The goal of this clinical trial is to learn about Hyperthermic Intraperitoneal Chemotherapy in the Treatment of Locally Advanced Gastric Cancer after Laparoscopic Gastrectomy with D2 Lymphadenectomy. The main question it aims to answer is: whether HIPEC can effectively improving the 5-year overall survival rate and decrease the peritoneal metastases rate of patients with advanced gastric cancer underwent Laparoscopic Gastrectomy with D2 Lymphadenectomy. Participants will be divided into two groups, Experimental group received laparoscopic (robotic) D2 surgery plus HIPEC2 times plus systemic chemotherapy 6~8 cycles; and Control group received laparoscopic (robotic) D2 surgery plus systemic chemotherapy 6~8 cycles.

Inclusion Criteria:

(1) Newly treated patients who did not receive chemotherapy, radiotherapy or other antitumor therapy before the start of the clinical trial;(2) Aged 18-80 years;(3) male or non-pregnant or lactating female;(4) Gastric adenocarcinoma was pathologically confirmed, and laparoscopic (robotic) radical gastrectomy was planned;(5) Patients with T stage T3 or above, no distant metastasis, and feasible criteria for laparoscopic D2 radical resection (AJCC Eighth edition);(6) The estimated survival time is more than 6 months;(7) History of nonabdominal surgery (except laparoscopic cholecystectomy);(8) The bone marrow reserve function was good, and the blood routine met the following conditions: white blood cell count ≥3.5×109/L, neutrophil ≥1.5×109/L, platelet count ≥100×109/L, hemoglobin ≥90g/L;(9) Organ function was good, and biochemical examination met the following conditions: ALT≤2.5× upper limit of normal value (ULN), AST≤2.5×ULN, serum total bilirubin ≤1.5×ULN, serum creatinine ≤1.5×ULN;(10) Functional status: 0-1 (ECOG);(11) Preoperative ASA grade I-III;(12) Voluntarily sign the informed consent.

Exclusion Criteria:

(1) Lymph node BulkyN2 status was diagnosed by abdominal CT/MRI, that is, at least one lymph node meridian ≥3cm or three consecutive lymph nodes, each meridian ≥1.5cm;(2) pregnant or lactating women;(3) Other malignant tumors within 5 years;(4) Preoperative temperature ≥38℃ or complicated with infectious diseases requiring systematic treatment;(5) serious mental illness;(6) Severe respiratory diseases, FEV1< 50%;(7) Severe liver and kidney dysfunction, liver enzyme elevation more than 2 times the normal value;(8) History of unstable angina pectoris or myocardial infarction within 6 months;(9) History of cerebral infarction or cerebral hemorrhage within 6 months, except old infarct;(10) Systemic glucocorticoid therapy within 1 month;(11) Patients with gastric cancer complications (bleeding, perforation, obstruction) requiring emergency surgery;(12) The patient has participated in or is currently participating in other clinical studies (within 6 months);(13) Laparoscopic exploration, biopsy and cytology confirmed intraperitoneal implantation and metastasis.