Additional Gastrectomy Versus Surveillance After Non-curative Endoscopic Resection in Patients Aged 75 Years or Older: A Nationwide Multicenter Cohort Study

Background: The benefit of additional gastrectomy after eCuraC-2 non-curative endoscopic resection for early gastric cancer in older patients is uncertain because of competing mortality. Methods: This nationwide retrospective cohort included 1,038 patients aged ≥75 years with eCuraC-2 resection at 22 Korean hospitals (352 additional gastrectomy; 686 surveillance). The primary outcome was overall survival (OS). Secondary outcomes were gastric cancer (GC)-specific mortality and any recurrence. Multivariable Cox and competing-risk analyses were performed. Inverse probability of treatment weighting (IPTW) was used for sensitivity analysis. Results: At 5 years, OS was 76.5% with surveillance versus 83.0% after additional gastrectomy (hazard ratio [HR] 1.37, 95% confidence interval [CI] 1.08–1.74; P=0.01). However, surveillance patients were older (≥80 years: 43.3% vs 24.1%) and more frequently had ECOG-PS 2–4 (11.7% vs. 6.8%), whereas gastrectomy patients had higher-risk pathology, including lymphovascular invasion (60.8% vs 37.0%). Although recurrence was more frequent with surveillance (9.9% vs. 1.8%; adjusted SHR 5.71, 95% CI 2.57–12.69), GC-specific death was rare (17 events; 1.3% vs. 1.1%). The unadjusted SHR for surveillance versus gastrectomy was imprecise (1.62, 95% CI 0.53–4.96; P=0.40), whereas the IPTW-weighted sensitivity estimate was larger (SHR 3.34, 95% CI 1.28–8.72; P=0.014). The derived all-cause/GC-specific mortality-rate ratios were 22.2 with surveillance and 27.3 after gastrectomy. Conclusions: In elderly patients with non-curative ESD, prognosis is driven more by competing non-GC mortality than by GC-related death. Additional gastrectomy may improve cancer-specific outcomes in selected patients, but its OS benefit appears limited. Management should therefore be individualized rather than based on curability criteria alone, balancing pathological risk against operative risk, postoperative functional consequences, physiological reserve, and patient preferences.