Retrospective efficacy and safety analyses of erlotinib, pemetrexed, and docetaxel in EGFR-mutation-negative patients with previously treated advanced non-squamous non-small-cell lung cancer.

OBJECTIVE: Several guidelines recommend erlotinib, pemetrexed, or docetaxel for second-line chemotherapy in patients with advanced non-squamous non-small-cell lung cancer (NSCLC). The aim of this study was to retrospectively evaluate the efficacy of erlotinib, pemetrexed, and docetaxel in epidermal growth factor receptor (EGFR) mutation-negative patients with previously treated advanced non-squamous NSCLC.

MATERIALS AND METHODS: We analyzed the efficacy of these agents in patients with previously treated advanced non-squamous NSCLC who had EGFR wild-type tumors, performance status (PS) of 0, 1, or 2 and received erlotinib, pemetrexed, or docetaxel between December 2007 and September 2011. Variability among patient backgrounds was evaluated using propensity scores to assess comparability. The efficacy of these agents was evaluated in patient subgroups with low variability.

RESULTS: The propensity scores showed that the backgrounds of the groups that received second-line therapy with each agent had low variability and were adequate for comparison. Patients were divided into the PS0/1 and PS2 groups for analysis. The median progression-free survival (PFS) in patients treated with erlotinib was 2.8 months in the PS0/1 group, as compared with 1.0 month in the PS0/1/2 group and 0.90 months in the PS2 group. PFS in PS0/1 patients who received erlotinib was comparable to that in PS0/1 patients who received pemetrexed (2.5 months) or docetaxel (1.9 months). Overall survival (OS) in erlotinib-, pemetrexed-, and docetaxel-treated PS0/1 patients was 16.1, 7.4 and 10.0 months, respectively. The study had limited power to detect differences in PFS and OS because of the small sample size.

CONCLUSIONS: Erlotinib appears to be a useful second-line option in PS0/1 patients with EGFR mutation-negative advanced non-squamous NSCLC given its mild adverse effects. The results should be carefully interpreted because of the small sample size, limited power, and retrospective nature of the study.