Colorectal Cancer

Diagnosis

Colorectal cancer usually is diagnosed by a sigmoidoscopy or colonoscopy. In these tests, a flexible viewing tube is inserted into your rectum and colon to look for polyps or cancerous masses. You also may have a test called a barium enema. In this test, a fluid containing a substance called barium is pumped into your rectum before X-rays are taken. The barium helps abnormalities show up on the X-rays. These tests provide information about the size and location of the cancer.

Sometimes, if the cancer has spread outside the colon or rectum, you may need a biopsy of that area. In a biopsy, a small piece of tissue is removed and examined in a laboratory.

Other tests also may be needed, including:

• An abdominal computed tomography (CT) scan can provide further information.

• An endorectal ultrasound scan can be useful with cancer of the rectum.

• A complete physical examination and a chest X-ray will be done after the cancer is diagnosed to see if it has spread.

• Blood tests will measure levels of a substance called carcinoembryonic antigen, which sometimes is higher than normal in people with colorectal cancer. Blood tests also can check how well your liver is functioning, as colon cancer frequently spreads to the liver.

Expected Duration

Without treatment, colon cancer will continue to grow.