Intracranial control and survival outcome of tyrosine kinase inhibitor (TKI) alone versus TKI plus radiotherapy for brain metastasis of epidermal growth factor receptor-mutant non-small cell lung cancer.

INTRODUCTION

The efficacy of tyrosine kinase inhibitors (TKIs) with and without radiotherapy (RT) has not been determined in patients with brain metastases from epidermal growth factor receptor-mutant TKI naïve non-small cell lung cancer (NSCLC).

METHODS

Between 2008 and 2016, 586 patients were diagnosed with NSCLC and treated with TKIs at a hospital in Seoul, South Korea; 81 of these patients met the eligibility criteria for our study. Outcomes analyzed included intracranial progression (ICP), neurological death, and overall survival (OS).

RESULTS

The 2-year cumulative incidence of ICP was 36.5% in the TKI plus RT group and 62.2% in the TKI alone group (P = 0.006). The chronological pattern analysis indicated that 64.3% of ICP developed within 12 months of the start of TKI treatment in the TKI alone group. The multivariate analysis revealed that treatment group (P = 0.003) and duration of TKI treatment ≤ 12 months (P < 0.001) were significantly associated with ICP. However, no significant differences were observed in the 2-year OS rate (P = 0.267) or the 2-year cumulative incidence of neurological death (P = 0.740).

CONCLUSIONS

Cumulative incidence of ICP was significantly lower with TKI plus RT than with TKI alone; however, there was no significant difference in OS or neurological death. Deferring brain RT may not compromise neurologic and survival outcome in selected patients, but close magnetic resonance imaging follow-up is recommended for patients who defer brain RT.