P0741Endoscopic Resection of Visible Dysplastic Lesions in Inflammatory Bowel Disease: A Retrospective Observational Cohort Study

Background Visible dysplastic lesions without optical characteristics of deeply invasive cancer should be considered for endoscopic resection (ER). However, there is a lack of evidence regarding outcomes of ER in IBD-related dysplastic lesions. This study assesses the curative effectiveness and safety of ER for dysplastic lesions in IBD patients. Methods This was a retrospective observational cohort of IBD patients referred to the St. Michael’s Hospital, Toronto, Canada between 2012 and 2025 who underwent ER for management of sporadic polyps or IBD-related dysplasia. The primary outcome was to assess curative resection in this population, defined as; complete endoscopic removal of the lesion with no adverse histologic features and no additional indications for colectomy based on background colitis. Results Among 60 patients with colitis-associated neoplasia, most had ulcerative colitis (85.0%; Crohn’s disease 15.0%), with a mean disease duration of 17.8 years (0–35); disease type was predominantly extensive colitis (75.0%), with smaller proportions of left-sided colitis (10.0%) and Crohn’s colitis (15.0%). Neoplasia was most commonly right-sided (43.3%), followed by left-sided (31.7%), rectal (13.3%), and transverse colon lesions (11.7%). Lesions were frequently ≥30 mm (43.3% were 30–50 mm; 6.7% >50 mm), with 35.0% <20 mm and 15.0% 20–29 mm. EMR was selected in (81.7%) of patients, with (13.3%) requiring hybrid techniques and ESD (5.0%), without significant difference by curative status (p = 0.295). Overall technical success was 90.0% and was universal in the curative cohort (100%, p < 0.0001). En bloc resection and R0 resection were achieved in 25.0% and 26.7% of all lesions, respectively. By Vienna classification, 46.7% had low-grade dysplasia, 20.0% high-grade dysplasia, 11.7% indefinite dysplasia, 20.0% were negative for dysplasia, and 1.7% had submucosal invasive carcinoma; the distribution differed between curative and non-curative resections (p = 0.024). Intra-procedural bleeding requiring endoscopic intervention occurred in 15.0% and perforation in 1.7%, with no delayed bleeding or perforation events. Four patients (6.7%) ultimately underwent colectomy, including 2 (3.8%) with prior curative resections (p = 0.013), at a median of 13.5 months (range 3–16) after index polypectomy. Conclusion ER does not appear to be limited by the presence of colitis itself; rather, success is driven by lesion factors such as size, morphology, and histology. Clinically, this supports treating well-demarcated, endoscopically resectable lesions in IBD using standard advanced resection strategies, reserving colectomy for patients with high-risk histology, unresectable lesions, or diffuse colitis-associated dysplasia. Conflict of interest: Khalaf, Kareem: No conflict of interest Li, Huaqi: No conflict of interest Chis, Roxana: No conflict of interest Causada Calo, Natalia: No conflict of interest May, Gary R.: GRM – Consultant for Olympus. Speaker: Pentax, Fuji and Medtronic Mosko, Jeffrey D.: JDM - Speaker: Boston Scientific, Pendopharm, Vantage, Medtronic.