Survival Outcomes in EGFR-Mutant Non-Small Cell Lung Cancer With Brain Metastases: Kaplan–Meier and Cox Regression Analyses Across Treatment Stages

Abstract

Background: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have shown significant efficacy in patients with brain metastases (BMs) from EGFR-mutated non-small cell lung cancer (NSCLC). However, acquired resistance is inevitable, and clinical data addressing key questions across treatment stages remain insufficient, limiting the formulation of precise treatment strategies. Methods: This retrospective study analyzed 302 EGFR-mutant NSCLC patients with BMs treated at Shandong Cancer Hospital (2014–2022). Patients were divided into three cohorts: cohort A (first-/second-generation EGFR-TKIs without third-generation use), cohort B (first-/second-generation followed by third-generation EGFR-TKIs), and cohort C (first-line third-generation EGFR-TKIs). Survival outcomes were evaluated using Kaplan–Meier and Cox regression analyses across three treatment stages. Propensity score matching (PSM) adjusted for baseline imbalances. Results: Third-generation EGFR-TKIs demonstrated superior progression-free survival (PFS) in first-line therapy compared to earlier-generation agents (median PFS1: 14.2 vs. 11.2 months; p = 0.0021), particularly for intracranial control (median iPFS1: 18.0 vs. 12.2 months; p = 0.0058). Patients with uncommon EGFR mutations had significantly shorter PFS on third-generation EGFR-TKIs than those with common mutations (4.4 vs. 12.9 months; p = 0.012). After resistance, combination therapy with immune checkpoint inhibitors (ICIs), antiangiogenics, and chemotherapy extended overall survival (OS) versus non-ICI regimens (median OS2: 17.3 vs. 10.4 months; p = 0.004). Conclusions: Third-generation EGFR-TKIs are effective first-line options for BMs but show limited efficacy against uncommon mutations. Post-resistance regimens integrating ICIs, antiangiogenics, and chemotherapy may improve survival. Reassessment of genetic and PD-L1 status is critical for guiding sequential therapy.