The Effect of Different Digestive Tract Reconstruction Methods on Postoperative Quality of Life After Proximal Gastrectomy

Inclusion Criteria: * Age from over 18 to under 75 years. * Preoperative gastroscopic pathological biopsy was performed, and histologically confirmed as carcinoma (papillary adenocarcinoma, tubular adenocarcinoma, mucinous adenocarcinoma, signet ring cell carcinoma, poorly differentiated adenocarcinoma, mixed adenocarcinoma, etc.) or adenoma. * Diagnosed with upper gastric cancer (T1N0M0, T1N1M0, or T2N0M0) or esophagogastric junction cancer with a diameter ≤4 cm based on the 8th edition of the AJCC staging system, as confirmed by CT, MRI, endoscopic ultrasound, and pathology. * Undergoing proximal gastrectomy with D2 lymphadenectomy is expected to achieve curative resection, with the remaining gastric volume required to be at least half of the pre-resection volume. * Performance status of 0 or 1 on ECOG (Eastern Cooperative Oncology Group) scale. * ASA (American Society of Anesthesiology) class I to III. * The patient has adequate organ function and is capable of tolerating surgery. * Written informed consent. Exclusion Criteria: * Patients who have received preoperative radiotherapy, chemotherapy, targeted therapy, or immunotherapy. * Presence of multiple malignant tumors in the stomach. * History of upper abdominal surgery, except for laparoscopic cholecystectomy. * History of gastric surgery, except for endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR) for gastric cancer. * Evidence of distant metastasis diagnosed by thoracoabdominal CT/MRI or PET-CT. * Pregnant or lactating women. * History of uncontrolled epilepsy, central nervous system disorders, or psychiatric illness. * Patients with limb disabilities or motor function impairment. * History of other malignant diseases within the past five years, except for cured skin cancer and cervical carcinoma in situ. * Clinically severe (i.e., active) heart disease, such as symptomatic coronary artery disease, New York Heart Association (NYHA) class II or higher congestive heart failure, severe arrhythmia requiring medical intervention, or myocardial infarction within the past six months. * History of stroke or cerebral hemorrhage within the past six months. * Severe, uncontrolled recurrent infections or other serious uncontrolled comorbidities. * Pulmonary function test showing FEV1 \< 50% of the predicted value. * Patients requiring emergency surgery due to tumor-related complications (e.g., bleeding, perforation, or obstruction).