Individual Approach to Hormone Replacement Therapy – A Computer Assisted Method of Assessment of the Minimal Useful Dose

Estrogen replacement therapy (ERT) was primarily used to treat vasomotor symptoms, it had been increasingly viewed as a way to prevent chronic diseases of aging, including coronary heart disease (CHD), cognitive impairment and osteoporosis [1-3]. Osteoporosis leads to bone fractures. Death rate due to osteoporosis is higher than the mortality rate attributed to breast and endometrial cancer combined. Estrogens are considered the gold standard in assessing the efficacy of various medications in osteoporosis treatment [1,2]. At least 40% of postmenopausal women in the United States were using ERT before the publication of the Women's Health Initiative (WHI) report, which addressed the risks and benefits of ERT [1,4]. WHI trials addressed the most commonly used hormone formulations at the time in the United States -- conjugated equine estrogen (CEE) plus medroxyprogesterone acetate (MPA). Findings from these trials have been extensively published during the past decades [5-7]. Manson et al. [1] conducted an extensive study involving 27,347 postmenopausal women aged 50 to 79 years from 1993 to 1998 at 40 US medical centers; 16,608 women with uterus present were randomized to oral CEE (0.625 mg/d) plus MPA (2.5 mg/d) (Prempro) or placebo, and 10,739 women with prior hysterectomy were randomized to oral CEE (0.625 mg/d) alone (Premarin) or placebo. CHD and invasive breast cancer served as primary outcomes. The study results were summarized as follows: For every 10,000 women taking CEE plus MPA per year, there were 6 more coronary events, 9 more strokes, 9 more pulmonary emboli, 9 more cases of breast cancer compared to the placebo group, and 6 fewer cases of colorectal cancer, 1 fewer case of endometrial cancer, 6 fewer hip fractures, and 1 fewer death compared to the placebo group [1].