Treatment Patterns and Survival of Elderly Patients With Breast Cancer Brain Metastases

The main objective of this study was to analyze treatment patterns of elderly patients with breast cancer brain metastases (BCBM), evaluate characteristics associated with treatment selection, and to analyze trends in overall survival (OS) over time.

We included women with BCBM reported to the Surveillance, Epidemiology, and End Results Medicare Program from 1992 to 2012. Treatments were recorded from Medicare claims from the date of brain metastases diagnosis until 60 days after. Treatments included resection, radiation, and chemotherapy. Cochran-Armitage tests were used for analysis of treatment patterns. Multinomial logistic regression was applied to determine factors associated with treatment selection. Cox regression modelled OS trends within each treatment modality across time.

Among 5969 patients included, treatment rates increased from 50% in 1992 to 64.1% in 2012 (P<0.01). Therapy combining radiation, resection, and/or chemotherapy also increased from 8.8% to 18% over the same period (P<0.01). Combined therapy was significantly more likely among patients with extracranial metastases, those with estrogen-negative tumors, younger age at diagnosis, no comorbidities and more recently diagnosed brain metastases. OS improved over time for patients who received a combination of ≥2 treatments (hazard ratio, 0.89 per every 5 more recent diagnosis years; P<0.05). Older patients, those with extracranial metastases, or estrogen/progesterone-negative tumors showed significantly shorter OS.

We observed substantial changes in treatment patterns and OS over time in patients with BCBM. We identified several factors associated with specific treatment use. Patients who underwent a combination of ≥2 treatments experienced a significant improvement in OS over time.