Diabetes treatment may impact breast density

Women who take insulin for diabetes may be more likely to have dense breasts than women who manage their diabetes with other medications or lifestyle modifications, a new study suggests.

Dense breast tissue is a known risk factor for breast cancer, and women with dense breasts are 1.2 to 2.0 times more likely to develop breast cancer than women with average breast density, according to the American Cancer Society.

For the study, presented at the European Breast Cancer Conference in Amsterdam, researchers evaluated more than 5,600 women who had mammograms between 1993 and 2001. The results also showed that women with diabetes who take insulin “have considerably increased breast density [compared to] women without diabetes,” said lead researcher Zorana Andersen, in a news release.

The American Cancer Society explains that having a dense breast means having more glandular and fibrous tissue and less fatty tissue. Breast density can change over time and can be affected by age, menopausal status, certain medications, pregnancy and genetics.

“While high breast density does increase a woman’s breast cancer risk, unfortunately it’s a factor that largely can’t be controlled,” says Dr. Rosalinda Alvarado, a breast surgeon at Advocate Illinois Masonic Medical Center in Chicago. “A common misconception is that breast density is related to breast size, when really it refers to the different types of tissue that make up the breasts and their appearance on a mammogram.”

Researchers stress that the study does not prove that insulin increases a woman’s risk for breast cancer. They say that further research will be needed to test that correlation and links between other diabetes medications and breast cancer as well.

If you have diabetes, Dr. Alvarado recommends talking with your doctor about your treatment options and discussing if increased screenings, including a mammogram and possibly an ultrasound, might be right for you.