Published in Cancer Detection and Prevention 2000; 24(Supplement 1).

Endocrine disrupting chemicals: Pesticides, xenoestrogens, and breast or prostate cancer

MS Wolff

Mount Sinai School of Medicine, New York NY

Environmental exposures and diet have been widely studied as risk factors for breast and prostate cancer. Although their precise etiologies are not well understood, it is recognized that both the external environment and the hormonal milieu are important major risk factors for these diseases. Understanding the role of exogenous agents also offers potential for prevention. Environmental factors may help explain well-known international and ethnic variations in incidence of breast and prostate cancer; these malignancies occur more frequently among residents of Western countries than in Asian and developing countries. To date, evidence has not supported a major role for chemical exposures in the causation of these two cancers. However, laboratory evidence supports a role for numerous chemical and dietary agents in initiation and promotion of both breast and prostate cancer. The so-called endocrine disruptors are environmental chemicals whose hormonal activity may affect the course of carcinogenesis. Measurement of exposures to these chemicals represents a challenge in epidemiologic studies which can limit our ability to establish links with human disease. The risk for reproductive cancers associated with environmental exposures may reside among susceptible subgroups of individuals or may be limited to certain age-windows of susceptibility. Specific times may include onset of puberty, epithelial cell development and proliferation, bone growth, onset and duration of the climacteric, and tumor promotion. Variants in several hormone-metabolizing genes and in genes that metabolize environmental carcinogens are now becoming recognized as risk factors for both breast and prostate cancers, although neither the mechanisms nor the gene-related risks are yet clearly defined. Appreciation of these susceptibility factors is essential to an understanding of the contribution of environmental exposures or occupational exposures as well as physical activity and dietary factors to breast and prostate cancer risk and to pursuing means of their prevention.

KEY WORDS: breast cancer, prostate cancer.

Paper presented at the International Symposium on Impact of Biotechnology on Cancer Diagnostic & Prognostic Indicators; Geneva, Switzerland; October 28 - 31, 2000; in the section on environment & lifestyle.