A232 RISK OF TOTAL METACHRONOUS ADVANCED NEOPLASIA AT SURVEILLANCE COLONOSCOPY AFTER DETECTION OF SERRATED LESIONS: A MATCHED COHORT STUDY

Abstract Background Serrated lesions (SLs), including sessile serrated (SSL) and traditional adenomas (TSA) have become subject of increased interest for their role as CRC precursors. Purpose Study aim was to evaluate the risk develop total metachronous advanced neoplasia (T-MAN) at follow-up in patients with index SL compared a matched cohort without SL. Method Patients 45-74y SLs were identified through pathology database search. 2:1 by sex; age; synchronous polyps (high-risk adenoma [HRA], low-risk [LRA], no-adenoma); timing index, Primary outcome T-MAN (advanced or high-risk SL) follow-up. Secondary outcomes included stratified characteristics. Result(s) 1425 (475 patients, 642 SLs; 950 controls (mean 2.9 vs 3.9y). The group had greater non-SL [Hazard-ratio (HR)=6.12 (95%confidence-interval (CI)3.91-9.58)]. SL+HRA higher HRA alone [HR=2.62 (95%CI 1.45-4.71)], well SL+LRA LRA [HR=7.03 2.78-18.44)], no-adenoma [HR=14.87 6.51-33.95)]. Presence proximal SSL (HR=9.30), large (HR=17.87) (HR=24.99), but not distal SSL, associated T-MAN. Conclusion(s) are developing regardless adenomas. HRA, those SSLs appear be greatest Please acknowledge all funding agencies checking applicable boxes below Other indicate your source funding; ACG Disclosure Interest R. Djinbachian Grant / Research support from: from American College Gastroenterology conduction this project, M.-L. Lafontaine: None Declared, J. Anderson: H. Pohl: T. Dufault: M. Boivin: Bouin: D. von Renteln Daniel is supported “Fonds de Recherche du Québec Santé” (FRQS) career development award has received research ERBE, Ventage, Pendopharm, Fujifilm, Pentax., Consultant of: Boston Scientific