A new NIH-backed study is putting a harsh spotlight on PFAS, the so-called forever chemicals that linger in the body and environment for years. Researchers found a link between two of these chemicals and a higher risk of ER-negative breast cancer, a tougher and more aggressive form of the disease.
PFAS show up in plenty of everyday places, from nonstick cookware and clothing to food packaging and personal care products. The concern is not just that they are common, but that they can build up quietly over time while people go about normal routines.
The research drew on the Sister Study, a large U.S. project focused on environmental and genetic influences on breast cancer. Scientists measured 17 PFAS in blood samples taken before diagnosis from more than 1,600 women who later developed breast cancer, then compared them with a larger group of women who did not.
The clearest signal showed up with PFOA and PFOS, two of the older, better-known PFAS compounds. Women in the highest exposure groups had higher rates of ER-negative breast cancer, including a 67% higher rate in the top PFOA group and a 93% higher rate in the top PFOS group compared with the lowest group.
That does not mean every woman with PFAS exposure will develop breast cancer. The numbers reflect relative differences between groups, not an individual prediction, and the study did not find a clear link between these chemicals and breast cancer overall.
Still, the pattern caught the attention of researchers because ER-negative breast cancers tend to behave badly. They are often more aggressive and less responsive to estrogen-targeted treatment, which can make them harder to manage and more dangerous once they appear.
NIH researcher Alexandra White said the findings, along with earlier studies, add to the case that these two PFAS are tied to a higher ER-negative breast cancer risk. She also pointed out that the science on newer replacement PFAS is still thin, which leaves a big question mark around what is coming next.
That uncertainty matters because many of the older compounds studied here have already been phased out, even if they have not disappeared from the world around us. Newer versions may be shorter-chain chemicals, but experts say there is still a lot to learn about how they behave in the body and what they may do over time.
Medical oncologist Dr. Tiffany Troso-Sandoval said PFAS are the kind of exposure that can quietly stack up and create trouble later. She noted that the study stood out because the association appeared only in the ER-negative subtype, not across all breast cancers.
She also raised the possibility that PFAS may damage DNA or interfere with the body’s ability to repair it or clear out damaged cells. Even so, she stressed that the study shows association, not proof that the chemicals caused the cancers.
The practical side of the story is what makes it hit home. Researchers and doctors alike say exposure may be modifiable, which means everyday choices still matter even when the chemicals themselves are stubborn and long-lasting.
Troso-Sandoval pointed to common exposure sources such as drinking water, cookware and utensils, and cosmetics or personal care products. She also suggested paying close attention to the items used most often, since those are the easiest to swap first.
Her advice was straightforward: use stainless steel pots and pans when possible, avoid heating food in plastic containers, and be cautious about products that may contain PFAS or other questionable additives. It is not about panic, just a better look at what is touching food, skin, and water every day.
