Salvage Stereotactic Radiosurgery in Breast Cancer Patients with Multiple Brain Metastases

BACKGROUND: The overall survival rates for breast cancer are increasing due to controlled brain disease and improved systemic treatments. This study examined neurologic outcomes, tumor control, and survival data in breast cancer patients with multiple brain metastases and who required salvage stereotactic radiosurgery (SRS) for recurrent breast cancer brain metastases. METHODS: The study included 231 patients with a primary diagnosis of breast cancer who underwent SRS for more than 1 brain metastases from May 1993 and July 2007. Survival analyses via univariate and multivariate Cox regression demonstrated interactions between survival and predictor values including Karnofsky Performance Scale, Recursive Partitioning Analysis Class, number of brain metastases, whole-brain radiotherapy (WBRT), immunotherapy, and chemotherapy. RESULTS: Of the 231 patients, the survival rate was 53% at 1 year and 26% at 5 years from initial SRS. Controlled systemic disease, adjuvant chemotherapy, and Recursive Partitioning Analysis class II were significant predictors of increased survival, while WBRT was a significant predictor of decreased survival. The median survival in patients who received WBRT after SRS was 11 months versus 23 months in those who did not. The local tumor control rate at initial follow-up was 95%. Of these, 40% of patients underwent additional brain SRS. Following salvage SRS, 8% of patients developed symptomatic adverse radiation events; however, the development of symptomatic adverse radiation events had no effect on patient survival. CONCLUSIONS: This report indicated that both initial and salvage SRS procedures in breast cancer patients with multiple brain metastases are effective for local control of intracranial disease while minimizing adverse radiation effects.