Perfluorooctane Sulfonate and Perfluorooctanoic Acid in Surgical Thyroid Specimens of Patients with Thyroid Diseases

Abstract

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are ubiquitous compounds that may act as endocrine disruptors, neurotoxic agents, and fetal development perturbing substances and may also be carcinogenic, as recently demonstrated in experimental animal models. There is little information on the potential for these compounds to affect the thyroid. Therefore, this study was performed to measure the intrathyroidal levels of PFOA and PFOS in surgical specimens of thyroid glands and to determine if there was a relationship between the concentrations of these substances and the clinical, biochemical, and histologic phenotype of the patients from whom the thyroids were obtained. We also sought to determine if there was a relationship between tissue and serum levels of both PFOA and PFOS. PFOA and PFOS were measured in 28 patients undergoing thyroid surgery for benign (15 multinodular goiters and 7 Graves' disease) and malignant (5 papillary and 1 follicular carcinoma) thyroid disorders. PFOA and PFOS were detectable in all surgical specimens of thyroid tissue. Their median concentrations were 2.0 ng/g (range = 0.4-4.6 ng/g) and 5.3 ng/g (range = 2.1-44.7), respectively. Intrathyroidal concentrations of PFOA and PFOS were similar in the thyroids of patients with thyroid diseases as in thyroid glands obtained at autopsy. There was no relationship between the intrathyroidal concentrations of either PFOA or PFOS and the underlying thyroid disease. A significant correlation between the serum and the tissue levels of PFOS was found in all patients. The serum concentrations of PFOA and PFOS were significantly higher than those in the correspondent surgical specimens. These observations do not support the view that PFOA and PFOS are actively concentrated in the thyroid. PFOA and PFOS, however, are both found in surgical and autopsy thyroid specimens. Therefore, further studies to determine if they have disrupting effects in thyroid cells or tissue, and studies to compare populations with and without these compounds in their thyroid glands, are important.