Triple negative breast cancer (TNBC), which is already more aggressive and more difficult to treat than other forms of the disease, also tends to have worse outcomes in patients who have type 2 diabetes. New research may have uncovered one of the reasons why, opening up the potential for new treatments that could help these patients.

A study recently published in the journal Molecular Cancer Research looked at exosomes from non-cancerous fat cells to see if they may have something to do with making TNBC more aggressive or causing it to spread to other parts of the body.

To determine this, the research team studied how microRNAs in exosomes impact cell behavior, by adding them to cancer cells in lab experiments and to experimental models of breast cancer metastasis.

They found that insulin-resistant fat cell exosomes have miRNAs that can change the tumor microenvironment, make triple negative breast cancer more aggressive, and promote the cancer’s spread to the brain, most likely through miRNA pathways.

Dr. Gerald V. Denis, study co-author and professor of pharmacology, physiology, and biophysics at Boston University School of Medicine, says, “Our study highlights the growing understanding that cancer does not develop in isolation—it is influenced by a person’s overall health, including metabolic conditions like diabetes. This problem is urgent because the epidemic of obesity-driven diabetes is worsening and now affects over 537 million adults worldwide. This finding adds to the idea that treating underlying conditions, not just cancer itself, could improve patient outcomes.”

The team says that current TNBC treatments may need to be different for patients with type 2 diabetes and a high risk of their cancer spreading to the brain. Because their study uncovered patterns that may help explain why these patients have worse outcomes, the findings could ultimately lead to new treatment options.