Increased risk of cancer in patients with primary sclerosing cholangitis

Background and aims Primary sclerosing cholangitis (PSC) is associated with an increased risk of hepatobiliary and colorectal cancer, but the risks of other cancer forms have not been explored. The aim of this study was to evaluate the risk of intestinal and extraintestinal cancers in a large, well-defined cohort of PSC patients. Material and method A matched cohort study of Swedish PSC patients was performed with up to ten comparators for each patient, matched for sex, age, and residency. The data were retrieved from national registers. Patients were followed from PSC diagnosis until cancer diagnosis, liver transplantation, first emigration date, death, or December 31, 2016. The risk of cancer was estimated using the Kaplan-Meier method and Cox regression models. Results In total, 1432 PSC patients with a verified diagnosis and 14,437 comparators were studied. The mean follow-up time was 15.9 years. Eighty-eight percent of the PSC patients had concomitant inflammatory bowel disease. PSC patients ran significantly increased risks of developing any cancer [HR 3.8, 95% confidence interval (CI) 3.3-4.3], hepatobiliary cancer (HR 120.9, 95% CI 72.0-203.1), colorectal cancer (HR 7.5, 95% CI 5.6-10.0), pancreatic cancer (HR 8.0, 95% CI 3.2-20.2), gastric cancer (HR 4.2, 95% CI 1.5-11.3), small bowel cancer (HR 21.1, 95% CI 3.5-128.2), and lymphoma (HR 3.0, 95% CI 1.6-5.7). PSC was not associated with a lower risk of any cancer form. Conclusions PSC patients have a four times overall increased risk of developing cancer compared to the general population, with increased risk of developing hepatobiliary, colorectal, and pancreatic cancer, as well as lymphoma.