Are the risks of colorectal cancer and biliary cancer really increased if patients with ulcerative colitis have primary sclerosing cholangitis?

Ulcerative colitis (UC), a chronic and inflammatory disease, mainly affects the colon, rarely accompanied by primary sclerosing cholangitis (PSC).1 PSC is a chronic cholestatic disease of liver in which bile ducts are progressively destroyed by repeated inflammation and fibrosis leading to liver cirrhosis.2 Previous studies have reported an increased risk of colorectal cancer (CRC) in patients with UC, and a further increased risk has been reported in patients with UC and PSC.3 In addition, the risk of cholangiocarcinoma in PSC patients is reported to be 1,560 times higher than in the general population, with a lifetime prevalence of 5% to 10%.4 However, because the number of PSC and cholangiocarcinoma cases in UC patients is limited, reports on cholangiocarcinoma risk and follow-up recommendations are limited. The number of studies reporting PSC in patients with UC is limited, and even fewer studies have reported CRC in patients with UC and PSC. Therefore, it may have been limited to ascertaining whether the risk of CRC accompanying PSC is increased in UC patients. © 2023. Korean Association for the Study of Intestinal Diseases.