C olorectal cancer (CRC) remains a feared complication of ulcerative colitis (UC). Surveillance programs utilizing colonoscopy to identify dysplasia and colorectal cancer have been incorporated into guidelines for patients with longstanding extensive UC and Crohn's colitis. 1 The use of chemopreventive agents as an adjunct to these endoscopic surveillance programs has been the subject of multiple studies. 2 In this retrospective case-control study, Ullman et al 3 from the Mount Sinai School of Medicine examine the effect of mesalamine as a chemopreventive agent in UC patients with and without dysplasia.
The study included three cohorts of UC patients: 311 with no dysplasia (NoD), 56 with indefinite dysplasia (IND), and 26 with flat low-grade dysplasia (fLGD). The rates of progression to advanced neoplasia (high-grade dysplasia or CRC) were compared, stratified by the use of highdose mesalamine (>2 g/day average) or low-dose mesalamine (<2 g/day average). While there were no significant differences in gender, age, number of colonoscopic examinations, duration or extent of colitis between the cohorts, there was a slightly higher frequency of primary sclerosing cholangitis in the patients on low-dose mesalamine with NoD and IND than in those taking high-dose mesalamine. As one might expect, the median time from initial colonoscopy to the primary endpoint of advanced neoplasia or last available colonoscopy without progression or surgery without progression was seven years for the initial NoD group, but three years for the groups with initial IND or fLGD.
Of the 311 patients in the NoD cohort, 17 patients developed advanced neoplasia, including seven who developed CRC. In the 56 IND patients, four developed advanced neoplasia including two CRCs. In the 26 fLGD patients, 10 developed advanced neoplasia including 3 CRCs. Thus, the five-year rate of progression to advanced neoplasia was 1.1% in the NoD cohort, 9% in the IND cohort, and 44.9% in the fLGD cohort. Overall, no statistically significant effect was demonstrated by comparing the effects of mesalamine dose