The association between per-fluoroalkyl and poly-fluoroalkyl substances exposure and thyroid cancer: a meta-analysis

Abstract

Over the last couple of decades, thyroid cancer cases have dramatically increased in frequency year by year. According to certain research, thyroid cancer may be linked to per-fluoroalkyl and poly-fluoroalkyl substances (PFAS) exposure. Our study aimed to investigate the possible link between thyroid cancer and PFAS exposure. Three researchers have looked up the following electronic databases: PubMed, Embase, Web of Science, Scopus, Cochrane, Science Direct, Chinese BioMedical Literature Database (CBM), Wanfang Database, China Science and Technology Journal Database, and China National Knowledge Infrastructure (CNKI) to get the whole articles before March 2024. In addition, Google Scholar was used as a complementary search engine. Finally, eight articles were included in our meta-analysis. It was shown by our results that the link between thyroid cancer and PFAS exposure was not statistically significant, for perfluorononanoic acid (PFNA), odds ratio (OR): 0.71, 95% confidence interval (95% CI): 0.30–1.12; for perfluorooctane sulfonate (PFOS), OR: 0.89, 95% CI: 0.5–1.28; for PFAS mixtures, OR: 1.10, 95% CI: 0.19–2.01. Furthermore, our study revealed that perfluorooctanoic acid (PFOA) exposure could decrease the risk of thyroid cancer (OR: 0.69, 95% CI: 0.44–0.95). These associations of PFOS and PFNA with thyroid cancer were robust in sensitivity analyses. In conclusion, these results increase our knowledge of the impact of PFAS on the thyroid cancer in a novel manner. At the same time, our study has certain limitations, we encourage the inclusion of more high-quality studies in the future.