Effect of genistein on growth of human breast cancer cells in vitro and in vivo

BREAST cancer is strongly associated with affluence, and occurrence rates can vary by as much as five-to 10-fold between countries. Asian women have a much lower incidence of breast cancer compared to those in Western countries. When these women migrate from Asian countries to Western countries, their incidence of breast cancer increases; and by the second generation, breast cancer risk is similar to those in the high-risk countries. These results strongly suggest that environmental factors, including diet, play a role in the etiology of breast cancer (Wynde, 1980; Willet, 1989). In general, Asian women consume diets low in fat and high in fruits and vegetables. Additionally, these women consume soy protein as a dietary staple. In recent years, soy has been the focus of considerable research for potential heath benefits. These studies have focused on reduction of various chronic diseases; in fact, a health claim regarding soy and cardiovascular disease is in the final stages of approval by the Food and Drug Administration (FDA). Our research focus is on the soy phytoestrogen, genistein, and its possible growth-altering effects on estrogendependent breast cancers.