Bisphenol A, the widely used compound in polycarbonate plastic, has the ability to alter the activity of genes in normal breast cells in ways that resemble what is found in extremely dangerous breast cancers, according to a new study.

The study, conducted by researchers in California and published this month in the journal Cancer Research, found that many genes in non-cancerous breast cells exposed to trace amounts of bisphenol A began acting in a way that closely resembled the gene activity in highly aggressive breast tumours that led to an increased likelihood that women would die of the disease.

The link “is highly supportive of the concept that overexposure to BPA and/or similar compounds could be an underlying factor in the aggressiveness, if not in the causality” of breast cancers, said Shanaz Dairkee, lead author of the study and senior scientist at the California Pacific Medical Center Research Institute in San Francisco, in an e-mail.

The study results were designated a “priority report” by the journal, published by the American Association for Cancer Research, one of the world’s largest scientific organizations devoted to cancer studies.

Earlier this week, it was disclosed that Health Canada has concluded bisphenol A, or BPA, is a dangerous substance, making it the first regulatory body in the world to reach such a determination. An announcement on possible measures to curb its use is expected soon from federal Health Minister Tony Clement.

BPA, is one of the most widely used synthetic chemicals in modern industry. It is the basic building block for polycarbonate, the see-through, shatterproof plastic that resembles glass.

Bisphenol A is also used to make the epoxy resins lining most tin cans, along with some dental sealants, sports helmets and compact discs.

Many scientists are looking at the possible links between breast cancer and BPA because the synthetic chemical is able to mimic estrogen and was tested in the search for estrogen drugs before industry began using it to make polycarbonate plastic.

There is strong evidence linking breast cancer to long-term estrogen exposure, and many researchers have been worried that BPA leaching from consumer products is giving women what amounts to an extra dose of hormones, raising lifetime risk of malignancy.

Full Story: http://www.theglobeandmail.com/servlet/story/RTGAM.2008
0418.wlcancer18/BNStory/specialScienceandHealth/home