When carcinoma is detected, the histologic findings (fine-tissue findings) should include the following features, according to the S3 guideline:
- The extent of deep infiltration (pT category), and for sessile polyps (firmly grown polyps), the sm invasion measurement in μm,
- The histological degree of differentiation (grading),
- Presence or absence of lymphatic vessel invasion (L classification),
- And assessment of resection margins (R classification) with respect to local removal in healthy individuals (to depth and to the side).
The following staging classifications are distinguished in colon carcinoma (colorectal cancer): The TNM classification is a prognosis-oriented classification system of the UICC (Union internationale contre le cancer).
TNM system – tumor size / nodus (lymph node involvement) / metastases (daughter tumor) 0 = not present ; 1 = present.
Stage | Tumor size | Nodus | Metastasis |
0 | Tis – tumor in situ | N0 | M0 |
I | T1 | N0 | M0 |
T2 | N0 | M0 | |
II | T3 | N0 | M0 |
T4 | N0 | M0 | |
III | each T | N1 | M0 |
each T | N2, N3 | M0 | |
IV | each T | each N | M1 |
Dukes classification
Dukes | UICC | Findings | 5-year survival rate |
A | I | Tumor growth confined to intestinal wall, infiltration maximal to muscularis propria, no lymph nodes affected | 95-100 % |
B1 | II | Tumor growth beyond muscularis propria, no lymph nodes involved | 85-95 % |
B2 | II | Invasion of serosa or pericolic adipose tissue, no lymph nodes involved | |
C | III | Lymph node involvement (for tumor spread A or B). | 55-65 % |
D | IV | Distant metastases | 5 % |
Consensus Molecular Subtypes (CMS).
Approximately 87 percent of all colorectal cancers are distributed among four molecular subtypes:
Subtype | Description | |
CMS 1 | (“MSI Immune”, share 14 %) |
|
CMS 2 | (“canonical”, share: 40%) | |
CMS 3 | “metabolic”, share 15%) | |
CMS 4 | (“mesenchymal”, proportion 30%) |
|