Soetikno said that in a general screening, the chance of finding a polyp is about 30 percent, and that doctors are about five times more likely to find polyps than non-polypoid lesions. But, non-polypoid lesions are far more likely to be cancerous than polyps are. The new study found the odds were 9.78 times higher that a non-polypoid lesion would be cancerous than a polyp.
Generally, non-polypoid lesions can be removed at the time of a colonoscopy. If the center where you have your colonscopy done doesn't have the expertise yet, you may have to undergo a second procedure to have the lesion removed. Also, Soetikno said that if the lesion is completely flat, you'll probably need to go to a more experienced center to have it removed.
Dr. David Lieberman is chief of the division of gastroenterology at Oregon Health and Science University and the Portland VA Medical Center, and author of an accompanying editorial in the journal. He said, "I think this study will be very enlightening for the [gastroenterology] community. It points out that the non-polypoid lesions are found in the U.S., and that they can be somewhat ominous because they carry a reasonably high risk of cancer."
Both Soetikno and Lieberman stressed that this study's findings don't mean that a colonoscopy isn't useful. It definitely is, at both screening for and preventing colorectal cancer, the second leading cause of cancer death in the United States.
"Colonoscopy is a very good tool. It's not perfect, but it's a good tool," Lieberman said. "This study emphasizes the need for a high-quality examination with a fully-trained endoscopic technician," he added.
More information
To learn more about colonoscopy, visit the American Gastroenterological Association.
