TORONTO, Dec. 16 (UPI) -- Colonoscopy saves lives but may not be as effective at reducing cancer deaths as many think, a study by Canadian researchers indicates.
Colonoscopy most effectively reduces deaths from colon cancer only when the cancer is on the left side of the colon, said Dr. Nancy Baxter, a colorectal surgeon at St. Michael's Hospital in Toronto.
Baxter was the lead author on a study reported this week in the Annals of Internal Medicine, the Chicago-Sun-Times reported Tuesday.
The study found colonoscopy does little to nothing to reduce deaths if the cancer is on the right side of the colon, Baxter said, noting right-sided cancers and polyps tend to be flatter than those on the left, making them more difficult to find.
"When you compare colonoscopy to something like mammography, this is a much better test, but it's not perfect," Baxter said.
The study, based on more than 10,000 Ontario residents who died of colon cancer, indicates colonoscopy reduces the risk of dying from colon cancer by 60 to 70 percent, rather than 90 percent as is widely believed.
