Lymph Node Dissection After Neoadjuvant Therapy for Gastric and EGJ Adenocarcinoma

This multicenter retrospective observational cohort study will evaluate approximately 2,000 adults with gastric or esophagogastric junction adenocarcinoma who received at least two cycles of neoadjuvant therapy followed by R0 gastrectomy with lymph node dissection. The study will estimate the frequency of pathological metastasis at individual lymph node stations according to the final preoperative imaging-based ycT and ycN categories and tumor location. The findings are intended to provide evidence for future prospective studies of risk-adapted reduction of perigastric lymph node dissection. No treatment is assigned by this study.