An international study has established a link between type 2 diabetes and advanced breast cancer. It has been found that women who are resistant to insulin, or who are overweight, are 50 per cent more likely to be diagnosed with the cancer, and only when it is in its advanced stages. It has been known for a while that being overweight puts post-menopausal women at greater risk of breast cancer. But now it has been found that women who are resistant to insulin, or who are overweight, are 50 per cent more likely to be diagnosed with the cancer, and only when it is in its advanced stages.
The finding comes after an international research team followed more than 60,000 Swedish women over 20 years.
Dr Anne Cust from the University of Melbourne is a collaborator in the study presented the findings at a medical conference. The study looked at the stage of breast cancer and the diagnosis. "We found that women who were overweight or with insulin resistance were more likely to be diagnosed with an advanced stage of breast cancer," she said.
"We don’t know the exact reasons why that might be. It might be that the cancer is growing more quickly or that it wasn’t diagnosed early but we need to do more research to find out exactly why that might be."
She says there are a number of hypotheses as to why overweight or diabetic women aren’t diagnosed earlier with breast cancer.
"It may be that the hormones that are involved, that are linked with being overweight or having insulin resistance, might be making the tumour grow more quickly but we need to do more research to find out exactly why that might be the case," she said.
But Dr Cust says that does not necessarily mean that women who are at risk of type 2 diabetes should be screened for breast cancer more often.
"The question of screening is something that would need to be looked at separately but I think it is just providing another indication that being overweight is linked to lots of different health problems and this is another reason to get off the couch and try to stay active and maintain a healthy weight," she said.
"And also, the link with insulin resistance may provide a new avenue of research for looking at the causes of breast cancer and possibly new treatments."
New estimates show diabetes affects 24 million and another 57 million with prediabetes. That means that 40% of the U.S. population either has or is at risk for developing diabetes. Almost 25 percent of the population 60 years and older had diabetes in 2007, the CDC found. The highest rates are among Native Americans and Alaska Natives, with 16.5 percent affected. Close to 12 percent of blacks and 10 percent of Hispanics have diabetes, but just 7.5 percent of Asian Americans and 6.6 percent of whites. "It is concerning to know that we have more people developing diabetes, and these data are a reminder of the importance of increasing awareness of this condition, especially among people who are at high risk," said Dr. Ann Albright, director of the CDC’s Division of Diabetes Translation.