National Cancer Database analysis of radiation treatment patterns for breast cancer brain metastases

Treatment of breast cancer brain metastases (BCBMs) involves radiotherapy (RT), surgery, and CNS-penetrating systemic therapies. A study using the National Cancer Database (NCDB) evaluated treatment patterns in brain RT and corresponding survival outcomes among patients with BCBMs diagnosed between 2010 and 2021. OF 8909 patients with BCBMs, 43.4% received brain RT (74.1% WBRT, 25.9% SRT). Patients who were African American, lower income, urban, triple-negative, or at community facilities were more likely to receive WBRT of SRT (p<0.05). Median overall survival for the entire cohort was 10.9 months (95% CI 10.4-11.5). Systemic therapy alone (HR 0.40; 95% CI 0.36-0.43) or combined with RT (0.38; 0.35-0.42) improved OS, however RT alone did not improve survival on multivariable analysis (0.96; 0.91-1.02). Among RT recipiemts, SRT was associated with improved OS versus WBRT (HR 0.76; 95% CI 0.69-0.83). Older age, comorbidities, lack of insurance, community facilities, and aggressive subtypes were associated with worse OS. The authors conclude that treatment patterns, particularly access to SRT, differ among BCBM patients, highlighting the need for strategies to promote equitable implementation of evidence-based guidelines.