Obesity and Breast Cancer: Molecular and Epidemiological Evidence

 Carcinoma of the breast is a leading cause of cancer deaths among women world-wide. Obesity is recognized as a well-established risk factor for epithelial tumors including the mammary epithelium. Adipose tissue is considered to be metabolically active organ with the ability to secrete a wide range of biologically active adipokines. Multiple studies have evaluated the potential mechanisms correlating obesity to increased risk of breast cancer. Altered circulating levels of adipokines or changed adipokine signaling pathways are now increasingly recognized to be associated with breast cancer development and progression. Leptin and adiponectin were the main adipokines that have been investigated in the context of breast cancer in both preclinical and epidemiological studies. Obesity is also believed to promote inflammatory response and induce activity of key enzymes like aromatase, leading to higher risk of breast cancer development. The goal of this review is to provide recent insights into the potential molecular mechanisms linking adipokines to the etiopathogenesis of breast cancer including recently identified adipokines and trying to correlate these molecular mechanisms to more established metabolic and hormonal dysregulations of obesity. A better understanding of the interplay between adipokines and other deregulated mechanisms in obesity is important for the development of preventive strategies with therapeutic potential against breast cancer in obese patients.