Procedure: LECS combined with LSNNS

Early gastric cancer (EGC) is traditionally treated with either endoscopic resection or standard laparoscopic gastrectomy with formal lymph node dissection. However, endoscopic resection cannot evaluate or treat regional lymph node metastasis, whereas standard surgery significantly impairs postoperative gastric physiological function and patient quality of life (QoL). The LENS trial is a prospective, single-arm clinical study designed to evaluate the feasibility, safety, and long-term efficacy of Laparoscopic and Endoscopic Cooperative Surgery (LECS) combined with Laparoscopic Sentinel Node Navigation Surgery (LSNNS) using Indocyanine Green (ICG) fluorescence tracing for patients with cT1N0M0 early gastric cancer. In this trial, eligible patients will undergo intraoperative sentinel lymph node (SN) biopsy guided by ICG. Patients with negative SN status will receive stomach-preserving surgery (primarily Non-exposed Endoscopic Wall-inversion Surgery, NEWS), while those with positive SN status will convert to standard laparoscopic gastrectomy. The primary goal is to confirm whether this combined procedure provides long-term oncological safety comparable to standard radical gastrectomy, while significantly improving postoperative gastric function, nutritional status, and quality of life.