Beyond raloxifene for the prevention of osteoporosis and breast cancer.

Selective oestrogen receptor modulators (SERMs) can build bone in the postmenopausal woman and lower circulating cholesterol. These oestrogen-like properties contrast with the anti-oestrogenic properties observed in the breast where SERMs inhibit the oestrogen-mediated development and growth of ER positive breast cancers. The two clinically useful SERMs, tamoxifen and its chemical cousin raloxifene, are currently used successfully either for the treatment and prevention of breast cancer (tamoxifen) or the treatment and prevention of osteoporosis (raloxifene). However, raloxifene has the beneficial side-effect of breast cancer prevention. These multifunction medicines provide proof of concept that novel molecules can be selectively targeted to diseases mediated by the endocrine system.