Colorectal dysplasia and carcinoma in patients with ulcerative colitis and primary sclerosing cholangitis.

Background: The aim of this study was to evaluate the role of primary sclerosing cholangitis (PSC) as a cofactor in the dysplasia-carcinoma sequence in ulcerative colitis (UC).
Methods: Forty-five patients with UC and concomitant PSC and 45 pair-matched control patients with UC only were examined for colorectal dysplasia and carcinoma.
Results: The median duration of UC was 11 years in the group with UC and PSC and 15 years in the control group. Thirteen of the 45 patients (29%) with UC and PSC had colorectal neoplasia: 4, carcinoma; 2, high-grade dysplasia; and 7, low-grade dysplasia. Four of the 45 control patients (9%) had neoplastic findings: 1, carcinoma; 1, high-grade dysplasia, and 2, low-grade dysplasia (P < 0.05).
Conclusion: The results suggest that the risk of colorectal dysplasia and carcinoma in patients with UC is increased by concomitant PSC.