Author Affiliations: The Prudential Center for Health Care Research (Dr Franks) and Molecular Biology Branch, Centers for Disease Control and Prevention (Dr Steinberg), Atlanta, Ga.
The discovery that pharmacologic agents can be estrogenic in some tissues while
antiestrogenic in others has led to intense interest in better
understanding the mechanism by which molecular structure interacts with
cellular receptors to selectively affect DNA transcription in different
organs. Appreciation for these selective estrogen receptor modulators
(SERMs) has inevitably given way to the hope of developing one that
could confer all of the benefits of estrogen without any of its risks.
The first widely used SERM, tamoxifen citrate, has been found to have
the antiestrogenic effect of reducing risk for breast cancer as well as
beneficial estrogenic effects on serum lipids and bone density in
women.1 However, tamoxifen also has the undesirable
antiestrogenic effect of causing hot flashes and the undesirable
estrogenic effects of increasing risk for endometrial cancer and
venous thromboembolism in women.1 Because raloxifene
hydrochloride, a second-generation SERM, has been shown to increase
women's bone density without increasing risk for endometrial
cancer,2,3 results of clinical trials designed to study its
protective effects against breast cancer have been eagerly awaited.
Franks AL, Steinberg KK. Encouraging News From the SERM Frontier. JAMA. 1999;281(23):2243-2244. doi:10.1001/jama.281.23.2243