The impact of the length of proximal margin on the prognosis of adenocarcinoma of gastroesophageal junction and strategies : A real-world study

Abstract Background: The optimal proximal margin (PM) length for SiewertII/III adenocarcinoma of the esophagogastric junction (AEJ) remains unclear. This study aimed to determine the optimal PM length using an abdominal approach to guide surgical decision-making. Methods: A prospective study analyzed 304 consecutive patients diagnosed with SiewertII/III AEJ between January 2019 and December 2021. Total gastrectomy was performed via the abdominal approach, and PM length was measured on fixed gross specimens. X-Tile software determined the optimal PM cut-point based on progression-free survival (PFS). Univariate analyses compared baseline characteristics across PM groups, while survival analyses utilized Kaplan-Meier estimation and Cox proportional hazards regression for assessing the impact of margin length on survival. Multivariable analyses were conducted to adjust for confounding variables. Results: The study included 264 AEJ cases classified as Siewert II (71.97%) or III (28.03%). The median gross PM length was 1.0 cm (IQR: 0.5 cm-1.5 cm, range: 0 cm-6 cm). PM length ≥1.2 cm was associated with a lower risk of disease progression compared to PM length 0.4 cm on PFS (HR = 0.41, 95% CI 0.20-0.84, P = 0.015). Moreover, PM ≥1.2 cm improved prognosis in subgroups of T4 or N3, tumor size <4 cm, Siewert II, and Lauren classification. Conclusions: For Siewert type II/III AEJ, a proximal margin length ≥1.2 cm (1.65 cm in situ) is associated with improved outcomes. These findings offer valuable insights into the association between PM length and outcomes in SiewertII/III AEJ, providing guidance for surgical approaches and aiding clinical decision-making to enhance patient outcomes.