Since the emergence of the first results from the Women's Health Initiative (WHI), a lot has been learned in the past ten years. Hormone therapy (HT) remains the most effective treatment available for menopausal hot flashes and night sweats. However, there is a growing body of evidence that formulation, route of administration, timing of therapy and duration of therapy may produce different effects.
It is essential to evaluate a personal benefit-risk profile for each woman considering HT. Individual factors contributing to the HT decision include the severity of menopausal symptoms and effect on quality of life.
The absolute risks of HT in healthy women ages 50 to 59 are low. In contrast, long-term HT or HT initiation in older women is associated with greater risks.
- The recommendation for duration of therapy differs for Estrogen Progestogen Therapy (EPT) in women with a uterus, and Estrogen Therapy (ET) in women who have had a hysterectomy.
- For EPT, duration is limited by the increased risk of breast cancer associated with more than 3 to 5 years of use. ET has a more favorable benefit-risk profile with no apparent increase in risk of breast cancer during an average of 7 years of use, a finding that allows more flexibility in duration of therapy.
- Individualizing is still key in the decision to use HT and should incorporate the woman's health and quality of life priorities as well as her personal risk factors, such as risk of blood clots, heart disease, stroke, and breast cancer.
- For relief of hot flashes, women with a uterus should take EPT so that a progestogen will protect the lining of the uterus from the cancer-promoting effects of estrogen alone.
- Low-dose vaginal ET is advised when symptoms are limited to vaginal dryness or discomfort with intercourse.
- Neither ET nor EPT increases the risk of heart disease in healthy women under age 60 years or within 10 years of menopause. The risk of stroke can be increased but is considered rare in the 50s.
- Women with premature or early menopause who are otherwise appropriate candidates can use HT until the average age of natural menopause (age 51). Longer duration of treatment can be considered if needed for symptom management.
- There is a lack of safety data supporting the use of HT in breast cancer survivors.
- Both ET delivered through the skin and low-dose oral ET have been associated with lower risks of blood clots and stroke than standard doses of oral estrogen, but confirmation of benefits in randomized trials is not yet available.
Additional research is needed to understand the different effects of ET and EPT and how they apply to individual women.