NIH study finds 2 ‘forever chemicals’ associated with higher risk of aggressive breast cancer

A study released Nov. 5 by the National Institutes of Health found that women with higher blood levels of two common per- and polyfluoroalkyl substances, or PFAS, have a higher risk of developing an aggressive form of breast cancer known as estrogen receptor-negative, or ER-negative. PFAS are a large group of chemicals used in common consumer products and are often referred to as "forever chemicals," since they do not break down easily in the environment and can remain in the body for years. The study found women with higher levels of perfluorooctanoic acid, or PFOA, and perfluorooctanesulfonic acid, or PFOS, were associated with higher rates of ER-negative breast cancer.

The NIH said there was no clear association found between the two chemicals and overall breast cancer risk. Researchers measured 17 PFAS in blood that was collected from women years before they were diagnosed with cancer. Those in the group with the highest PFOA levels had a 67% higher rate of ER-negative breast cancer than those in the lowest group. For women with the highest PFOS levels, the rate was 93% higher.