A new study out of the National Institutes of Health has found that two widely used “forever chemicals” are associated with a higher risk of an aggressive form of breast cancer in women.
The chemicals, known as PFAS, are synthetic compounds that break down extremely slowly and accumulate in the environment and the human body. They’ve been used for decades in nonstick cookware, upholstery, clothing, food packaging and personal care products.
The study, published in the Journal of Clinical Oncology, found that women with higher blood levels of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) were more likely to develop estrogen receptor-negative (ER-negative) breast cancer. That subtype tends to be more aggressive and carries worse outcomes than breast cancers that respond to estrogen, according to a U.S. Department of Health and Human Services press release.
Researchers drew on data from the Sister Study, a large U.S. research project examining environmental and genetic factors tied to breast cancer. Every participant had a sister who had been diagnosed with breast cancer, though none had the disease themselves at enrollment. Researchers measured 17 PFAS compounds in blood samples collected before diagnosis from 1,609 women who later developed breast cancer, comparing them against a sample of 2,269 women.
The numbers were stark. Women in the highest PFOA exposure group had a 67% higher rate of ER-negative breast cancer than those in the lowest group. For PFOS, the rate was 93% higher in the highest exposure group. These are relative differences between groups, not a prediction of any individual woman’s odds of developing cancer. Researchers found no clear link between either chemical and breast cancer overall.
Study leader Alexandra White, Ph.D., a researcher at NIH, told Fox News Digital the findings, combined with a meta-analysis of earlier studies, provide evidence that the two chemicals are tied to higher ER-negative breast cancer risk. She also flagged a limitation: the study focused on older PFAS chemicals that have largely been phased out, and far less is known about the shorter-chain compounds now replacing them.
“They tend to be shorter-chain compounds and may be less persistent in our bodies and the environment, but we know little about how they may influence health outcomes, such as breast cancer,” White said.
The authors are clear that this is an association, not proof of cause and effect, and say more research is needed.
Government Response
HHS Secretary Robert F. Kennedy Jr. weighed in on the findings, saying women deserve clear answers about how chemicals in their environment may affect their health and calling for further investigation.
“Under President Trump’s leadership, we will pursue the evidence, confront environmental health risks and give women the information they need to protect their health,” Kennedy said.
What Doctors Are Saying
Dr. Tiffany Troso-Sandoval, a New York City-based breast and gynecological cancer specialist who spent more than 25 years at Memorial Sloan Kettering, said forever chemicals can accumulate in the body and raise cancer risk.
“Oftentimes, once you’ve been exposed to them, they will accumulate in your body and cause havoc, and can actually increase the risk of carcinogenic transformation of cells,” Troso-Sandoval told Fox News Digital. “What was interesting about this study is that the link was found only in ER-negative breast cancers, which is a known aggressive subtype of cancer.”
She noted few risk factors beyond genetics are known for ER-negative breast cancer, and stressed the study did not show an increased risk across breast cancers in general. She suggested PFAS might damage DNA directly or interfere with the body’s ability to repair that damage or clear cancerous cells. She also cautioned that higher chemical levels in patients with ER-negative cancer does not prove the chemicals caused the disease.
First author Che-Jung Chang, Ph.D., a former NIH research fellow now at DLH, noted that while PFAS persist in the environment and the body, exposure is potentially modifiable.
“People can take steps to reduce their exposure, and these findings could open new avenues for prevention,” Chang said.
Practical Steps
Troso-Sandoval recommends people review everyday sources of PFAS and other potentially harmful chemical exposure, including cookware, food storage and personal care products.
“Try to look at the products that you are using very frequently, and those are the first ones to swap out,” she advised. “Maybe consider cooking with stainless steel pots and pans … I recommend not heating up any food in plastic containers, because as you heat these plastics, they tend to leach more of the compounds into our foods.”
She also flagged black plastic utensils as a concern, though for a different reason — their association with other contaminants, including flame retardants — and urged people to scrutinize cosmetics and personal care items that may contain PFAS.
