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ENVIRONMENTAL FACTORS AFFECTING BREAST CANCER SUSCEPTIBILITY
Citation:
Fenton, S E. ENVIRONMENTAL FACTORS AFFECTING BREAST CANCER SUSCEPTIBILITY. Presented at Society of Toxicology, New Orleans, LA, March 6-10, 2005.
Description:
Environmental Factors Affecting Breast Cancer Susceptibility
Suzanne. E. Fenton
US EPA, ORD, MD-67 NHEERL, Reproductive Toxicology Division, Research Triangle Park, NC 27711.
Breast cancer is still the most common malignancy afflicting women in the Western world. Although substantial progress has been made in elucidating some of the genetic contributors to breast cancer (i.e., the highly penetrant susceptibility genes, BRCA1 and 2), it has been estimated that only 6-12% of all breast cancer cases are due to heritable factors. Few other specific factors have been identified that contribute significantly to the an individuals lifetime risk of breast cancer. It has become apparent that elements affecting cancer susceptibility (genetic or environmental components) cannot be considered separately.
Environmental factors (e.g., industrial compounds, pharmaceuticals, diet, occupational hazards) that alter breast development and tumor formation have been identified in both epidemiological and rodent studies. These constituents may act as either a mutagen or as a developmental compound able to alter susceptibility to carcinogens. In addition to the contributions of environmental factors, a large percentage of cancer cases are due to sporadic mutations that may occur as a result of spontaneous genetic events, and the interactions between gene and environmental factors. A relatively recent focus in the breast cancer field is on the interaction between genes and environment as the causal mechanism in the disease. Primary candidates for gene-environment interaction studies have been genes that encode enzymes involved in the metabolism of established cancer risk factors and those involving oxidative stress response. There are common varying forms of these genes (polymorphisms) that may directly result in impacting the risk of cancer by altering normal metabolism, circulating hormone levels, ability to respond correctly to normal stressors, or response to environmental factors.
We will present data from both epidemiological and rodent studies demonstrating the importance of environmental factors in breast cancer susceptibility. These studies will elucidate the importance of evaluating gene-environment interactions and the various environmental factors, such as diet and endocrine disrupting chemicals, on breast cancer risk assessment.
(This is an abstract of a proposed presentation and does not necessarily reflect EPA policy)