The Impact of Biologic Therapies on Rate of Colectomy in Paediatric-onset Ulcerative Colitis - A Population-Based Cohort Study.

Aim: Biologic therapies have been associated with reduced rate of colectomy in ulcerative colitis (UC) in adults, but data are limited in paediatric-onset UC. Our aim was to define the rate of colectomy in paediatric-onset UC, including post-transition into adult care, and to evaluate the impact of biologic therapies on rate of colectomy.

Method: All prevalent patients diagnosed with paediatric-onset UC in South-East Scotland were identified from a prospectively accrued database at our regional tertiary centre. Patients exposed to biologics or surgery were identified and further data collected from health records. Kaplan-Meier analysis was used to calculate cumulative risk of colectomy over time.

Results: 145 prevalent patients were identified between 2000 and 2021. Median follow-up was 7.9 years (IQR 4.1-13.1). 23 patients (16 %) underwent a colectomy. 50/145 (34 %) patients received biologic therapy, and 13/23 (57 %) patients who underwent colectomy received biologics. The cumulative risk of colectomy across the whole cohort at 1, 5, and 10 years was 3 %, 13 % and 16 %, respectively. Patients exposed to biologics had a higher colectomy rate at 5 and 10 years (22 % and 34 %). Patients in the pre-biologic era (2000-2008) had non-significantly reduced time from diagnosis to colectomy (2.4 vs 3.7 years, p = 0.204).

Conclusion: We have defined the 1-, 5-, and 10-year colectomy rate in a population-based cohort of Paediatric-onset UC patients. Patients who received biologic therapy had a significantly increased risk of colectomy. Increased severity of disease in these patients may account for the greater colectomy risk.

Level Of Evidence: Level 1.