Stage Information for Nasopharyngeal Cancer
Staging systems are all clinical staging and are based on the best possible estimate of the extent of disease before treatment.[1,2] Assessment of the primary tumor is based on inspection and palpation, and fiberoptic endoscopic evaluation. The tumor must be confirmed histologically, and any other pathologic data obtained on biopsy may be included. Evaluation of the function of the cranial nerves is especially appropriate for tumors of the nasopharynx. The appropriate nodal drainage areas are examined by careful palpation and radiologic evaluation. The retropharyngeal lymph nodes are the first echelon of drainage.[3,4] Information from diagnostic imaging studies may be used in staging. Magnetic resonance imaging provides additional information to computed tomographic scanning in the evaluation of skull base invasion and intracranial spread.[5] Positron emission tomography scans combined with CT are helpful in radiation treatment planning for target delineation of the primary tumor, aids in detection of metastatic nodal involvement and metastatic spread such as lung or skeletal metastases in patients with advanced nasopharyngeal cancer.[6]
If a patient has a relapse, a complete reassessment must be done to select the appropriate additional therapy.
Definitions of TNMThe American Joint Committee on Cancer (AJCC) has designated staging by TNM classification to define nasopharyngeal cancer.[7]
Table 1. Primary Tumor (T)a| TX | Primary tumor cannot be assessed. |
| T0 | No evidence of primary tumor. |
| Tis | Carcinoma in situ. |
| T1 | Tumor confined to the nasopharynx, or tumor extends to oropharynx and/or nasal cavity without parapharyngeal extension.b |
| T2 | Tumor with parapharyngeal extension.b |
| T3 | Tumor involves bony structures of skull base and/or paranasal sinuses. |
| T4 | Tumor with intracranial extension and/or involvement of cranial nerves, hypopharynx, orbit, or with extension to the infratemporal fossa/masticator space. |
| aReprinted with permission from AJCC: Pharynx. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 41-56. | |
| bParapharyngeal extension denotes posterolateral infiltration of tumor. |
Table 2. Regional Lymph Nodes (N)a, b
| NX | Regional lymph nodes cannot be assessed. |
| N0 | No regional lymph node metastasis. |
| N1 | Unilateral metastasis in cervical lymph node(s), ≤6 cm in greatest dimension, above the supraclavicular fossa, and/or unilateral or bilateral, retropharyngeal lymph nodes, ≤6 cm in greatest dimension.c |
| N2 | Bilateral metastasis in cervical lymph node(s), ≤6 cm in greatest dimension, above the supraclavicular fossa.d |
| N3 | Metastasis in a lymph node(s)c >6 cm and/or to supraclavicular fossa.d |
| N3a | >6 cm in dimension. |
| N3b | Extension to the supraclavicular fossa.d |
| aReprinted with permission from AJCC: Pharynx. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 44-56. | |
| bThe distribution and the prognostic impact of regional lymph node spread from nasopharyngeal cancer, particularly of the undifferentiated type, are different from those of other head and neck mucosal cancers and justify the use of a different N classification scheme. | |
| cMidline nodes are considered ipsilateral nodes. | |
| dSupraclavicular zone or fossa is relevant to the staging of nasopharyngeal carcinoma and is the triangular region originally described by Ho. It is defined by three points: (1) the superior margin of the sternal end of the clavicle, (2) the superior margin of the lateral end of the clavicle, (3) the point where the neck meets the shoulder. Note that this would include caudal portions of levels IV and VB. All cases with lymph nodes (whole or part) in the fossa are considered N3b. |
Table 3. Distant Metastasis (M)a
| aReprinted with permission from AJCC: Pharynx. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 41-56. | |
| M0 | No distant metastasis. |
| M1 | Distant metastasis. |
Table 4. Anatomic Stage/Prognostic Groupsa
| Stage | T | N | M |
| aReprinted with permission from AJCC: Pharynx. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 41-56. | |||
| 0 | Tis | N0 | M0 |
| I | T1 | N0 | M0 |
| II | T1 | N1 | M0 |
| T2 | N0 | M0 | |
| T2 | N1 | M0 | |
| III | T1 | N2 | M0 |
| T2 | N2 | M0 | |
| T3 | N0 | M0 | |
| T3 | N1 | M0 | |
| T3 | N2 | M0 | |
| IVA | T4 | N0 | M0 |
| T4 | N1 | M0 | |
| T4 | N2 | M0 | |
| IVB | Any T | N3 | M0 |
| IVC | Any T | Any N | M1 |
References
- Teo PM, Leung SF, Yu P, et al.: A comparison of Ho's, International Union Against Cancer, and American Joint Committee stage classifications for nasopharyngeal carcinoma. Cancer 67 (2): 434-9, 1991. [PUBMED Abstract]
- Lee AW, Foo W, Law SC, et al.: Staging of nasopharyngeal carcinoma: from Ho's to the new UICC system. Int J Cancer 84 (2): 179-87, 1999. [PUBMED Abstract]
- Mendenhall WM, Werning JW, Pfister DG: Treatment of head and neck cancer. In: DeVita VT Jr, Lawrence TS, Rosenberg SA: Cancer: Principles and Practice of Oncology. 9th ed. Philadelphia, Pa: Lippincott Williams & Wilkins, 2011, pp 729-80.
- Laramore GE, ed.: Radiation Therapy of Head and Neck Cancer. Berlin: Springer-Verlag, 1989.
- Consensus conference. Magnetic resonance imaging. JAMA 259 (14): 2132-8, 1988. [PUBMED Abstract]
- Liu FY, Chang JT, Wang HM, et al.: [18F]fluorodeoxyglucose positron emission tomography is more sensitive than skeletal scintigraphy for detecting bone metastasis in endemic nasopharyngeal carcinoma at initial staging. J Clin Oncol 24 (4): 599-604, 2006. [PUBMED Abstract]
- Pharynx. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 41-56.
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