POSTMENOPAUSAL HORMONE REPLACEMENT THERAPY

In 2002, The Women’s Health Initiative, WHI, a study of the health habits of American women, completely shut down hormone replacement therapy, HRT. If you remember, as I do, this study concluded, among many other things, that post menopausal estrogen replacement therapy was associated with an increased risk of breast cancer, stroke, or blood clots. Panic ensued leading millions of women to immediately discontinue estrogen replacement therapy, and to experience the return of hot flashes, mood swings, trouble sleeping, and all the menopausal symptoms that had been controlled by HRT.  It was a tumultuous time for women and doctors who were besieged with questions, uncertainty, and misery. 

Well, time and calmer heads cleared up the confusion surrounding the WHI. The pendulum swang back into the HRT camp when later scientific studies showed that estrogen actually benefitted younger women by reducing cardiovascular events such as heart attack. It was once again safe for women to take estrogen and end the vasomotor misery they had been fighting since stopping it. 

Now, we have a report from Israel that may shake things up a bit. A study of more than 80,000 women aged 50 years or older found the cardiovascular benefits still existed, but they also found HRT raised the risks of stroke and cancer. The main conclusion was if HRT was started after age 65, the risk for both cancer and cerebrovascular events rose “significantly.” Some cancers are sensitive to hormone stimulus while others are not. This fact forces doctors to decide about HRT based on careful scrutiny of the individual patient’s history and profile. The most notable effect of HRT that women experience is the near elimination of vasomotor symptoms, ie. hot flashes, sweating, sleep problems. Patients are aware of these benefits immediately whereas other benefits, eg. improvement in bone mineral density, take years and require testing to determine.

If HRT was started at ages 50-65, there was also an increase in risk of heart attack and stroke, but in those patients starting HRT at 65 or older, the risks for stroke and cancer both increased “significantly.” A fortunate truth the study showed was that only 1% of women start HRT after age 65. An unfortunate note is that 40% of women who start HRT between ages 50-65, take it for 10 years or longer. The long duration contributes to increased risk. 

Bottom Line: If you must take HRT, and a lot of women do, take the lowest dose that eliminates symptoms for the shortest length of time possible. It is recommended that every few months go off HRT to see if you still have symptoms, and stop it if you don’t. Guidelines discourage HRT after age 60 or for more than 10 years post menopause. Longer duration of treatment was associated with even greater morbidity. Starting HRT at age 50-65 and continuing it beyond age 65 significantly increased risks for stroke, cancer, and MI. 

Reference: Tucker M. Hormone Therapy Past Age 65 Tied to Cancer, Vascular Events. Medscape 2026 March 18.