Although estrogen has been clinically available for more than six decades, women have been confused by different opinions regarding the risks and benefits of menopausal hormone therapy (HT), estrogen therapy (ET), and estrogen-progestin therapy (EPT). The publication of randomized controlled trials (RCTs), notably, the Heart and Estrogen/progestin Replacement Study (HERS) and Women’s Health Initiative (WHI), has intensified the risk vs. benefit controversy. Millions of women are treated with HT for relief of menopausal symptoms, including vasomotor flushes and sweats, for which estrogen is uniquely and highly effective. Others may continue longer-term treatment in the hope that HT will help to prevent chronic disease. The preservation of bone mass with continuing estrogen therapy and reduction of subsequent risk of fracture is well established. Observational studies of the metabolic and vascular effects of estrogens have suggested a potential benefit in reducing the risk of vascular disease, but recently published randomized controlled trials demonstrated no evidence of benefit in women with established vascular disease or in apparently healthy women. The increased risks of breast cancer and thromboembolic disease have been confirmed in these trials, with evidence of increased risk of stroke. The absolute incidence of an adverse event is low, and the risk of stroke in an individual woman in a single year is very small, but with long-term use, the risks are cumulative over time. The risk-benefit balance needs to be individualized for each woman.
Menopause; replacement therapy; estrogen; side effects; windows safe