MELBOURNE, April 14 (UPI) — Australian scientists say they’ve found breast stem cells are very sensitive to female hormones — a finding that might lead to new breast cancer treatments.
Associate Professors Jane Visvader and Geoff Lindeman at the Walter and Eliza Hall Institute of Medical Research said their discovery explains decades of evidence linking breast cancer risk to female hormone exposure.
Visvader and Lindeman, who led the research, said sustained exposure to estrogen and progesterone was a well-established risk factor for breast cancer.
“There is a clear evidence that the more menstrual cycles a woman has the greater her breast cancer risk,” Visvader said. “There is even an increase in breast cancer risk in the short-term following pregnancy. However the cellular basis for these observations has been poorly understood.”
Using mouse models, the scientists showed that when the ovaries were removed or the animals were treated with hormone inhibitors, breast stem cell numbers dropped and the cells appeared to become dormant.
Lindeman, who is also a medical oncologist, said that finding helped explain why the effects of “chemoprevention” — a treatment aimed at breast cancer prevention — continued long after anti-estrogen tablets have been stopped.
The study is detailed in the early online edition of the journal Nature.
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