New approaches to the endocrine prevention and treatment of breast cancer

All major endocrine prevention approaches act via the estrogen receptor (ER). A simple hypothesis concerning ER expression and breast cancer risk is outlined. We review breast cancer prevention trials with tamoxifen, raloxifene, aromatase inhibitors, and ovarian suppression. Current and planned endocrine prevention trials in populations of pre- and postmenopausal women at risk of breast cancer are summarized and endocrine therapy after primary surgery and for advanced disease discussed.