A scientific review has raised fresh concerns about the long term cancer risks of vaping, concluding that e cigarettes are probably carcinogenic, while also acknowledging significant gaps in the evidence. The analysis of reviews Where There's Vapor, Is There Fire? We Need Evidence on E Cigarettes RAND Evidence strengthens that vaping is effective for stopping smoking but not reaching its full potential with adult smokers King's College London New Study Provides Strong Evidence That E Cigarettes Boost Smoking Cessation Why Youth Vape Smoking and Tobacco Use CDC That big claim that vaping leads to smoking may be based on insubstantial evidence