Ongoing research to identify environmental risk factors in breast carcinoma

Environmental exposures, timing and duration of exposure, and one's genetic susceptibility all contribute to breast carcinoma and its progression. The purpose of this article was to identify known and suspected environmental causes of breast carcinoma, identify some Environmental risk factors that m ay represent significant risk factors for certain groups, and describe curr ent studies, supported by the National institutes of Health/National Instit ute of Environmental Health Sciences, that clarify how environmental factor s contribute to the development of breast carcinoma. Known and suspected en vironmental risk factors include organochlorine pesticides and other synthe tic chemicals, hormonal factors (including exogenous endocrine disrupters), diet, tobacco and alcohol use, radiation, and magnetic fields. In at least 50% of breast carcinoma cases, none of the known risk factors apply. It is likely that an environmental component accounts for much of the unknown 50 % of risk. Knowing the environment al factors For breast carcinoma developm ent is an area that should be investigated intensely because it offers our best hope for prevention. Understanding why African-American women have a m ore aggressive form of breast carcinoma, whether they receive adequate foll ow-up treatment, and how these Factors contribute to increased mortality ra tes requires further exploration. Data that demonstrate the lower incidence rate of breast carcinoma in Asian women, the relation to low far diets and diets high in phytoestrogens, and how this might serve as a model for all women should be investigated. Finally, differences in behavioral and cultur al attitudes, ethnicity, economic status, and life-style influences among d ifferent groups of women require further study to determine how these facto rs contribute to enhancing or reducing breast carcinoma risk. (C) 2000 Amer ican Cancer Society.