After colon cancer has been diagnosed, the next step is to perform tests to determine if the cancer has spread within the intestine or to distant parts of the body. This is called staging. Staging helps the doctor to decide the most appropriate treatment for the cancer at its current stage.

Tests for Staging
A number of tests may be used to determine the extent of the cancer, including:

• Lymph node biopsy. A pathologist views a tissue sample from the lymph node to see if there are cancer cells present.
• Complete blood count (CBC). A CBC uses a blood sample to check for
  
  • the number and proportion of red blood cells
  • the number of white blood cells
  • the number of platelets
  • the amount of hemoglobin in the red blood cells

• Carcinoembryonic antigen (CEA) assay. This test that measures the level of CEA in the blood. Higher than normal amounts can be a sign of colon cancer.
• CT or PET/CT scan
• MRI
• Chest X-ray
• Surgery. Surgery may be performed to remove the tumor and see how far it has spread in or outside of the colon.

Stages of Colorectal Cancer
Cancer spreads in three ways: by invading surrounding tissue, by invading the lymph system and traveling through the lymph vessels to other places in the body, and by invading veins and capillaries and traveling through the blood to other places in the body.

The stages of colorectal cancer reflect its progress through the layers of the colon wall and its spread to lymph nodes and distant organs.

• Stage 0 (carcinoma in situ): Abnormal cells are found in the innermost lining of the colon (the mucosa). These abnormal cells may become cancerous and invade nearby tissue.
• Stage I: Cancer has formed and spread beyond the mucosa to the middle layers of the intestinal wall. Stage I colon cancer is sometimes called Dukes A colon cancer.
• Stage II: Divided into stage IIA and stage IIB. Stage II colon cancer is sometimes called Dukes B colon cancer.
  
  • Stage IIA: Cancer has spread beyond the middle tissue layers of the intestinal wall or has spread to nearby tissues.
  • Stage IIB: Cancer has spread beyond the colon wall into nearby organs and/or through the peritoneum (the membrane that lines the abdominal cavity and covers most of the abdominal organs).
• Stage III: Divided into stage IIIA, stage IIIB, and stage IIIC. Stage III colon cancer is sometimes called Dukes C colon cancer.
  
  • Stage IIIA: Cancer has spread from the mucosa to the middle layers and has spread to as many as three lymph nodes.
  • Stage IIIB: Cancer has spread to as many as three 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 four 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: Cancer may have spread to nearby lymph nodes and has spread to other parts of the body, such as the liver or lungs. Stage IV colon cancer is sometimes called Dukes D colon cancer. It is not typically considered curable.

Recurrent: Cancer has returned after treatment. It may recur in the colon, rectum, or a different part of the body.

More on this topic

Colorectal Cancer Screening (VIDEO)
Colorectal Cancer
Colon Anatomy & Function
What Is Colorectal Cancer
Tumor Growth
Cancer Staging
Signs & Symptoms
Screening & Diagnosis
A Less Invasive Look
Treating Colorectal Cancer
Detecting Cancer Recurrence
Preventing Cancer

Related Health Centers:

Breast Cancer, Cancer Introduction, Colorectal Cancer, Prostate Cancer