Ursodiol and colorectal cancer or dysplasia risk in primary sclerosing cholangitis and inflammatory bowel disease: a meta-analysis.

Background: Patients with primary sclerosing cholangitis (PSC) and colonic inflammatory bowel disease (IBD) demonstrate increased risk of colorectal cancer. Prior studies have yielded conflicting information on the relationship between ursodiol (UDCA) and the risk of colorectal cancer or dysplasia in this group.

Aims: To examine the impact of UDCA on risk of colorectal cancer or dysplasia in adult PSC and IBD patients.

Methods: A systematic review and meta-analysis of case-control and cohort studies was performed. Subgroup analysis compared the effects of "low-to-medium" (<25 mg/kg/day) versus "high" dose (≥ 25 mg/kg/day) UDCA exposures.

Results: Inclusion and exclusion criteria, as well as all variables, were determined a priori. Seven papers, with 707 participants and greater than 5,751 person-years of follow-up time, met the criteria for final analysis. The overall pooled relative risk using a random effects model was not statistically significant (RR = 0.87, 95 % CI 0.51-1.49, p = 0.62). Subgroup analysis by UDCA dose category in a random effects model was not statistically significant (RR = 0.64, 95 % CI 0.38-1.07, p = 0.09), but suggested a possible trend in risk reduction at low-to-medium-dose exposures that may warrant further investigation.

Conclusion: UDCA use was not associated with risk of colorectal cancer or dysplasia in adult PSC and IBD patients, but UDCA dose was a source of heterogeneity across studies. Subgroup analysis suggests a possible trend toward decreased colorectal cancer risk in low-to-medium-dose exposures. Additional study of UDCA treatments at low doses in PSC and IBD patients may be warranted.