Hormone therapy to treat menopause-related symptoms or to reduce the risk of certain disorders in postmenopausal women is associated with a favorable benefit-risk ratio when initiated around the time of menopause, but the benefits diminish as the duration of time since menopause increases and among older women, according to the 2010 position statement published by the North American Menopause Society.
The new document updates the organization's 2008 position statement on the role of estrogen and progestogen hormone therapy (HT) by including consensus recommendations derived from key data published since the earlier statement, the authors wrote, noting that the revised statement includes new sections on ovarian and lung cancer, as well as updates to the sections on breast cancer, cognitive aging and decline, dementia, coronary heart disease, stroke, and discontinuance (Menopause 2010;17:242–55)
“Recent data support the initiation of hormone therapy around the time of menopause” to treat menopause-related vasomotor symptoms, sleep disturbance, vaginal atrophy, dyspareunia, or diminished libido and to reduce the risk of osteoporosis and fractures in some women, the authors wrote.
Specifically, findings from the Women's Health Initiative (WHI) trial of estrogen therapy showed that 0.625 mg/day of oral conjugated estrogen effectively treats menopause-related symptoms with low absolute risks. Similarly, in the WHI trial of combined estrogen-progestogen therapy, most risks were deemed rare—except for stroke, which was above the rare category—based on the criteria of the Council for International Organizations of Medical Sciences, the authors wrote.
They noted, however, that “there is a growing body of evidence that each type of estrogen and progestogen, route of administration, and timing of therapy has distinct beneficial and adverse effects.” As such, more research is needed before the risks and benefits of HT can be generalized, and “it cannot be assumed that benefits and risks of [HT] apply to all age ranges and durations of therapy,” they wrote.
The most notable changes in the NAMS 2010 position statement on postmenopausal HT are the two new sections on ovarian cancer and lung cancer, which were not included in the 2008 position statement, as well as the assertion that HT is not recommended in women with a history of endometrial cancer, Dr. Margery L.S. Gass, executive director of NAMS, commented in an interview.
The new statement also reflects the latest research on the effect of age on the benefit/risk ratio of postmenopausal HT. The current understanding that the benefit/risk ratio is greatest among women who start HT close to the time of menopause and decreases with time since menopause should make clinicians and women more comfortable using HT right at the time of menopause and more cautious about using it later in life for the prevention of osteoporosis. Most of the side effects associated with HT become more common with aging, even without the use of HT. Adding the HT just compounds the problem. Therefore, rather than recommending oral or transdermal estrogen for such problems as vaginal dryness and painful intercourse, we place emphasis on using local/topical estrogen, said Dr. Gass, also a consultant to the Cleveland Clinic Center for Specialized Women's Health, Mayfield Heights, Ohio.
Regarding the association between hormone therapy and cancer, the data are conflicting, according to the NAMS statement authors. “Unopposed systemic estrogen therapy in postmenopausal women with an intact uterus is associated with increased endometrial cancer risk related to the [estrogen therapy] dose and duration,” they wrote. Thus, concomitant progestogen is recommended in those who use systemic estrogen therapy, and HT is not recommended for women with a history of endometrial cancer.
With respect to ovarian cancer, most epidemiologic studies show no association or a modest association with HT, but observational trial data suggest an increased ovarian cancer risk, the authors wrote. Based on the available data, “the association between ovarian cancer and hormone therapy beyond 5 years, if any, would fall into the rare or very rare category,” they stated, noting that women with a positive family history or other risk factors for ovarian cancer “should be counseled about this rare association.”
The link between HT and breast cancer also is uncertain. Studies have demonstrated that diagnosis of breast cancer increases with estrogen-progestogen use beyond 3–5 years. However, a reanalysis of WHI data suggested that women who started estrogen-progestogen shortly after menopause experienced an increased breast cancer risk over the next 5 years, while those with a gap of more than 5 years between menopause and treatment did not, the authors explained.
Among breast cancer survivors, estrogen-progestogen therapy has not been proven safe and may be associated with an increased risk of recurrence, as indicated in a one randomized controlled trial, which “showed a statistically significant 2.4 fold increase in new breast cancer events,” the authors wrote.