Fat rats show why breast cancer may be more aggressive in patients with obesity
A University of Colorado Cancer Center study published in the journal Hormones & Cancer offers a possible explanation: In an animal model of obesity and breast cancer (affectionately referred to as the "fat rat"), tumor cells in obese animals, but not lean animals, had especially sensitive androgen receptors, allowing these cells to magnify growth signals from the hormone testosterone. Similar to the way in which many breast cancers drive their growth with estrogen receptors, these tumors in obese rats drove their growth with androgen receptors. "Our original goal was to make a model of obesity and breast cancer that would reflect the condition in women. At first, we were disappointed to discover that rats don't make much estrogen in fat tissue like humans do. But we then realized that this aspect of the model gave us an excellent opportunity to study cancer progression after anti-estrogen treatment. Because fat cells in these rats don't make estrogen...