Phase II Study of Docetaxel and S-1 (DS) as Neoadjuvant Chemotherapy for Clinical Stage III Resectable Gastric Cancer

Abstract

We conducted a phase II trial to evaluate the efficacy and safety of preoperative chemotherapy with docetaxel (DTX) plus S-1 for resectable advanced gastric cancer. A total of 47 patients from 14 centers were centrally registered. Patients received DTX (35 mg/m(2)) on days 1 and 15, and daily oral administration of S-1 (80 mg/m(2)/day) for days 1-14 every 4 weeks for two courses, followed by gastrectomy with D2 lymphadenectomy. The primary endpoint was pathological response rate (pRR). This study was registered in the UMIN clinical trial registry (UMIN000000875). The primary endpoint pRR was 47 % (90 % confidence interval (CI), 34-60 %; p < 0.0001). The response rate to preoperative chemotherapy using Response Evaluation Criteria in Solid Tumors (RECIST) was 34 %. Forty-six patients (98 %) underwent surgery, and curative resection was performed in 44 patients. Thirty-seven patients completed the protocol treatment. The most common toxicities of neoadjuvant chemotherapy were grade 3/4 neutropenia (42 %), febrile neutropenia (4 %), grade 2 anorexia (21 %), and fatigue (15 %). Treatment-related death and operative mortality was not observed in this study. The combination of docetaxel and S-1 was well tolerated. This is promising as a preoperative chemotherapy regimen for patients with potentially resectable advanced gastric cancer.