Exposure to per-and polyfluoroalkyl substances and early-onset cancers.

Environmental exposures, such as per-and polyfluoroalkyl substances (PFAS), are suspected to play a role in the significant increase in incidence of some early-onset cancers. PFAS are chemicals of concern due to their persistence in the environment, long biological half-lives, and potential carcinogenic properties. Exposure during sensitive windows of development may exert durable effects on cancer-related biological pathways leading to greater risks of early-onset cancers. This review summarizes the current evidence of PFAS exposure and early-onset carcinogenesis, with an emphasis on potential exposure routes, early-onset cancer development in humans linked with PFAS exposure, and mechanistic pathways. Emerging evidence supports a potential role for PFAS exposure in carcinogenesis during early life, particularly through prenatal and early postnatal windows of susceptibility. While epidemiologic studies increasingly link PFAS to several types of cancer, the evidence specifically addressing early-onset cancers remains limited and heterogeneous. Future research should prioritize prospective, longitudinal cohort studies with repeated exposure measurements spanning prenatal, infancy, and childhood periods, coupled with long-term follow-up into early adulthood to capture early-onset cancer outcomes.