Clinical Research Directory

Inclusion Criteria: * Age 18 years or older. * Histologically confirmed gastric adenocarcinoma or esophagogastric junction adenocarcinoma. * Completion of at least two cycles of neoadjuvant chemotherapy, chemotherapy combined with immunotherapy, or chemoradiotherapy. * Final preoperative imaging assessment within four weeks before surgery with evaluable ycT and ycN categories according to the AJCC/UICC eighth edition. * ycM0 disease before surgery. * R0 curative-intent total, distal, or proximal gastrectomy with lymph node dissection. * Identifiable surgical procedure and evaluable station-specific lymph node pathological records. * Surgery performed between January 1, 2021, and August 30, 2026. Exclusion Criteria: * Histological diagnosis other than adenocarcinoma, including squamous cell carcinoma, lymphoma, gastrointestinal stromal tumor, or neuroendocrine neoplasm. * Conversion therapy for initially unresectable or metastatic disease. * Intraperitoneal hyperthermic perfusion treatment. * ycM1 disease, including peritoneal, hepatic, or other distant metastasis. * R1 or R2 resection, palliative surgery, or exploratory surgery without curative gastrectomy. * Previous gastrectomy. * Synchronous multiple primary gastric cancers. * Another active malignant tumor. * Missing core data required for eligibility or the primary analysis, including ycT, ycN, gastrectomy type, or station-specific pathological records.