Obesity-Related Blood Signals Promote Aggressive Breast Cancer Progression, Study Finds

Recent research highlights a compelling link between obesity and the development of aggressive breast cancers, particularly triple-negative breast cancer (TNBC), which is known for its high recurrence and poor prognosis. Breast cancer remains the most common cancer among women globally, with nearly 300,000 new invasive cases in the United States alone in 2023, leading to over 43,000 deaths. Among its subtypes, TNBC stands out due to the absence of estrogen receptor, progesterone receptor, and HER2, making it resistant to many targeted therapies and reliant mainly on chemotherapy.

A groundbreaking study by researchers from Boston University School of Medicine has uncovered that exosomes—tiny vesicles released into the bloodstream—serve as carriers of harmful signals in obese, insulin-resistant models. These exosomes can modify triple-negative breast cancer cells, transforming them from slow-moving to highly invasive and metastatic. This process involves Rho-proteins, which are molecular switches that regulate signal transduction pathways critical to cell movement and invasion.

The researchers used two groups of experimental animals fed different diets for three months: one on a high-fat diet inducing obesity and insulin resistance, and the other on a low-fat diet maintaining leanness. Blood and fat tissue exosomes were collected from both groups, and their effects on cultured TNBC cells were examined. The results showed that exosomes from obese models significantly promoted cell migration and metastasis. Further testing by injecting treated cancer cells into healthy models confirmed that exosomes from obese subjects increased the metastatic potential, especially to the lungs and brain.

These findings suggest that obesity not only contributes to cancer risk but also actively enhances the aggressiveness of existing tumors via exosomal signaling. The researchers propose that measuring obesity-derived exosomes could serve as a non-invasive biomarker for early detection of metastatic risk, enabling personalized treatment strategies. Additionally, targeting the molecular pathways involved, such as Rho-proteins, offers promising therapeutic avenues.

The study emphasizes the importance of managing obesity and metabolic health to reduce the burden of aggressive breast cancers. It opens new possibilities for developing blood tests and novel drugs to interrupt the obesity-cancer link, potentially improving survival rates and quality of life for affected women.

This research is detailed in the journal BMC Cancer and underscores the complex biological mechanisms by which obesity influences cancer progression.