Long-term Colectomy Rates of Ulcerative Colitis over 40 Years of Different Therapeutic Eras-Results from a Western Hungarian Population-based Inception Cohort Between 1977 and 2020

Background and Aims Few populaion-based studies have investigated the long-term colectomy rates of ulcerative colitis [UC]. We aimed to assess the colectomy rates over 40 years of different therapeutic eras in a prospective population-based inception cohort from Veszprem Province, Western Hungary. Methods Patient inclusion lasted between January1, 1977, and December31, 2018. Patient follow-up ended December 31, 2020. Colectomy rates and disease course were examined in three different eras based on the time of UC diagnosis; cohort A [1977-1995], cohort B [1996-2008], and cohort C [2009-2018]. Results A total of 1370 incident UC patients were included [male 51.2%, median age at diagnosis 37 years]. Median follow-up was 17 years (interquartile range [IQR] 9-24); 87 patients [6.4%] underwent colectomy. The cumulative probability of colectomy in the total population was 2.6% (95% confidence interval [CI] 2.2-3.0), 4.2% [95% CI 3.6-4.8], 7.0% [95% CI 6.2-7.8], and 10.4% [95% CI 9.1-11.7] after 5, 10, 20, and 30 years, respectively. The proportion of extensive colitis at diagnosis increased over time [24.2%/24.3%/34.9% in cohorts A/B/C, respectively, p = 0.001]. Overall exposure to immunomodulators [11.3%/20.9%/34.4% in cohorts A/B/C, respectively, p <0.001], as well as the probability for biologic therapy initiation increased over time (0%/3.3% [95% CI 2.6-4.0]/13.9% [95% CI 12.1-15.7], p <0.001). There were no statistically significant differences in the cumulative probability of colectomies between cohorts A/B/C: 1.7% [95% CI 1.0-2.4], 2.5% [95% CI 1.9-3.1], and 3.7% [95% CI 2.7-4.7] after 5 years; 3.5% [95% CI 2.5-4.5], 4.2% [95% CI 3.4-5.0], and 4.5% [95% CI 3.3-5.7] after 10 years; and 7.5% [95% CI 6.1-8.9] and 6.3% [95% CI 5.2-7.4] in cohorts A/B after 20 years [log-rank = 0.588]. Extensive colitis (hazard ratio [HR] 2.24, 95% CI 1.55-3.23) and continuous active disease activity [HR 6.36, 95% CI 3.46-11.67] were independent predictors for colectomy. Conclusion No differences in colectomy rates have been observed in the incident UC patients over 40 years despite increasing use of immunomodulators and biologic therapies.