"What we have now found is a molecule- not cholesterol itself, but an abundant metabolite of cholesterol - called 27HC, that mimics the hormone estrogen and can independently drive the growth of breast cancer," senior author Donald McDonnell, Ph.D., chair of the Department of Pharmacology and Cancer Biology at Duke, said.
The research also suggested that dietary changes or therapies to reduce cholesterol may also offer a simple, accessible way to reduce breast cancer risk.
The data also highlights how increased 27HC may reduce the effectiveness of aromatase inhibitors, which are among the most commonly used breast cancer therapeutics.
McDonnell said the findings suggested there may be a simple way to reduce the risk of breast cancer by keeping cholesterol in check, either with statins or a healthy diet.
Additionally, for women who have breast cancer and high cholesterol, taking statins may delay or prevent resistance to endocrine therapies such as tamoxifen or aromatase inhibitors.
The study is published in the journal Science.