cancer prevention

Doctors often don’t reveal cancer test overtreatment and harms

Howard LeWine, M.D.

Chief Medical Editor, Harvard Health Publishing

There’s no question that tests to detect cancer before it causes any problems can save lives. But such tests can also cause harm through overdiagnosis and overtreatment. A study published yesterday in JAMA Internal Medicine indicates that the majority of people aren’t informed by their doctors that early warning cancer tests may detect slow-growing, or no-growing, cancers that will never cause symptoms or affect health. Undergoing surgery, chemotherapy, or radiation for such cancers provides no benefits and definite harms. The researchers found that only 9.5% of people were informed by their doctors of the risk of overdiagnosis and possible overtreatment. Compare that to 80% who said they wanted to be informed of the possible harms of screening before having a screening test. Informing patients about the risks of screening isn’t easy to do in a brief office visit. It’s complicated information. And the researchers suggest that many doctors don’t have a good grip on relative benefits and harms of screening.

Laxative-free colonoscopy on the way?

An experimental approach to virtual colonoscopy could eliminate the unpleasant day-before bowel prep that keeps many people from having this potentially life-saving test. Virtual colonoscopy uses computed tomography (CT) scanning with X-rays, instead of a scope, to check the colon for cancers and precancerous polyps. Earlier version have required bowel cleaning, just like regular colonoscopy. A Harvard-based team led by Dr. Michael Zalis uses sophisticated computer software to make stool in the colon disappear. It’s a little like Photoshopping blemishes from still photos. “Laxative-free CT colonography has the potential to reach some of the unscreened population and save lives,” says Dr. Zalis, an associate professor of radiology at MGH and director of CT colonography at MGH Imaging.