Until 1942, women simply endured the discomfort that accompanied menopause. That year, the first synthetic estrogen, Premarin, was patented and sold as a treatment for menopausal symptoms. A few years later, Dr. Robert A. Wilson's book, Feminine Forever, touted estrogen as the cure for the "tragedy of menopause." Premarin sales soared as women demanded it from their doctors. However, in 1975, the New England Journal of Medicine published two studies showing that women who took estrogen alone without progesterone had a higher risk of endometrial cancer, and the risk doubled for women who stayed on estrogen for seven years or more. Doctors responded by prescribing a synthetic progesterone, called progestin, along with estrogen.
Combination estrogen-progestin hormone replacement therapy (HRT) became the standard prescription for menopausal symptoms. A variety of synthetic estrogen/progestin products were available, all promising to relieve the hot flashes, vaginal dryness, mood swings, loss of libido and other symptoms that occurred with the change of life. It was even thought that HRT could help prevent other conditions, such as heart disease, osteoporosis and breast cancer, which accelerated in women after menopause.
Beginning in 1991, a major 15-year research program was undertaken to explore the most common causes of death, disability and diminished quality of life in postmenopausal women. The Women's Health Initiative (WHI) was a set of clinical trials and observational studies involving 161,808 generally healthy, postmenopausal women. The clinical trials tested the effects of combination estrogen-progestin HRT, diet modification, and calcium and vitamin D supplements in relation to heart disease, bone fractures, and breast and colorectal cancers. Findings from this landmark study indicated that instead of warding off common postmenopausal diseases, long-term combination HRT actually increased the risk of heart attack and stroke, particularly in older women.
As a result of the WHI study, concern grew about the widespread use of combination hormone replacement therapy. Doctors were now less inclined to prescribe it freely. However, new clinical trials have shown that HRT can be effective for some women depending on their risk factors.
Currently, HRT is prescribed in one of two ways. Systemic estrogen therapy in the form of a pill, skin patch, gel, cream or spray is prescribed to relieve hot flashes and night sweats, as well as vaginal dryness, itching, burning and painful intercourse. The other option is a low-dose vaginal cream, tablet or ring containing estrogen; these treat vaginal symptoms but do little to alleviate hot flashes and night sweats.
Some of the risks associated with HRT include heart disease, stroke, blood clots and breast cancer. HRT can also make breasts look denser on mammograms, making breast cancer more difficult to diagnose. In general, the risks may depend on a woman's current age and age at menopause, her family medical history, whether estrogen is given alone or in combination with progestin, and the dose and type of estrogen given. Women should probably avoid HRT if they have a current or past history of the following:
- Breast cancer
- Ovarian cancer
- Endometrial cancer
- Blood clots in the legs or lungs
- Liver disease
- Cigarette use