Phase II study of S-1, docetaxel and cisplatin combination chemotherapy in patients with unresectable metastatic gastric cancer

We evaluated the activity and toxicity of docetaxel, cisplatin, and S-1 (DCS) combination chemotherapy in patients with unresectable metastatic gastric cancer. Patients with histologically proven, unresectable metastatic gastric adenocarcinoma, performance status (PS) 0-2, and no prior chemotherapy were eligible. Patients received oral S-1 (40 mg/m(2) b.i.d.) on days 1-14 and intravenous cisplatin (60 mg/m(2)) and docetaxel (60 mg/m(2)) on day 8 every 3 weeks. Thirty-four patients were enrolled between March 2005 and April 2007. Three patients were considered ineligible and did not receive the DSC therapy. Clinical characteristics were as follows: median age, 63 years (range, 44-77); PS, 0/1/2: 23/8/0; women/men, 8/23; and well-differentiated/undifferentiated adenocarcinoma, 10/21. The objective response rate was 87.1% with 1 complete response (3.2%) and 26 partial responses (83.9%) in 31 assessable patients. Four had stable disease (12.9%) but none had progressive disease. Of these 27 responders, 8 (25.8%) achieved downstaging and 7 (22.6%) underwent curative surgery. The median survival time and progression-free survival were 687 days [confidence interval (95% CI), 600.0-1,138.1] and 226 days (95% CI, 182.5-379.3), respectively. Most common grade 3/4 hematologic toxicity was neutropenia (77.4%). Most common grade 3 nonhematologic toxicities included anorexia (35.5%) and nausea (32.3%). All treatment-related toxicities resolved, and no toxic deaths were observed. DCS combination chemotherapy is highly active against unresectable metastatic gastric cancer and can be given safely with proper management of adverse events. Further studies of this combination are warranted.