EGFR and non-small cell lung carcinoma: To the best of our knowledge, there has been so far no randomized-controlled trials comparing the efficacy of afatinib with gefitinib/erlotinib (collectively grouped as first-generation EGFR-TKI in the latter text) in those who had prior failure to first-generation EGFR-TKI for their metastatic EGFR-mutated NSCLC.