Is Proximal Gastrectomy Oncologically Justifiable for Advanced Siewert II/III Adenocarcinoma of the Esophagogastric Junction?

[PURPOSE] The oncological safety of proximal gastrectomy (PG) for advanced Siewert II/III adenocarcinoma of the esophagogastric junction (AEG) remains controversial. We compared the long-term oncological outcomes of PG and total gastrectomy (TG) to refine the indications for PG.

[MATERIALS AND METHODS] This dual-center retrospective study included 443 patients with pT2-4NanyM0 Siewert II/III AEG who underwent PG (n=192) or TG (n=251). Propensity score matching yielded 149 matched pairs. Perioperative outcomes, overall survival (OS), recurrence-free survival (RFS), and recurrence patterns were analyzed. Logistic regression analysis was used to assess risk factors for perigastric lymph nodes (PLN) recurrence after PG and key distal lymph nodes (KDLN) metastases after TG. The therapeutic index (TI) of KDLN metastases was calculated.

[RESULTS] Although survival rates were lower after PG, no significant differences were observed in OS (hazard ratio [HR],1.39; P=0.109) or RFS (HR, 1.30; P=0.212). PG was associated with more local recurrences (24.12% vs. 8.7%; P<0.001), especially PLN metastases (13.4% vs. 5.4%; P=0.023). In subgroup analyses, PG was associated with worse OS in pT4 patients (HR, 2.17; P=0.006) and worse RFS in pN3 patients (HR, 2.37; P=0.011). In patients who underwent TG, tumor size >6 cm (OR, 3.72) and pT4 (OR, 13.9) predicted KDLN metastasis. Patients with KDLN metastases had significantly worse OS (HR, 2.51; P<0.001).

[CONCLUSIONS] TG is more suitable for patients with advanced Siewert II/III AEG with pT4, tumors >6 cm, or those with a high predicted risk of KDLN metastases. Accurate preoperative staging and intraoperative reassessment are essential for safe PG selection.

[TRIAL REGISTRATION] Chinese Clinical Trial Registry Identifier: ChiCTR2500102562.