Survival and Incidence of Colorectal Cancer in Patients with Ulcerative Colitis in Funen County Diagnosed between 1973 and 1993

Abstract

Background: The aim of the study was to determine the death rate and the risk of developing colorectal cancer in patients with ulcerative colitis in Funen County. Methods: The medical records of 801 patients with ulcerative colitis diagnosed in 1973-93 in Funen County were scrutinized with regard to colectomy, survival, and colorectal cancer, and in 1998 a follow-up was carried out. Results: The patients were managed at nine different hospitals: one university hospital, one central hospital, and seven smaller hospitals. The mean age at diagnosis was 41 years, and the mean duration of disease was 10.11 years. Sixty-one per cent of the patients were classified as having proctosigmoiditis, 21% as having left-sided colitis, and 18% as having pancolitis. In 127 patients who underwent proctocolectomy during the study period lethal complications occurred in 8 cases: 5 of 110 in Odense University hospital and 3 of 17 in the other hospitals. One hundred and twenty patients in the cohort died during the period of observation, nine of them of colitis-related causes. There was a slightly increased risk of early death in the cohort after 15 years of disease. Six colorectal cancers were found, whereas four were expected, giving a standard incidence ratio of 1.665. The cumulative cancer risk after 20 years' disease duration was 5.3% in the observed group, contrasting with an expected rate of 0.49%, and 10.1% after 25 years. Conclusion: In this cohort of ulcerative colitis patients the mortality and the risk of developing colorectal cancer were slightly higher than expected compared with the background population.