Study provides insights into the obesity–breast cancer link

Obesity and cancer are two major health challenges of our time, yet the link between them remains only partially understood. New research now highlights a molecular chain of events in estrogen receptor-positive breast cancer, revealing how leptin, a hormone produced by fat cells, signals cancer cells to grow. This leads to increased activity of the enzyme stearoyl-CoA desaturase (SCD), which fuels the growth and motility of cancer cells. The findings from a study in The American Journal of Pathology, published by Elsevier, provides insights into the obesity–breast cancer link and identifies potential new therapeutic targets to counter obesity-driven breast cancer progression.

According to the World Obesity Federation's 2025 Atlas, the global number of adults living with obesity is projected to reach 1.13 billion by 2030. Given the well-established epidemiological link between obesity and breast cancer, elucidating the molecular mechanisms underlying this association has become a major research priority.

By integrating transcriptomic, lipidomic, and functional analyses, we uncovered a crucial role of the leptin-SCD axis in breast cancer biology. Our data indicate that the combined upregulation of leptin and SCD identifies a subgroup of breast cancers with poorer recurrence-free survival. This metabolic signature could serve as a prognostic marker, helping to stratify patients according to obesity-related metabolic risk."

Ines Barone, PhD, lead investigator of the study of the University of Calabria, Italy

The researchers found that blocking SCD activity abolished leptin-induced oncogenic traits, such as enhanced cell growth, motility, mitochondrial respiration, and adenosine triphosphate (ATP) molecule production. Together, these findings provide a mechanistic explanation for how obesity can fuel hormone-responsive breast cancer progression.

Dr. Barone concludes, "We were fascinated to see that selectively blocking SCD could almost completely counteract the pro-tumorigenic effects driven by leptin, revealing a striking vulnerability in this pathway. Our findings hold promise for patients with estrogen receptor-positive breast cancer, the most common subtype of breast cancer, as targeting SCD could limit disease progression in obese breast cancer patients."