Treatment outcomes of EGFR-TKI with or without locoregional brain therapy in advanced EGFR-mutant non-small cell lung cancer patients with brain metastases

Introduction:
This study aimed to evaluate the treatment outcomes of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy alone or in combination with locoregional brain therapy for advanced EGFR-mutant non-small cell lung cancer (NSCLC) patients with brain metastases.

Material and methods:
A retrospective study involving 72 advanced EGFR-mutant NSCLC patients with brain metastases at the Vietnam National Cancer Hospital were conducted. Patients were divided into 2 groups: EGFR-TKI (erlotinib) monotherapy and EGFR-TKI combined with locoregional therapy (γ knife surgery – GKS or whole-brain radiation therapy). Evaluation criteria included clinical and laboratory characteristics, central nervous system (CNS) progression time, progression-free survival (PFS), overall survival (OS), T790M mutation rate, and adverse events.

Results:
Epidermal growth factor receptor tyrosine kinase inhibitor monotherapy patients had better performance status (PS), fewer CNS symptoms, and significantly fewer brain metastases (p < 0.05). Median PFS and OS were 11 and 25 months, respectively, in both groups. Patients with PS 0–1 had longer median PFS (15 months) than those with PS 2 (7 months) (p = 0.039). Exon 19 deletion patients in both groups had longer median OS (26 months) than those with L858R exon 21 (15 months) (p = 0.023). Patients with T790M mutation who received osimertinib after progression had longer median OS (41 months vs. 23 months, p = 0.0001). Median time to CNS progression was 13.9 months (48 patients). Longer time to CNS progression correlated with longer OS (R² = 0.89).

Conclusions:
Epidermal growth factor receptor tyrosine kinase inhibitor therapy, with or without locoregional therapy, is effective for advanced EGFR-mutant NSCLC patients with brain metastases. Exon 19 deletion patients had better prognosis.