Ken Runkle Chief, Division of Environmental Health Senior
Toxicologist Illinois Department of Public Health Breast Cancer
& Environmental Exposures
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Carcinogens Definition: Substances & exposures that lead to
cancer Name a carcinogen. What does it cause?
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Cancer Classifications Carcinogens or not? Methylene Chloride
1, 3butadiene
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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
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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
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Exposure and Chemical Fate Exposure Distribution
Biotransformation Absorption Elimination
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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
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Breast Cancer & Tumor Development Most tumors originate in
the ducts and spread to other tissues More than of breast tumors
rely on estrogen for growth Perhaps 5 to 10% due to inherited
genetic mutation
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Difficulties in Determining Carcinogen Link Correlation does
not equal causation Multiple factor interactions Lack of consistent
evidence Genetic influences
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Chemicals Potentially Linked to Breast Cancer
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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
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Xenoestrogens & Endocrine Disrupting Compounds 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
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Xenoestrogens & Endocrine Disrupting Compounds PAHs
(Polycyclic Aromatic Hydrocarbon) Created during the combustion of
coal and gasoline Pesticides/Herbicides Animal/food products
Phthalates Plastics Polybrominated diphenyl ether (PBDE) Used as
flame retardants Organochlorides DDT/DDE (Pesticides)
Polychlorinated bi-phenols (PCBs) used as coolants and insulating
fluid
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Food Hormones Phytoestrogens Found in plant-based products
Zeranol Animal products Bovine Growth Hormone (rBST)
Take Home Messages Little epidemiological evidence for link
between environmental exposures and breast cancer Nature vs.
nurture Early detection
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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 (6 th 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
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Contact Information Ken Runkle Chief, Division of Environmental
Health Illinois Department of Public Health Email:
[email protected]