E-cigarettes are likely carcinogenic to users, according to a qualitative risk assessment that pulls together human biomarker data, animal studies, and mechanistic evidence.
Scientists found that vape-derived metabolites are associated with DNA damage caused by carcinogens such as nicotine-derived nitrosamines, volatile organic compounds, and certain metals. Additional biomarkers pointed to oxidative stress, epigenetic changes, and inflammation in oral and respiratory tissues.
In a rodent study, mice exposed to e-cigarette aerosol developed lung adenocarcinomas in 22.5% of cases. The aerosol mixture may act through both genotoxic and non-genotoxic pathways.
The findings reinforce a precautionary stance: e-cigarettes should not be promoted as a risk-free alternative to smoking. Clinicians are urged to recognize that biologically plausible pathways now link vaping with oral and lung cancer risk, even though the full cancer burden remains undetermined.