Efficacy of EGFR-TKIs with or without upfront brain radiotherapy for EGFR-mutant NSCLC patients with central nervous system metastases

Abstract

Background: Although the clinical efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC) patients has been demonstrated, their efficacy in EGFR-mutant NSCLCs with central nervous system (CNS) metastases and the role of radiotherapy remain unclear. This study aimed to determine if it is preferable to add upfront cranial radiotherapy to EGFR-TKIs in patients with EGFR-mutant NSCLC with newly diagnosed brain metastases.

Methods: We retrospectively analyzed the data of EGFR-mutant NSCLC patients with CNS metastases who received EGFR-TKIs as a first-line therapy.

Results: A total of 104 patients were enrolled and 39 patients received upfront brain radiotherapy, while 65 patients received first and second generation EGFR-TKIs first. The median time to treatment failure (TTF) was 7.8 months (95% confidence interval [CI]: 6.3-9.4). The median survival time (MST) was 24.0 months (95% CI: 20.1-30.1). The overall response rate of the CNS was 37%. The median CNS progression-free survival (PFS) was 13.2 months (95% CI: 10.0-16.2). Brain radiotherapy prior to EGFR-TKI prolonged TTF (11.2 vs. 6.8 months, P = 0.038) and tended to prolong CNS-PFS (15.6 vs. 11.1 months, P = 0.096) but was not significantly associated with overall survival (MST 26.1 vs. 24.0 months, P = 0.525). Univariate and multivariate analyses indicated that poor performance status and the presence of extracranial metastases were poor prognostic factors related to overall survival.

Conclusion: EGFR-TKI showed a favorable effect for EGFR-mutant NSCLC patients with CNS metastases. Prolonged TTF and CNS-PFS were observed with upfront brain radiotherapy.

Keywords: EGFR mutation; Brain metastases; EGFR tyrosine kinase inhibitor; non-small cell lung cancer; radiotherapy.

Figure 1

Kaplan‐Meier analysis of time to treatment failure, CNS‐PFS, and overall survival in the entire population (a, b, and c). Kaplan‐Meier analysis of time to treatment failure, CNS‐PFS, and overall survival compared between patients treated with upfront brain radiotherapy (RT) and those treated without upfront RT (d, e, and f). CI, confidence interval; CNS, central nervous system; PFS, progression‐free survival. 1st RT and 1st TKI.