Biologically important natural estrogens and progestins include estradiol, estrone, estriol, and progesterone. Estradiol-17 is the most potent estrogen that is found naturally in women. Estrone is one-tenth as biologically active as estradiol, and estriol is the weakest of the three. Estriol is synthesized by the placenta and is excreted at high levels in the urine of pregnant women. Progestero...

Premenopausal women are at highest risk for papillary and follicular thyroid carcinoma, implicating a role for estrogens in thyroid cancer. The expression of estrogen receptors · and ß (ER), the effects of estradiol (E2), selective estrogen receptor modulators (SERMs) 4-hydroxytamoxifen and raloxifene, and ER subtype selective agonists were examined in NPA87 and KAT5 papillary and WRO follicula...

We have compared the antitumor activities of SP500263, a novel next-generation selective estrogen receptor modulator (SERM), tamoxifen, and raloxifene side-by-side in in vitro and in vivo MCF-7 breast cancer models. In vitro, SP500263 acted as an antiestrogen and potently inhibited estrogen-dependent MCF-7 proliferation with IC(50) values in the nanomolar range. SP500263 also strongly inhibited...

MAIN PROBLEM Testosterone replacement therapy inhibits spermatogenesis, representing a problem for hypogonadal men of reproductive age. METHODS A literature review of PubMed from 1990-2013. Semen analysis and pregnancy outcomes, time to recovery of spermatogenesis, serum and intratesticular testosterone levels were examined. RESULTS Exogenous testosterone suppresses intratesticular testoste...

The use of estrogens and androgens to prevent bone loss is limited by their unwanted side effects, especially in reproductive organs and breast. Selective estrogen receptor modulators (SERMs) partially avoid such unwanted effects, but their efficacy on bone is only moderate compared with that of estradiol or androgens. Estrens have been suggested to not only prevent bone loss but also exert ana...

Since its introduction more than 30 years ago, tamoxifen has been the most widely used endocrine therapy for the treatment of women with advanced breast cancer. More recently, a number of alternative endocrine treatments have been developed, including several selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs) and, most recently, fulvestrant ('Faslodex'). Fulvestrant is a...

Risk for breast cancer can be easily and rapidly assessed using validated, quantitative models. Multiple randomized studies show that the selective estrogen response modifiers (SERMs) tamoxifen and raloxifene can safely reduce the risk of invasive breast cancer in both pre- and postmenopausal women. Treatment resulted in a 38% reduction in breast cancer incidence, and 42 women would need to be ...

BACKGROUND Estrogen receptors (ER) alpha and beta play an important role in breast cancer. Recently, systemic adjuvant endocrine therapy with selective estrogen receptor modulator (SERM) tamoxifen has been challenged by aromatase inhibitors. Compared to antiestrogens, third-generation aromatase inhibitors (anastrozole and letrozole) exhibit an improved efficacy and tolerability. MATERIALS AND...

Selective estrogen-receptor (ER) modulators (SERMs) are synthetic nonsteroidal compounds that switch on and switch off target sites throughout the body. Tamoxifen, the pioneering SERM, blocks estrogen action by binding to the ER in breast cancers. Tamoxifen has been used ubiquitously in clinical practice during the last 30 years for the treatment of breast cancer and is currently available to r...

Although SERMs are currently being evaluated and are approved for breast cancer prevention in several countries, aromatase inhibitors and inactivators may represent interesting options in this setting. The encouraging results revealing these drugs to be superior to conventional therapy in metastatic breast cancer confirm their therapy efficacy and suggest that they may also have a role in adjuv...