Risk for colorectal neoplasia in patients with colonic Crohn's disease and concomitant primary sclerosing cholangitis.

BACKGROUND & AIMS: Patients with ulcerative colitis and concomitant primary sclerosing cholangitis (PSC) have a greater risk of developing colorectal dysplasia or invasive cancer than patients with only ulcerative colitis. Therefore, annual surveillance colonoscopies are recommended. We investigated whether primary sclerosing cholangitis is also a risk factor for colorectal dysplasia or cancer in patients with Crohn's disease of the colon. METHODS: We performed a retrospective review of data from a tertiary care hospital on 166 patients with PSC and inflammatory bowel disease; 120 had concomitant ulcerative colitis, 35 had Crohn's disease, and 11 had indeterminate colitis. The controls comprised 114 patients with colonic involvement of Crohn's disease and 102 patients with ulcerative colitis. The main outcome parameter was the development of colorectal cancer or intraepithelial neoplasia. RESULTS: Only 1 patient with colonic Crohn's disease and concomitant PSC developed dysplasia in an adenomatous polyp during a median follow-up of 10 years (range, 7-16 years). In contrast, 2 cancers and 8 cases of colorectal dysplasia were diagnosed in patients with ulcerative colitis and PSC during a median follow up of 11 years (range, 8-16 years); the crude annual incidence of dysplasia or colorectal cancer was 1 in 150 patients with ulcerative colitis. Among patients with colonic Crohn's disease without PSC, 2 developed colorectal cancer during follow-up. The presence of PSC did not increase the risk of developing colorectal dysplasia in patients with Crohn's disease (P = 1.00). CONCLUSIONS: PSC does not seem to increase the risk for dysplasia of the colon in patients with colonic Crohn's disease.