Co-expression of ER-beta and HER2 associated with poorer prognosis in primary breast cancer.

Purpose: To assess the prognostic value of co-expression of estrogen receptor (ER)-beta and human epidermal growth factor receptor 2 (HER2) in primary breast cancer patients in China.

Methods: Tumour specimens from 308 patients undergoing surgery for primary breast cancer were evaluated. Expression of ER-beta and HER-2 was investigated by the immunohistochemistry.