Outcome of advanced NSCLC patients harboring sensitizing EGFR mutations randomized to EGFR tyrosine kinase inhibitors or chemotherapy as first-line treatment: a meta-analysis

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) are effective as first-line treatment of advanced non-small-cell lung cancer patients with EGFR mutations (EGFR-M+). We conducted a literature-based meta-analysis to quantify the magnitude of benefit with upfront EGFR TKI in EGFR-M+ patients. Meta-regression and sensitivity analyses were also carried out to identify additional predictors of outcome and to assess the influence of trial design. Five trials (805 patients) were identified (three trials prospectively enrolling EGFR-M+ patients and two retrospective analyses of EGFR-M+ patients). TKI significantly increased progression-free survival (PFS) [hazard ratio (HR) 0.45, 95% confidence interval (CI) 0.36–0.58, P < 0.0001] and overall response rate (ORR) (HR 2.08, 95% CI 1.75–2.46, P < 0.0001)] over chemotherapy, while significantly decreasing neutropenia. No significant difference was observed in overall survival. The rate of exon-19 mutations, female gender, and nonsmoking status were identified as additional predictors of outcome at meta-regression analysis. A significant interaction with trial design was found for both PFS (P = 0.028) and ORR (P = 0.008), suggesting a larger advantage for patients treated within prospective trials. In EGFR-M+ patients, first-line TKI increase both PFS and ORR by ∼25%, while significantly decreasing toxicity. The role of additional predictive factors and the influence of trial design on the magnitude of the observed benefit warrant further investigation.