Early-life Chemical Exposure Critical to Later-Life Breast Cancer Risk

Wednesday, February 4, 2009
Contact: Shannon Coughlin, 415-346-8223 x14 / 415-336-2246 cell

San Francisco - A scientific review article published in the International Journal of Occupational and Environmental Health shows that a host of chemicals that mimic or alter the activities of natural hormones can potentially increase breast cancer risk. A companion article outlines research and policy priorities needed to better understand and regulate these endocrine-disrupting chemicals, which are found in everything from pesticides to plastics to personal care products.

“The picture of breast cancer causation that emerges is complex,” said Jeanne Rizzo, R.N., president of the Breast Cancer Fund, the organization that presented the articles. “While there is no single smoking gun, the trends that emerge lead us to stop asking IF there is a link between breast cancer and synthetic chemicals, and to instead ask how to act to reduce our exposure, given the strong and compelling evidence we now have.”

The scientific review article, which summarizes the findings of more than 400 epidemiological and experimental studies, indicates that exposures to common chemicals and radiation, alone and in combination, are contributing to the increases in breast cancer incidence observed over the past several decades. This article comes at a time when the public and lawmakers’ attention is particularly focused on two of the “bad actor” chemicals covered in the piece: phthalates and bisphenol A. On February 10, a federal ban on phthalates in toys and childcare articles goes into effect—a response to growing evidence that these plasticizers can disrupt hormones and trigger early puberty (a risk factor for later-life breast cancer), among other health concerns. And there is mounting pressure to regulate bisphenol A, a synthetic estrogen that has been linked to breast cancer and is used in plastic baby and water bottles, as well as in the lining of food and baby formula cans.

“Early-life exposures to endocrine disruptors like phthalates and BPA—particularly during fetal development and childhood, but also continuing through first childbirth and breastfeeding—are closely linked to later-life breast cancer risk,” said Janet Gray, Ph.D., lead author of the scientific review article. “These compounds have yet to be classified as carcinogens, even though recent studies show an explicit health risk.”

Other risks discussed in the scientific review article include the pesticides DDT and atrazine; air pollutants called polycyclic aromatic hydrocarbons; hormone replacement therapy; and ionizing radiation. The companion article outlines the federal and state regulation needed to protect against and reduce environmental exposures, as well as the research required to better understand and track toxic exposures.

Janet Nudelman, lead author of the companion article, noted that “The science linking environmental toxins like phthalates and BPA to increasing rates of breast cancer is clear and compelling. It is imperative that we use this impressive and growing body of evidence to more strictly regulate these unsafe chemicals. We have a responsibility to our children and grandchildren to take action now that could prevent breast cancer diagnoses in 10, 20 or 50 years.

Scientific review article abstract at http://www.ijoeh.com/index.php/ijoeh/article/view/858

Policy article abstract at http://www.ijoeh.com/index.php/ijoeh/article/view/859