The incidence of cholangiocarcinoma in primary sclerosing cholangitis after long-time treatment with ursodeoxycholic acid

BACKGROUND/AIMS: Cholangiocarcinoma represents a serious complication of primary sclerosing cholangitis. Ursodeoxycholic acid may possibly influence the incidence of cholangiocarcinoma in man. The aim of this study was to evaluate the incidence rate of cholangiocarcinoma in a large group of primary sclerosing cholangitis patients after long-time treatment with ursodeoxycholic acid. PATIENTS AND METHODS: From May 1987 up to May 2005 a total of 150 patients with primary sclerosing cholangitis but without evidence of cholangiocarcinoma at entry were included in the study. All patients were treated with ursodeoxycholic acid and controls were performed in at least yearly intervals. RESULTS: The median treatment time of the 150 patients was 6.4 years. Altogether five patients developed a cholangiocarcinoma during treatment yielding a rate of 3.3%. The patients developed 0.58 cholangiocarcinoma per 100 patient-years in years 0-2.5, 0.59 cholangiocarcinoma in years 2.5-8.5, and no cholangiocarcinoma thereafter up to 18 years after entry into the study. The Kaplan-Meier estimate of cholangiocarcinoma incidence during ursodeoxycholic acid treatment reached a plateau after 8.3 years. SUMMARY AND CONCLUSION: The annual incidence rate of cholangiocarcinoma in primary sclerosing cholangitis treated with ursodeoxycholic acid is lower than expected and decreases with time of treatment.