Cumulative Local and Metachronous Recurrence Rates in Patients with Ulcerative Colitis-Associated Neoplasia after Endoscopic Submucosal Dissection.

BACKGROUND/AIMS: Endoscopic submucosal dissection (ESD) has emerged as a curative alternative for ulcerative colitis-associated neoplasia (UCAN), particularly when endoscopic mucosal resection is not feasible for complete resection. This study aimed to evaluate cumulative incidence and timing of local and metachronous dysplasia in UCAN patients after ESD. METHODS: We retrospectively reviewed 55 patients diagnosed with established or suspected UCAN at Asan Medical Center between August 2009 and August 2025. The patients were classified as colectomy or ESD candidates according to endoscopic resectability. The primary outcome was the cumulative incidence of local and metachronous dysplastic recurrence after ESD. RESULTS: ESD was performed for 46 lesions in 45 patients. En bloc and R0 resection rates were 91.3% and 82.6%, respectively; no perforations were observed. Among 40 patients who underwent post-ESD surveillance, local recurrence and metachronous dysplasia were identified in 3 and 12 patients, respectively, over a median follow-up of 39 months. The cumulative incidence of local recurrence reached 7.6% at 1 year and remained unchanged thereafter. The cumulative incidence of metachronous dysplasia was 10.5% at 1 year, 22.6% at 3 years, and 39.4% at 5 years. Three patients underwent colectomy during surveillance due to local (n=1) or metachronous (n=2) recurrence. CONCLUSIONS: ESD appears to be a feasible and effective therapeutic option for selected nonpolypoid UCAN when performed by experienced endoscopists. The observed recurrence patterns may help inform post-ESD surveillance strategies, although the optimal surveillance interval requires validation in larger multicenter cohorts.