Identifying risk factors for brain metastasis in breast cancer patients: Implication for a vigorous surveillance program

Abstract

Brain metastasis occurs in 10-15% of metastatic breast cancer patients and is associated with poor prognosis. This study aims to identify tumor characteristics of primary breast cancer, which are related to brain metastases in Hong Kong Chinese patients. A retrospective study of patients with invasive breast cancer receiving treatment in a university hospital from January 2001 to December 2008 was performed. The clinicopathological factors of patients with brain metastases were analyzed and compared with those who had no brain metastasis. Risk factors for brain metastasis were identified by univariate analysis first and then by multivariate analysis. A total of 912 patients with invasive breast cancer were treated during the study period. Of these, 30 patients were found to have distant metastases to brain. Patients with brain metastases had more breast tumors of higher histological grade (Grade III, 78.9% vs. 30.2%; p=0.001). Their tumors also had a significantly higher rate of negative estrogen receptors (78.9% vs. 30.2%, p=0.001). On multivariate analysis, only high tumor grading was found to be predictive of developing brain metastasis. Chinese breast cancer patients with brain metastasis were more likely to have high-grade tumors and negative estrogen receptor status. A more vigorous surveillance program for the central nervous system should be considered for this group of patients.