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Breast Cancer & Environmental Exposures. Ken Runkle Chief, Division of Environmental Health Senior Toxicologist Illinois Department of Public Health. Carcinogens. Definition: Substances & exposures that lead to cancer. Name a carcinogen. What does it cause?. Cancer Classifications.
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Breast Cancer &Environmental Exposures Ken Runkle Chief, Division of Environmental Health Senior Toxicologist Illinois Department of Public Health
Carcinogens Definition:Substances & exposures that lead to cancer • Name a carcinogen. What does it cause?
Cancer Classifications Methylene Chloride 1, 3–butadiene Carcinogens or not?
U.S. Environmental Protection Agency • Group A – Human carcinogen • Group B – Probable human carcinogen • B1 – Limited evidence of carcinogenicity from epidemiological studies • B2 – Inadequate or no data from epidemiological studies • Group C – Possible human carcinogen • Group D – Not classifiable as to human carcinogenicity • Group E – Evidence of non carcinogenicity for humans
International Agency for Research on Cancer (IARC) • Group 1 – Carcinogenic • Group 2A – Probably carcinogenic • Group 2B – Possibly carcinogenic • Group 3 – Not classifiable • Group 4 – Probably not
Exposure and Chemical Fate • Exposure • Distribution • Biotransformation • Absorption • Elimination
Breast Cancer Causes vs. Risk Factors • Causes • High energy radiation • Japanese survivors of WWII • Tubercular woman with repeated chest X-rays • Risk Factors • 1713, Bernardino Ramazzini observed that nuns are more subject to cancer of the breast than other women • So do women who have not borne children • Risk factors are not causes, but may provide clues to causes
Breast Cancer & Tumor Development • Most tumors originate in the ducts and spread to other tissues • More than ½ of breast tumors rely on estrogen for growth • Perhaps 5 to 10% due to inherited genetic mutation
Difficulties in Determining Carcinogen Link • Correlation does not equal causation • Multiple factor interactions • Lack of consistent evidence • Genetic influences
Hormones • Hormone Replacement Therapy (HRT) & oral contraceptives • Diethylstilbestrol (DES) • Synthetic form of estrogen • Prescribed to women from 1938 to 1971 to help with pregnancy complications; interfered with fetal development • Estrogens/placental hormones in personal care products • Often used in: • Topical anti-aging creams • Some shampoos/conditioners
Xenoestrogens & Endocrine DisruptingCompounds • Alkylphenols • Cleaning products/detergents • Aromatic amines • Foams, dyes, pesticides, pharmaceuticals, diesel exhaust • Bisphenyl-A (BPA) • Plastics, food packaging, lining of canned foods, etc • Dioxins • Created during the production and burning of plastics
Xenoestrogens & Endocrine Disrupting Compounds • PAHs (Polycyclic Aromatic Hydrocarbon) • Created during the combustion of coal and gasoline • Pesticides/Herbicides • Animal/food products • Phthalates • Plastics • Polybrominateddiphenyl ether (PBDE) • Used as flame retardants • Organochlorides • DDT/DDE (Pesticides) • Polychlorinated bi-phenols (PCBs) – used as coolants and insulating fluid
Food Hormones • Phytoestrogens • Found in plant-based products • Zeranol • Animal products • Bovine Growth Hormone (rBST)
Non-Endocrine Disrupting Industrial Chemicals • Benzene • Gasoline fumes/exhaust, cigarette smoke, industrial burning • Organic Solvents • Computer components, cleaning products, cosmetics, dry cleaning • Vinyl chloride • Plastics, tobacco smoke • 1,3 – butadiene • Ethylene oxide • Cosmetics, also used to sterilize surgical instruments
Take Home Messages • Little epidemiological evidence for link between environmental exposures and breast cancer • Nature vs. nurture • Early detection
References • American Cancer Society (www.cancer.org)Environmental Protection Agency (http://www.epa.gov/raf/publications/pdfs/CA%20GUIDELINES_1986.PDF ) • International Agency for Research on Cancer(http://monographs.iarc.fr/ENG/Classification/index.php) • Nudleman, J., & Engle, C. (2010). State of the evidence: the connection between breast cancer and the environment (6th ed.) Retrieved from http://www.breastcancerfund.org/media/publications/state-of-the-evidence. • Nudelman, J. et al. (2009, Jan/March). Policy recommendations emerging from the scientific evidence connecting environmental factors and breast cancer. International Journal of Occupational and Environmental Health, 2009, 79 – 101. • Snedeker, S. (2002, May). Environmental chemicals and breast cancer risk: Why is there concern? Program on Breast Cancer and Environmental Risk Factors in New York State. Retrieved from http://envirocancer.cornell.edu
Contact Information Ken Runkle Chief, Division of Environmental HealthIllinois Department of Public HealthEmail: ken.runkle@illinois.gov