ABSTRACT
Breast cancer is a complex and heterogeneous group of malignancies that encompass distinct clinical entities, pathologies, and etiologies. Nevertheless, three major classes of overall risk factors for breast cancers have been and still are conventionally recognized. The first is a familial history of breast cancer, particularly early age at onset. The second is reproductive or “estrogen-window” factors. The third is a high-fat diet. The role of these risk factors in the aggregate has been incriminated in only 20 to 30 percent of all breast cancers. DDT promotes breast cancer induced in male rodents by the unrelated carcinogen acetamidophenanthrene. Estrogens are an important class of dietary contaminants, resulting from their virtually unregulated use as growth-promoting feed additives for cattle, hogs, and poultry. In view of the known carcinogenicity of exogenous estrogens, lifelong exposure to these contaminants is clearly a risk factor for breast cancer, as emphasized by Roy Hertz, the National Cancer Institute’s former leading authority on endocrine cancer.
