Risk for dysplastic polyps associated with location, male gender
Colon polyps are more likely to be dysplastic in men and when located on the right colon, according to recent results.
Researchers evaluated data from 2,400 patients (50.5% women) who underwent colonoscopy for varied indications at the Mayo Clinic in Jacksonville, Fla., between February 2010 and December 2011. Information was collected from the database of the Endoscopic Quality Improvement Program trial, and also included age, gender, race, size and location of lesions and aspirin use.
Surgeons removed 3,045 polyps from 1,237 patients, including 912 patients who had at least one dysplastic/neoplastic lesion. Among the removed polyps, 54% were located on the right colon and 46% on the left colon. The median polyp size was 5 mm for both sides of the colon (P=.11).
Adenomas were significantly more common among right colon polyps than those on the left (69.4% vs. 39.3%, P<.0001), but incidence rates were similar for advanced adenomas (1.5% on the right vs. 1.9% on the left, P=.4) and adenocarcinomas (0.6% vs. 0.4%, P=.62). More patients had dysplastic lesions located on the right colon only (42%) compared with those with dysplastic lesions only on the left colon (22%). Adenocarcinomas also were more common on the right side (81% vs. 19%, P=.0003).
Multivariate analysis indicated that the right colon location was significantly associated with dysplasia after controlling for confounders (OR=3.1; 95% CI, 2.3-4). Women were at a reduced risk for dysplasia (OR=0.6; 95% CI, 0.46-0.78), while men were at increased risk for developing advanced adenomas (OR=2.2; 95% CI, 1.02-4.7). Other factors significantly associated with dysplasia included polyp size (OR=1.04; 95% CI, 1.01-1.07) and advanced age (OR=1.03; 95% CI, 1.02-1.04).
“Missing a small polyp in the right colon is likely more significant than missing one in the left colon, where most polyps are hyperplastic,” the researchers wrote. “Improved examination of the right colon is needed in order to detect and resect adenomatous polyps. In older males, extra time/attention should be devoted to detection and removal of right-sided lesions, which are more likely to have dysplasia.”
Disclosure: See the study for a full list of relevant disclosures.