'Forever chemicals' could heighten risk, NIH says

Key Points:

• NIH researchers found no clear overall link between PFOA and PFOS chemicals and breast cancer, but identified an association with higher risk of estrogen receptor-negative (ER-negative) breast cancer, a more aggressive subtype with few known risk factors.
• ER-negative breast cancers lack estrogen receptors, making them less understood and harder to treat, so the potential link to PFAS chemicals is significant for future research and prevention efforts.
• PFOA and PFOS are part of PFAS, or “forever chemicals,” which persist in the environment and human bodies; although their use has declined in the US, exposure remains widespread.
• The study analyzed blood samples from over 1,600 women who developed breast cancer and compared them to controls, using data from the long-term Sister Study, and suggested PFAS might influence cancer risk through immune or genetic pathways beyond hormonal effects.
• Researchers emphasize the need for further studies on newer PFAS chemicals and caution that while reducing exposure could potentially lower risk, causation has not been established and more evidence is required.