An NIH study found women with high blood levels of two forever chemicals had up to 93% higher rates of ER-negative breast cancer, an aggressive form of the disease.
A National Institutes of Health study has linked two common "forever chemicals" to higher rates of an aggressive form of breast cancer, according to research published in the Journal of Clinical Oncology.
Women with higher blood levels of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) were more likely to develop estrogen receptor-negative, or ER-negative, breast cancer, the NIH said. The study found no clear link between either chemical and breast cancer risk overall.
Women in the highest PFOA exposure group had a 67% higher rate of ER-negative breast cancer than women in the lowest group. For PFOS, the highest exposure group showed a 93% higher rate, nearly twice that of the lowest group.
"Our findings, which we confirmed using a meta-analysis of prior research, indicate that certain legacy PFAS, including PFOA and PFOS, are associated with a higher risk of ER-negative breast cancer, a more aggressive tumor type with few known risk factors," explained NIH Stadtman Investigator Alexandra White, Ph.D., who led the study.
The percentages represent relative differences between groups rather than the absolute probability that an individual woman will develop breast cancer. The findings establish an association, not proof that the chemicals directly cause the disease.
The analysis used data from the Sister Study, conducted by NIH's National Institute of Environmental Health Sciences (NIEHS). Between 2003 and 2009, the study enrolled 50,884 women ages 35-74 from across the United States and Puerto Rico. All participants were free of breast cancer when they enrolled, although each had a full or half-sister who had already been diagnosed with the disease.
For the PFAS investigation, researchers analyzed information from 1,609 women who subsequently developed breast cancer and a comparison group of 2,269 women. The researchers measured concentrations of 17 different PFAS chemicals in blood samples collected years before participants received a cancer diagnosis.
ER-negative breast cancer differs from more common forms because its tumor cells lack the receptors that allow estrogen to stimulate cancer growth. These cancers are often more aggressive and generally have poorer outcomes than tumors that respond to estrogen.
PFOA and PFOS belong to a large family of per- and polyfluoroalkyl substances, commonly called PFAS. These chemicals have been used in numerous everyday consumer products and are often described as "forever chemicals" because they resist breaking down in the environment. They can also accumulate in the human body and remain there for years.
Both substances have largely been phased out and replaced with other PFAS compounds, but measurable amounts are still present in most people's bodies. The researchers said additional investigations should focus on populations with greater PFAS exposure and on newer replacement PFAS chemicals.
"More research is needed, particularly evaluating the risk of breast cancer associated with newer replacement PFAS chemicals," White said.
The research received support from NIEHS grants Z01ES044005; Z1AES103332; and R01ES032831.
Sources
This article was drafted with AI assistance and checked against the sources above. Company claims are reported as claims. Cover image is AI-generated.
The day's checked news, by email
One short email a day with the top stories. Free, and you can unsubscribe in one click.
Or follow for the latest news:
No comments yet. Start the discussion.
Denmark's nationwide RSV vaccination program for pregnant people, launched October 1, 2025, led to a sharp drop in infant hospital admissions, according to research published in Nature.
Preliminary research found cardiac arrest was mentioned about 11 times more often in FDA reports involving caffeinated energy drinks and stimulant supplements than in reports involving products without those ingredients.
