Suppressing the microenvironment for cancer spread may help obese people with breast cancerFebruary 18th, 2016
A new study may have uncovered a new mechanism to explain how obesity can promote cancer progression.
The American study focused on the effects of obesity on pancreatic and breast cancer, since more than half of people diagnosed with such tumours are overweight or obese.
In addition, a number of large-scale studies have found that obesity leads to an increased risk of death in pancreatic, breast and other types of cancer. But prior to the current study the mechanism of how obesity could contribute to the progression of pancreatic and breast cancers was unclear.
“We found that obesity increased the infiltration of tumour-promoting immune cells, and the growth and spread of pancreatic cancers,” says Dr Dai Fukumura, Steele Laboratory of Tumor Biology at Massachusetts General Hospital.
The researchers first found that obesity was associated with increased tumour inflammation and reduced ability to suppress the immune response to tumour growth. They discovered that by altering the immunosuppressive tumour environment they could prevent the acceleration of tumour growth and spread.
“With the majority of pancreatic and breast cancer patients being overweight or obese at diagnosis, uncovering potential therapeutic targets within the mechanisms that associate obesity with poor cancer prognoses is the first step towards developing remedies that could disrupt this association and significantly improve patient outcome,” says co-senior author Rakesh K. Jain, PhD, director of the Steele Laboratory.
“The fact that this new mechanism underlies obesity’s impact on two types of cancer suggests that it may be a common mechanism of tumour induction that could apply to other cancer types.”
Investigating the relationship of obesity and breast cancer at the cellular level is an important area of research funded by NBCF. Dr Kristy Brown has been investigating a gut hormone, ghrelin, which may hold the key to halting estrogen production in fat cells and tumour growth in breast tissue.
Her team made the novel discovery that ghrelin blocks estrogen production in breast fat cells which has profound implications for treating breast cancers, 70 per cent of which are oestrogen dependent.
She is now working to determine the precise mechanisms of the relationship between obesity, ghrelin, estrogen reduction and tumour growth to define potential drug treatments for those with breast cancer.