Blood metabolomic signatures linking air pollution to lung cancer in the Cancer Prevention Studies.

Air pollution is a leading environmental cause of lung cancer, yet the underlying biological pathways remain poorly understood. Identifying circulating biomarkers that capture early molecular responses may clarify how air pollutants contribute to carcinogenesis and help identify individuals at elevated risk. We conduct a prospective nested case-control study within two Cancer Prevention Study cohorts, profiling more than 1100 metabolites in pre-diagnostic plasma samples from 1357 participants. Residential concentrations of six major air pollutants are estimated at the time of blood draw. Here we show that eight circulating metabolites are associated with both air pollution exposure and subsequent lung cancer risk. Four metabolites, including γ-glutamylglutamine, phenylacetylglutamate, N-(2-furoyl)glycine, and 4-vinylguaiacol glucuronide, significantly mediate associations for particulate matter and ozone (adjusted q-value < 0.2). These findings suggest that air pollution may promote lung cancer partly through metabolic pathways related to inflammatory and oxidative processes, providing key insights into potential mechanisms and targets for prevention.