PFAS Linked to Higher ER-Negative Breast Cancer Risk

A National Institutes of Health study found that women with higher blood levels of two legacy PFAS chemicals, PFOA and PFOS, had higher rates of estrogen receptor-negative (ER-negative) breast cancer, a generally more aggressive form of the disease. The highest-exposure groups had 67% higher rates for PFOA and 93% higher rates for PFOS than the lowest-exposure groups, while researchers found no clear association with breast cancer overall. A meta-analysis of earlier research also supported an association for PFOA, though evidence for PFOS was less conclusive. The findings show an association, not proof that the chemicals cause cancer; researchers said further investigation is warranted, and noted that exposure remains widespread despite the chemicals’ phaseout.