Hormone Therapy: A Shift in Thinking
Changes in hormone replacement therapy (HRT)
Over the past decades, hormone replacement therapy (HRT) was thought to offer health- and youth-preserving benefits to postmenopausal women. But recent studies have led to a dramatic shift from this way of thinking.
One large study done by the Women's Health Initiative (WHI) has shown that HRT does not protect against heart disease. In fact, in a small number of women who are 10 or more years past menopause, it causes heart disease, including heart attacks.8 In the WHI study, short-term use of HRT was also linked to an increase in the numbers of strokes and blood clots. Using HRT for several years was linked to increased cases of breast cancer and dementia. Overall, most women using HRT in the WHI study had no serious side effects, but they also had no long-term benefits.
Among all women, average hormone therapy risks are very low. Your personal risks may be lower or higher than the average. This depends on your risk factors for breast cancer, ovarian cancer, cardiovascular problems, blood clots, or dementia.
Based on the WHI study, the U.S. Food and Drug Administration (FDA) has updated its HRT recommendations. Estrogen-progestin HRT is approved for:
- Short-term treatment of menopause symptoms. HRT effectively relieves menopause symptoms for most women. Women who decide that HRT benefits outweigh their risks are advised to use the lowest effective dose for as short a time as possible.9 For most women, menopause symptoms naturally improve within a few years' time, making long-term symptom treatment unnecessary.
- Osteoporosis prevention and treatment, in select cases. Most experts recommend that long-term HRT only be considered for women with a high osteoporosis risk. In this case, estrogen's bone-protecting benefit may outweigh the risks of taking HRT. Women are now encouraged to consider all possible osteoporosis treatments and to compare their risks and benefits.14
Changes in estrogen replacement therapy (ERT)
Women who have early, sudden menopause after a hysterectomy with both ovaries removed are usually advised to use estrogen replacement therapy (ERT) to protect against bone loss. The low estrogen levels of menopause cause bone thinning. Compared to women who are not taking hormone therapy, women taking ERT have fewer hip fractures (a sign of estrogen's bone-protecting effect).15
ERT also helps with menopausal symptoms. Known ERT risks come from studies of women older than 50. It may be that the benefits outweigh the risks for younger women who take ERT until the age of natural menopause.16 This question needs further research.
The Women's Health Initiative (WHI) studied estrogen-only therapy in older women and found that it increases the risks of blood clots in the legs (deep vein thrombosis) and lungs (pulmonary embolism) and the risk of stroke during the first year of use.15 ERT may increase the risk of dementia in women who are older than 65.17 ERT offered no protection against heart disease. In fact, it was linked to heart disease and ovarian cancer in a small number of women.8, 18
Some studies have found a possible link between ERT and breast cancer.19 In the WHI trial, women using ERT had no increase in breast cancer risk during the study's nearly 7 years of ERT treatment.15 But the Million Women Study of British women ages 50 to 64 suggests that after 10 years of taking ERT, a small number of women develop breast cancer that is related to ERT.6, 20 (Many women in this age group also develop breast cancer without taking hormone therapy.)
If you have had breast cancer or ovarian cancer, do not take ERT or HRT.19
- Should I take estrogen replacement therapy (ERT) after a hysterectomy or oophorectomy?
What are my hormone options now?
- Short-term HRT or ERT effectively relieves hot flashes and vaginal dryness for most women, though side effects are common. Side effects that lead women to stop HRT include unpredictable menstrual-like bleeding, breast tenderness, and depression.21
- Short-term, low-dose HRT or ERT is hoped to offer a balance between HRT benefits and risks. It can be taken for 4 to 5 years, with regular checkups. This may work well for many women, who will find that their menopause symptoms have subsided within this period of time. As more healthy postmenopausal women use low-dose hormones for shorter periods of time, researchers will be able to evaluate the actual benefits and risks.
If you are taking long-term HRT or ERT, talk to your doctor about whether its benefits outweigh its risks, considering your own needs, age, and health history. For you, the increased risks of breast cancer, heart attack, stroke, blood clots, and dementia may be small. Or, if you have a personal or family history of breast cancer or heart disease, HRT risks may outweigh HRT benefits.
Stopping HRT or ERT. Talk to your doctor before you stop hormone therapy. There is no way of knowing in advance whether you will have menopause symptoms when you stop using estrogen. About 70% of women who stop HRT have tolerable symptoms or no symptoms at all. The remaining 30% have symptoms that are less tolerable or more long-lasting.22