Natural History of Adult Ulcerative Colitis in Population-based Cohorts: A Systematic Review

A comprehensive knowledge of the natural history of ulcerative colitis (UC) helps understand disease evolution, identify poor prognostic markers and impact of treatment strategies, and facilitates shared decision-making. We systematically reviewed the natural history of UC in adult population-based cohort studies with long-term follow-up.Through a systematic literature review of MEDLINE through March 31, 2016, we identified 60 studies performed in 17 population-based inception cohorts reporting the long-term course and outcomes of adult-onset UC (n = 15,316 UC patients).Left-sided colitis is the most frequent location, and disease extension is observed in 10%-30% of patients. Majority of patients have a mild-moderate course, which is most active at diagnosis and then in varying periods of remission or mild activity; about 10%-15% of patients experience an aggressive course, and the cumulative risk of relapse is 70%-80% at 10 years. Almost 50% of patients require UC-related hospitalization, and 5-year risk of re-hospitalization is ∼50%. The 5-year and 10-year cumulative risk of colectomy is 10%-15%; achieving mucosal healing is associated with lower risk of colectomy. About 50% of patients receive corticosteroids, although this proportion has decreased over time, with a corresponding increase in the use of immunomodulators (20%) and anti-tumor necrosis factor (5%-10%). Although UC is not associated with an increased risk of mortality, it is associated with high morbidity and work disability, comparable to Crohn's disease.UC is a disabling condition over time. Prospective cohorts are needed to evaluate the impact of recent strategies of early use of disease-modifying therapies and treat-to-target approach with immunomodulators and biologics. Long-term studies from low-incidence areas are also needed.