Chemoprevention of breast cancer with selective oestrogen-receptor modulators.

Twenty years ago, a new therapeutic dimension was conceived that not only had the potential to treat and prevent osteoporosis, but to prevent breast and endometrial cancer at the same time. As osteoporosis was known to be caused by oestrogen withdrawal after menopause, whereas breast and endometrial cancer are caused by unopposed oestrogen action, the new tissue-selective oestrogens and anti-oestrogens, or selective oestrogen-receptor modulators (SERMs), had to recruit new networks to activate or suppress target tissues selectively. New medicines now promise to provide chemoprevention strategies for women at risk for the development of many diseases.