In the study, researchers exposed human breast cancer cells to low levels of BPA, consistent with those found in the blood of many adults, and discovered that BPA acts on cancer cells in much the same way that estrogen does—by inducing proteins that shield the cells from the effects of chemotherapy.
“It’s actually acting by protecting existing cancer cells from dying in response to anti-cancer drugs, making chemotherapy significantly less effective,” said Nira Ben-Jonathan, a professor of cancer and cell biology who has studied BPA for more than 10 years.
More Evidence That BPA is Hazardous to Human Health
The findings of this study, published in the journal Environmental Health Perspectives, add to the growing concern about the effects of BPA on human health. Previous studies have linked BPA to heart disease, diabetes, liver abnormalities, cancer, behavioral disorders, reproductive problems and obesity, and a study by the U.S. Centers for Disease Control and Prevention found detectable levels of BPA in 93 percent of the urine samples collected from more than 2,500 adults and children older than six who participated in the study.
Despite growing evidence of the dangers of BPA, the U.S. Food and Drug Administration has reassured consumers that the chemical is safe at the levels it sanctions, but the National Toxicology Program at the Department of Health and Human Services has continued to question the safety of BPA and to raise concerns about the risks it poses to human health and public safety.
“These data provide considerable support to the accumulating evidence that BPA is hazardous to human health,” the study authors wrote.
Linking BPA to Chemotherapy Resistance May Help Prevent Future Problems
But it’s not all bad news. Sometimes, identifying a problem can help point the way to a solution. Scientists have previously recorded the link between the protein-inducing action of estrogen and chemotherapy resistance, but they’ve never been able to explain why the resistance also occurs in some patients with low levels of estrogen.
"Patients with less circulating estrogen—post-menopausal women, for example—can also suffer from chemotherapy resistance," said Ben-Jonathan. "Linking BPA to this problem gives us one more avenue to explore in terms of preventing chemotherapy resistance.
"Resistance to chemotherapy is a major problem for cancer patients, especially those with advanced or metastatic disease," she said. "Finding out what contributes to that resistance can give us an idea of what to target in order to make chemotherapy as effective as possible."
