Researchers find cause of breast cancer in post-menopausal women

A woman examining her breast.
A woman examining her breast.
Photo credit: SHUTTERSTOCK

What you need to know:

  • Exosomes (small vesicles secreted by many cell types and released into blood or nearby tissues and fluids) are involved in breast cancer progression and treatment resistance.
  • Metabolic and inflammatory complications of obesity have a role in the formation of cancer.

Researchers at Boston University School of medicine have for the first time found that exosomes (small vesicles secreted by many cell types and released into blood or nearby tissues and fluids) are involved in breast cancer progression and treatment resistance.

They say that obesity, insulin resistance and Type 2 diabetes are risk factors for breast cancer in post-menopausal women. 

According to a peer-reviewed study published in Science Signalling, a global scientific journal expert further explains that metabolic and inflammatory complications of obesity have a role in the formation of cancer though the cellular and molecular pathways that mediate breast cancer incidence, progression and metastasis in patients who also have metabolic complications, are still not fully understood.

“We have identified a potential biological difference that might explain this higher risk and inform clinical decision making. This novel biology may also suggest new drugs or treatments to reduce risk for metastasis in cancer patients who are also obese and diabetic,” said the author of the study Gerald V. Denis, who is a professor of medicine and pharmacology at Boston University School of Medicine.

The study further points out that currently, more than 100 million Americans are diabetic or pre-diabetic, with 90 per cent of these cases due to obesity. 

“If these adults develop an obesity-driven cancer, there is higher likelihood that the cancer will metastasise or become resistant to targeted treatments or hormone therapies,” it notes.  

The researchers isolated and characterised exosomes to identify factors that promote breast cancer progression and metastasis. 

They found that exosomes from insulin resistant adipocytes (fat cells), or from adipose tissue of adults with Type 2 diabetes, provoked much more dangerous changes in human breast cancer cells than exosomes from insulin sensitive or non-diabetic adipocytes.

As per the professor, metabolic diagnoses (blood glucose, A1c levels, lipid profiles, elevated insulin, and cardiovascular risk markers like elevated CRP) are not normally considered by oncologists who are evaluating the  risk of breast cancer progression, treatment resistance or recurrence.

“It has also been difficult to identify blood tests that would assist clinicians to plan treatment or change treatment plans, because clinical trials have not yet been conducted to define the most important biomarkers. Inexpensive diagnostic and prognostic tests that are covered by insurance and that require only a small amount of blood would help oncologists improve treatment for these patients,” he highlights. 

The scientist believes this discovery has implications for any obesity-related cancer where nearby fat deposits may be metabolically abnormal and inflamed.