Application of prolonged microdialysis sampling in carboplatin-treated cancer patients

Purpose  To determine the dose-limiting toxicity (DLT) and activity of combination with docetaxel and S-1 on unresectable gastric cancer. Patients and methods  Docetaxel was administered intravenously on day 1 and S-1 was administered orally on days 1–14, every 3 weeks. Doses of each drug in phase I study were docetaxel 60–75 mg/m² and S-1 60–80 mg/m². A phase II study was conducted with the recommended dose (RD) based on phase I. Results  Sixty-five patients (median age 54 years) were enrolled. The DLTs were neutropenia with fever or stomatitis. The RD was docetaxel 75 mg/m² and S-1 60 mg/m². Two patients (aged 66 and 64 years) developed septic shock during the initial part of phase II study. A phase I study at lower dose (docetaxel 60 mg/m² and S-1 80 mg/m²) was conducted for patients older than 60 years, and this dose was determined as the RD for these patients. In the phase II study, frequent grade 3/4 toxicities were neutropenia (47%) and febrile neutropenia (26%). The overall response rate was 50% (95% CI, 35–66%) and median survival was 15.3 months (95% CI, 10.0–20.6 months). Conclusions  Combination with docetaxel and S-1 was active against advanced gastric cancer and gave manageable toxicities. Supported in part by a grant from the Korea Health 21 R&D Project, Ministry of Health and Welfare, Republic of Korea (0412_CR01_0704_0001).