Perfluorooctanoic acid and cancer incidence: an updated investigation of a cohort in the mid-Ohio Valley.
TL;DR
The findings in this high PFOA-exposed cohort provide additional epidemiologic evidence of increased kidney and testicular cancer risk, as well as new evidence of associations with thyroid and pancreatic cancers, which have important implications regarding understanding of the carcinogenic potential of PFOA and the cancer burden related to this ubiquitous environmental contaminant.
Abstract
Background
Perfluorooctanoic acid (PFOA) has been classified as a human carcinogen based partly on limited epidemiologic evidence of increased kidney and testicular cancer risk. We conducted an updated analysis of cancer incidence in a high PFOA-exposed cohort of community members and workers in the mid-Ohio Valley with follow-up extended by approximately 10 years on average and linkage to the Virtual Pooled Registry-Cancer Linkage System to better characterize risk of malignancies of a priori interest and to explore risk of other cancers.
Methods
Based on estimates of annual serum PFOA concentrations during 1952-2020, we evaluated associations between cumulative PFOA exposure and site-specific cancer incidence through 2020 among 32,050 participants (28,398 community members and 3,652 workers). Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards models adjusted for potential confounding factors.
Results
In the overall study population, we observed positive associations with kidney and testicular cancers. Associations with kidney cancer for high PFOA exposure were most pronounced among younger community members (≤60 years: HRQ4 = 1.82, 95% CI 1.02-3.26; Ptrend = 0.03) and those with localized disease (HRQ4 = 1.72, 95% CI 1.01-2.95; Ptrend = 0.17). High PFOA exposure was also associated with increased testicular cancer risk among community members (HRQ4 = 3.62, 95% CI 1.03-12.7; Ptrend = 0.12). We also observed positive associations with thyroid cancer, particularly among female participants, and with pancreatic cancer among older participants; notably, exposure-response relationships for both thyroid and pancreatic cancer were strongest among the more highly exposed workers (per 1-unit increase on the natural log scale, HRcont = 1.79, 95% CI 1.07-2.97; and HRcont = 1.70, 95% CI 1.08-2.67 for thyroid and pancreatic cancers, respectively).
Conclusions
Our findings in this high PFOA-exposed cohort provide additional epidemiologic evidence of increased kidney and testicular cancer risk, as well as new evidence of associations with thyroid and pancreatic cancers. These findings have important implications regarding our understanding of the carcinogenic potential of PFOA and the cancer burden related to this ubiquitous environmental contaminant.