Study: Diabetes treatments linked to reductions in mammographic breast density

Researchers have discovered that common types of treatment for diabetes can decrease mammographic breast density—a significant indicator of increased breast cancer risk—while female patients who receive insulin injections may have increased density levels, according to a study recently presented at the European Breast Cancer Conference in Amsterdam.

Although diabetes has been linked to an increased risk of developing breast cancer, the ability to decipher how one disease affects the other has continued to elude scientists, according to presenter Zorana Jovanovic Andersen, PhD, of the University of Southern Denmark in Esjberg.

“One of the characteristics of cancer cells is their ability to grow rapidly and uncontrollably, and to resist the programmed death that occurs in non-cancer cells,” said Andersen, in a press release from the European Cancer Organization. “Therefore, growth factors are critical to cancer development and progression. We know that insulin is an important growth factor for all body tissues, and even if we do not know exactly how it affects the development of cancer cells, it is also highly plausible that it increases breast density."

Andersen reported the results from a study of 5,644 women recruited into the Danish Diet, Cancer and Health (DCH) study group who received mammographic screening between 1993 and 2001.

The findings showed that women with diabetes were less likely to have mixed or dense breasts, while diabetic women using insulin injections had increased odds of having mixed or dense breasts.

Andersen told attendees that the study results highlight the need for additional research into the effects of diabetes, insulin and diabetic treatments on breast density—research that she and her colleagues are anxious to commence.

“Now we would like to extend our research by following up these women for breast cancer and observing the effect of different diabetes treatments on breast cancer risk,” she said. "In the meantime, we would urge all women, both with diabetes and without, to take measures to reduce their risk of developing breast cancer through simple lifestyle changes, such as avoiding obesity, reducing alcohol consumption and exercising."