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Link - obesity, hormones, breast cancer
Posted 27 December 2009
Media Coverage
27/12/2009, ABC TV News more info
27/12/2009, Herald Sun, Obesity link to cancer
Link - obesity, hormones, breast cancer
Media Release - December 23, 2009
Researchers at Prince Henry’s Institute (PHI) in Melbourne have made a new and “critical link” between obesity, hormones and breast cancer that may lead to a fresh approach to preventing breast cancer in older women.
In a paper to be published in the international journal Cancer Research the researchers say that understanding the new link is vital given the latest Australian figures that show breast cancer cases are increasing and also that obesity is very common in older women.
The latest Australian figures show that 1 in 9 women will develop breast cancer before age 85 years. Recent survey data also indicates that more than 2 in 3 older women in the population are overweight or obese.
“The consequences of the obesity pandemic are that tens of millions more women than previously thought might develop breast cancer worldwide” says the paper’s author Dr Kristy Brown, the Terry Fox Foundation Fellow at PHI.
It has been known for some time that the risk of breast cancer increases with obesity but the new findings explain how fat cells can drive breast cancer development. The researchers have shown that factors produced by fat tissue can stimulate oestrogen production in the breast. They suggest that AMP kinase, a master regulator of cellular energy metabolism, may provide a key link between obesity and increased breast cancer risk.
The growth of most breast cancers in older women is driven by the key hormone oestrogen. Previous PHI research has shown that in obese postmenopausal women it is the local formation of oestrogen in the breast itself which is responsible for their increased risk of breast cancer.
Current breast cancer treatments include drugs that block oestrogen production throughout the body and these have been clinically demonstrated to slow or stop further breast cancer growth. However shutting down levels of this hormone throughout the body with these “broad approach” drugs can also have some serious side effects, especially on bone and joint health and possibly also the brain.
“We now have a new pathway to develop highly targeted breast cancer therapies directed at the breast itself” says Professor Evan Simpson who leads the Victorian Breast Cancer Research Consortium funded research group at PHI.
The PHI researchers suggest that the new link they have found could form the basis to developing a preventative drug based approach which reduces the increased breast cancer risk faced by growing numbers of overweight and obese women.
The team is now exploring several drug candidates that would shut down hormone production specifically in breast tissue but not affect other parts of the body which benefit from oestrogen. One drug showing particular promise in reducing breast cancer is Metformin, which is already commonly used to treat Type 2 diabetes.