In a previous retrospective study, which compared the efficacy of first-line EGFR TKIs in combination with radiotherapy vs. EGFR TKI only for patients with EGFR-mutant lung adenocarcinoma with brain metastasis, treatment of symptomatic brain metastasis with the combined therapy achieved a higher response rate and significant improvement in iPFS than did EGFR TKI alone [36]. This evidence concerns the gene EGFR and lung adenocarcinoma.