Cholesterol now linked to breast cancer
A by-product of cholesterol fuels the growth and spread of breast cancer, research has shown.
Scientists also discovered that cholesterol-lowering statin drugs can reduce its harmful effects. Modifying diet, or taking statins, to lower cholesterol could provide a straightforward way to lower breast cancer risk, they believe.
Previous studies had already shown a link between raised cholesterol and breast cancer, but one that could not be explained.
The new US research, conducted on mice, shows for the first time how a breakdown product of cholesterol called 27HC drives breast cancer by mimicking the effects of the hormone oestrogen.
Three-quarters of breast cancers are sensitive to oestrogen, which stimulates tumour growth.
Lead scientist Dr Donald McDonnell, from Duke University Medical Centre in Durham, North Carolina, said: "A lot of studies have shown a connection between obesity and breast cancer, and specifically that elevated cholesterol is associated with breast cancer risk, but no mechanism has been identified.
"What we have now found is a molecule -- not cholesterol itself, but an abundant metabolite of cholesterol -- called 27HC that mimics the hormone oestrogen and can independently drive the growth of breast cancer."
Earlier research from Dr McDonnell's laboratory confirmed that 27HC behaves like oestrogen in animals.
Clinical trials are now needed to investigate whether breast cancer really can be tackled by targeting cholesterol, said the scientists, who suggested that 27HC may also play a role in other cancers.