There was a report from the WHI that focused on breast cancer cases and risk of dying associated with the use of common hormones used in menopause….Prempro (combined conjugated equine estrogens and medroxyprogesterone acetate).   The study consisted of an average treatment time of 5.6 years and followed patients for an average of 11 years.

The new data relates to the risk of dying from breast cancer.  The study showed an extra 1 to 2 deaths from breast cancer per 10,000 women per year.  Specifically, for every 10,000 women in the study who were randomized to placebo, there were 1.3 deaths from breast cancer per year. For every 10,000 women randomized to combined hormone therapy, there were 2.6 deaths from breast cancer per year.  

Importantly, these results apply to the use of the combination of estrogen and progestin and not to estrogen alone. Therefore, for women who have had a hysterectomy and taking only estrogen…these results do not apply.  Similarly, the study did not study all types of hormone therapy.  Neither estradiol products or progesterone products were studied….therefore, no conclusion can be drawn about these products. 

It is important to keep in mind the following:  The increased risk of breast cancer using estrogen plus progestin for 5 years is very similar to the increased risk of breast cancer associated with having menopause 5 years later. This increased risk of breast cancer occurs with a woman’s own internal, natural estrogen and progesterone.

 The current Position Statement from The North American Menopause Society recommends using hormone therapy only when needed to treat moderate to severe symptoms of menopause. Consistent with that approach is the recommendation to use the lowest effective dose for the shortest amount of time. Each woman, in consultation with her healthcare provider, needs to prioritize her midlife health concerns and determine whether hormone therapy is an acceptable choice for her.

Published in the Journal of the American Medical Association on 10/20/10 (Chlebowski RT, et al)