The Efficacy of First-Generation EGFR-TKI Combined With Brain Radiotherapy as the First-Line Treatment for Lung Adenocarcinoma Patients With Brain Metastases and EGFR Sensitive Mutations: A Retrospective study

Background: It was controversial that whether LUAD patients with brain metastases (BMs) and EGFR sensitive mutations should be conducted using brain radiotherapy when treated with first-generation EGFR-TKI. Herein, a retrospective study was designed to compare the efficacy of first-generation EGFR-TKI combined with brain radiotherapy and EGFR-TKI alone as first-line treatment for these LUAD patients. Patients and Methods: We retrospectively analyzed the status of patients with advanced LUAD carrying EGFR sensitive mutations who received first-generation EGFR-TKI treatment in our center. iPFS was the first time of intracranial progression or death from the diagnosis of BMs, PFS was the time of progression of any site or death from the diagnosis of BMs, and OS was the time of confirmed BMs to death or the last follow-up time. Differences in characteristics between groups were compared using the Chi-square test. The Kaplan-Meier method was used to calculate the iPFS, PFS, and OS. Univariate analysis, multivariate analysis, and subgroup analysis were conducted by Cox regression model. Results: There were 77 patients (77/134, 57.5%) in the TKI + RT group and 57 patients (57/134, 42.5%) in the TKI group. TKI + RT group had a significant higher intracranial ORR and DCR, and the combination therapy was independently significantly associated with a longer iPFS (18.9 vs. 10.5 months, P = 0.0009), systematic PFS (12.5 vs. 8.4 months, P = 0.0071) and OS (30.8 vs. 22.7 months, P = 0.0183). Females, non-smokers, and younger patients benefited more from the combination therapy. Subgroup analysis demonstrated that the combination therapy could improve the iPFS in patients with more than 3 BMs (P = 0.005); however, it couldn't improve the OS for these patients. Conclusion: Our study confirmed the effect of the combination of EGFR-TKI and brain radiotherapy as first-line treatment for LUAD patients with BMs and EGFR sensitive mutations.