Association of repeated endoscopic inflammation with dysplasia and colorectal cancer in ulcerative colitis

ulcerative colitis (UC) confers an increased risk of dysplasia and colorectal cancer (CRC), largely driven by sustained mucosal inflammation. While inflammatory burden is a known risk factor, the specific impact of repeated endoscopic inflammation and contemporary therapies exposure warrant further investigation. We aimed to investigate the impact of cumulative inflammation in the risk of dysplasia and CRC development in UC.

a retrospective cohort study of adult UC patients diagnosed between 1975 and 2023 was performed at a tertiary IBD center. Repeated colonoscopies were analyzed using the Andersen-Gill extension of the Cox proportional hazards model. Propensity score matching (1:2 ratio) was applied based on age at diagnosis, sex, smoking status, disease duration and extent to adjust for confounding.

a total of 571 patients and 1,614 colonoscopies were included. There were 304 (53.2 %) men, with a median age at diagnosis of 39.5 years (IQR 27.3-54.2) and a median follow-up of 7.1 years (IQR 3.7-13.3). At diagnosis, 147 patients (25.7 %) had proctitis, 203 (35.6 %) had left-sided colitis and 191 (33.5 %) had extensive colitis. During follow-up, 56 (9.8 %) developed dysplasia or CRC. Advanced therapy was used in 152 patients (26.8 %). In the propensity-matched cohort (n = 123), repeated higher endoscopic inflammation measured by Mayo endoscopic score (adjusted HR: 1.600; 95 % CI: 1.082-2.366; p  =  0.019), family history of CRC (adjusted HR 1.518; 95 % CI: 1.011-2.290, p = 0.039) and exposure to advanced therapies (adjusted HR 2.048; 95 % CI: 1.392-3.013, p < 0.001) were associated with higher dysplasia/CRC risk.

our findings indicate that repeated endoscopic inflammation, a family history of CRC, and the use of advanced therapy are associated with an elevated risk of dysplasia and CRC in adult UC patients.