Inflammatory bowel disease with primary sclerosing cholangitis: A Danish population‐based cohort study 1977‐2011

BACKGROUND AND AIMS: Inflammatory bowel disease (IBD) may be complicated by primary sclerosing cholangitis (PSC). We aimed to assess the characteristics of Danish PSC-IBD patients and to compare their prognosis with IBD patients without PSC. METHODS: A retrospective nationwide population-based cohort of 257 PSC-IBD patients was assessed through Danish national registries and manual scrutiny of patient files. RESULTS: For all PSC-IBD patients diagnosed after 1976 (n = 222) and 8231 IBD controls (ie, without PSC), the cumulative probability of resective surgery, liver transplantation, cancer, and survival from 1977 through 2011 was estimated and compared by log-rank test and Cox regression. PSC-IBD patients primarily had ulcerative colitis (UC) (72%), were diagnosed in young adulthood (median age at IBD diagnosis, 23 years), and 9% were smokers. Among PSC-UC patients 78% had pancolitis at diagnosis. Among patients with PSC and Crohn's disease (CD) 91% had colonic involvement. The PSC-IBD patients had a significantly higher probability of receiving resective surgery (HR; 2.13, 95% CI: 1.50-3.03); of developing colorectal cancer (CRC) (HR; 21.4, 95% CI: 9.6-47.6), of cholangiocarcinoma (HR; 190, 95% CI: 54.8-660), and of dying (HR; 4.39, 95% CI: 3.22-6.00) as compared to non-PSC-IBD controls. The 25-year cumulative risk of liver transplantation was high (53%). CONCLUSIONS: This unselected population-based study shows that PSC-IBD patients not only have an extensive phenotype of IBD, they are also treated more intensively than other patients with IBD. However, the prognosis remains poor and without any apparent improvement over calendar time.