The purpose of this study is to investigate the efficacy and safety of HIPEC plus apatinib and S-1 in the conversion therapy of gastric cancer with positive exfoliative cancer cells

Inclusion Criteria:

• 1. Untreated (e.g. chemotherapy, radiotherapy and other antitumor therapy); 2. Age:18 to 70 years old; 3. Man or female (except pregnant and lactating women); 4. Confirmed to gastric adenocarcinoma; 5. Proven gastric cancer of T stage was T3 and T4, and no distant metastasis was observed. The exfoliative cancer cells detection in peritoneal washes was positive; 6. Blood cell count has to meet the following certeria: WBC≥3.5×109/L; ANC≥1.5×109/L; PLT≥100×109/L; HB≥90g/L; 7. Liver/kidney function has to meet the following certeria: ALT and AST≤2.5×ULN TBIL<1.5×ULN； Serum creatinine ≤1.5×ULN; 8. Eastern Cooperative Oncology Group (ECOG) performance status of 0-1; 9. Participants were willing to join in this study, good adherence and written informed consent.

Exclusion Criteria:

- 1. Patients with other malignant tumors within 5 years; 2. Metastasis was found to be visible to the naked eye; 3. It has serious or uncontrolled heart diseases and infections (Including atrial fibrillation, angina pectoris, cardiac insufficiency, ejection fraction less than 50%, poor-controlled hypertension and so on); 4. History of psychiatric drugs abuse and can't quit or patients with mental disorders; 5. Patients with severe or uncontrollable mental illness; 6. Patients with tendency of gastrointestinal bleeding, including the following: a local active ulcerative lesions, and defecate occult blood (+ +).Has melena and hematemesis in two months; 7. Pregnant or lactating women; 8. It have serious harm to the patient's safety or affect the patients who have completed the research.

9. The researchers think inappropriate.