In 2002, the Journal of the American Medical Association (JAMA) unleashed the findings of the Women's Health Initiative (WHI) study.¹ Millions of women who had been prescribed Prempro (a combination of horse-derived estrogens and synthetic progestin) to ease menopausal symptoms were now being told it significantly increased their risk of blood clots, heart disease, stroke, and even breast cancer. Women were disillusioned, frightened or angry, and many discontinued hormone replacement therapy. Prempro’s maker Pfizer, Inc., agreed to pay approximately $330 million to settle lawsuits filed by breast cancer patients who believed that the hormones were at fault and that the drug company had knowingly concealed their risks.

Estrogen avoidance is linked to hip fractures and breast cancer

During the hysteria that followed the WHI results, findings from another arm of the study (WHI-ET), which evaluated the risks of horse-derived estrogens without progestin, were reported without much fanfare in 2004.² Although the study uncovered a greater risk of stroke among women given horse-derived estrogen, it also revealed a lower risk of hip fracture and breast cancer compared to a placebo. Post-intervention data published in 2011 confirmed earlier findings of a reduced risk of breast cancer and hip fracture in estrogen users, along with a reduced risk of deep vein thrombosis and death compared to a placebo.

Estrogen avoidance is associated with death

In July 2013, Yale University researchers published a study showing that only about one-third of women who have undergone a hysterectomy (along with removal of their ovaries) are currently using hormone replacement, compared to 90% of women before the 2002 WHI findings were published.³ The researchers estimate that 18,601 to 91,610 postmenopausal women have died (ages of 50 and 59 years) since 2002 as a result. "Sadly, the media, women, and health care providers did not appreciate the difference between the two kinds of hormone therapy," commented Dr. Sarrel, lead author. "As a result, the use of all forms of FDA-approved menopausal hormone therapy declined precipitously."⁴ The Yale study did not include data on transdermal estradiol and bioidentical hormones. The authors remark that transdermal estradiol “has been reported to be more effective than are oral estrogens in preventing cardiovascular events, so decline in its use could contribute further to the mortality toll."³ They also mention that vaginally administered estrogen has recently been associated with a reduction in heart attack risk. Dr. Sarrel and his colleagues believe their findings will stress the importance of estrogen therapy.  "Estrogen avoidance has resulted in a real cost in women's lives every year for the last 10 years — and the deaths continue," Dr. Sarrel noted. "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."⁴

References:

1. JAMA. 2002 Jul 17;288(3):321-33.
2. JAMA. 2004 Apr 14;291(14):1701-12.
3. Am J Public Health. 2013 Sep;103(9):1583-8.
4. Karen N. Peart. For women with hysterectomies, estrogen may be a lifesaver after all. Available at: http://news.yale.edu/2013/07/18/women-hysterectomies-estrogen-may-be-lifesaver-after-all July 18, 2013. Last accessed August 23, 2013.