A Phase Ib/II Study of Efficacy and Feasibility of Cytoreductive Surgery, Extensive Peritoneal Lavage, Hyperthermicintraperitoneal Chemotherapy and Post-operative Intraperitoneal Chemotherapy Combination in Gastric Cancer With Peritoneal Metastasis

"1. Ib~ * Dose-escalation of intraperitoneal paclitaxel will follow a modified 3 + 3 dose escalation procedure.~2. II~ ① CRS If PCI \<12, CRS will be performed by gastrectomy with D2-lymphadenectomy and resection of any involved adjacent structures.~ If PCI≥12, instead of CRS, 3 times of IP paclitaxel +cisplatin and oral S-1 chemotherapy every 3 weeks, and then PCI \<12, CRS will be done.~ ② Extensiveintraperitoneal lavage Peritoneal lavage after CRS will be done with 10 L before HIPEC.~ ③ HIPEC Following surgery HIPEC will be performed using CDDP (60 mg/m2) and PTX (P2RD mg/m2). IP chemotherapy will be performed.~ ④ Post-operative intraperitoneal chemotherapy Postoperative chemotherapy will be done 8 cycles of IP paclitaxel+ cisplatin and oral S-1 after 4 weeks."