T - Primary tumor:
- T x = Primary tumor can not be evaluated
- T 0 = No indication for primary tumor
- T is = Carcinoma in situ
- T 1 = Tumor infiltrates lamina propria or submucosa
- T 2 = Tumor infiltrates muscularis propria
- T 3 = Tumor infiltrates adventitia
- T 4 = Tumor infiltrates surrounding structures
N - Regional lymph nodes:
- N x = Regional lymph nodes can not be evaluated
- N 0 = No regional lymph nodes metastases
- N 1 = regional lymph node metastases
M - Metastases:
- M x = Can not be evaluated
- M 0 = No metastases
- M 1 = Metastases
Stages:
- Stage 0: T is, N 0, M 0
- Stage I: T 1, N 0, M 0
- Stage IIA: T 2 or T 3, N 0, M 0
- Stage IIB: T 1 or T 2, N 1, M 0
- Stage III: T 3, N 1, M 0, T 4, every N, M 0
- Stage IV: every T, every N, M 1