Conversion Therapy of Hyperthermic Intraperitoneal Chemotherapy Plus Chemotherapy and Chemotherapy in Stage IV Gastric Cancer

Inclusion Criteria: * Diagnosed as gastric adenocarcinoma by pathology and had not received any other anti-tumor treatment such as radiotherapy and chemotherapy; * ≥ 18 and ≤ 70 years of age; Eastern Cooperative Oncology Group Performance Status (ECOG): 0-1; * Intraoperative pathological diagnosis was peritoneal metastasis (stage ≤ P1b), with or without ascites (ascites volume exceeding pelvic cavity but not reaching full abdominal ascites) * Patients have adequate baseline organ and marrow function :hemoglobin≥9g/dL; absolute neutrophil count (ANC) ≥1,500/mm3; PLT(platelets)≥1000,000/mm3; total bilirubin ≤1.5×upper normal limit(ULN); AST ≤2.5 ×ULN, ALT ≤2.5 ×ULN; prothrombin time-international normalized ratio≤1.5, and APTT(activated partial thromboplastin time) was within normal range; creatine ≤ 1.5 x ULN; * Written informed consent provided; Exclusion Criteria: * Diagnosed as Her-2(+++)/FISH(+) by pathology; * With other distant metastasis(ovarian metastasis was excluded) * Patients with Serious liver disease (such as cirrhosis, etc.), kidney disease, respiratory disease or uncontrolled diabetes, hypertension and other chronic systemic diseases, heart disease with Clinical symptoms, such as congestive heart failure, coronary heart disease symptoms, drug is difficult to control arrhythmia, hypertension, or six months had a myocardial infarction attack, or cardiac insufficiency; * Organ transplantation patients need immunosuppressive therapy; * Severe recurrent infections were not controlled or with other serious concomitant diseases; * Patients got other primary malignant tumors (except curable skin basal cell carcinoma and cervical cancer in situ) except gastric cancer within 5 years; Psychiatric disease which require treatment; * Within 6 months before study starts and in the process of this study, patients participate in other clinical researches; * Patients with peripheral nervous system disorder or apparent mental disorders or had the history of central nervous system disorders; * Pregnant or lactating women, women of child-bearing potential, unwilling to use adequate contraceptive protection during the process of the study; * Patients without legal capacity,or medical/ethical reasons may influence the study to continue.