
Antral follicle count |
For reproductive late effects information, including risk factors, evaluation, and health counseling, see the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers.
Respiratory function may be compromised in long-term survivors of childhood cancer who were treated with the following therapies:
The effects of early lung injury from cancer treatment may be exacerbated by the decline in lung function associated with normal aging, other comorbid chronic health conditions, or smoking. The quality of current evidence regarding this outcome is limited by retrospective data collection, small sample size, cohort selection and participation bias, description of outcomes following antiquated treatment approaches, and variability in time since treatment and method of ascertainment. No large cohort studies have been performed that include clinical evaluations coupled with functional and quality-of-life assessments.
The true prevalence or incidence of pulmonary dysfunction in childhood and adolescent cancer survivors is not clear. For children treated with HSCT, significant clinical disease has been observed. Population-based studies have demonstrated that survivors experience excess morbidity and mortality related to respiratory conditions.[1,2]
Evidence (selected cohort studies describing long-term pulmonary function outcomes):
Radiation therapy that exposes the lung parenchyma can result in pulmonary dysfunction related to reduced lung volume, impaired dynamic compliance, and deformity of both the lung and chest wall.
These sequelae are uncommon after contemporary therapy, which most often results in subclinical injury that is detected only by imaging or formal pulmonary function testing.
The Pediatric Normal Tissue Effects in the Clinic (PENTEC) pulmonary task force reviewed dosimetric and clinical factors to develop predictive models for radiation therapy–associated pulmonary toxicity in children.[10]
Evidence (selected cohort studies describing pulmonary outcomes):
Chemotherapy agents with potential pulmonary toxic effects commonly used in the treatment of pediatric malignancies include bleomycin, busulfan, and the nitrosoureas (carmustine and lomustine). These agents induce lung damage on their own or potentiate the damaging effects of radiation to the lung.
Combined-modality therapy, including pulmonary toxic chemotherapy and thoracic radiation therapy or thoracic/chest wall surgery, increases the risk of pulmonary function impairment.[7]
Evidence (outcomes among cohorts treated with pulmonary toxic chemotherapy):
Evidence (pulmonary dysfunction in former or current smokers):
Table 18 summarizes respiratory late effects and the related health screenings.
Predisposing Therapy | Respiratory Effects | Health Screening/Interventions |
---|---|---|
DLCO = diffusing capacity of the lung for carbon monoxide; GVHD = graft-versus-host disease; HSCT = hematopoietic stem cell transplant. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Busulfan; carmustine (BCNU)/lomustine (CCNU); bleomycin; radiation exposing lungs; surgery impacting pulmonary function (lobectomy, metastasectomy, wedge resection) | Subclinical pulmonary dysfunction; interstitial pneumonitis; pulmonary fibrosis; restrictive lung disease; obstructive lung disease | History: cough, shortness of breath, dyspnea on exertion, wheezing |
Pulmonary examination | ||
Pulmonary function tests (including DLCO and spirometry) | ||
Chest x-ray | ||
Counsel regarding tobacco avoidance/smoking cessation | ||
In patients with abnormal pulmonary function tests and/or chest x-ray, consider repeat evaluation before general anesthesia | ||
Pulmonary consultation for patients with symptomatic pulmonary dysfunction | ||
Influenza and pneumococcal vaccinations | ||
HSCT with any history of chronic GVHD | Pulmonary toxicity (bronchiolitis obliterans, chronic bronchitis, bronchiectasis) | History: cough, shortness of breath, dyspnea on exertion, wheezing |
Pulmonary examination | ||
Pulmonary function tests (including DLCO and spirometry) | ||
Chest x-ray | ||
Counsel regarding tobacco avoidance/smoking cessation | ||
In patients with abnormal pulmonary function tests and/or chest x-ray, consider repeat evaluation before general anesthesia | ||
Pulmonary consultation for patients with symptomatic pulmonary dysfunction | ||
Influenza and pneumococcal vaccinations |
For respiratory late effects information, including risk factors, evaluation, and health counseling, see the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers.
Hearing loss as a late effect of therapy can occur after exposure to platinum compounds (cisplatin and carboplatin), cranial radiation therapy, or both. These therapeutic exposures are most common in the treatment of central nervous system (CNS) and non-CNS solid tumors. Children are more susceptible to otologic toxic effects from platinum agents than adults.[1]
Evidence (hearing loss):
Risk factors associated with hearing loss include the following:
The SIOPEL-6 trial compared cisplatin alone with cisplatin plus delayed administration of sodium thiosulfate (sodium thiosulfate administered 6 hours after cisplatin) resulted in a 48% lower incidence of cisplatin-induced hearing loss among children with standard-risk hepatoblastoma. Sodium thiosulfate treatment did not jeopardize the overall survival or event-free survival.[15] These trials led to regulatory approval of sodium thiosulfate for prevention of cisplatin-induced hearing loss. However, each trial used a different hearing end point. In 2010, the SIOP-Boston ototoxicity scale was developed to overcome key limitations of the available scales, and it is central to harmonizing hearing end points. Using the SIOP scale, hearing outcomes from the ACCL0431 trial were re-evaluated. This analysis showed that children treated with sodium thiosulfate were approximately 90% less likely to develop higher than grade 2 cisplatin-induced hearing loss during the trial period or at the end of cisplatin therapy, compared with the observation group.[16]
Children treated for malignancies may be at risk of early- or delayed-onset hearing loss. This can affect learning, communication, school performance, social interaction, and overall quality of life.
The Children’s Oncology Group has published recommendations for the evaluation and management of hearing loss in survivors of childhood and adolescent cancers to promote early identification of at-risk survivors and timely referral for remedial services.
Table 19 summarizes auditory late effects and the related health screenings.
Predisposing Therapy | Potential Auditory Effects | Health Screening/Interventions |
---|---|---|
FM = frequency modulated. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Platinum agents (cisplatin, carboplatin); radiation exposing the ear | Otologic toxic effects; sensorineural hearing loss; tinnitus; vertigo; dehydrated ceruminosis; conductive hearing loss | History: hearing difficulties, tinnitus, vertigo |
Otoscopic examination | ||
Audiology evaluation | ||
Amplification in patients with progressive hearing loss | ||
Speech and language therapy for children with hearing loss | ||
Otolaryngology consultation in patients with chronic infection, cerumen impaction, or other anatomical problems exacerbating or contributing to hearing loss | ||
Educational accommodations (e.g., preferential classroom seating, FM amplification system, etc.) |
Orbital complications are common after radiation therapy for retinoblastoma, head and neck sarcomas, CNS tumors, and after total-body irradiation (TBI).
The PENTEC ocular task force reviewed dosimetric and clinical factors to quantify the radiation dose dependence of late ocular adverse effects, including retinopathy, optic neuropathy, and cataract, in childhood cancer survivors who received cranial radiation therapy.[46]
For more information about the treatment of retinoblastoma, see Retinoblastoma Treatment.
For more information about the treatment of rhabdomyosarcoma in children, see Childhood Rhabdomyosarcoma Treatment.
Survivors of optic pathway gliomas are also at risk of visual complications, resulting in part from tumor proximity to the optic nerve.
Survivors of childhood cancer are at increased risk of ocular late effects related to both glucocorticoid and radiation exposure to the eye.
Evidence (cataract development from radiation exposure):
Visual acuity decline is rare after radiation therapy for intracranial malignancies in children.
Evidence (visual acuity decline from radiation exposure):
Chronic comorbidities were assessed in a cohort of 6,778 2-year survivors of adolescent and young adult cancer (defined as diagnosed with cancer between the ages of 15–39 years), with a median follow-up of 5.1 years after cancer diagnosis. The risk of developing chronic comorbidities was compared with matched individuals without a history of cancer. The crude IRR was 8.1 for vision loss associated with radiation exposure higher than 30 Gy to the head.[32]
Ocular complications, such as cataracts and dry eye syndrome, are common after HSCT in childhood.
Evidence (ocular effects of HSCT):
Table 20 summarizes ocular late effects and the related health screenings.
Predisposing Therapy | Ocular/Vision Effects | Health Screening/Interventions |
---|---|---|
GVHD = graft-versus-host disease; HSCT = hematopoietic stem cell transplant; 131I = iodine I 131. | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Busulfan; corticosteroids; radiation exposing the eye | Cataracts | History: decreased acuity, halos, diplopia |
Eye examination: visual acuity, funduscopy (yearly) | ||
Ophthalmology consultation | ||
Radiation exposing the eye, including radioiodine (131I) | Ocular toxicity (orbital hypoplasia, lacrimal duct atrophy, xerophthalmia [keratoconjunctivitis sicca], keratitis, telangiectasias, retinopathy, optic chiasm neuropathy, enophthalmos, chronic painful eye, maculopathy, papillopathy, glaucoma) | History: visual changes (decreased acuity, halos, diplopia), dry eye, persistent eye irritation, excessive tearing, light sensitivity, poor night vision, painful eye |
Eye examination: visual acuity, funduscopy (yearly) | ||
Ophthalmology consultation | ||
HSCT with any history of chronic GVHD | Xerophthalmia (keratoconjunctivitis sicca) | History: dry eye (burning, itching, foreign body sensation, inflammation) |
Eye examination: visual acuity, funduscopy (yearly) | ||
Enucleation | Impaired cosmesis; poor prosthetic fit; orbital hypoplasia | Ocular prosthetic evaluation |
Ophthalmology |
For information on the late effects of special senses, including risk factors, evaluation, and health counseling, see the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers.
Acute toxicity of the urinary system from cancer therapy is well known. Less is known about the genitourinary outcomes in long-term survivors.[1] The evidence for long-term renal injury in childhood cancer survivors is limited by studies characterized by small sample size, cohort selection and participation bias, cross-sectional assessment, heterogeneity in time since treatment, and method of ascertainment. In particular, the inaccuracies of diagnosing chronic kidney dysfunction by estimating equations of glomerular dysfunction should be considered.[2]
The incidence of late major surgical interventions among childhood cancer survivors was examined through data from the Childhood Cancer Survivor Study (CCSS). Childhood cancer survivors were more likely to undergo a major renal or urinary surgical late intervention than siblings (adjusted relative risk [RR], 2.0). Locoregional surgery or radiation therapy cancer treatments were associated with undergoing late surgical intervention in the same body region or organ system.[3]
Cancer treatments predisposing to renal injury and/or high blood pressure later in life include the following:
The risk and degree of renal dysfunction depend on type and intensity of therapy, and the interpretation of the studies is compromised by variability in testing.
The incidence of and risk factors for late-onset kidney failure among long-term survivors of childhood cancer has not been well studied.
Among 25,530 CCSS participants (median follow-up, 22.3 years), the 35-year cumulative incidence of self-reported late-onset kidney failure—defined as dialysis, renal transplant, or death attributable to kidney disease—was 1.7% (compared with 0.2% in the sibling cohort).[4]
Few large-scale studies have evaluated late renal-health outcomes and risk factors for renal dysfunction among survivors treated with potentially nephrotoxic modalities.
Evidence (renal dysfunction in childhood cancer survivors):
Chronic comorbidities were assessed in a cohort of 6,778 2-year survivors of adolescent and young adult (AYA) cancer (defined as diagnosed with cancer between ages 15–39 years), with a median follow-up of 5.1 years after cancer diagnosis. Survivors of AYA cancer had a twofold to threefold increased risk of renal failure. The risk of developing chronic comorbidities was compared with matched individuals without a history of cancer.[8]
Cancer treatments predisposing to late renal injury and hypertension include the following:[9,10]
Cisplatin, carboplatin, and ifosfamide are all risk factors for the development of kidney tubular dysfunction.[5]
Cisplatin can cause glomerular and tubular damage, resulting in a diminished GFR and electrolyte wasting (particularly magnesium, calcium, and potassium).
Carboplatin is a cisplatin analogue and is less nephrotoxic than cisplatin.
Ifosfamide can also cause glomerular and tubular toxicity, with renal tubular acidosis and Fanconi syndrome, a proximal tubular defect characterized by impairment of resorption of glucose, amino acids, phosphate, and bicarbonate.
High-dose methotrexate (1,000–33,000 mg/m2) has been reported to cause acute renal dysfunction in up to 12.4% of patients. Long-term renal sequelae have not been described.[21]
Radiation therapy to the kidney can result in radiation nephritis or nephropathy after a latent period of 3 to 12 months.
