Randomized phase III trial of surgery plus neoadjubant TS-1 and cisplatin compared with surgery alone for type 4 and large type 3 gastric cancer: Japan Clinical Oncology Group Study (JCOG 0501)

INTERVENTION: Gastrectomy with more than D2 disseciton + adjuvant chemotherpy(TS‐1) Neoadjubant chemotherpy(TS‐1+CDDP) followed by gastrectomy + adjuvant chemotherpy(TS‐1) CONDITION: gastric neoplasm PRIMARY OUTCOME: overall survival SECONDARY OUTCOME: progression free survival (PFS), response rate, proportion of protocol achievement, proportion of curative resection, and adverse events. ; In this trial, curative resection means R0 resection (TNM classification) with more than D2 dissection. INCLUSION CRITERIA: (1) histologically proven adenocarcionoma of stomach (2) Borrmann type 4 or large (>=8 cm) type 3 (3) no evidence of distant metastasis including liver(M0) (4) macroscopic curative resection is judged as possible (5) no evidence of a macroscopic unresectable factor with laparoscopic confirmation. Dissemination to peritoneal surfaces adjacent to stomach (above the transverse colon, including omentum) and/or positive peritoneal lavage cytology is eligible. (6) no involvement of the esophagus with > 3cm (7) an age of 20‐75 years (8) an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1 (9) no prior chemotherapy, radiotherapy for any malignancy (10) no prior surgery for gastric cancer except for endoscopic membrane resection (EMR) (11) no breeding from primary tumor or gastrointestinal stenosis (12) sufficient oral intake (13) adequate organ function (14) written informed consent