Hormone replacement therapy — medications containing female hormones to replace the ones the body no longer makes after menopause — is an option for women with hot flashes and other menopausal symptoms. Hormone therapy has long-term benefits of preventing osteoporosis, incontinence, sexual dysfunction and possibly dementia.
Use of hormone therapy changed abruptly when a large clinical trial, monitored predominately by clinicians promoting selective estrogen receptor modulators (SERMs) produced by Ely Lilly, found that treatment with Prempro increased the lifetime risk for breast cancer by 5% and did not affect and could even worsen heart disease risk. Also, women having never taken estrogen that were decades into the menopause and at increased risk for heart disease actual had an early increase in heart attack risk, but this risk diminished and decreased with continued use past three years. Women taking estrogen from the start of menopause did not have an increase in cancer or heart attacks and continued to show a low risk for heart disease. The concern about health hazards attributed to Prempro grew and doctors reacted by taking all their patients off any and all hormones, not just Prempro. However, further review of clinical trials and new evidence show that hormone therapy may be a good choice for certain women, depending on their risk factors. Recent NIH studies show a significant decrease in breast cancer risk if a woman’s testosterone level is maintained at a premenopausal level – with or without progesterone use.
What are the benefits of hormone therapy?
The benefits of hormone therapy depend, in part, on how you take hormone therapy. Estrogen is typically prescribed along with progesterone unless the uterus has been removed. Estrogen alone, when not balanced by progesterone and testosterone, can stimulate growth of the lining of the uterus, causing the return of menstruation. Long term unopposed, unmonitored estrogen excess, as seen in cases of obesity or unopposed estrogen therapy is known to increase the risk for endometrial cancer. A recent, randomized, controlled clinical trial — the Kronos Early Estrogen Prevention Study (KEEPS) — explored estrogen use and heart disease in younger postmenopausal women. The study found no significant association between hormone therapy and the increase in risk for heart disease.
Oral estrogen therapy (pills) — remains the most common treatment for relief of troublesome menopausal hot flashes and night sweats. Estrogen can also ease vaginal symptoms of menopause, such as dryness, itching, burning, incontinence and discomfort with intercourse. Food and Drug Administration (FDA) still approves estrogen for the prevention of the bone-thinning disease called osteoporosis. Oral hormone therapy does increase the risk for blood clots and stroke.
Topical estrogen therapy - Low-dose vaginal preparations of estrogen — which come in cream, tablet or ring form — can effectively treat vaginal symptoms and some urinary symptoms, while minimizing absorption into the body. Low-dose vaginal preparations can help with hot flashes, night sweats but offer little protection against osteoporosis. They have not been shown to increase the risk for blood clots or stroke. This is the best choice for patients that have been diagnosed with breast cancer – given their oncologist’s approval.
Injectable bioidentical hormone therapy – monthly injections of depot estrogen combined with testosterone mimics the premenopausal state and give a highly controlled hormone balance. NIH studies show that the addition of testosterone may reduce the incidence of breast cancer from 390/100,000 women years to 73/100,000 women years – a fivefold decrease in breast cancer incidence. Progesterone is used to manage the endometrium if required – the use of progesterone with testosterone does not increase the risk for breast cancer as seen with progesterone alone.
What are the risks of hormone therapy?
In the largest clinical trial to date, a combination estrogen-progestin pill (Prempro) increased the risk of certain serious conditions, including:
- Heart disease
- Blood clots
- Breast cancer
A related clinical trial evaluating estrogen alone in women who previously had a hysterectomy found no increased risk of breast cancer or heart disease. The risks of stroke and blood clots were similar to the combination therapy.
Hormone therapy, particularly oral estrogen combined with a progestin, can make your breasts look denser on mammograms, making breast cancer more difficult to detect. Also, especially when taken for more than a few years, progesterone increases the risk of breast cancer if unopposed by testosterone, a finding confirmed in multiple studies of different estrogen and progesterone therapy combinations, not just limited to Prempro.
The risks of hormone therapy may vary depending on whether estrogen is given alone or with a progestin, whether it is in pill, topical gel or injection. Other health risks such as your risks of heart and blood vessel (cardiovascular) disease, cancer risks and family medical history will affect the decision to use hormone replacement therapy.
Who should consider hormone therapy?
Estrogen is still the most effective treatment for menopausal symptoms and osteoporosis. The benefits of hormone therapy outweigh the risks if you're healthy and:
- Experience moderate to severe hot flashes or other menopausal symptoms or have low bone mass
Women who experience an early menopause, particularly those who had their ovaries removed have a higher risk of:
- Coronary heart disease
- Earlier death
- Parkinsonism (Parkinson's-like symptoms)
- Anxiety or depression
Your age, type of menopause and time since menopause play a significant role in the risks associated with hormone therapy.