PFAS Update: Thyroid Cancer
The incidence of thyroid cancer has been increasing over the past few decades. This increase could be attributed to over diagnosis due to the improved access to diagnostic tools which lead to the detection of small, non-threatening thyroid cancers. However, there is a growing body of evidence that supports a true rise in thyroid cancer incidence. Apart from well-known risk factors such as obesity and exposure to ionizing radiation, exposure to endocrine-disrupting chemicals (EDCs) has been identified as a potential risk factor that requires further investigation. Per- and polyfluoroalkyl substances (PFAS) are a group of harmful chemicals that persist in the environment and are found everywhere. Many institutions have emphasized the urgent need to investigate the potential negative health impacts of exposure to PFAS. The International Agency for Research on Cancer (IARC) has classified one type of PFAS, perfluorooctanoic acid (PFOA), as possibly causing cancer. The National Academies of Sciences, Engineering, and Medicine (NASEM) recommends testing for PFAS followed by thyroid function testing in patients who have been highly exposed to PFAS. The European Union and the United States Environmental Protection Agency have both recognized that exposure to PFAS (per- and polyfluoroalkyl substances) can pose a significant risk to human health. Although there is evidence linking PFAS exposure to certain types of cancer and thyroid dysfunction, studies investigating the link between PFAS and thyroid cancer have yet to yield conclusive results, and no longitudinal studies have been conducted on the matter.
The study we are featuring this week supports the idea that PFAS exposure increases one’s risk of thyroid cancer by providing further evidence for a causal link. PFAS needs to be removed from our environment as more and more evidence emerges suggesting carcinogenic associations. This particular study focuses on the link to thyroid cancer in particular. Spoiler alert, they found that an increased level of exposure to PFAS chemicals (about double the exposure) increased the risk and occurrence of thyroid cancer by about 52%.