A comprehensive Pediatric Normal Tissue Effects in the Clinic (PENTEC) review by the genitourinary task force evaluated dosimetric and clinical factors to radiation dose-volume relationships for genitourinary dysfunction, including kidney, bladder, and hypertension, for pediatric malignancies. The effect of chemotherapy was also considered.[33]
CCSS investigators developed prediction models for kidney failure using demographic and treatment characteristics of 5-year survivors of childhood cancer. The models were validated using follow-up data from survivors in the SJLIFE study and National Wilms Tumor Study.[37]
Pelvic or central nervous system surgery, alkylator-containing chemotherapy such as cyclophosphamide or ifosfamide, pelvic radiation therapy, and certain spinal and genitourinary surgical procedures have been associated with urinary bladder late effects, as follows:
In a study of solid organ transplants in 13,318 survivors in the CCSS, 71 survivors had end-stage kidney disease that warranted kidney transplants, 50 of whom received a kidney transplant.[45]
Table 21 summarizes kidney and bladder late effects and the related health screenings.
Predisposing Therapy | Renal/Genitourinary Effects | Health Screening |
---|---|---|
BUN = blood urea nitrogen; NSAIDs = nonsteroidal anti-inflammatory drugs; RBC/HFP = red blood cells per high-field power (microscopic examination). | ||
aAdapted from the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. | ||
Cisplatin/carboplatin; ifosfamide; calcineurin inhibitors | Renal toxicity (glomerular injury, tubular injury [renal tubular acidosis], Fanconi syndrome, hypophosphatemic rickets) | Blood pressure |
BUN, Creatinine, Na, K, Cl, CO2, Ca, Mg, PO4 levels | ||
Urinalysis | ||
Electrolyte supplements for patients with persistent electrolyte wasting | ||
Nephrology consultation for patients with hypertension, proteinuria, or progressive renal insufficiency | ||
Methotrexate; radiation exposing kidneys/urinary tract | Renal toxicity (renal insufficiency, hypertension) | Blood pressure |
BUN, Creatinine, Na, K, Cl, CO2, Ca, Mg, PO4 levels | ||
Urinalysis | ||
Nephrology consultation for patients with hypertension, proteinuria, or progressive renal insufficiency | ||
Nephrectomy | Renal toxicity (proteinuria, hyperfiltration, renal insufficiency) | Blood pressure |
BUN, Creatinine, Na, K, Cl, CO2, Ca, Mg, PO4 levels | ||
Urinalysis | ||
Discuss contact sports, bicycle safety (e.g., avoiding handlebar injuries), and proper use of seatbelts (i.e., wearing lap belts around hips, not waist) | ||
Counsel to use NSAIDs with caution | ||
Nephrology consultation for patients with hypertension, proteinuria, or progressive renal insufficiency | ||
Nephrectomy; pelvic surgery; cystectomy | Hydrocele | Testicular examination |
Cystectomy | Cystectomy-related complications (chronic urinary tract infections, renal dysfunction, vesicoureteral reflux, hydronephrosis, reservoir calculi, spontaneous neobladder perforation, vitamin B12/folate/carotene deficiency [patients with ileal enterocystoplasty only]) | Urology evaluation |
Vitamin B12 level | ||
Pelvic surgery; cystectomy | Urinary incontinence; urinary tract obstruction | History: hematuria, urinary urgency/frequency, urinary incontinence/retention, dysuria, nocturia, abnormal urinary stream |
Counsel regarding adequate fluid intake, regular voiding, seeking medical attention for symptoms of voiding dysfunction or urinary tract infection, compliance with recommended bladder catheterization regimen | ||
Urologic consultation for patients with dysfunctional voiding or recurrent urinary tract infections | ||
Cyclophosphamide/Ifosfamide; radiation exposing bladder/urinary tract | Bladder toxicity (hemorrhagic cystitis, bladder fibrosis, dysfunctional voiding, vesicoureteral reflux, hydronephrosis) | History: hematuria, urinary urgency/frequency, urinary incontinence/retention, dysuria, nocturia, abnormal urinary stream |
Urinalysis | ||
Urine culture, spot urine calcium/creatinine ratio, and ultrasound of kidneys and bladder for patients with microscopic hematuria (defined as ≥5 RBC/HFP on at least 2 occasions) | ||
Nephrology or urology referral for patients with culture-negative microscopic hematuria AND abnormal ultrasound and/or abnormal calcium/creatinine ratio | ||
Urology referral for patients with culture negative macroscopic hematuria |
For urinary late effects information, including risk factors, evaluation, and health counseling, see the Children's Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers.
