Proximal colorectal dysplasia or cancer in ulcerative colitis. The impact of primary sclerosing cholangitis and sulfasalazine - Results from a 20-year surveillance study

PURPOSE: Known risk factors for the development of colorectal dysplasia or cancer in ulcerative colitis are total colonic involvement and long duratio n of the disease. It has recently been suggested that presence of primary s clerosing cholangitis is another independent risk factor-especially for pro ximal colorectal dysplasia or cancer-and that treatment with sulfasalazine might reduce the frequency of colorectal cancer in ulcerative colitis; the present study was undertaken to shed light on the validity of these theorie s. METHODS: A total of 143 patients with ulcerative colitis underwent regul ar colonoscopies and multiple biopsies in a 20-year surveillance program fo r studies of long-standing total ulcerative colitis. Fifty-one of the patie nts developed colorectal dysplasia or cancer. Patient records were scrutini zed retrospectively for information of presence of primary sclerosing chola ngitis, site of the colorectal malignancy, and results of sulfasalazine tre atment. RESULTS: Nineteen of the patients had primary sclerosing cholangiti s; these ran a significantly higher risk of developing colorectal dysplasia or cancer than patients with ulcerative colitis only. All colorectal cance rs (n = 3) and 75 percent of all colorectal dysplasias or cancers among pat ients with primary sclerosing cholangitis were located in the proximal part of the colon, whereas 36 percent were found in that same region among the patients with ulcerative colitis without primary sclerosing cholangitis (P = 0.02). Sulfasalazine treatment showed no significant protective effect on the development of colorectal dysplasia or cancer in patients with ulcerat ive colitis. CONCLUSION: The risk evaluation, as assessed by multivariate a nalysis, shows that primary sclerosing cholangitis proves to be an addition al and independent risk factor for the development of colorectal dysplasia or cancer in patients with ulcerative colitis-particularly in the proximal part of the colon. The findings do not support the theory that sulfasalazin e treatment exerts a protective effect against colorectal dysplasia or canc er.