A new study has revealed that overweight, insulin resistant women are at a higher risk of being diagnosed with an advanced breast cancer.
The study, which was led by University of Melbourne researcher Dr Anne Cust, found that women who were overweight or had signs of insulin resistance - such as elevated blood glucose or insulin levels - were about 50 per cent more likely to be diagnosed with an advanced breast cancer tumor.
Researchers tracked more than 60,000 Swedish women over a 20-year-period from 1985 to 2005.
All were cancer free when recruited and their blood tested for glucose, insulin and other hormones associated with obesity and diabetes risk.
Insulin resistance is most commonly caused by being overweight and inactive and is often a precursor to Type 2 diabetes.
Cust said that previous research had shown a strong link between being overweight and increased breast cancer risk in postmenopausal women- but this study was the first to demonstrate the influence of insulin resistance on the stage of cancer diagnosis.
"Women with insulin resistance or who were overweight were less likely to be diagnosed with stage 1 breast cancers but at greater risk of being diagnosed with stage 2 to 4 tumors - larger more advanced cancers,'' Cust said.
"We know that being overweight and having insulin resistance is a risk factor for getting cancer but - in the case of breast cancer - our study indicates that the cancer will be more advanced," she added.
The study has been presented to the Population Health 2008 Conference in Brisbane.