Effects of epidermal growth factor receptor‐tyrosine kinase inhibitors alone on EGFR ‐mutant non‐small cell lung cancer with brain metastasis

Background Epidermal growth factor receptor‐tyrosine kinase inhibitors ( EGFR ‐ TKI s) are remarkably effective for treating EGFR ‐mutant non‐small cell lung cancer ( NSCLC ). However, the individual role of EGFR ‐ TKI s in patients with brain metastasis ( BM ) arising from EGFR ‐mutant NSCLC remains unclear. Methods Patients with BM secondary to NSCLC and harboring EGFR ‐activating mutations were retrospectively screened. Patients who received gefitinib or erlotinib to control both extracranial lesions ( ECL s) and intracranial lesions ( ICL s) were eligible. If ECL s remained stable or remissive while ICL s progressed; asymptomatic BM progressed to symptomatic BM ; BM symptoms were not alleviated within two weeks; or BM symptoms deteriorated after initial release, patients received brain radiotherapy or other local treatments and continued taking TKI s until ECLs progression occurred. Results In 43 eligible patients, the objective response and disease control rates for ICL s were 57% and 91%, respectively. Median progression‐free survival ( PFS ) was 9.3 months. The median PFS for ICL s and ECL s was 9.7 and 13.7 months, respectively. Non‐smokers and second‐line TKI s were found to be independent positive prognostic factors for PFS and overall survival ( OS) respectively, with a hazard ratio of 0.29 (95% confidence interval [ CI] 0.14–0.61; P  = 0.001) and 0.34 (95% CI 0.16–0.70; P  = 0.003). No significant difference in median OS was observed between patients who did or did not receive brain radiotherapy (23.6 vs. 18.7 months; P  = 0.317). Conclusion EGFR‐TKI s alone are effective for treating BM arising from EGFR ‐mutant NSCLC . The efficacy of TKI s in ICL s and ECL s should be evaluated separately.