Background/aim: primary sclerosing cholangitis (PSC) is associated with ulcerative colitis (UC) and seems to be a risk factor for colon cancer. However, taking into account that no data are available in South American population, we analyzed the prevalence of PSC in 1,333 patients with UC and the risk for developing colon cancer.
Material: patients with persistent increases of alkaline phosphatase were studied by cholangiography and liver biopsy. To assess the risk of colon cancer, each patient with PSC and UC was matched with two control patients with UC without PSC of the same age, gender, extent and duration of UC.
Results: the whole prevalence of PSC was 2.9% (39 patients) reaching 6.2% in extensive colitis. Seven (18%) out of 39 patients with PSC developed colorectal carcinoma compared with 2 out of 78 (2.6%) in the control group (p=0.006). The cumulative risk of colorectal carcinoma was 11% and 18% after 10 and 20 years in the PSC group compared with 2% and 7% in the control group, respectively (p=0.002).
Conclusion: this is the first prospective study performed in Latin America showing that the prevalence of PSC in patients with UC is similar to that reported in the Anglo-Saxon population. Patients with UC and PSC have a high risk of colorectal cancer.