Do forever chemicals cause thyroid cancer? Study reveals alarming link between the two

A recent study published in eBioMedicine has uncovered concerning connections between exposure to per- and polyfluoroalkyl substances (PFAS) and the rising trend of thyroid cancer. While suspicions have lingered regarding PFAS exposure as a contributor to thyroid cancer, limited research has delved into this association within human populations. This study sought to bridge that gap, investigating the link between plasma PFAS levels and thyroid cancer diagnoses.

The study conducted a nested case-control investigation, focusing on patients diagnosed with thyroid cancer with plasma samples collected at or before the time of diagnosis. It involved 88 patients with thyroid cancer, using diagnosis codes, and pair-matched them with 88 healthy non-cancer controls. The matching criteria included sex, age (within 5 years), race/ethnicity, body mass index, smoking status, and the year of sample collection. Among the thyroid cancer patients, 74 had papillary thyroid cancer.

Eight plasma PFAS were measured using an untargeted analysis with liquid chromatography-high-resolution mass spectrometry and suspect screening. The study revealed a substantial 56% increase in the rate of thyroid cancer diagnosis per doubling of linear perfluorooctanesulfonic acid (n-PFOS) intensity. The adjusted odds ratio indicated a significant risk. When narrowing the focus to patients with papillary thyroid cancer, the findings were similar.

Further analysis into the timing of exposure unveiled that the positive association persisted for patients diagnosed with thyroid cancer more than a year after plasma sample collection.

Reference: Per- and polyfluoroalkyl substances (PFAS) exposure and thyroid cancer risk, Maaike van Gerwen et al, Published:October 24, 2023 DOI:https://doi.org/10.1016/j.ebiom.2023.104831