Breast Cancer and Hormone Therapy: Is This News?

By: Red Hot Mamas

Published: November 18, 2010

Yet another firestorm of controversy is brewing in the world of hormone therapy, based on a report recently published in The Journal of the American Medical Association (JAMA) of WHI Secondary Outcomes. The new publication, based on reanalysis and follow-up data from the 2002 Women’s Health Initiative (WHI) states that women who use combined hormone therapy (estrogen-progestin) are at an increased risk for contracting and dying from aggressive breast cancers. Before your head starts spinning with confusion, let’s take a deeper look at what the findings and numbers really mean.

This particular part of the WHI delves a little deeper into the follow-up data regarding hormone therapy and breast cancer. Approximately 13,000 women between the ages of 50 and 79 were involved. Women either took a placebo or a specific combination and dose of combined conjugated equine estrogens and medroxyprogesterone acetate, also called Prempro.

Taken in pill form, the women were given a placebo or a relatively high dose (CEE 0.625 mg/d plus MPA 2.5 mg/d), for a relatively significant length of time (on average almost 6 years) and were followed for an average of 11 years. For women taking HT, approximately one or two extra deaths occurred from breast cancer per 10,000 women per year. For those on placebo, there were 1.3 deaths from breast cancer per year. These results apply only to the usage of estrogen plus progestin. The WHI found no increase in breast cancer risk with estrogen alone among women with hysterectomy.

What we already know

Back in 2002, the combined (estrogen with progestin) hormone therapy branch of the WHI study was halted due to preliminary results linking mainly increased cardiovascular risks such as stroke and heart attacks and breast cancer risk. Follow-up studies began revealing additional (yet relatively small) increases in lung cancer mortality, and now breast cancer mortality.

Today, we know the WHI study had its limitations and the media prompted a plethora of confusing headlines, many of which were exaggerated. The WHI scared many women into thinking hormone therapy was a scary, unthinkable treatment option yet they didn’t even know the essential details.

  • The median age women in the WHI study were 62 when they started HT which is significantly older than the average woman who enters menopause around age 52. We now know that the benefit-risk ratio for HT is more favorable when initiated at a younger age but decreases with aging and time since menopause in previously untreated women.
  • Women in the WHI study were taking oral preparations of the specific drug. The study design left out all other types of FDA approved estrogens and delivery methods such as vaginal, injections and transdermals (through the skin).
  • Women in the WHI study were taking the dose for 5+ years. Short term risks of the same drug were not examined.
  • We already knew that use of the specific estrogen plus progestin used in the WHI increases the frequency of abnormal mammograms and risk for breast cancer.
  • We already know that we are not supposed to take the specific estrogen plus progestin dose for the prevention of heart disease.

Bottom line, what should we take from this report

Treatments and drugs have changed a lot since the study was planned in the early 1990’s. The WHI study only examined one dose and schedule, Prempro, which was used 17 years ago by 93% of women when the study started. Now, typical doses are about half of what they used to be and other preparations and delivery systems are being used. There is currently no study like this examining the effects for lower dose or shorter duration of doses and delivery systems Women with significant menopausal symptoms should evaluate the risks and benefits of hormone therapy with their healthcare providers. And if they choose to go on hormone therapy, use the lowest dose for the shortest duration.

Hormone therapy should never be used to prevent heart disease. All women who want to lower their risk of heart disease should make healthy lifestyle choices including a healthy diet, maintaining a healthy weight, engaging in regular physical activity and not smoking.

Hormone therapy is currently the most effective method for treating hot flashes but be aware of all your options. Choosing your treatment method is a very individualized decision and your choices should be thoroughly discussed with your healthcare professional.

For more information, read RHM Medical Experts Comment on WHI Follow Up


Dechert, Sandy. “Women Journalists Break Story of Hormonal Breast Cancer Risk.” Examiner. N.p., 20 10 2010. Web. 16 Nov 2010. website.

Menopause: The Journal of The North American Menopause Society Vol. 17, No. 2, pp. 242/255

Rowan T. Chlebowski; Susan L. Hendrix; Robert D. Langer; Marcia L. Stefanick; Margery Gass; Dorothy Lane; Rebecca J. Rodabough; Mary Ann Gilligan; Michele G. Cyr; Cynthia A. Thomson; Janardan Khandekar; Helen Petrovitch; Anne McTiernan Influence of Estrogen Plus Progestin on Breast Cancer and Mammography in Healthy Postmenopausal Women: The Women’s Health Initiative Randomized Trial JAMA. 2003;289(24):3243-3253.