Phase II study of S-1 plus either irinotecan or docetaxel for non-small cell lung cancer patients treated with more than three lines of treatment

Purpose: This study was designed to evaluate the efficacy of a combination treatment of S-1 plus either irinotecan or docetaxel for advanced/metastatic non-small cell lung cancer (NSCLC) patients who have already failed 3 or more lines of treatment. Materials and Methods: This was a prospective single center phase II study. The eligible patients received S-1 40 mg/m ² twice a day orally on days 1 though 14 combined with irinotecan 150 mg/m ² on D1 only or docetaxel 35 mg/m ² on D1 and D8. The treatment was repeated every 3 weeks until disease progression, unacceptable toxicity, or patient refusal. The choice between the two regimens was made at the discretion of the treating physician. Results: A total of 14 patients participated in the study. There were 3 patients with squamous cell carcinoma, 9 with adenocarcinoma, and 2 with NSCLC, NOS. Eight of the patients were male. There were 8 patients with an Eastern Cooperative Oncology Group (ECOG) of 1, and 6 patients with an ECOG of 2. All the patients had already been treated with platinum-based chemotherapy and epidermal growth factor receptor tyrosine kinase inhibitor therapy. Out of the 14 patients, 10 received irinotecan and S-1 and the other 4 received docetaxel and S-1. Twelve patients had also received pemetrexed. Disappointingly, there were no response from 2 patients with a stable disease, and therefore, as per the protocol, we stopped the study early. With a median follow-up time of 49 months, the median survival time was 5.6 months (95% confidence interval, 4.3 to 6.9 months). Conclusion: S-1 containing doublets did not show activity in this population as a salvage treatment and further investigation cannot be recommended.