From Our 2010 Archives

Prenatal Exposure to Chemicals Linked to Breast Cancer Risk

WEDNESDAY, May 26 (HealthDay News) -- The children of women who are exposed to certain industrial chemicals while pregnant are at an increased risk for developing breast cancer as adults, a new animal study suggests.

The chemicals -- bisphenol-A (BPA) and diethylstilbestrol (DES) -- are primarily produced for industrial manufacturing purposes, and are known for interfering with hormonal and metabolic processes, while disturbing neurological and immune function, among both people and animals.

"BPA is a weak estrogen and DES is a strong estrogen, yet our study shows both have a profound effect on gene expression in the mammary gland [breast] throughout life," study author Dr. Hugh Taylor, from the Yale University School of Medicine in New Haven, said in a news release from the Endocrine Society.

"All estrogens, even 'weak' ones, can alter the development of the breast and ultimately place adult women who were exposed to them prenatally at risk of breast cancer," he added.

The findings will be published in the June issue of Hormones & Cancer, the journal of the Endocrine Society.

The authors draw their conclusions from work with pregnant mice who were exposed to both BPA and DES. Once reaching adulthood, the offspring were found to produce higher than normal levels of a protein involved in gene regulation, called EZH2.

Above-normal EZH2 levels have previously been linked to a higher risk for breast cancer, the research team noted.

"We have demonstrated a novel mechanism by which endocrine-disrupting chemicals regulate developmental programming in the breast," said Taylor. "This study generates important safety concerns about exposures to environmental endocrine disruptors such as BPA and suggests a potential need to monitor women exposed to these chemicals for the development of breast lesions as adults."

-- Alan Mozes

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SOURCE: The Endocrine Society, news release, May 21, 2010