The value of colon cancer screening

Timothy Maly, MD, is a family physician at Berthoud Family Physicians.

Question: I'm nervous about going in for a colonscopy. What can you tell me about it?

Answer: According to the American Cancer Society, excluding skin cancers, colorectal cancer is the third most common cancer diagnosed in the United States.

American Cancer Society statistics show there will be an estimated 106,100 new cases of colon cancer diagnosed and 40,870 new cases of rectal cancer diagnosed in 2009.

The good news is that the death rate from colorectal cancer has been dropping for more than 20 years. Polyps are being found and removed earlier before they develop into cancers. Screenings and tests allow more cancers to be found earlier when it is easier to cure. Better treatment of colon cancer also means more people are able to survive the diagnosis.

It begins with the conversation about colon health and getting screened. Experts recommend routine colon cancer screening for people over 50. This is for the person whose risk for having colon cancer is average: no family history of colon cancer or polyps, no previous polyps or colon cancer and no symptoms of colon cancer.

In a colonoscopy, the doctor can inspect the entire colon for polyps and cancer. Samples of any growths may be biopsied and cancerous growths removed. Recommendations vary, but most experts say people should have a colonoscopy every 10 years beginning at age 50. You should also have one if another screening detected possible polyps or cancer. Screenings may begin earlier for people who have symptoms of polyps or are at higher risk for colon cancer and colon polyps.

Other screenings and tests include:

• Stool DNA tests to check for changes to the cells in the colon by looking at DNA in the stool.
• Fecal occult blood test to look for microscopic amounts of blood in the stool.
• Fecal immunochemical test to look for blood in the stool. It is more specific than the fecal occult blood test.
• Flexible sigmoidoscopy to allow the doctor to look inside the body at the lower part of the colon. Samples of growths can be biopsied and precancerous and cancerous growths may be removed.
• Double-contrast barium enema X-rays the large intestine. It can be used to screen for colon cancer because it can detect polyps in the entire colon. This is not as accurate as a colonoscopy and is does not allow the removal or biopsy of polyps if any are found.
• Computed tomographic colonography, or virtual colonoscopy creates detailed pictures of the colon to help the doctor look for polyps. Again, this type of screening does not allow the removal or biopsy of polyps.

The decision about which screening or test to have and how often it should be done rests with you and your physician. When making the decision, you will consider your age, family history, health problems you have and what benefits and/or risks you can expect from the screening.

When it comes to colon health, you can see you do have a lot to talk about!