THCa Vape Pens: Benefits, Risks, and Safer Use Guidelines Best of 2014: The 12 vape pens we loved the most this year, reviewed The Denver Post Evidence update on the cancer risk of vaping e cigarettes: A systematic review Many people believe that vaping is less harmful than smoking, but that's a common misconception. In fact, in addition to nicotine, vapes can contain toxic chemicals that could be linked to cancer, Is vaping safer than smoking? A pulmonologist weighs in.