Outcome of sporadic adenomas and adenoma-like dysplasia in patients with ulcerative colitis undergoing polypectomy

Background: Ulcerative colitis (UC) patients are at increased risk of colorectal dysplasia and cancer. Few studies have examined the clinical outcomes of dysplastic polyps resembling sporadic adenomas that are removed with endoscopic polypectomy. Methods: A centralized diagnostic index identified patients evaluated between 1994 and 2004 with UC and polypoid dysplasia who were followed from the time of polypectomy until the most recent colonoscopy. They were stratified into two groups by polyp occurrence, either within (adenoma-like dysplasia) or outside (sporadic adenoma) the most proximal endoscopic or histologic extent of colitis. The endpoints of interest were the development of subsequent colorectal neoplasia, flat dysplasia, or cancer. The cumulative probabilities of these endpoints were estimated using the Kaplan-Meier method, and the association with clinical factors assessed using Cox proportional hazards regression. Results: Ninety-five patients were found to have polypoid dysplasia; of these, 77 underwent polypectomy. The cumulative probability of subsequent colorectal neoplasia in polypectomy patients was 18% at 1 year and 69% at 5 years. After polypectomy, cumulative incidence of cancer or flat dysplasia was 2% at 1 year and 13% at 5 years. The proportional hazards models indicated that these outcomes were not significantly associated with polyp type, primary sclerosing cholangitis, family history of colorectal cancer, 5-aminosalicylate use, extent of colitis, or duration of disease. Conclusions: While polypectomy may be safe for the management of adenomas occurring in most UC patients, the 5-year cumulative incidence of a combined endpoint (cancer or flat dysplasia) was 13%. Such patients should be followed closely.