Early stage colon cancer

Table 1 Colon cancer staging

AJCC stage	TNM stage	TNM criteria
Stage 0	Tis N0 M0	Tumor confined to mucosa
Stage I	T1 N0 M0	Tumor invades submucosa
Stage I	T2 N0 M0	Tumor invades muscularis propria
Stage IIA	T3 N0 M0	Tumor invades subserosa
Stage IIB	T4 N0 M0	Tumor invades adjacent organs
Stage IIIA	T1-2 N1 M0	Tumor metastases to 1-3 nodes
Stage IIIB	T3-4 N1 M0	Tumor metastases to 1-3 nodes
Stage IIIC	Any T, N2, M0	Tumor metastases to 4 or more nodes
Stage IV	Any T or N, M1	Metastases to distant sites

AJCC: American Joint Committee on Cancer; TNM: Tumor/Nodes/Metastases. Other classification methods include: Dukes System: A, tumor confined to intestinal wall; B, tumor invading through the intestinal wall; C, tumor with lymph node involvement; D, tumor with distant metastases; and Astler-Coller System: A, Tumor limited to mucosa; B1, Tumor through muscularis mucosa but not muscularis propria; B2, Tumor beyond muscularis propria; C1, B1 with lymph node metastases; C2, B2 with lymph node metastases; D, Distant metastases. Other criteria include: venous and lymphatic invasion and differentiation.