Clinical outcome of tyrosine kinase inhibitors alone or combined with radiotherapy for brain metastases from epidermal growth factor receptor (EGFR) mutant non small cell lung cancer (NSCLC)

Abstract

This study compared treatment outcomes between TKI monotherapy and TKI administration combined with brain radiotherapy (TKI + RT) in 133 non-small cell lung cancer (NSCLC) patients with brain metastasis (BM). We also evaluated the association of different epidermal growth factor receptor (EGFR) mutation subtypes with treatment outcome. To screen for potential variables affecting cranial progression free survival (PFS) and overall survival (OS), we performed univariate and multivariate analysis based on Cox proportional-hazards models. Median cranial PFS and OS were longer for the TKI + RT group (n = 67) than TKI alone group (n = 66). Intracranial metastasis correlated with a better median OS than extracranial metastasis. For patients with exon 21 mutations, TKI + RT yielded a better median OS and cranial PFS than TKI alone. However, there were no significant differences in median OS and cranial PFS between the two treatment groups for patients with exon 19 deletions. Thus EGFR-mutant NSCLC patients with BM could benefit more from TKI + RT than from TKI monotherapy, especially when they suffer from exon 21 mutations. However, TKI + RT confers no advantage over TKI treatment alone for patients with exon 19 deletions. These results underscore the urgent need to develop individualized disease management strategies in clinical practice.