The colon cancer staging is done based on the TNM system of staging.
The TNM system of staging has the following factors:
Tumor (T): This refers to how far the cancer has grown into the wall of the colon. These layers include, the mucosa which is the inner lining, the submucosa which is the fibrous tissue below the muscle, the muscularis propria which is a thick muscle layer and the serosa and subserosa which are a thin layer of connective tissue.
Lymph node s (N): This factor indicates if the cancer has spread to the lymph nodes.
Metastasis (M): This factor refers to whether the cancer has spread to other parts of the body.
At stage 1 colon cancer, the cancer is a little more advanced than the previous stage and the cancer has already spread beyond the muscularis mucosa and into the submucosa or it may have also grown into the muscularis propria. At this stage the cancer has not spread to the nearby lymph node or distant sites.
The stage 1 colon cancer diagnosis is done according to the following TNM categories
If the cancer has grown beyond the muscularis mucosa and into the submucosa it is considered as T1. If the cancer has grown into the muscularis propria it is known as T2.
The cancer has not spread to the lymph nodes
The cancer has not spread to distant organs or sites.
The 5 year relative survival rate of stage 1 colon cancer is 92%