The risk of colon cancer deaths in the patients overall was small -- 593 occurred over an average of 12 years of follow-up. But the risk fell by 26 percent in those who had the procedures compared to people in the usual care group, who only got colonoscopies or sigmoidoscopies if they asked for one or their doctor recommended one. The researchers estimated that if they had used colonoscopies rather than sigmoidoscopies in their study, they would have spotted 16 percent more cancers.
However, the researchers discovered that even colonoscopies sometimes failed to find precancerous polyps.
When it comes to the ability of regular colonoscopies to detect polyps, "we may have to do better," said study author Dr. Robert Schoen, a professor of medicine and epidemiology at the University of Pittsburgh School of Medicine. "Or maybe we can't do better."
The study appears online May 21 in the New England Journal of Medicine, to coincide with a presentation at the annual Digestive Diseases Week meeting in Chicago.
For more about colon cancer, try the U.S. National Library of Medicine.
SOURCES: Robert Schoen, M.D., MPH, professor, medicine and epidemiology, University of Pittsburgh; John Inadomi, M.D., Cyrus E. Rubin Professor of Medicine, University of Washington, Seattle; May 21, 2012, The New England Journal of Medicine, online; May 21, 2012, presentation, Digestive Diseases Week, Chicago
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