Stages of Colon Cancer

If your treatment team diagnoses you with colon cancer, the next critical step is figuring out the stage of the cancer, or how advanced it is. Staging helps us design a plan that treats your colon cancer in the most effective way possible. To determine the stage of your cancer, your team will order diagnostic tests to assess:

  • how deeply the cancer involves the wall of your colon
  • whether the cancer has metastasized (spread) to other parts of your body

The following are the stages of colon cancer:

Stage 0 — This very early cancer is found only in the innermost lining of the colon.

Stage I — The tumor has spread beyond the inner lining but remains within the colon and has not spread to the lymph nodes (small organs that are part of the immune system).

Stage II — The cancer extends through the thick outer muscle layer of the colon but has not spread to the lymph nodes.

Stage III — The cancer has spread outside the colon to one or more lymph nodes.

Stage IV — The cancer has spread to other parts of the body, such as the liver or lungs. The cancer may or may not be present in the lymph nodes.

Your treatment team may recommend CT and MRI scans to determine the stage of your cancer and to show if the cancer has metastasized to other organs.