Study provides reassurance regarding the safety of using hormone therapy after age 65 years

After the Women's Health Initiative (WHI) in 2002, many women have resisted taking hormone therapy (HT), especially after age 65 years, because of fears of increased risks for various cancers and heart disease. A new study shows that those fears may be unfounded, depending on the type, route, and dose of HT. Results of the study are published online today in Menopause, the journal of The Menopause Society.

Despite the conflicting results of a follow-up WHI study in 2004 and dozens of other studies since that time, a percentage of healthcare professionals and their middle-aged female patients continue to believe that HT, especially when taken past the age of 65 years, can increase the occurrence of invasive breast cancer, stroke, and coronary heart disease. Such fears have prevented many menopausal women from getting relief from such symptoms as hot flashes because HT is today recognized as being the most effective treatment option for managing an array of bothersome symptoms associated with the menopause transition.

A new large-scale study based on the records of 10 million senior Medicare women from 2007 to 2020, however, suggests that the implications of HT use beyond age 65 years vary by type, route, and dose. These findings are in line with the 2022 HT Position Statement of The Menopause Society that states there is no general rule for stopping HT in a woman based on age alone. The statement goes on to say that, for healthy women with persistent hot flashes, continuing HT beyond age 65 years is a reasonable option with appropriate counseling and regular assessment of risks and benefits. Moreover, the mitigation of risks through the choice of low-dose and nonoral routes of administration becomes increasingly important as women age.

A challenge, to date, has been that information on the effects of different HT formulations, doses, and routes of administration is lacking. That's why the researchers in this latest study specifically sought to assess the use of HT beyond the age of 65 years and its health implications by the type of estrogen and progestogen, route of administration, and dose.

Based on the results of the study, the researchers concluded that, compared with never use or discontinuation of HT before the age of 65 years, the use of estrogen monotherapy beyond age 65 years was associated with significant risk reductions in mortality, breast cancer, lung cancer, colorectal cancer, congestive heart failure, venous thromboembolism, atrial fibrillation, acute myocardial infarction, and dementia. The use of a combination estrogen and progestogen therapy was found to increase the risk of breast cancer, but such risk can be mitigated using low doses of transdermal or vaginal progestin. In addition, progestin usage resulted in significant risk reductions in endometrial cancer, ovarian cancer, ischemic heart disease, congestive heart failure, and venous thromboembolism.

Study results are published in the article "Use of menopausal hormone therapy beyond age 65 years and its effects on women's health outcomes by types, routes, and doses."

This large observational study of women in Medicare provides reassurance regarding the safety of longer-term hormone therapy use and even potential benefits, particularly in women using estrogen alone. It also offers important insights into variations among different hormone therapy doses, routes of administration, and formulations that could facilitate individualization of treatment."

Dr. Stephanie Faubion, medical director for The Menopause Society