Review article: colorectal neoplasia in patients with primary sclerosing cholangitis and inflammatory bowel disease.

BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease strongly associated with inflammatory bowel disease (IBD). IBD patients diagnosed with PSC have an increased risk of colorectal dysplasia and cancer.

AIMS: To review the available evidence regarding colorectal neoplasia epidemiology, preventive strategies and outcomes in patients with PSC and IBD, and to advance some hypotheses regarding possible mechanisms involved in cancer pathogenesis in these patients.

METHODS: A PubMed search was conducted for the English language publications with predetermined search criteria. Reference lists from studies selected were manually searched to identify further relevant reports. Relevant manuscripts considering colorectal neoplasia in patients with PSC-IBD were selected.

RESULTS: Primary sclerosing cholangitis increases the risk of colorectal neoplasia in patients with ulcerative colitis; fewer data are available for Crohn's disease. PSC-IBD patients tend to be younger at diagnosis of IBD and at diagnosis of colorectal cancer. Colorectal cancer in PSC-IBD patients predominates in the right colon. The increased risk of neoplasia is maintained after liver transplant and proctocolectomy. The role of ursodeoxycholic acid as a chemopreventive agent is controversial. The mechanisms underlying increased risk of colorectal neoplasia in these patients remain unknown.

CONCLUSIONS: A more comprehensive understanding of the mechanisms involved in colorectal neoplasia development in PSC-IBD patients is needed. Until then, early cancer detection through enrolment in surveillance programmes is the only available strategy to decrease cancer risk.