Colorectal Cancer Staging

The process used to find out if cancer has spread within the colon/rectum or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment.

Basic Overview

Stage 0: This is the earliest stage possible. Cancer hasn't moved from where it started; it's still restricted to the innermost lining of the colon. Also called Carcinoma in Situ.

Stage I: Cancer has begun to spread, but is still in the inner lining.  Also called Dukes A colorectal cancer.

Stage II: Cancer has spread to other organs near the colon or rectum. It has not reached lymph nodes. Also called Dukes B colorectal cancer.

Stage III: Cancer has spread to lymph nodes, but has not been carried to distant parts of the body. Also called Dukes C colorectal cancer.

Stage IV: Cancer has been carried through the lymph system to distant parts of the body. This is known as metastasis. The most likely organs to experience metastasis from colorectal cancer are the lungs and liver. Also called Dukes D colorectal cancer.

Staging for Colon vs. Rectal Cancer

Colon Cancer

Stage 0: In stage 0, abnormal cells are found in the innermost lining of the colon. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I: In stage I, cancer has formed and spread beyond the innermost tissue layer of the colon wall to the middle layers.

Stage II:  In stage II, colon cancer is divided into stage IIA and stage IIB.

• Stage IIA: Cancer has spread beyond the middle tissue layers of the colon wall or has spread to nearby tissues around the colon or rectum.
• Stage IIB: Cancer has spread beyond the colon wall into nearby organs and/or through the peritoneum.

Stage III:  In stage III, colon cancer is divided into stage IIIA, stage IIIB, and stage IIIC.

• Stage IIIA: Cancer has spread from the innermost tissue layer of the colon wall to the middle layers and has spread to as many as 3 lymph nodes.
• Stage IIIB: Cancer has spread to as many as 3 nearby lymph nodes and has spread:
  • beyond the middle tissue layers of the colon wall; or
  • to nearby tissues around the colon or rectum; or
  • beyond the colon wall into nearby organs and/or through the peritoneum.
• Stage IIIC: Cancer has spread to 4 or more nearby lymph nodes and has spread:
  • to or beyond the middle tissue layers of the colon wall; or
  • to nearby tissues around the colon or rectum; or
  • to nearby organs and/or through the peritoneum.

Stage IV:  In stage IV, cancer may have spread to nearby lymph nodes and has spread to other parts of the body, such as the liver or lungs.

 

Rectal Cancer

Stage 0: In stage 0, abnormal cells are found in the innermost lining of the rectum. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I: In stage I, cancer has formed and spread beyond the innermost lining of the rectum to the second and third layers and involves the inside wall of the rectum, but it has not spread to the outer wall of the rectum or outside the rectum.

Stage II: In stage II, cancer has spread outside the rectum to nearby tissue, but it has not gone into the lymph nodes (small, bean-shaped structures found throughout the body that filter substances in a fluid called lymph and help fight infection and disease).

Stage III: In stage III, cancer has spread to nearby lymph nodes, but it has not spread to other parts of the body.

Stage IV: In stage IV, cancer has spread to other parts of the body, such as the liver, lungs, or ovaries.