Association between Serum 6:2 Chlorinated Polyfluorinated Ether Sulfonate Concentrations and Lung Cancer

6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) exhibits pronounced estrogenic effects, potentially influencing the etiology of lung cancer. This study assessed the potential associations between serum concentrations of 6:2 Cl-PFESA and lung cancer risk at the population level. Odds ratios (ORs) for lung cancer across serum 6:2 Cl-PFESA quartiles were assessed using conditional logistic regression. Additionally, we investigated potential effect modification by various confounding factors. Elevated serum levels of 6:2 Cl-PFESA were consistently associated with an increased risk of lung cancer in both the crude model (OR = 1.62, 95% CI: 1.08-2.42, <i>p</i> = 0.018) and the adjusted model (OR = 1.59, 95% CI: 1.06-2.39, <i>p</i> = 0.026). Stratified analyses revealed that elevated serum levels of 6:2 Cl-PFESA were associated with increased risk estimates of lung cancer among males (adjusted OR = 2.04, 95% CI: 1.19-3.51, <i>p</i> = 0.006), smokers (adjusted OR = 2.48, 95% CI: 1.25-4.89, <i>p</i> = 0.003), and drinkers (adjusted OR = 2.20, 95% CI: 0.94-5.16, <i>p</i> = 0.049). The results of this study imply that exposure to 6:2 Cl-PFESA at levels considered environmentally relevant may be linked to an elevated risk of developing lung cancer.