The expression of ERβ protein correlates with vascular endothelial growth factor and its prognostic significance in human breast cancer

Abstract

Although cloning of ER beta has prompted a reevaluation of the role of ERs in human breast cancer and there have been many studies focusing on the clinical value of ER beta detection, however, few reports evaluated the prognostic significance of ER beta based on follow-up data. The VEGF gene transcription may be mediated by different ER subtypes directly. The aim of this study was to evaluate the relationship of angiogenesis factor VEGF with different ER subtypes and the prognostic value of ER beta and VEGF in 116 human breast cancer patients. Of these patients, 40 (34.5%) were ER beta protein high expressed and 76 (65.5%) were ER beta protein low expressed. When correlated the ER beta protein levels with other clinical characteristics, statistical significance (p<0.05) was found between ER beta protein expression and menopausal status, and tumor grade. No significance was found between ER beta protein level and node status, stage, or tumor size. Inverse relationship was found between ER beta protein expression and PR status (p<0.05). When comparing the VEGF levels with different ER subtypes a significant difference between ERs and VEGF was found. In ER beta protein high expression group, the VEGF protein was highly expressed (p<0.01), inverse relationship was also found between ER alpha and VEGF. In univariate analysis ER alpha, ER beta and VEGF levels had prognostic value for both relapse-free survival and overall survival (p<0.05). However, in a multivariate study, ER beta and ER alpha protein levels lost the prognostic value either to relapse-free survival or to overall survival. Only VEGF levels acted as an independent prognostic factor to disease-free survival. The result suggested that ER beta protein may have important prognostic value in human breast cancer patients. VEGF expression may be mediated through different ER subtypes.