Understanding the Stages of Colon Cancer

Since every colon cancer is unique, it is important to gather as much information as possible about your tumor to determine the best treatment approach for you. The following factors provide important information that can help you and your doctor understand your individual cancer and your different treatment options.

Colon Cancer Staging

Once you have been diagnosed with colon cancer, your doctor will order tests to determine the size and location of your tumor and whether it has spread. This process, known as staging, helps determine what treatments are most appropriate for you. Staging tests may include procedures such as abdominal and chest CT scans. Often, the stage of your cancer is not determined until after you have had colon cancer surgery. The stages of colon cancer are:

  • Stage 0: Your cancer is small and limited to the inner wall of the colon (it has not spread). Carcinoma in situ is another name for Stage 0 colon cancer.
  • Stage I. Your cancer has grown through the superficial lining (mucosa) of the colon, but hasn't spread beyond the colon wall.
  • Stage II. Your cancer has grown into or through the wall of the colon to nearby tissue, but has not spread to the lymph nodes. Also called Dukes B colon cancer.
  • Stage III A/B. Your cancer has spread beyond the outer layers of the colon to nearby lymph nodes, but not to other tissues or organs.
  • Stage IV. Your cancer has spread to distant sites, such as your liver or lung.

Other Important Factors

Detailed information about your colon cancer can be found in your pathology report. This information is obtained from tests performed on the biopsy or surgical sample taken from your tumor. Be sure talk to your doctor about your pathology results, which may include:

  • Tumor T-stage – How large is your tumor?  Has it spread?
  • MMR status – How aggressive is your tumor?
  • Tumor grade – How do your cancer cells look compared to normal cells?
  • Bowel perforation or obstruction – Is your tumor affecting the health and function of your bowels?
  • Lymphatic or vascular invasion – Are there cancer cells in your bloodstream or lymph system?

Looking at the Biology of your Tumor

Additional tumor tests, such as the Oncotype DX® colon cancer assay, can provide valuable, quantitative recurrence risk  information to help guide personalized treatment decisions. It is an advanced genomic test and can help patients with stage II and stage III A/B colon cancer learn how likely it is that their cancer may return in the future. 

Next: Treatment Options