Cancer of the colon (large intestine) or rectum (end of the colon) is called colorectal cancer. In the United States, it is the third most common cancer in men and women. Caught early, it is often curable. It is more common in people over 50, and the risk increases with age. Deaths from colon cancer have fallen nearly 9 percent in the past decade. Better and earlier screening gets much of the credit, along with better treatments, but the cause of the disease is still unknown.
Screening and Diagnosis
You are more likely to get colorectal cancer if you have polyps, growths inside the colon and rectum that may become cancerous. A family history of colon or rectal cancer puts you at higher risk, as does ulcerative colitis or Crohn's disease (also known as inflammatory bowel disease). Symptoms can include blood in the stool, narrow stools, a change in bowel habits, and general stomach discomfort. However, you may not have symptoms at first, so screening is important. Everyone who is 50 or older should be screened for colorectal cancer. The most thorough examination of the colon is done with a colonoscope, which is inserted into the rectum. A colonoscope is a thin, tube-like instrument, with a light and a lens for viewing. It may also have a tool to remove tissue (polyps) to be checked under a microscope for signs of disease.
Standard treatments include surgery, chemotherapy, radiation therapy, or a combination of these methods. Treatment depends partly on the stage of the cancer. At the earliest stage (stage 0), doctors may treat colon cancer with localized surgery, possibly by removing the cancer cells during a colonoscopy. For stages I, II, and III cancer, more extensive surgery is needed. With advanced colorectal cancer, your doctor will most likely prescribe chemotherapy. While radiation therapy is occasionally used in patients with colon cancer, it is usually used in combination with chemotherapy for patients with advanced rectal cancer.