T stage T1: Tumor invades the intramucosal layer or submucosal layer.
T1a: Tumor invaded the lamina propria of mucosa.
T1b: Tumor invaded the submucosa.
T2: Tumor invaded the intrinsic muscular layer.
T3: Tumor invades the subplasma layer (formerly T2b).
T4: T4a: tumor invades through the plasma membrane (formerly T3).
T4b: tumor invades other adjacent organs.
N stage N0: No adjacent lymph node metastasis.
N1: 1~2 lymph node metastasis.
N2: 3~6 lymph node metastases.
N3: N3a: 7~15 lymph node metastases (originally N2).
N3b: >16 lymph node metastases (formerly N3).
M staging M0: Tumor without distant organ and lymph node metastasis.
M1: With distant metastasis.