Advanced Polyps Are Smaller on the Right Side of the Colon

Multiple observational studies suggest that colonoscopy is less effective at preventing right-sided than left-sided colon cancer (JW Gastroenterol Feb 20 2009 and JW Gastroenterol Feb 5 2010). Possible reasons include worse bowel preparation and higher incidence of endoscopically subtle lesions (e.g., flat and depressed conventional adenomas and serrated lesions) in the right versus the left side of the colon. To explore whether polyps of advanced pathology might be smaller — and thus more likely to be missed — in the right side versus the left side, investigators conducted a cross-sectional study of 233,414 polyps from 142,686 patients across the U.S. All samples were sent to a single laboratory for pathology analysis, and lesion size was …