The role of oestrogen receptor beta in invasive breast cancer

Background The presence of estrogen receptor (ER) in breast cancer cell is a good prognostic factor. It is also a predictive factor used in hormonal therapy. Aim To evaluate the expression of oestrogen receptors alpha and (ER alpha and ER beta) in the neoplastic tissues of patients with invasive breast cancer and to determine whether ERP expression may be correlated with some clinical parameters and biological markers. Materials/Methods Paraffin embedded tissues from 67 patients with breast cancer were used in this study. Monoclonal antibodies against a oestrogen receptors, progesterone receptors (DakoCytomation) and polyclonal antibodies against beta oestrogen receptors (CHEMICON) were used. The EnVision detection system was applied. Results Expression of ER alpha was demonstrated in 57% of all patients, while in patients over 50 years it was higher - 71%. Expression of ER beta was demonstrated in 48% of patients and this percentage was not dependent on the age of the patients. In tumours expressing ER beta, expression of p53 and Ki-67 was less common. In addition, these tumours were of a lower grade of malignancy. Conclusions Our results demonstrate a negative correlation between the expression of ER beta and the expression of p53 and Ki-67. The expression of ER beta may be a good prognostic indicator.