Exposure to per- and poly-fluoroalkyl substances and hematological cancer: A systematic review and meta-analysis.

Recent literature suggests that exposure to per- and polyfluoroalkyl substances (PFAS) may be associated with increased cancer risk. However, evidence regarding their association with hematological cancers is inconclusive. Hence, we aimed to summarize findings of epidemiological studies on the issue. We conducted a systematic review by searching Pubmed and Scopus in April 2025 to identify studies on the association between PFAS and cancer types other than liver, kidney, and testis. We pooled relative risks (RRs) and 95 % confidence intervals (CIs) for the association between PFAS exposure and hematological cancers with restricted maximum likelihood method. Fourteen studies were included in the review. We found pooled RRs of 1.04 (95 % CI: 0.98, 1.10; I2=12.0 %, phet=0.332), 1.04 (95 % CI: 0.95, 1.14; I2=0.0 %, phet=0.523), and 1.06 (95 % CI: 0.94, 1.19; I2=42.9 %, phet=0.105) for the association between environmental or occupational PFAS exposure and total hematological cancer, leukemia, and lymphoma, respectively. As for types of lymphoma, environmental or occupational PFAS exposure was associated with incidence of non-Hodgkin lymphoma (RR: 1.15; 95 % CI: 1.01, 1.29; I2=0.0 %, phet=0.579), while no association with its mortality or with Hodgkin lymphoma was observed. The RR for the association between high serum levels of perfluorooctanoic acid and total hematological cancer was 1.13 (95 % CI: 0.72, 1.75; I2=64.6 %%, phet=0.023). Our results are suggestive of an association between PFAS exposure and non-Hodgkin lymphoma. Weak associations were also observed for total hematological cancer and leukemia among male individuals. Due to potential exposure misclassification in included studies, further evidence is needed to confirm our findings.