P1.179. Association of Proximal Margin Length With Survival and Recurrence Following Esophageal Resection

Abstract

Abstract Topic Esophageal Cancer: Surgical Treatment of Esophageal Cancer Background R0 resection is a mainstay in the curative resection of esophageal cancer. However, the optimal length of proximal margin (PM) remains debated, as operative approach is dependent on tumor location and surgeon preference. The aim of this study was to determine the influence of proximal margin length on long-term survival and oncologic outcomes. Methods We performed a retrospective, single-institution study of patients undergoing esophagectomy or gastrectomy for esophageal and gastroesophageal junction cancers between January 2010 and 2023. Proximal margin length was defined as the measured distance between the proximal resection margin and the tumor on final pathology. Primary outcomes were overall survival (OS) and disease-free survival (DFS). Cox proportional hazards models were used to evaluate the independent association between PM length and survival outcomes after adjustment for established clinicopathologic factors. Results A total of 352 patients met inclusion criteria. Median age was 66 years, 73.8% were male, and 80.4% had adenocarcinoma. Median PM was 4cm (range 0.1-11.5cm). PM distance differed by location (p=0.001), surgery type (p<0.001) and open/minimally invasive approach (p<0.001). On multivariable Cox regression, PM length was not independently associated with OS (HR per cm increase 0.93, 95% CI 0.85–1.01, p=0.095) or DFS (HR 0.95, 95% CI 0.88–1.03, p=0.219). Conclusion PM length was not independently associated with overall or disease-free survival after adjustment for established prognostic factors. This finding suggests that once a microscopically negative margin is achieved, additional proximal margin length does not confer additional oncologic benefit.