Abstract:

Objective To assess the role of systemic treatment after whole-brain radiotherapy（WBRT） in immunohistochemically defined biological subsets of breast cancer patients with brain metastases. MethodsThe clinical data of 101 consecutive breast cancer patients with brain metastases treated in our hospital from Jan. 2002 to Dec. 2010 was analyzed retrospectively. Forty-eight patients were received systemic treatment after WBRT. Patients were divided into 4 immunohistochemically biological subsets based on the levels of estrogen， progesterone， human epidermal growth factor receptor 2 （HER-2） and Ki-67 index， and labeled as luminal A，luminal B，HER-2 positive and triple-negative. Survival was calculated from brain metastases diagnosed. Patients from 4 subtypes were divided into 2 subgroups according to receiving systemic treatment after WBRT or not. Survival analysis was used by Kaplan-Meier method. ResultsThe median survival time of patients received systemic treatment or not after WBRT were 5.1 and 8.5 months， respectively （P＜0.0001）. In the triplenegative subset， median survival of patients received systemic treatment or not were 4.8 and 6.1 months （P=0.051）， in the luminal A subset were 5.3 and 11.0 months （P＜0.0001），in the luminal B subset were 4.8 months and 8.6 months， respectively （P＜0.0001）， in the HER-2 positive subset were 4.8 months and 8.2 months （P＜0.0001）. Conclusion Systemic therapy after WBRT appears to improve survival in patients with the luminal A， luminal B and HER-2 positive breast cancer subtypes.