Hormones in body fat provide bridge between breast cancer and obesity.
Hormones produced by fat cells can promote breast cancer growth in obese individuals, a study published in the Journal of Applied Physiology found.
Previously, researchers thought of adipose tissue as a storage form of energy. Today, the fat cells are understood to be active cells that produce more than 400 adipokines (hormones), which enter into the blood and travel throughout the body.
Using a rodent model, researchers wanted to determine if the hormones found in body fat can account for the association between breast cancer and obesity. Furthermore, they wanted to see if interventions that target obesity counteract any of the life-threatening effects of breast cancer.
“Our research has found that the characteristics of hormones produced by fat cells in obese people can promote breast cancer growth, whereas in lean people it prevents growth,” said lead researcher Michael Connor. “The characteristics of those hormones differ depending on whether the person is lean or obese and that determines whether the cancer grows or not.”
The findings suggest that adiponectin and leptin are possible reasons for poorer chemotherapy response, and a higher risk of death in obese individuals compared with others. Authors noted that exercise, which does not have any of the harmful side effects as many cancer drugs, could be a potentially beneficial therapy in some breast cancer patients.
“Our study shows that voluntary and rigorous exercise can counteract, and even completely prevent the effects on cancer growth that are caused by obesity,” Connor said. “We also show that even moderate exercise can lead to slowing of breast cancer growth and that the more exercise you do, the greater the benefit.”