Survival analysis for older patients with epidermal growth factor receptor mutation-positive advanced non-small cell lung cancer after progression of first-line gefitinib.

Abstract

Currently, little studies focus on treatment strategies and survival after progression of gefitinib in older patients with epidermal growth factor receptor )EGFR( mutant advanced non-small-cell lung cancer (NSCLC). The aim of this study was to investigate the influence of different treatment modalities on survival after progression of gefitinib in older patients. This is a retrospective analysis included 62 consecutively recruited EGFR-mutant advanced NSCLC patients aged over 70 years who failed first-line gefitinib between 2008 and 2018. Kaplan-Meier method was used to estimate curves for overall survival (OS). Multivariate analysis identified independent prognostic risk factors of OS. The median age at diagnosis was 75 years (range, 70-88years). The median progression-free survival of gefitinib was 11.0 months. Forty-four (69.4%) patients continued gefitinib beyond progressive disease (PD), and median gefitinib treatment duration was 18.0 months. Only 67.7% patients received anticancer treatments after discontinuation of gefitinib. The median OS was 24.5 months (95% confidence interval [CI], 19.7-29.3 months). After failure of gefitinib, the osimertinib only group had significantly improved OS compared with chemotherapy or palliative care only groups (37.5 versus 17.5 and 15.3 months, respectively; P=.017). Multivariate analysis showed that continuous gefitinib after Response Evaluation Criteria in Solid Tumor-defined PD (hazards ratio [HR] 0.273, 95% CI: 0.132-0.564, P<.001), osimertinib treatment (HR 0.244, 95% CI: 0.122-0.487, P<.001), and better performance status (HR 0.360, 95% CI: 0.163-0.796, P=.012) were significantly and independently correlated with better survival. For older patients with EGFR-mutant advanced NSCLC, EGFR tyrosine kinase inhibitors are the most important treatment. Survival benefit of chemotherapy after failure of gefitinib seems limited.