Colorectal or Colon Cancer Stages
Two systems are customary for the classification of colorectal cancer stages: First, there are the so-called TNM classifications, which are common to almost all tumors and describes the spread of the tumor. Based on the TNM classification the cancer can be divided in certain colorectal cancer stages by the UICC (Union for International Cancer Control).
TNM classification of colon cancer:
TNM is an abbreviation for:
T for tumor: how big the tumor is and how deep it has penetrated into the tissue
N for nodes (lymph nodes): how many lymph nodes are infested by cancer cells
M for metastases (secondary tumors): where and how many metastases are present
For each of these three categories, a numerical value is assigned. The more advanced the disease, the greater the numerical value. The tumor spread (T) is determined by the so-called infiltration depth. By this is meant that colon cancer has advanced in which fabric layer of the intestinal wall. The TNM classifications for colon cancer are:
| Tis
|
Carcinoma in situ
|
In a carcinoma in situ (CIS) is an early form of colorectal cancer. The cancer is still in the top fabric layer (epithelium)
|
| T1
|
Infestation of the submucosa
|
Tumor involvement to the tissue layer beneath the mucosa
|
| T2
|
Infestation of the muscularis propria
|
Tumor involvement to the muscle layer beneath the submucosa
|
| T3
|
Infestation of subserosa and pericolic, or perirectal fat
|
Tumor infestation to the connective tissue layer (subserosa) of the outer intestinal wall, or the adipose tissue adjacent to the intestinal wall
|
| T4
|
Infiltration of the peritoneum (T4a) or other organs / structures (T4b)
|
Tumor involvement to the abdominal membrane (peritoneum) or spread even to other organs
|
| N0
|
No lymph node involvement
|
|
| N1
|
1-3 regional lymph nodes
|
Regional lymph nodes are the lymph node station near the tumor
|
| N2a
|
4-6 regional lymph nodes
|
|
| N2b
|
≥7 regional lymph nodes
|
|
| M0
|
No distant metastasis
|
|
| M1a
|
Distant metastases: Only an organ affected
|
A so-called peritoneal carcinomatosis is a scale infestation of the peritoneum with cancer cells.
|
| M1b
|
Distant metastases: More than one organ affected or peritoneal
|
Colorectal cancer stages UICC:
The colorectal cancer stages of UICC (Union for International Cancer Control) based on the TNM classification. Depending on the extent of the tumor infestation, colon cancer is associated with a particular UICC stage in each patient. The type of treatment depends on these stages. In addition, rough estimates regarding the prognosis can be dependent on the UICC stage hit.
Examples: A patient with an advanced tumor (T4) to the TNM classification is still in stage II, as long as no daughter metastases exist in lymph nodes or other organs (N0, MO). On the other hand, is an interested party with a proven distant metastasis (M1) always read in severe cancer stage IV.:
| UICC stage:
|
TNM: |
| 0 | Tis |
| 1 | Until T2 when N0, M0
|
| II
|
Until T4 when N0, M0
|
| III | Each T, N1 / N2, M0
|
| IV | Each T, any N, M1
|
For more general information…..