EGFR and non-small cell lung carcinoma: Overall, we noted that the percentage of patients receiving TKI might affect the relationship between EGFR status and OS in NSCLC patients with brain metastases (P = 0.015), while percentage of adenocarcinoma (P = 0.279), sample size (P = 0.671), mean age (P = 0.112), percentage male (P = 0.275), and percentage smokers (P = 0.196) were all not significant factors contributing to this relationship.