Oestrogen receptor β:: what it means for patients with breast cancer

Oestrogen receptor (ER) a is a well established prognostic marker in breast cancer, and all patients who are ERalpha positive receive tamoxifen as adjuvant endocrine therapy. Although ERalpha predicts a favourable disease outcome, the usefulness of ERbeta as a clinical prognostic marker remains to be defined. Here, we outline the history of both ERs and discuss the implications ERbeta has to patients with breast cancer.