Phase II study of oral S-1 and cisplatin with concurrent radiotherapy for locally advanced non-small-cell lung cancer

Purpose: To determine the efficacy and safety of oral S-1 in combination with cisplatin and thoracic radiotherapy in patients with unresectable stage III non-small-cell lung cancer (NSCLC). Methods and materials: S-1 (50mg/m²) was administered orally twice daily for 14 days, with cisplatin (40mg/m²) on days 1 and 8 of each cycle every 3 weeks, for 2-4 cycles. Thoracic radiation therapy was administered in 2Gy fractions five times weekly for a total dose of 60Gy. The primary endpoint was the response rate, and secondary endpoints included progression-free survival, overall survival and safety. Results: Forty-one patients were enrolled in this study. The objective response rate was 87.8% (98% CI: 77.8-97.8%). The median progression-free survival was 467 days (15.4 months), and the median survival time was 904 days (29.7 months). The overall survival rates at 1- and 2-years were 85.7% and 52.9%, respectively. Hematological toxicities included grade 3/4 neutropenia (17%) and grade 3/4 leukopenia (27%). No grade 3 febrile neutropenia was detected, and grade 3/4 non-hematological toxicities were also mild. A grade 3 gastrointestinal hemorrhage was observed in one patient. Conclusions: The combination of oral S-1 plus cisplatin with concurrent radiotherapy is a promising treatment with a high efficacy and lower toxicity in patients with locally advanced NSCLC.