Flach S, et al. - Researchers examined how e-cigarettes are correlated to head and neck (HN) cancers by performing a qualitative systematic review. Searching Pubmed/Medline, Cochrane, CINAHL Plus, Trip medical database and Web of Science they identified 359 relevant articles and selected 18 articles for use in this review. Exposure to e-cigarettes was suggested to cause DNA-damage potentially by increasing oxidative stress in a few studies. More harm seemed to be caused by flavored e-liquids.