Colon Cancer Staging

Colon Carcinoma Staging:

Only in the colon can invasion of lamina propria be carcinoma in situ due to lack of lymphatics within this region. T1 is invasion of submucosa.

Tis: carcinoma in situ (intraepithelial or invasion of lamina propria)
T1: tumor invades submucosa only

REST OF GI TRACT
TX: cannot be assessed
T0: no evidence of primary tumour
Tis: carcinoma in situ (intraepithelial only)
T1: tumor in lamina propria or submucosa
T2: tumor invades muscularis propria
T3: tumor invades through the muscularis propria into the subserosa
T4a: tumor directly invades other organs
T4b: perforates visceral peritoneum

Note: pT4 (serosal involvement) includes (a) tumor close to or at, serosal surface due to mesothelial inflammatory or hyperplastic reaction

Regional lymph nodes (N)
NX: cannot be assessed
N0: none
N1: 1-3
N2: 4+
Classify tumour nodule as:
lymph node: if form and smooth contour of a lymph node
tumour: if irregular contour

Notes: 12-15 lymph nodes are required for accurate staging

Distant Metastasis (M)
MX: distant metastasis cannot be assessed
M0: no distant metastasis
M1: distant metastasis