Dietary Isoflavones and Breast Cancer Risk

Breast cancer is the deadliest neoplasm in women globally, resulting in a significant health burden. In many cases, breast cancer becomes resistant to chemotherapy, radiation, and hormonal therapies. It is believed that genetics is not the major cause of breast cancer. Other contributing risk factors include age at first childbirth, age at menarche, age at menopause, use of oral contraceptives, race and ethnicity, and diet. Diet has been shown to influence breast cancer incidence, recurrence, and prognosis. Soy isoflavones have long been a staple in Asian diets, and there appears to be an increase, albeit modest, compared to Asian populations, in soy consumption among Americans. Isoflavones are phytoestrogens that have antiestrogenic as well as estrogenic effects on breast cancer cells in culture, in animal models, and in clinical trials. This study will investigate anticancer and tumor promoting properties of dietary isoflavones and evaluate their effects on breast cancer development. Furthermore, this work seeks to elucidate the putative molecular pathways by which these phytochemicals modulate breast cancer risk by synergizing or antagonizing the estrogen receptor (ER) and in ER-independent signaling mechanisms.