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 e Cigarettes Safety Not Yet Proven CANSA The Cancer Association of South Africa CANSA The Cancer Association of South Africa A analysis of more than 100 studies found the vaping can have long term health consequences. Most E cigarette Users Ages 18 to 29 Never Smoked Before American Cancer Society New study comes the closest yet to proving that e cigarettes aren't as dangerous as smoking