Colorectal cancer/staging

For the classification of colorectal cancer, 2 classification systems are commonly used - TNM and Dukes.

=== TNM classification ===


 * T = tumor (Tis = carcinoma in situ, T1 = submucosa, T2 = muscularis propria, T3 = subserosa, pericolic or perirectal tissues, T4a = visceral peritoneum, T4b = other organs or structures )
 * N = regional lymph node involvement (N0 = no LU involvement, N1a = 1 regional node, N1b = 2–3 regional nodes, N1c = satellites without regional nodes, N2a = 4–6 regional LU, N2b = 7 or more regional LUs, Nx = unknown number of affected nodes – examined less than 12 LUs from resected bowel)
 * M = distant metastases (M0 = no distant metastases, M1a = 1 organ, M1b = more than 1 organ, peritoneum)

=== Dukes Classification ===