Abstract
PURPOSE: Pemetrexed is a recognized active agent for the second-line treatment for advanced non-small cell lung cancer (NSCLC). This study was undertaken to evaluate the clinical benefits of pemetrexed and to identify patient characteristics that predict response to pemetrexed. METHODS: We retrospectively reviewed the medical records of patients with histologically proven stage IIIB or IV NSCLC who were treated with pemetrexed after the failure of prior chemotherapy. RESULTS: The objective response rate for the 99 enrolled patients was 13.1% and 22 patients achieved stable disease (SD)-a disease control rate of 35.4%. Progression-free survival and overall survival (OS) were 1.8 months (95% CI, 1.32-2.28) and 7.6 months (95% CI, 6.23-8.97), respectively. The patients who achieved SD and pemetrexed-responders showed similar OSs (14.6 vs. 14.8 months, P = 0.55). However, a squamous cell carcinoma histology showed no significant OS difference between those that achieved disease control or progression (8.1 vs. 5.6 months, P = 0.07). Subgroup analysis of OS revealed that histology and response to first-line therapy predicted response to pemetrexed. CONCLUSIONS: Pemetrexed has comparable survival benefits in NSCLC patients that show objective response or stable disease.