After diagnosis, one of the most important procedures done is staging. Staging refers to the extent of the cancer and how far it has spread. Colon cancer staging is very important as it can help doctors determine the kind if treatment that is required.
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 stage depends on how far the cancer has grown into the wall of the colon. These layers include, the mucosa which is the inner lining, the sub mucosa which is the fibrous tissue below the muscle, the muscularis propria which is a thick muscle layer and the serosa and suberosa 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.
The TNM system of staging uses the pathological stage which is also called the surgical stage, which examines a tissue that has been removed during surgery. This process is also called surgical staging and is more accurate than clinical staging which consist of a physical exam, biopsies and imaging tests which are done before surgery.
This is the earliest stage of colon cancer and it also means that the cancer has not grown beyond the mucosa or the innermost layer of the colon. The cancer has also not spread to the nearby lymph nodes and has also not spread (metastasized) to distant organs.