NSCLC: non-small cell lung cancer; BM: brain metastases; EGFR: epidermal growth factor receptor; Mut: mutated; WT: wild type. The categorical data were presented as numbers (percentages) and the comparisons between groups used the chi-squared test. Non-adenocarcinoma group included squamous cell carcinoma, large cell carcinoma and NSCLC-not otherwise specified in this analysis. Uncommon mutations included 3 with an exon 18 mutation, 6 with an exon 20 insertion, and 1 with an exon 18 mutation and exon 20 insertion.