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Colon Cancer Diagnosis

Colon cancer can be a very manageable disease, if caught early. People with colon cancer might not have any symptoms, but receive a diagnosis during a routine colon test. Others may have symptoms such as:

  • Cramps, gas, pain or uncomfortable feeling in the abdomen that won’t go away
  • Diarrhea, constipation, or change in consistency of stool
  • Bleeding from the rectum (anus) or blood in stool
  • A feeling that the bowel doesn’t completely empty
  • Weakness or fatigue
  • Unexplained weight loss

To confirm if cancer is present, the gastroenterologist (specialist in digestive organs) will take a small sample of tissue during a colonoscopy or sigmoidoscopy:

  • A colonoscopy uses a long flexible tube inserted into the entire colon. (You must follow special instructions to prepare for this test. See Preparing for Your Colonoscopy.)
  • A sigmoidoscopy uses a lighted tube inserted into only the lower part of the colon.

The sample will be looked at by a pathologist (specialist in studying tissue) to confirm if cancer is present. Your gastroenterologist will let you know which test they will use and the results of the test.  If colon cancer is found at a young age or if there are several family members with colon cancer, genetic testing may be recommended.

Stages of Colon Cancer

Colon cancer is staged from 0 to 4. Staging measures the size of the tumor, whether it has spread to nearby lymph nodes, and whether it has spread (metastasized) to other parts of the body.

Stage 0

  • The tumor is still in its earliest stage and hasn’t grown beyond the lining (mucosa) of the colon (carcinoma in situ).
  • It hasn’t spread to lymph nodes.
  • It hasn’t spread to other parts of the body.

Stage 1

  • The cancer has grown through the lining, but not through the wall of the colon.
  • It hasn’t spread to lymph nodes.
  • It hasn’t spread to other parts of the body.

Stage 2

  • The cancer has grown into the outermost layers and perhaps through the wall of the colon.
  • It has not spread to lymph nodes.
  • It may have grown into nearby tissue.  

Stage 3

  • The cancer has grown through the wall of the colon and might have spread to other areas of the colon.
  • It has spread to nearby lymph nodes or into areas of fat near the lymph nodes.
  • It has not spread to other parts of the body.

Stage 4

  • The cancer may have grown through the wall of the colon.
  • It has spread to at least one other organ (such as the liver or lung) or spread to the lining of the abdomen.

After determining the stage, your cancer doctor will be able to recommend a treatment plan and discuss your options with you. Many people like to take some time to think about what the doctor recommends before starting treatment.

Your doctors and cancer care team at Group Health Medical Centers can answer any questions you might have about testing and diagnosis.

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