This [Study Type: Clinical Trial] aims to [Primary Objective: evaluate the long-term efficacy and safety of robotic gastrectomy for locally advanced gastric cancer] in [Participant Population: patients with locally advanced gastric cancer, aged >18 years and <75 years]. The primary questions it seeks to answer are:

Is the 3-year disease-free survival rate of robotic gastrectomy non-inferior to that of laparoscopic gastrectomy? Is the perioperative safety of robotic gastrectomy superior to that of laparoscopic gastrectomy? Researchers will compare [Intervention Groups: Robotic Gastrectomy vs. Laparoscopic Gastrectomy] to determine whether [robotic surgery offers advantages in long-term efficacy and perioperative safety].

Participants will:

Sign an informed consent form and be randomly assigned to either the robotic surgery group or the laparoscopic surgery group.

Undergo the assigned surgical procedure and receive regular follow-up visits (at 30 days, 3 months, 6 months, 9 months, 12 months, 15 months, 18 months, 21 months, 2 years, 2.5 years, and 3 years postoperatively).

Complete physical examinations, blood tests (including complete blood count, biochemical markers, and tumor markers), and imaging studies (such as abdominal CT, upper gastrointestinal endoscopy, and chest X-ray) during the follow-up period.

Inclusion Criteria:

1. Age > 18 years and < 75 years.
2. Primary gastric lesion histologically confirmed as gastric adenocarcinoma (including papillary adenocarcinoma, tubular adenocarcinoma, mucinous adenocarcinoma, signet ring cell carcinoma, poorly differentiated adenocarcinoma, etc.) via endoscopic biopsy.
3. Preoperative clinical staging as locally advanced gastric cancer (cT2-4a, N0-3, M0) according to the 8th edition of the AJCC TNM staging system.
4. No distant metastasis on preoperative examination, and no direct invasion of the pancreas, spleen, or other adjacent organs.
5. Preoperative ECOG performance status score of 0 or 1.
6. Preoperative ASA (American Society of Anesthesiologists) physical status score of I-III.
7. Consent to participate in the study and signing of the informed consent form.

Exclusion Criteria:

1. Previous history of gastric malignancy surgery, including submucosal resection and/or endoscopic mucosal resection.
2. History of upper abdominal surgery (excluding laparoscopic cholecystectomy).
3. Preoperative imaging shows regional lymph nodes with confluent enlargement (maximum diameter ≥3cm).
4. Patient underwent emergency surgery due to gastric tumor bleeding or perforation.
5. History of other malignancies, or presence of other malignant tumors detected during preoperative examination.
6. Patient has a history of malignant tumor, or other malignant tumors were found during preoperative examination
7. ASA (American Society of Anesthesiologists) score >3.
8. Severe psychiatric disorders.
9. History of unstable angina or myocardial infarction within the past 6 months.
10. History of cerebral infarction or cerebral hemorrhage within the past 6 months.
11. Severe pulmonary disease with FEV1 < 50%.
12. Systemic corticosteroid therapy within 1 month prior to the study.
13. Need for concurrent surgery for other diseases.
14. Pregnant or breastfeeding women.