Comparing survival and subsequent treatment of first-line tyrosine kinase inhibitors in patients of advanced lung adenocarcinoma with epidermal growth factor receptor mutation

Abstract

Three first-line epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are widely available to treat advanced lung adenocarcinoma harboring EGFR mutation. However, studies comparing efficacy or effectiveness of these EGFR TKIs came out with inconclusive results. In this real-world data analysis with a nationwide retrospective cohort design, adult patients with newly diagnosed advanced lung adenocarcinoma with EGFR mutation between 2011 and 2016, who received a first-line EGFR TKI, were included. Overall survival (OS) and time to next treatment (TTNT) were compared between patients receiving different EGFR TKIs after overlap weighting. We enrolled 10,431 patients, including 6,230, 2,359, and 1842 in gefitinib, erlotinib, and afatinib groups, respectively. The median (95% confidence interval [CI]) OS were 24.2 (22.9-26.2), 25.7 (24.0-27.9), and 29.1 (25.8-32.1) months for those receiving gefitinib, erlotinib, and afatinib, respectively (p=0.001). The hazard ratios (95% CI) for the afatinib group were 0.85 (0.74-0.98) and 0.91 (0.79-1.05) comparing with the gefitinib and erlotinib groups, respectively. The median (95% CI) TTNT were 10.9 (10.4-11.2), 11.7 (11.3-12.1), 13.4 (12.5-14.3) months for those receiving gefitinib, erlotinib, and afatinib, respectively (p<0.001). The hazard ratios (95% CI) for the afatinib group were 0.79 (0.70-0.88) and 0.89 (0.79-1.00) comparing with the gefitinib and erlotinib groups, respectively. There were 6111 (59%) patients receiving subsequent therapies, and the majority of them received a second-line chemotherapy, particularly platinum-based chemotherapy. Afatinib, compared with gefitinib, might provide better effectiveness as the first-line targeted therapy for patients of advanced lung adenocarcinoma with EGFR mutation.