Estrogens between hormone replacement

The associations between hormone replacement therapy and breast, endometrial, and ovarian cancers are discussed in the monograph on estrogens. 

Cardiovascular disease (CVD) is one of the leading causes of death worldwide. There are a number of established risk factors including serum cholesterol levels, smoking and family history, which are responsible for between 50 and 75% of the CVD cases, with the remainder due to factors that cause atherosclerosis. Estrogen treatment such as hormone replacement therapy is known to protect against CVD by decreasing the levels of low-density... 

Hormone replacement therapy should be distinguished from the short-term therapeutic use of estrogen (or hormonal combinations) around the time of the climacteric for the relief of acute (primarily vasomotor) symptoms such treatment can generally be limited to some 6-12 months although if it is then withdrawn the symptoms may recur (4). Confusion between these two forms of treatment has led to a series of misunderstandings regarding the adverse effects of true hormone replacement therapy. 

Some of the other possible disease conditions or risks are being studied in relationship to less serious polymorphisms. In most of these cases, the relationships are more difficult to establish in the serious diseases. A possible link of CYPl 7A1 polymorphism has been made with rheumatoid arthritis . Little influence of polymorphism was seen on age of menarche. However, a link was made between a particular polymorphism and the prediction to use hormone replacement therapy (i.e., postmenopausal estrogen therapy) . No association was found with polycistronic ovarian syndrome in a study with an SNP at the regulatory Spl site . 

Figure 26.2 Effects of castration and hormone replacement or hyperprolactinemia on prostate D1 activity. For sex hormone replacement, rats were bilaterally castrated via the scrotal route and treated with supraphysiological doses of testosterone (1.0 mg) and/or estrogen (20 rg). Hormones were administered by slow delivery in oil via s.c. Hyperprolactinemia was induced by implanting one pituitary under the kidney capsule of animals whose pituitary remained intact. D1 activity was measured by the radiolabeled iodide release method (n = 5 rats/group). Data were analyzed with one-way ANOVA, and differences between means were evaluated by the Tuckey test. Different letters indicate significant differences between groups, p < 0.05. D1, type 1 deiodinase T, testosterone E2, 17p-estradiol. Data adapted from Anguiano et al., (2006).

Colditz GA. Relationship between estrogen levels, use of hormone replacement therapy, and breast cancer. J Nat Cancer Inst 1998 390 814-823. 

Many studies have evaluated the relationship between exogenous hormones and development of breast cancer. Postmenopausal estrogen replacement therapy has been the subject of several recent meta-analyses, with conflicting results. The recently reported NCI-sponsored Women s Health Initiative study randomized 80,000 women to take postmenopausal estrogen replacement therapy combined with progesterone or a placebo. This study reported an... 

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