The drug anastrozole cuts breast cancer incidence in half among high-risk post-menopausal women, according to an study just published in the Lancet.
Anastrozole, also known as “Arimidex”, is a type of drug known as an aromatase inhibitor. It works by reducing the production of estrogen, like its better-known cousin, Tamoxifen.
In the study, nearly 4000 post-menopausal women at increased risk for breast cancer were randomized to receive daily anastrozole or placebo for 5 years. During the 5 years of average follow-up time, breast cancer developed 53% less often among anastrozole recipients (2% vs. 4%). The researchers estimate that 36 women would need to receive Arimidex to prevent one cancer during a 7-year period.
The researchers say their results “strongly support” anastrozole for preventing breast cancer in high-risk women. The once- daily pill is relatively inexpensive, since the patent has expired. And it works better than tamoxifen in this group.