Association of early brain radiotherapy with survival outcomes in patients with asymptomatic brain metastases from non-small cell lung cancer treated with third-generation EGFR tyrosine kinase inhibitors: a retrospective single-center study

ObjectiveTo evaluate whether upfront brain radiotherapy confers a survival benefit in patients with asymptomatic brain metastases from non-small cell lung cancer (NSCLC) receiving first-line third-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs).MethodsWe retrospectively analyzed 163 pathologically confirmed NSCLC patients with asymptomatic brain metastases who received third-generation EGFR-TKIs as first-line therapy. Patients were stratified according to whether they received early brain radiotherapy in addition to EGFR-TKI treatment. Survival outcomes were compared between groups.ResultsAmong the 163 patients, 81 received combined EGFR-TKI therapy and brain radiotherapy, while 82 received EGFR-TKI monotherapy. The overall response rate (ORR) was significantly higher in the combination group than in the monotherapy group (95.1% vs. 80.1%, P = 0.001). Median iPFS, PFS, and OS were also significantly prolonged in the combination group compared with EGFR-TKI alone (18.4 vs. 12.8 months, P = 0.003; 17.6 vs. 12.8 months, P = 0.004; and 37.1 vs. 25.8 months, P = 0.010, respectively). Subgroup analyses demonstrated that in patients with oligometastatic brain disease, combined therapy significantly improved iPFS (26.4 vs. 16.5 months, P = 0.011), PFS (26.2 vs. 16.5 months, P = 0.010), and OS (42.4 vs. 29.7 months, P = 0.007) compared with EGFR-TKI monotherapy. In contrast, among patients with multiple brain metastases, no significant differences in iPFS, PFS, or OS were observed between treatment groups. Conclusion: Early brain radiotherapy is associated with improved survival outcomes in patients with asymptomatic brain metastases from NSCLC treated with third-generation EGFR-TKIs, particularly in those with oligometastatic disease.