Stage Information for Anal Cancer
The anal canal extends from the rectum to the perianal skin and is lined by a mucous membrane that covers the internal sphincter. The following is a staging system for anal canal cancer that has been described by the American Joint Committee on Cancer (AJCC) and the International Union Against Cancer. Tumors of the anal margin (below the anal verge and involving the perianal hair-bearing skin) are classified with skin tumors.
Definitions of TNM
The following is a staging system for anal canal cancer that has been described by the AJCC and the International Union Against Cancer.
Table 1. Primary Tumor (T)a
|TX||Primary tumor cannot be assessed.|
|T0||No evidence of primary tumor.|
|Tis||Carcinoma in situ (i.e., Bowen disease, high-grade squamous intraepithelial lesion, and anal intraepithelial neoplasia II–III.)|
|T1||Tumor ≤2 cm in greatest dimension.|
|T2||Tumor >2 cm but ≤5 cm in greatest dimension.|
|T3||Tumor >5 cm in greatest dimension.|
|T4||Tumor of any size invades adjacent organ(s), e.g., vagina, urethra, and bladder.b|
Table 2. Regional Lymph Nodes (N)a
|NX||Regional lymph nodes cannot be assessed.|
|N0||No regional lymph node metastasis.|
|N1||Metastases in perirectal lymph node(s).|
|N2||Metastases in unilateral internal iliac and/or inguinal lymph node(s).|
|N3||Metastases in perirectal and inguinal lymph nodes and/or bilateral internal iliac and/or inguinal lymph nodes.|
Table 3. Distant Metastasis (M)a
|M0||No distant metastasis.|
Table 4. Anatomic Stage/Prognostic Groupsa
|IV||Any T||Any N||M1|
- Anus. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 167-169.