Study says hormone replacement therapy increases breast cancer mortality, but barely

By ACSH Staff — Oct 20, 2010
Hormone replacement therapy (HRT), particularly the oft-prescribed estrogen-progesterone combination therapy Prempro, increases the risk of dying from breast cancer, according to a new study. The study, a follow-up to the Women s Health Initiative (WHI), was published in today s Journal of the American Medical Association.

Hormone replacement therapy (HRT), particularly the oft-prescribed estrogen-progesterone combination therapy Prempro, increases the risk of dying from breast cancer, according to a new study. The study, a follow-up to the Women s Health Initiative (WHI), was published in today s Journal of the American Medical Association. The study followed the same WHI participants for an average of 11 years and found that while women on Prempro are about twice as likely to die from invasive breast cancer compared to those on a placebo. But the death rates for both groups are relatively low 2.6 deaths per 10,000 women per year among those on Prempro versus 1.3 per 10,000 per year in the placebo group. In other words, Prempro use accounts for an extra 1.9 deaths per 10,000 women each year. First author Dr. Rowan T. Chlebowski, an oncologist with the Harbor-UCLA Medical Center, believes these findings demonstrate the need for patients to cut off HRT after one or two years, compared to the recommended four or five years.

ACSH's Dr. Gilbert Ross, on the other hand, believes that these results are not enough to justify a curtailed HRT regimen for women with severe menopausal symptoms. You can say that women who get breast cancer while on Prempro are at double the risk of death, but the increased risk of breast cancer death is very low both for those on HRT and those who are not. Every death is tragic, but this is a lot of media coverage for what amounts to a very small amount of new information.