Diabetes, obesity increases breast cancer risk
Adult women with diabetes or obese women over age 60 are significantly more likely to develop breast cancer, according to a study presented earlier this week at the 2011 San Antonio Breast Cancer Symposium.
The study from Lund University in Sweden found that adult women living with diabetes had a 37 percent increased risk for developing breast cancer if their diabetes was diagnosed up to four years before cancer was diagnosed.
Analysis of data from more than 23,000 Swedish women also found that use of one diabetes medication, glargine, almost doubled the rate for developing any cancer. Metformin, a different diabetes drug, was linked to an 8 percent lower rate of any cancer in women living with diabetes.
According to researchers, the number of patients in this study was too small to make a link between use of these diabetes medications and breast cancer risk.
Obesity and cancer
The data showed that obesity in women older than age 60 increased the risk for developing breast cancer by 55 percent.
Also, women with abnormally low blood lipids were 25 percent more likely to develop breast cancer. High blood lipid levels were associated with a lower risk. Researchers still do not understand the reasons behind this, and more studies are required.
“We are looking at everybody, and we found that diabetes in adult women and obesity in women age 60 and older significantly increased breast cancer risk,” said Hakan Olsson, MD, professor in the departments of oncology and cancer epidemiology at Lund University in Sweden. “This is useful information for women who want to know their risk and who can take steps to lower it.”
Diabetes is linked to an 11 percent increased risk of cancer mortality in women and a 17 percent increased risk in men, according to the American Association for Cancer Research (AACR). The correlation between having diabetes and developing cancer appears to be independent of other cancer risk factors.
The AACR, The Cancer Therapy & Research Center (CTRC) at The University of Texas Health Science Center at San Antonio, and Baylor College of Medicine are joint sponsors of the San Antonio Breast Cancer Symposium.
Source: American Association for Cancer Research