Colon Cancer Screening

with Sunil Kapur, M.D., gastroenterologist, Advanced Healthcare

Last Updated: June 1, 2003

Colon cancer is one of the most common cancers in the United States and is the second leading cause of cancer deaths in the United States.

Symptoms of colon cancer can vary and may only occur some time after the cancer has begun growing. Among the more common are changes in bowel habits, blood in the stool or black, sticky stools (an indication of blood), abdominal pain, unexplained fatigue or weakness due to anemia, rectal hemorrhage, bowel obstruction and weight loss.

“Sometimes a patient can have no symptoms at all. I’ve had patients come in for a routine screening feeling wonderful, then find out they have cancer. This is why screening is so important,” said Dr. Sunil Kapur, a gastroenterologist with Advanced Healthcare.

Dr. Kapur added that studies have shown colon cancer screening is as cost effective as breast cancer screening, if not more. The timing of the initial screening and how often it needs to be repeated will depend on an individual patient’s risk factors.

Risk and screening
Like many cancers, the risk of colon cancer increases with age, becoming more common in those over 50. However, because there is a genetic component to colon cancer, certain people should be screened earlier and more frequently.

Increased screening would be recommended for the following groups:
- Those with a first-degree relation (parent or sibling) with colon cancer diagnosed at age 60 or older should have their first screening at age 40.

- Those with first-degree relations diagnosed with colon cancer before age 50 should have their first screening 10 years earlier than the age of the cancer diagnosis in their families.

- Those suffering from inflammatory bowel disease or ulcerative colitis (both of which may raise the risk for colon cancer) should be tested more frequently.

- Those with a genetic predisposition to colon cancer, such as familial polyposis, may need screening on a far more frequent basis, starting at a much earlier age.

“Patients need to have a close relationship with their primary care physician and their gastroenterologist. They need to become well-educated about colon cancer,” Dr. Kapur said.

Minimizing risk
As is true for many types of cancer, people can minimize the risk of colon cancer with a healthy lifestyle. This should include a balanced diet, low in fats and red meat and high in fiber; and exercise. “Studies also have shown a lower risk in those who take calcium. Some studies also have suggested that aspirin and other NSAIDS (non-steroidal anti-inflammatory drugs) reduce the risk of polyps. So if a person is taking aspirin for something else, it may have an added benefit in preventing polyps,” Dr. Kapur said.

However, the doctor stressed that the best way of reducing risk is to catch a problem early, either before polyps become cancerous or when colon cancer is at an early, treatable stage. “You can do all you want in terms of diet, but there is no substitute to having a screening test. Cancer caught early is the key to a cure,” he said.

Screening exams
There are four screening tests for colon cancer.

• Fecal blood testing is done by the patient at home. Patients follow a diet that minimizes the presence of blood in the stool (such as no red meat and no drugs such as aspirin which might cause internal bleeding in some people) then collect small samples in a lab kit that is mailed to a lab for testing. This test should be done yearly beginning at age 50 and is often part of a routine physical.

• Sigmoidoscopy is an endoscopic exam of the last third of the colon. About 70% to 75% of all polyps are found in this area. Polyps are tissue growths that protrude from the colon’s inner wall. The test should be done once every five years. Presence of polyps in this area may indicate the need for a more thorough look at the entire colon.

• Colonoscopy is an endoscopic exam of the entire colon. It is recommended every 10 years.

• Double contrast barium enema takes an X-ray of the entire colon. It may be done every five years.

Dr. Kapur emphasizes that barium enemas are an inadequate substitute for endoscopic exams. Endoscopy reveals problems and allows physicians to treat polyps. Since large polyps may become cancerous, physicians can remove them via the endoscope during the screening procedure and perform a biopsy if a problem is suspected. Future tests will include stool genetic markers for colon cancer, but are still experimental.

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