Low Risk Seen in Monitoring, Not Treating, Localized Prostate Cancer

The Bottom Line

Results from a long-term cohort study show that active surveillance, or "watchful waiting," may be a reasonable alternative to surgery or radiation therapy for elderly men with localized prostate cancer.

The Whole Story

Each year, more than 190,000 U.S. men are diagnosed with prostate cancer and approximately 27,000 die from the disease. Standard options for managing early-stage prostate cancer include surgery, radiation therapy, and active surveillance, or "watchful waiting." In active surveillance, patients are monitored closely with periodic prostate-specific antigen (PSA) tests and digital rectal examinations, as well as by repeat biopsy procedures, for signs that the cancer is growing and may need treatment. Because surgery and radiation therapy are associated with serious side effects, including urinary incontinence and impotence, many men decide to forgo initial treatment in favor of active surveillance.

In recent years, the use of PSA testing to screen for prostate cancer has increased and follow-up prostate biopsy procedures have been recommended at lower serum PSA values--leading to the detection of many small, low-grade cancers that might have otherwise gone unnoticed. Prostate tumors often grow slowly and may not threaten a man's health during his lifetime. Understanding how prostate cancer progresses if it is left untreated is important in helping doctors and patients make informed decisions about therapy. This question is especially important for elderly men, who may die of other causes before their prostate cancer becomes life threatening. Indeed, the U.S. Preventive Services Task Force now recommends against PSA screening in men age 75 and older.

Therefore, researchers wanted to know what happens to elderly men who choose active surveillance instead of treatment after a diagnosis of localized prostate cancer. By using Medicare claims data linked with data from NCI's Surveillance, Epidemiology and End Results (SEER) program, researchers at the Cancer Institute of New Jersey were able to review the medical outcomes of 9,018 men age 66 and older who were diagnosed with localized prostate cancer between 1992 and 2002 and who did not receive treatment in the first 6 months following diagnosis. . The men were between 66 and 104 years old when diagnosed, with a median age at diagnosis of 77. The researchers found that:

• During the study period, 72% of the men either died from a cause that was unrelated to prostate cancer or did not experience prostate cancer symptoms that required surgery or radiation therapy.
• The median time before a man received any form of prostate cancer treatment (surgery, radiation therapy, chemotherapy, or hormonal therapy) was 10.6 years.
• Only 5.3% of the men died from prostate cancer in the 10-year period following their diagnosis.

This study lends support to the use of active surveillance for localized prostate cancer in elderly men, particularly those with low-grade tumors. However, the findings do not address the appropriate management of younger men with localized prostate cancer. The results were presented at the first Genitourinary Cancers Symposium, sponsored by the American Society of Clinical Oncology (ASCO) in 2008.

Publication: Lu-Yao G, Barry MJ, Zietman A, et al. Disease trajectory of untreated localized prostate cancer in elderly men: a population-based study. 2008 ASCO Genitourinary Cancers Symposium, Abstract #10.