Post-hoc analyses of large randomized trials demonstrated EGFR-TKIs, including gefitinib, erlotinib, and afatinib, were associated with better symptom control and QOL outcomes in EGFR -mutated NSCLC patients when compared to conventional chemotherapy.6-9 In the LUX-Lung 7 trial, similar improvements in patient-reported outcomes and QOL were reported in patients treated with afatinib and gefitinib.10 To the best of our knowledge, however, factors associated with improvements in symptoms and QOL with EGFR-TKI treatment have not been investigated. This evidence concerns the gene EGFR and non-small cell lung carcinoma.