S-1 Plus Cisplatin with Concurrent Radiotherapy for Locally Advanced Non-small Cell Lung Cancer: A Multi-Institutional Phase II Trial (West Japan Thoracic Oncology Group 3706)

Purpose: To evaluate the combination chemotherapy using oral antimetabolite S-1 plus cisplatin (SP) with concurrent thoracic radiotherapy (RT) followed by the consolidation SP for locally advanced non-small cell lung cancer. Patients and Methods: Patients with stage III non-small cell lung cancer, 20 to 74 years of age, and Eastern Cooperative Oncology Group performance status 0 to 1 were eligible. The concurrent phase consisted of full dose S-1 (orally at 40 mg/m²/dose twice daily, on days 1–14) and cisplatin (60 mg/m² on day 1) repeated every 4 weeks for two cycles with RT delivered beginning on day 1 (60 Gy/30 fractions over 6 weeks). After SP-RT, patients received an additional two cycles of SP as the consolidation phase. Results: Fifty-five patients were registered between November 2006 and December 2007. Of the 50 patients for efficacy analysis, the median age was 64 years; male/female 40/10; Eastern Cooperative Oncology Group performance status 0/1, 21/29; clinical stage IIIA/IIIB 18/32; and adenocarcinoma/others 20/30. There were 42 clinical responses including one complete response with an objective response rate of 84% (95% confidence interval [CI], 71–93%). The 1- and 2-year overall survival rates were 88% (95% CI, 75–94%) and 70% (95% CI, 55–81%), respectively. The median progression-free survival was 20 months. Of the 54 patients for safety analysis, common toxicities in the concurrent phase included grade 3/4 neutropenia (26%), thrombocytopenia (9%), and grade 3 esophagitis (9%) and febrile neutropenia (9%). In one patient, grade 3 pneumonitis was observed in the consolidation phase. There were two treatment-related deaths caused by infection in the concurrent phase. Conclusions: SP-RT showed a promising efficacy against locally advanced NCSLC with acceptable toxicity.