Phase 2 Study of S-1 in Combination With Cisplatin as 1st Line Therapy in Advanced Non-Small Cell Lung Cancer

All patients will receive S-1 orally at a dose of 25 mg/m2 twice daily (BID) for 14 days followed by a 1-week recovery period, repeated every 3 weeks. The study may go to the third stage only if 7/31 (23%) or more patients have achieved a confirmed response (CR or PR) in stages 1 and 2 combined.