Risk of Colorectal and Other Cancers in Patients With Serrated Polyposis

Patients with serrated polyposis develop multiple colorectal hyperplastic and/or serrated sessile adenomas/polyps. We investigated the risk of colorectal and other cancers by analyzing data from 64 patients with serrated polyposis (mean age at diagnosis, 54 y; 41% men; 92% white) listed in the Johns Hopkins Polyposis Registry. Medical, endoscopic, and histopathology reports were evaluated. Six patients (9.4%) had a history of colorectal cancer, diagnosed at a mean age of 56 years; 6 additional patients (9.4%) had at least 1 advanced colorectal adenoma. Extracolonic cancers were found in 16% of the study population. The standard incidence ratio for colorectal cancer in patients with serrated polyposis was 18.72 (95% confidence interval, 6.87-40.74) and for extracolonic cancer was 31.20 (95% confidence interval, 14.96-57.37), compared with the Surveillance, Epidemiology, and End Results population. Patients with serrated polyposis therefore have a high risk for colorectal cancer and require vigilant colorectal surveillance, starting at the time of diagnosis of serrated polyposis. The risk of extracolonic cancer also appears to be increased, but this requires further evaluation.