Extra body fat and breast cancer risk

Abstract

Obesity has been epidemic in the US for over two decades. Obesity has been linked to the risk of development of various cancers, including breast cancer both in pre and postmenopausal women. Previously, we have reported that obesity is risk factor for breast cancer development using DMBA-induced mammary tumor model. Dehydroepiandrosterone (DHEA) is an over-the-counter dietary supplement used as an anti-cancer agent and anti-obesity supplement. The objectives of this study were to investigate the long-term effects of obesity using obese zucker rat as model and DHEA treatment on body weight gain, breast cancer development and also serum DHEA, DHEA-S, IGF-1and IGFBP-3 using 7,12-dimethylbenz(a)anthracene (DMBA)induced mammary tumor model. We used 43 six-week-old obese female Zucker rats and we randomly assigned them ad libitum to a diet either chow as a control diet or chow with the addition of DHEA at a concentration of 6 g/kg of chow as a DHEA diet. We induced mammary tumors by orally gavaging all of the rats at age 50 days with 65 mg DMBA/kg body weight and were sacrificed 155 days post-DMBA treatment. Fifty-five percent (55%) of the control diet group developed mammary tumors, while no tumors were detected in the DHEA diet group (P<0.001). Obese rats fed the DHEA diet gained significantly less weight (P<0.001) and had an increased (P<0.001) serum DHEA and DHEA-S compared to control rats. Also, obese DHEA-Fed rats had significantly (P<0.001) lower serum IGF-1 and IGF-BP3. Our results suggest that DHEA treatment can reduce body weight gain by lowering serum IGF-1 and IGFBP-3 which might protects against breast cancer development caused by obesity. Also, these results suggest that extra body fat can be a risk factor for breast cancer development and by losing the extra body fat, the risk of breast cancer development can be eliminated. Supported by ABI to RH.