Table Staging Colorectal Cancer * Stage Tumor (Maximum Penetration) Regional Lymph Node Metastasis Distant Metastasis 0 Tis N0 M0 I T1 or T2 N0 M0 II T3 N0 M0 III Any T or Any N M0 T4 N0 M0 IV Any T Any N M1 * TNM classification: Tis = carcinoma in situ; T1 = submucosa; T2 = muscularis propria; T3 = penetrates all layers (for rectal cancer, includes perirectal tissue); T4 = adjacent organs or peritoneum.