The relationship between examined lymph nodes and oncological outcome of proximal gastrectomy for Siewert II/III adenocarcinoma of the esophagogastric junction.

OBJECTIVE: The objective of this study was to summarize the oncological outcomes and long-term prognosis of patients with Siewert II/III adenocarcinoma of the esophagogastric junction (AEG) who underwent proximal gastrectomy (PG) at the China National Cancer Center (CNCC), with particular focus on the relationship between the number of examined lymph nodes (ELNs) and prognosis. METHODS: We retrospectively analyzed 242 patients with Siewert II/III AEG who underwent PG between 2017 and 2021 at the CNCC. Lymphadenectomy followed D1 + principles for early-stage and D2 for advanced-stage disease. Recurrence-free survival (RFS) and overall survival (OS) were assessed using Kaplan-Meier curves, and prognostic factors were identified through Cox regression. Restricted cubic spline (RCS) modeling was applied to explore the dose-response relationship between ELNs and OS. RESULTS: Of the 242 patients, 163 (67.4%) did not achieve textbook outcome with ≥ 30 ELNs (TO-30LN) and had significantly worse survival (OS: HR = 1.85, 95% CI: 1.08-3.18; RFS: HR = 1.88, 95% CI: 1.06-3.34; both P < .05). Multivariable analysis identified pN + status and Clavien-Dindo grade ≥ II complications as independent adverse prognostic factors. RCS analysis revealed a nonlinear association between ELN count and OS in cT2-3 disease, with an optimal range of 28-53 nodes, whereas no survival benefit was observed in cT4 disease. CONCLUSION: For Siewert II/III AEG following PG, achieving TO-30LN improved survival. RCS analysis revealed an optimal ELN threshold in cT2-3 patients, but no benefit in cT4, indicating limited suitability of PG for this subgroup.