EGFR and adenocarcinoma: Gefitinib was chosen for treatment because EGFR-TKIs are the standard first-line treatment for advanced NSCLC with an EGFR mutation.[5] In general, gefitinib results in better PFS and OS in advanced NSCLC patients with an exon 19 deletion, and it is more effective in non-smoking Asian females with adenocarcinoma.[6] Thus, gefitinib was expected to be effective.