Colon cancer risk high from hard-to-see lesions

Seven's On Call with Dr. Jay Adlersberg
March 5, 2008 9:00:00 PM PST
It's not often we hear Dr. Jay use the word scary. But there's some new information about detecting colon cancer and how difficult it can be that has him, and other experts, concerned. Dr. Jay Adlersberg is here with more.

Doctors have known for a long time that a common polyp in the colon can turn into cancer. There's another type of colon polyp about which less was known. Now, today's journal of the American Medical Association has some scary information about it.

Carl Monheit gets colonoscopies every few years. His father, several uncles and a cousin had colon cancer. His brother died of colon cancer. This year's test in January turned up something disturbing.

"They found a polyp which was a little bit more difficult to get out than the typically encountered," said colonoscopy patient, Carl Monheit.

It was the type of polyp that was the subject of today's report.

Rather than the common mushroom-shaped polyp that doctors can cut off at the stalk, Carl had a flat polyp.

The study found flat polyps were five times more likely to be cancerous than the mushroom type.

"Polyps turn in to cancer over time and this study suggests that these polyps may be further along to developing into cancer than the typical mushroom shaped polyp," said Dr. David Robbins at Beth Israel Medical Center.

Similar to the flat polyp is the depressed polyp. Both are difficult to remove, and removing the depressed polyp means cancer cells may be left behind.

In the 1980's there were reports from Japan that flat polyps were common and ominously, lead to cancer. But researchers in the west were skeptical because flat polyps were not commonly seen in North America.

Years later, these polyps were found here, but their prognosis was not clear. This colonoscopy study sheds a new and dark light on these dangerous growths.

If flat polyps are hard to find by looking at them directly, virtual colonoscopy done by cat scans is unlikely to find them at all because they don't stick out into the colon.

This study is important because it's a call to action that we need to be aware of these lesions. And we need to be able to deal with these flat or depressed polyps when we encounter them.

Robbins makes the point that colonoscopies are painless, safe and can be life-saving for people over fifty and especially for those with a family history of the disease.

This is Colon cancer prevention month and for more information click links below:

  • American Cancer Society
  • The Journal of the American Medical Association