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