April 16, 2007 (Los Angeles) -- Men who have had a potentially precancerous polyp removed during colonoscopy are more likely to develop new polyps than are women, a new study shows.
Obese people and those over age 65 are also at increased risk for having recurrent new growths that can lead to colon cancer, says researcher Adeyinka Laiyemo, MD, a cancer prevention fellow at the National Cancer Institute.
Laiyemo tells WebMD that doctors already knew that people who have three or more polyps removed are at significantly increased risk of developing new polyps. In fact, current guidelines, developed by the U.S. Multi-Society Task Force on Colorectal Cancer and the American Cancer Society, recommend that people with three or more polyps receive another colonoscopy within three years.
Colonoscopy a Powerful Prevention Tool
Though Laiyemo doesn’t suggest altering the guidelines based on one study, he says he hopes the findings will propel more at-risk people to get a colonoscopy in the first place.
“Men, in particular, never like going for the procedure. Women need to encourage their men to go,” he says
“After age 65, your risk really takes off, so it shows the importance of having colonoscopies as we age,” Laiyemo says. “And since obesity is a risk factor as well, it offers another reason to get those extra pounds off.”
Session moderator Alan Kristal, DrPH, of Fred Hutchinson Cancer Research Center in Seattle, agrees.
“Colonoscopy is one of our most powerful tools for prevention because by having polyps removed, you can prevent cancer. This offers a nice overall package of factors that affect risk, telling us who should be targeted for surveillance,” he tells WebMD.
Men, Older People at Increased Risk
For the study, the researchers analyzed data from nearly 2,000 participants in the Polyp Prevention Trial, designed to assess the impact of a low-fat, high-fiber diet on polyp recurrence.
All the participants had at least one polyp removed before they started following the low-fat diet mandated in the study.
Over the next four years, 524 of the participants developed new polyps.
Results showed that:
- People who had multiple polyps removed the first time around were 2.5 times more likely to have a recurrence than those who had one polyp removed.
- Men were 76% more likely to have a recurrence than women.
- People aged 65 to 69 were at 87% increased risk compared with younger adults; those aged 70 to 74 had four times the risk of younger adults.
- Obese people were 55% more likely to have a recurrence than nonobese people.
The findings were presented at the annual meeting of the Association for Cancer Research.