Prognostic significance of oestrogen receptor beta in breast cancer

Background: Endocrine therapy for breast cancer is now well established and with the identification of a second oestrogen receptor, ER beta, 3 years a go it is timely to review the possible significance of this receptor in bre ast cancer management. Methods: An up-to-date review of the current literature concerning the role and possible implications of ER beta in human breast cancer was undertaken . Results: Wild-type and variant ER beta are expressed in human breast tumour s. Expression of ER beta correlates with accepted prognostic indicators inc luding lymph node status and tumour grade. Furthermore, levels of ER beta m essenger RNA alter during carcinogenesis and are upregulated in breast tumo urs that develop antioestrogen resistance. Conclusion: ER beta has potential as a novel clinical prognostic marker in breast cancer, particularly in determining tumours that are resistant to ta moxifen.