BPA exposure in the womb might lead to daughter's breast cancer
New evidence from mouse studies suggests, but doesn’t prove, BPA exposure in the womb might up the risk of breast cancer by disrupting hormone response related to breast development. Researchers say the finding does mean pregnant and breastfeeding women should avoid BPA that could alter their daughter’s breast tissue and lead to cancer later in life.
Researchers at the Swiss Institute for Experimental Cancer Research added BPA, which is synthesized in the body as an estrogenic compound, to the drinking water of mice, simulating human exposure to bisphenol-A.
Mice exposed to BPA have altered breast tissue
Pups born to mice exposed to the BPA were removed from the mother after weaning and followed. They had no further exposure to the chemical.
The scientists monitored changes in breast tissue over time, finding an increase in response to the hormone progesterone in the mice exposed to BPA in the womb and during breast feeding. Lifetime exposure to progesterone is linked to breast cancer.
The mice also had a 1.5 fold increase in number of cells in the milk ducts.
Cathrin Brisken, MD, co-author of the study, says while the mouse findings can’t be extrapolated to humans, BPA exposure before birth also “cannot be dismissed” as a possible cause of breast cancer.
Ninety percent of the population has been found with detectable levels of BPA in body fluids.
Milk duct cells more numerous from BPA exposure in mouse pups
The increase in number of milk duct cells seen in mice exposed to BPA in utero is similar to what was noted when DES (diethylstilbestrol) was given to women decades ago to reduce pregnancy complications.
So called “DES daughters” are recommended to undergo regular screening because of the increased risk of breast cancer that can develop post menopause. The synthetic estrogen was also added to cattle feed.
Brisken says the study, published in the journal Molecular Endocrinology, doesn’t prove BPA exposure in the womb causes breast cancer. But she does suggest pregnant and breastfeeding women avoid exposure to bisphenol-A that might affect their daughter’s breast tissue, leading to breast cancer years later.