The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.
Added text to state that a comprehensive Pediatric Normal Tissue Effects in the Clinic (PENTEC) review analyzed the risk of SNs. The study reported a 10-year median latency period for the development of a malignant central nervous system (CNS) neoplasm and a 21-year median latency period for the development of a meningioma.
Added text about the results of a European PanCare Childhood and Adolescent Cancer Survivor Care and Follow-Up Studies (PanCareSurFup) investigation that described findings in childhood cancer survivors who developed meningiomas or gliomas (cited Heymer et al. as reference 66).
Added text about the results of a PENTEC analysis of CNS SNs that included 32 published studies of 1,035 subsequent meningiomas after previous radiation therapy in childhood cancer survivors.
Added text to state that in a PENTEC investigation on subsequent malignancies, the estimated pooled excess relative ratio (ERR)/Gy for subsequent sarcomas was 0.045. There was a possible biphasic dose response, with higher rates of relapse and subsequent sarcomas above 55 Gy. After 20 Gy and anthracyclines, the absolute excess risk is predicted to be 0.24% at 50 years and 0.86% at 75 years. The median latency time to the development of sarcomas was 11 years.
Revised text to state that a PENTEC systematic review reported a median latency period of 25 years between the childhood cancer diagnosis and the development of a lung SN. Also added text to state that the ERR/Gy was 0.068, compared with background cumulative risks. After 20 Gy, the excess absolute risk was predicted to be 0.27% at 50 years. After 50 Gy, the excess absolute risk was predicted to be 0.7% at 50 years.
Late Effects of the Central Nervous System (CNS)
Added text about the results of a St. Jude Life (SJLIFE) investigation that assessed motor and sensory impairment in 378 survivors of childhood CNS tumors and 445 age-, sex-, and race-matched controls, using the modified Total Neuropathy Score (cited Rodwin et al. as reference 113).
Late Effects of the Digestive System
Added text to state that in a cross-sectional study of 103 patients, 53% had moderate or greater hepatic siderosis, 80% had pancreatic siderosis, 4% had cardiac siderosis, and 45% had pituitary siderosis and/or volume loss. Ferritin levels were lower in the patients no longer receiving therapy than in patients receiving therapy. Ferritin was associated with liver iron concentration in only the patients who were no longer receiving therapy. Liver iron concentration and pancreatic iron did not differ between the two groups of patients. Cardiac T2 was slightly lower in patients still receiving therapy, but not at a clinically relevant level (cited Baskin-Miller et al. as reference 58).
Late Effects of the Endocrine System
Added Baran et al. as reference 35.
Added text to state that the investigators of a trial that included pediatric patients who were treated for medulloblastoma were not able to reliably distinguish between central and primary hypothyroidism, but they estimated that 8 of 85 patients were initially diagnosed with central hypothyroidism.
Added text to state that approximately one of ten adult survivors of childhood cancer is underweight. Also added text about the results of a Childhood Cancer Survivor Study that found that childhood cancer survivors who are underweight have an increased risk of late mortality (cited Tonorezos et al. as reference 118).
Added text to state that survivors of childhood cancer may experience accelerated biological aging, resulting in premature frailty and death. Added text about a study that used the SJLIFE cohort to evaluate the associations of seven measures of biological age acceleration with frailty and all-cause mortality in adult survivors of childhood cancer, compared with controls who have not had childhood cancer (cited Guida et al. as reference 159).
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This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about the late effects of treatment for childhood cancer. It is intended as a resource to inform and assist clinicians in the care of their patients. It does not provide formal guidelines or recommendations for making health care decisions.
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PDQ® Pediatric Treatment Editorial Board. PDQ Late Effects of Treatment for Childhood Cancer. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: https://www.cancer.gov/types/childhood-cancers/late-effects-hp-pdq. Accessed <MM/DD/YYYY>. [PMID: 26389273]
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