Findings from a large clinical trial reported in The New England Journal of Medicine add to previous evidence that undergoing a flexible sigmoidoscopy every three to five years reduces the risk of developing colorectal cancer later in life. This is important because sigmoidoscopy is less invasive and easier to prep for than full colonoscopy, which uses a longer instrument to examine the entire colon. Some people might choose to undergo sigmoidoscopy who might otherwise avoid screening.
“Sigmoidoscopy has fewer complications, easier prep and no sedation,” says Dr. William Kormos, editor in chief of Harvard Men’s Health Watch. “It is reasonable start for people at average risk.”
Half of the 154,900 people in the study had flexible sigmoidoscopy to examine the lower colon for precancerous growths, and then follow-up sigmoidoscopy every three to five years. The others underwent a mix of sigmoidoscopy, colonoscopy, or no screening at all. This second group would be expected to develop more cancers, due to the overall lower level of screening. After 12 years of follow up, the overall incidence of colorectal cancer in the people who underwent sigmoidoscopy was 21% lower.
The colorectal cancer screening options available each have important pros and cons, and you should discuss the details with your doctor.