The effect of radiotherapy on patients with EGFR-driven lung cancer brain metastasis: a systematic review and meta-analysis

BACKGROUND: Brain metastases (BMs) are a common and fatal consequence in patients with advanced malignancies. Mutations happening in the epidermal growth factor receptor (EGFR) are associated with an elevated risk BMs, occurring in approximately 20-40% of patients. This study evaluates the safety and efficacy of different radiotherapy (RT) modalities in patients with EGFR-mutant lung cancer brain metastases. METHOD: This study was conducted according to the PRISMA guideline. A comprehensive search was conducted on PubMed, Embase, Web of Science, and Scopus, until 13 March 2024. Stata v.17 was used for statistical analysis. RESULT: A total of 57 studies involving 4614 patients were analyzed, with a female predominance of 59.55% and a mean age of 50-70 years. The 6-month overall survival (OS) rate was 94% [95% CI 91-96%], 81% [95% CI 78- 84%] at 1-year, 55% [95% CI 50-60%] at 2-year, 37% [95% CI 32-42%] at 3-year, decreasing to 21% [95% CI 16-26%] at 5 years. Progression-free survival (PFS) rates were 84% [95% CI 79-89%] at 6 months and 20% [95% CI 14-26%] at 3 years. Meta-regression analysis indicated that a higher number of metastases, Karnofsky performance status below 80, and an ECOG score over one were significantly linked to OS outcomes. CONCLUSION: RT significantly improves survival outcomes in patients with EGFR-mutant brain metastases. However, the combination of RT with targeted therapies, such as tyrosine kinase inhibitors (TKIs), appears to offer more favorable outcomes.