The impact of induction chemotherapy on the outcome of second-line therapy with pemetrexed or docetaxel in patients with advanced non-small-cell lung cancer

Background: Using data from a large phase III study of previously treated advanced non-small-cell lung cancer (NSCLC) that showed similar efficacy for pemetrexed and docetaxel, this retrospective analysis evaluates the impact of first-line chemotherapy on the outcome of second-line chemotherapy. Patients and methods: In all, 571 patients with advanced NSCLC were randomly assigned to receive pemetrexed 500 mg/m₂ or docetaxel 75 mg/m₂ on day 1 of a 21-day cycle. Comparisons were made based on type of first-line therapy [gemcitabine + platinum (GP), taxane + platinum (TP), or other therapies (OT)], response to initial therapy, time since initial therapy, and clinical characteristics. The two second-line treatment groups were pooled for this analysis due to similar efficacy and were assumed to have no interaction with the first-line therapies. Results: Baseline characteristics were generally balanced. By multivariate analysis, gender, stage at diagnosis, performance status (PS), and best response to first-line therapy significantly influenced overall survival (OS). Additional factors by univariate analysis, histology, and time elapsed from first- to second-line therapy significantly influenced OS. Conclusions: Future trials in the second-line setting should stratify patients by gender, stage at diagnosis, PS, and best response to first-line therapy.