Nearly 50,000 women died unnecessarily over the last ten years because estrogen therapy was not given to patients aged 50 to 69 who had undergone a hysterectomy after the 2002 Women's Health Initiative (WHI) study.

In 2002, doctors and patients were seriously put off using HRT (hormone replacement therapy) because two trials - HERS and WHI - suggested that one type might raise the risk of cardiovascular problems. Up to that time, HRT had been seen as the savior for women who were in medical menopause; those who had undergone hysterectomy.

Dr. Philip Sarrel, emeritus professor in the Departments of Obstetrics, Gynecology & Reproductive Sciences, and Psychiatry, Yale University, and colleagues gathered and analyzed U.S. census data and hysterectomy rates, and estimated how much hormone replacement therapy had declined among female patients aged 50 to 59 between 2002 and 2011.

Before 2002, over 90% of these patients had been prescribed estrogen-only therapy for medical menopause symptoms, including hot flashes, as well as to prevent osteoporosis and other diseases caused by menopausal hormone deficiency.

Dr. Sarrel explained that the 2002 WHI study applied to women who took the combined estrogen plus progestin HRT - for patients with a uterus. Unfortunately, the study scared doctors away from any kind of HRT, including those who had undergone a hysterectomy.

Women who have a uterus (womb) are given the combination HRT because the progestin helps reduce the risk of cancer of the uterus.

Dr. Sarrel said:

"Sadly, the media, women, and health care providers did not appreciate the difference between the two kinds of hormone therapy," Sarrel said. "As a result, the use of all forms of FDA-approved menopausal hormone therapy declined precipitously."

The Yale researchers explained in the American Journal of Public Health (July 18th issue) that for those on the combined HRT, it was probably right to advise against taking it, because the WHI study demonstrated a heightened risk of blood clots, stroke, heart disease and breast cancer.

However, for the patients on just estrogen therapy, avoiding treatment appears to have been a bad decision that cost thousands of lives.

The second part of the WHI study, which focused on women who had had hysterectomies and compared estrogen-only patients with those on placebo, the results were quite different. Women on estrogen-only therapy had "mostly positive health outcomes", the authors wrote.

The WHI study in 2011 and 2012 found that over a ten-year period, fewer women on estrogen-only therapy died, or developed heart disease or breast cancer. The annual death rate over that decade for women not taking estrogen was 13 more per 10,000. The majority of them died from heart disease, while nearly half of the remainder died from breast cancer.

Dr. Sarrel said:

"Estrogen avoidance has resulted in a real cost in women's lives every year for the last 10 years - and the deaths continue. We hope this article will stir an overdue debate and raise consciousness about the health benefits of estrogen-only therapy for women in their 50s with no uterus."

In an Abstract in the journal, the authors wrote "Informed discussion between these women and their health care providers about the effects of ET is a matter of considerable urgency."

HRT has been a controversial subject for nearly a decade. Studies have produced conflicting results: