Therapeutic effect of whole brain radiotherapy on advanced NSCLC between EGFR TKI-naïve and TKI-resistant.

Background: The development of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) has dramatically improved the prognosis of patients with EGFR-mutant non-small-cell lung cancer (NSCLC). The purpose of this study is to investigate the clinical outcome with or without EGFR-TKI resistance before WBRT and the sequence between EGFT-TKIs and whole brain radiotherapy (WBRT) of EGFR-mutant NSCLC patients who developed multiple brain metastases (BMs).

Patients And Methods: Three hundred forty-four EGFR-mutant NSCLC patients with multiple BMs were reviewed. Enrolled patients were divided into TKI-naïve group and TKI-resistant group. The intracranial progression-free survival (PFS) and overall survival (OS) were analyzed via the Kaplan-Meier method.

Results: For patients with multiple BMs treated by WBRT, the median intracranial PFS and OS were longer in the TKI-naïve group than those in the TKI-resistant group, but there were no statistically significant between two groups (Intracranial PFS: 7.7 vs. 5.4 months, p = 0.052; OS: 11.2 vs. 9.2 months, p = 0.106). For patients with Lung-molGPA 0-2, no significant differences in median intracranial PFS (6.2 vs. 5.2 months, p = 0.123) and OS (7.8 vs. 6.7 months, p = 0.514) between TKI-naïve and TKI-resistant groups. For patients with Lung-molGPA 2.5-4, intracranial PFS: 12.8 vs. 10.1 months; OS: 23.3 vs. 15.3 months.

Conclusions: Our study found that there were no difference in intracranial PFS and OS in all patients between the two groups of TKI-naïve and TKI-resistant. But for patients in subgroup of Lung-molGPA 2.5-4, there were a better intracranial PFS and OS in TKI-naïve group.