MS O05 - HPB The ORDEAL Study: A Multi-Centre Retrospective Cohort Study Assessing the Optimal Resection for Proximal and Distal Duodenal Adenocarcinoma

Abstract Background Duodenal adenocarcinoma (DA) accounts for over 50% of all small bowel adenocarcinomas, however there is a paucity of cases and outcome data, no UK guidelines for surgical management, and a lack of contemporaneous UK patient data. There is debate as to whether oncological and perioperative outcomes differ between pylorus-preserving pancreaticoduodenectomy (PPPD) and classical PD (cPD) in proximal DA (D1/D2), and between PD (cPD or PPPD) and limited resection (LR) in distal DA (D3/D4). This study aimed to determine the optimal type of resection for proximal and distal DA through investigating differences in long-term survival and perioperative outcomes. Method A national retrospective audit of consecutive patients from 2008-2023 undergoing curative resection for DA was conducted, with data collected anonymously via REDCap. Baseline demographics, radiological, operative, pathological and short and long-term outcomes were collated. Analysis was performed using SPSS with standard descriptive statistical methods. Chi-Square, Mann-Whitney and ANOVA were used as appropriate to compare variables and outcomes between two groups, with statistical significance set at p<0.05. Survival analysis (overall survival (OS) and disease-free survival (DFS)) was performed using the Kaplan–Meier method and the log-rank test to compare differences between survival curves. Time-to-event analysis was calculated with Cox regression. Results The study cohort (median age 68 years, 54.4% males) had a mean follow-up of 35.6 months. For proximal DA, 56 underwent PPPD and 87 underwent cPD; for distal DA, 26 underwent PD and 37 underwent LR. For proximal DA, survival and lymph node clearance were similar, with severe complications and no adjuvant chemotherapy independently decreasing survival. For distal DA, survival was similar despite greater lymph node clearance with PD, with age and no adjuvant chemotherapy independently decreasing survival. Complications including pancreatic fistula, delayed gastric emptying, and post-pancreatectomy haemorrhage, were comparable for proximal DA but greater with PD in distal DA. Conclusion Preliminary findings suggest adequate lymphadenectomy and comparable long-term survival for cPD and PPPD in proximal DA. For distal DA, LR is associated with similar long-term survival but lower morbidity despite greater lymph node clearance with PD. Additional records will validate these findings further.