Stereotactic radiosurgical treatment of cerebral metastases arising from breast cancer.

OBJECTIVE

This study was undertaken to evaluate the outcome of patients undergoing stereotactic radiosurgery (SRS) as primary or salvage treatment of brain metastases arising from breast cancer.

MATERIALS AND METHODS

Between July 2000 and September 2005, the medical records of 49 breast cancer patients who underwent SRS for 84 brain metastases were reviewed retrospectively. Thirty-four patients received SRS as primary brain metastasis treatment and 15 patients received SRS as salvage treatment of brain metastasis recurrence following prior whole-brain radiation therapy. The Kaplan-Meier method, univariate comparisons with log-rank test, and multivariate analysis were performed.

RESULTS

Median follow-up was 12 months (range, 5-50 months) and median survival was 19 months for all patients. The 1- and 2-year overall survival (OS) rates were 60%, 56%, and 55%, 23% for initial SRS alone and SRS salvage groups, respectively (P = 0.99). A multivariate analysis showed that a high KPS score (KPS > or =90 vs. <90; P = 0.02), a higher SIR value (SIR > or =6 vs. <6; P = 0.001), postmenopausal status (P = 0.003), and positive estrogen receptor status (P = 0.04) were predictive of better survival. The 1- and 2-year local control rates were 79%, 49%, and 77%, 46% for SRS alone and SRS salvage group, respectively.

CONCLUSION

SRS can be used as primary treatment of brain metastases or salvage of recurrences after whole-brain radiation therapy to achieve good local control on the order of close to 80% at 1 year. The median survival of brain metastasis patients with breast cancer of 19 months appears favorable compared with the general brain metastasis population.