78 Interhospital Variations in Practice and Outcomes for Endoscopic Resection of Early Esophago-Gastric Adenocarcinoma: Multi-Center CONGRESS Dataset Analysis

Abstract Aim This study aimed to evaluate inter-hospital variation in practice and clinical outcomes following endoscopic resection (ER) for early-stage (T1N0) oesophago-gastric (OG) adenocarcinoma using a large multi-centre dataset. ER offers organ-preserving, potentially curative treatment but is a complex procedure performed in specialised centres. Centre volumes for ER vary significantly, yet the clinical implications of such variability remain unclear. Method A retrospective analysis was conducted using the CONGRESS database, a UK-centric multi-centre registry of patients treated for T1N0 OG cancer between 2015–2022. Demographics, tumour characteristics, and outcomes—including R1 resection, procedural complications, and progression to surgery— for patients undergoing ER were analysed. Patients were stratified into tertiles by hospital ER volume, and outcomes between high- and low-volume centres were compared. Multivariable logistic regression assessed the association between centre volume and clinical outcomes. Results 1215 patients from 28 centres were included. ER volume per centre for OG cancer ranged from 2–154 over the 7-year period. R1 resection rates ranged from 0-67%, complication rates ranged from 0-50%. High-volume centres had lower R1 resection (17.3% vs. 26.4%, p=0.001), complication rates (3.8% vs. 8.2%, p=0.007) and progression to surgery rates (9.8% vs 20.7%, p<0.001), compared to low-volume centres. These differences remained after adjustment for patient and tumour variables, with low-volume centres showing higher odds of R1 resection (OR 0.63, p=0.022), procedural complications (OR 0.41, p=0.007), and rates of subsequent surgery (OR 0.38, p<0.001). Conclusions This study demonstrates large variations in clinical outcomes for ER in OG cancer, with a significant association between centre volume and clinical outcomes.