The evolving role of oestrogen receptor beta in clinical breast cancer

Controversy surrounds the potential clinical importance of oestrogen receptor (ER)β in breast cancer, and three recent papers have sought to resolve this. In the present issue of Breast Cancer Research Novelli and colleagues explored the significance of ERβ1 expression in 936 breast cancer patients, and they showed diverse relationships according to lymph node status. A second paper examined 442 breast cancers in which ERβ1 was an independent predictor of recurrence, disease-free survival and overall survival. Finally a third paper showed that ERβ2 was a powerful prognostic indicator in 757 breast cancers but this was dependent on cellular location, with nuclear ERβ2 expression predicting good survival whilst cytoplasmic expression predicted worse outcome. These papers point to a clinical role for ERβ in breast cancer and shall be discussed.