Staging of colorectal cancer
(A) of the TNM classification of colorectal cancer
1. T – primary tumor
Tis: carcinoma in situ.
Tl: tumor invasion and the mucosa or submucosa.
T2: tumor invasion and muscular.
T3: tumor invasion through the muscular layer to the subserosa or into the side without peritoneal colon or rectum covered by tissue.
T4: Tumor penetrates the visceral peritoneum or direct invasion of other organs or structures.
2. N – Regional lymph nodes
NO: No regional lymph node metastasis.
Nl: the colon or rectum next to the 1-3 next to lymph node metastasis.
N collusion bowel or rectum next to the side 4 or more than 4 lymph node metastases.
N3: lymph node along the supply vessel.
3. M – distant metastasis
MO: no distant metastasis.
Ml: distant metastasis.
(B) stages of colorectal cancer
0 (carcinoma in situ): Tis NO MO
I a of: Tl NO MO
I b of: T2 NO MO
II,: T3 NO MO
III: any T, NI 3, MO; T4 NO MO
IV: any T, any N, Ml