NIH links PFOA and PFOS exposure to higher risk of ER-negative breast cancer
A prospective study found elevated blood levels of two common PFAS chemicals were associated with up to a 93% increase in ER-negative breast cancer.
Researchers at the National Institutes of Health (NIH) have identified an association between elevated blood concentrations of two widespread per- and polyfluoroalkyl substances (PFAS) and a higher incidence of estrogen receptor-negative (ER-negative) breast cancer, according to a report published via EurekAlert from the Journal of Clinical Oncology eurekalert.org
EurekAlerteurekalert.orgOpen source ↗. The analysis demonstrated that while overall breast cancer rates did not show a clear correlation with the compounds, specific risks for more aggressive tumors rose substantially.
Investigators measured 17 individual PFAS compounds in blood samples collected years prior to diagnosis from participants in the Sister Study, a cohort led by the National Institute of Environmental Health Sciences (NIEHS). Across a nested subcohort of 1,609 women who developed breast cancer and 2,269 comparison subjects, elevated levels of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) correlated with tumor development eurekalert.org
EurekAlerteurekalert.orgOpen source ↗. Women in the highest exposure tier for PFOA experienced a 67% higher rate of ER-negative breast cancer compared to the lowest tier, while the highest PFOS group showed a 93% higher rate
eurekalert.org
EurekAlerteurekalert.orgOpen source ↗.
Biomarkers and Cohort Data
The Sister Study initially enrolled 50,884 women aged 35 to 74 across the United States and Puerto Rico between 2003 and 2009. Eligible participants had a sister diagnosed with breast cancer but were cancer-free at enrollment. Researchers confirmed the observed link between these legacy compounds and ER-negative cancer through a meta-analysis incorporating prior studies eurekalert.org
EurekAlerteurekalert.orgOpen source ↗.
Potential Biological Pathways
ER-negative breast cancers lack receptors for the hormone estrogen, which typically makes them more aggressive and harder to treat due to fewer targeted therapy options. Because these tumors do not rely on estrogen signaling, the authors suggested that PFOA and PFOS may operate through non-hormonal biological mechanisms, such as alterations in gene expression or immune function eurekalert.org
EurekAlerteurekalert.orgOpen source ↗. The authors noted that while legacy compounds have been largely phased out of manufacturing, further research is required to evaluate replacement PFAS compounds.
