Abstract 2309: An ecological study on environmental exposure to PFAS and thyroid cancer incidence rates by races/ethnicities in Florida
Authors: Ming S. Lee, Laura Wild, Niko DiStefano, Garrett Forman, Elizabeth Franzmann, Natasha Solle, Alberto Caban-Martinez, Erin Kobetz
Journal: Cancer Research (2025)

Abstract Background: The incidence rate of thyroid cancer in the US has increased significantly over the last few decades. However, besides radiation exposure and obesity, no modifiable risk factors have been identified for thyroid cancer. Although theories suggest exposure to per- and polyfluoroalkyl substances (PFAS) could contribute to the development of papillary thyroid cancer, existing studies on the effects of PFAS on thyroid cancer risk do not yield consensus results. Using data for the state of Florida, this ecological study aims to determine whether incidence rates of thyroid cancer vary with respect to residential proximity to industrial facilities handling PFAS materials as well as living in areas where drinking water containing detectable levels of PFAS. Methods: Florida cancer registry data from 2011 to 2020 was used to calculate the incidence rates of papillary thyroid cancer by race/ethnicity (Hispanic, non-Hispanic White (NHW), and non-Hispanic Black (NHB)) for all census tracts in Florida. Environmental Protection Agency data was used to identify the locations of industrial facilities handling PFAS as well as ZIP codes with public drinking water testing positive for PFAS above reportable levels. A geographic information system was used to calculate the number of PFAS facilities within 10KM of a census tract. Correlation, linear regression, and t-tests for sample mean comparison were used to assess the associations between PFAS exposure and thyroid cancer rates at the census tract level. Results: A total of 14,994 cases (9,213 in NHWs, 3,995 in Hispanics, and 989 in NHB) of thyroid cancers were diagnosed in Florida from 2011 to 2020. Correlation analyses show a positive correlation between residential proximity to PFAS facilities and greater Hispanic and NHB population compositions by higher percentages of (r=0.36, p&amp;lt;0.001) with lower income (r=-0.192, p&amp;lt;0.001)) and higher obesity rate (r=0.197, p&amp;lt;0.001)). Regression analyses show that proximity to PFAS facilities is a significant factor for thyroid cancer rates in Hispanic (p=0.006) and NHW (p&amp;lt;0.001). Hispanic and NHW living are in IPZIP code areas with reportable PFAS in drinking water also have higher average thyroid cancer rates than those in areas with no reportable PFAS (t-test p=0.036 for Hispanic and p=0.039 for NHW). With a lower average incidence rate than Hispanic and NHW, thyroid cancer rates in NHB show no statistically significant associations to PFAS exposure. Conclusions: ecological Our findings suggest potential effects of environmental PFAS exposure on thyroid cancer disparities. set up trials to validate these effects by sampling volunteers for blood-level PFAS measurement from neighborhoods with different levels of PFAS exposure (facility proximity and drinking water). Citation Format: Ming S. Lee, Laura Wild, Niko DiStefano, Garrett Forman, Elizabeth Franzmann, Natasha Solle, Alberto Caban-Martinez, Erin Kobetz. An ecological study on environmental exposure to PFAS and thyroid cancer incidence rates by races/ethnicities in Florida [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2309.