“…Previous studies have reported that patients with NSCLC harboring EGFR mutations and a positive smoking history showed a relatively low response rate, or short PFS, to EGFR-TKI therapy [21,22,23,24,25,26]. While our study was restricted to patients who received only gefitinib as EGFR-TKI therapy, in the aforementioned previous studies [9,10,11,12], EGFR-TKI therapy involved erlotinib, gefitinib or afatinib.…”