Stage Information for Nasopharyngeal Cancer
Note: This Stage Information section has been updated to include information from the seventh edition (2010) of the American Joint Committee on Cancer's AJCC Cancer Staging Manual. The PDQ Adult Treatment Editorial Board, which is responsible for maintaining this summary, is currently reviewing the new staging categories to determine whether additional changes need to be made to other parts of the summary. Any necessary changes will be made as soon as possible.
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, when possible, and by both indirect mirror examination and direct endoscopy when necessary. 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.[3,4] Information from diagnostic imaging studies may be used in staging. Magnetic resonance imaging offers an advantage over computed tomographic scanning in the detection and localization of head and neck tumors and the distinction of lymph nodes from blood vessels. Positron emission tomography scans may be useful in detecting skeletal metastases in patients with advanced nasopharyngeal cancer.
If a patient has a relapse, a complete reassessment must be done to select the appropriate additional therapy.
Definitions of TNM
The American Joint Committee on Cancer (AJCC) has designated staging by TNM classification to define nasopharyngeal cancer.
Table 1. Primary Tumor (T)a
a Reprinted 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.
b Parapharyngeal extension denotes posterolateral infiltration of tumor.
|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.|
Table 2. Regional Lymph Nodes (N)a, b
a Reprinted 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.
b The 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.
c Midline nodes are considered ipsilateral nodes.
d Supraclavicular 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.
|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|