Prognosis of chronic ulcerative colitis in a community.

Utilising the population based data resources of the Rochester Epidemiology Project, we estimated survival and risk of subsequent colon cancer in the 182 residents of Rochester, Minnesota, initially diagnosed with chronic ulcerative colitis (CUC) between 1985 and 1979. Twenty five (13.7%) had a proctocolectomy during the course of follow up. Three patients developed colorectal adenocarcinoma after the initial diagnosis of CUC (relative risk = 1.9, 95% CI 0.4-5.4). Excluding proctitis cases, the relative risk of cancer was 2.4 (95% CI 0.3-8.7). At last follow up, 37 (20.3%) were dead; only 10 patients had chronic ulcerative colitis mentioned on the death certificate. Overall survival was similar to that expected for the general population of like age and sex. Our results suggest that chronic ulcerative colitis in the community is typically a milder disease than would appear from hospital or referral centre series.