Investigating the Effects of Different Lengths of Proximal Margin for Siewert Type II and Type III Adenocarcinoma of Esophagogastric Junction on Short- and Long-Term Prognosis

This is the authors' abstract. We don't add key points for this paper.

Introduction: The optimal proximal margin length for Siewert type II/III adenocarcinoma of the esophagogastric junction (AEJ) remains debated. This study aimed to evaluate the effect of different proximal margin lengths on short- and long-term prognosis. Methods: In this retrospective study, clinical data from patients undergoing surgery for Siewert type II/III AEJ between January 2019 and January 2024 were collected. Patients were stratified into three groups based on the length of the proximal margin (0.5-2 cm, 2-4 cm, and >4 cm). Short-term outcomes, including R0 resection rates and complications, along with long-term survival (OS and PFS), were evaluated. Kaplan-Meier survival analysis and Cox proportional hazards regression models were employed to assess prognostic impacts. Results: A total of 173 patients were included (0.5-2 cm, n=57; 2-4 cm, n=60; >4 cm, n=56). The 0.5-2 cm group had significantly higher R1 resection (12.28% vs 1.67%/0%) and anastomotic recurrence rates but a lower anastomotic leak incidence compared to the other groups (P<0.05). The >4 cm group showed longer operative times and higher leak rates. Survival analysis revealed poorer overall survival (OS) and progression-free survival (PFS) for the 0.5-2 cm group versus other groups (P<0.05), with no significant difference between the 2-4 cm and >4 cm groups. Cox regression confirmed that a margin length >2 cm reduced progression risk (HR=0.793, 95% CI 0.641-0.981, P=0.033), particularly for tumors <4 cm, Siewert type II, and intestinal-type Lauren classification. Conclusion: A 2-4 cm proximal margin appears to optimize the prognosis in Siewert type II/III AEJ, balancing oncologic safety and surgical outcomes. This margin length is especially beneficial for tumors <4 cm, Siewert II classification, and intestinal-type histology. A personalized surgical strategy is recommended.