A phase II study of systemic chemotherapy with Docetaxel, CDDP, and S-1 followed by surgery in advanced gastric cancer with extensive lymph node metastasis(JCOG1002, BulkyGC Pre-DCS Phase II)

INTERVENTION: Preoperative chemotherapy with Docetaxel+CDDP+S‐1 followed by gastrectomy with D2+No.16 lymph node dissection CONDITION: gastric neoplasm PRIMARY OUTCOME: response rate of preoperative chemotherapy by RECIST ver1.0 SECONDARY OUTCOME: 3‐year survival, 5‐year survival, proportion of R0 resection, proportion of completion of surgery, proportion of completion of protocol treatment, pathological response rate, toxicities INCLUSION CRITERIA: "1) Histologically proven primary gastric adenocarcinoma. 2) Enhanced abdominal CT revealed having any of the followings: i) Paraaortic lymph node metastasis (No.16a2/ 16b1) ii) Bulky lymph node (>=3cmx1 or >=1.5cmx2) iii) Both of No.16a2/ 16b1 and Bulky lymph node 3) Enhanced thoracic/ abdominal/ pelvic CT revealed having none of the followings: i) Mediastinal lymph node metastasis ii) Lung metastasis iii) Peritoneal metastasis iv) liver metastasis v) Pleural effusion, ascites vi) Paraaortic No.16a1 or No.16b2 swelling 1cm or greater vii) Other distant metastasis 4) Neither Borrmann type 4 nor large (8cm or more) type 3. 5) Length of esophageal invasion less or equal to 3cm. 6) Not stump cancer of stomach. 7) Clinically no sign of cervical lymph node nor distant metastasis. 8) No peritoneal metastasis and CY0 by laparoscopy or laparotomy. 9) Age between 20 and 75 at registration. 10) Performance St