An estrogen-like chemical widely used in the production of plastic food containers called bisphenol A (BPA) can stimulate the growth of prostate cancer cells in the laboratory, cancer researchers have learned.

“These preliminary findings are very interesting,” Dr. Karen E. Knudsen of the University of Cincinnati in Ohio told AMN Health, “and could potentially raise concerns about exposure of prostate cancer patients to estrogen-like chemicals. However, these observations should be validated in other systems before any lifestyle changes should be suggested,” she added.

BPA plastics are used in food and drink packaging and resins are used to line food cans, milk containers, and water pipes. Close to one million tons of BPA are produced each year in the US.

Many prostate cancers depend on androgens like testosterone to grow, in which case anti-testosterone hormonal therapy may be given. During hormonal therapy, some tumors develop mutations in a receptor for testosterone called the androgen receptor.

For patients with mutated androgen receptors, exposure to BPA may put them at higher risk for increased cancer cell growth, according to the new study in the medical journal Cancer Research.

“In this study, we showed that cultured tumor cells with this type of mutation can be stimulated to grow by an estrogen-like compound found in certain plastics,” Knudsen explained. Moreover, this stimulation takes place “at low, environmentally relevant doses.”

The safety of BPA has been debated for several years. Some argue that human exposure to the chemical is not harmful, while others believe that it may promote the growth of human cancer cells.

The current findings as well as others hint that BPA can serve as a potential “hormone sensitizer” of the mutant androgen receptors present in advanced prostate cancers, the researchers note in their report.

SOURCE: Cancer Research, January 1, 2005.