Mesalamine Prevents Dysplasia in Patients with Inflammatory Bowel Disease

Abstract

Purpose: The lifetime prevalence of colorectal cancer in a patients with inflammatory bowel disease (IBD), ulcerative colitis or Crohn's colitis, is 3 to 6%. Endoscopic surveillance for dysplasia in patients with long-standing colitis is an accepted method of preventing death from colorectal cancer. Recent studies have suggested that the incidence of colorectal cancer in patients with long-standing colitis is decreasing. It is not clear whether the decrease in colorectal cancer is associated with a decrease in the incidence of dysplasia, to changes in the natural history of the disease or increased use of maintance therapy with mesalamine and/or immunosuppressive agents. Methods: In order to determine the role of mesalamine in the prevention of colon cancer, we evaluated mesalamine use in patients with long-standing ulcerative colitis and Crohn's colitis who had a duration of disease greater than 8 years. Demographic information, duration of disease, number of flares, hospitalizations, extent of disease, and other medications taken were recorded. The mean dosage of mesalamine was calculated using the total dose per time period studied divided by the number of days from the time of diagnosis to May 1, 2005. Results: One hundred-two patients were included in the study. There were 53 female, 49 male patients, mean age 64 ± 18 years. The mean duration of disease was 16.5 ± 8.8 years. All patients had received mesalamine for a mean period of 14.4 ± 7.1 years. The mean dosage of mesalamine in all patients was 2.6 ± 1.2 grams. None of the patients studied developed colon cancer. Four patients developed dysplasia (3.9%). The mean dosage of mesalamine in patients who had not developed dysplasia 2.6 ± 1.2 grams was significantly higher than patients who had developed dysplasia 0.8 ± 0.35 grams (p = 0.003). There were no significant differences between the groups regarding age, gender, duration of disease, extent of disease, or other medications, including 6-mercaptopurine/azathioprine. Conclusions: We conclude that the incidence of dysplasia and colon cancer in patients with IBD is decreasing. In patients with long-standing IBD, increased total mesalamine exposure appears to decrease the incidence of dysplasia. These results suggest that the decreased incidence of colon cancer in patients with IBD may be related to increased use of mesalamine for maintainance therapy.