Study: E-Cigarette Use May Lead to Same Cancer-Related Molecular Changes as Cigarettes

E-cigarette users can develop molecular changes in oral tissue, some of which are the same as seen in cigarette smokers, that may be tied to eventual cancer development, according to a new study published in the International Journal of Molecular Science.¹

The findings challenge some assertions that e-cigarette vaping is a harmless alternative to smoking cigarettes. Although e-cigarettes have lower concentrations of carcinogenic compounds than cigarettes, any level of carcinogenic exposure can have negative health effects, according to the study.¹

E-cigarette use has significantly increased over recent years, with a particular uptick in prevalence of youth vaping. Despite its popularity, there is currently limited research on the safety of vaping. In addition, there is growing concern that e-cigarette use may lead to nicotine addiction and smoking uptake, especially among adolescents.

A JAMA Network Open study reported that adolescents who used e-cigarettes before trying any other tobacco products were more than 4 times as likely to be smoking traditional cigarettes within a couple of years.² However, other studies have suggested that vaping can offer a benefit to individuals attempting to quit smoking. A recent study involving approximately 900 smokers found that 18% of e-cigarette users were smoke-free after 1 year, compared with 9.9% who tried quitting using other products, such as patches, gum, lozenges, and sprays.³

In the current study, the researchers determined that vaping may cause molecular changes that can potentially lead to cancer development, adding to the mounting concerns over the long-term effects of e-cig use. The study focused on the oral epithelial cells which line the mouth. Over 90% of smoking-related cancers originate in epithelial tissue, they noted. The researchers examined gene expression in oral cells collected from 42 e-cig users, 24 cigarette smokers, and 27 individuals who didn’t smoke or vape.¹

Both smokers and vapers showed abnormal expression in a large number of genes linked to cancer development. In e-cig users, 26% of the deregulated genes were identical to those found in smokers. The researchers noted that some deregulated genes found in e-cig users, but not in smokers, can also be implicated in lung cancer, esophageal cancer, bladder cancer, ovarian cancer, and leukemia. These molecular changes are not an indication of cancer, or even pre-cancer, but represent an early warning signal of a process that could potentially develop into cancer in the future.¹

“Our findings warrant further investigations into the long-term effects of vaping not only in regular e-cig users but also in non-users who are involuntarily exposed to secondhand e-cig vapor, eg, children and fetuses of vaping pregnant mothers,” the researchers wrote in the study.¹

The researchers will be launching another study to examine changes in gene regulation among smokers who switch from cigarettes to e-cigarettes.¹

References

• Tommasi S, Caliri AW, Caceres A, et al. Deregulation of biologically significant genes and associated molecular pathways in the oral epithelium of electronic cigarette users. International Journal of Molecular Sciences. 2019. Doi: 10.3390/ijms20030738.

• Berry KM, Fetterman JL, Benjamin EJ, et al. Association of electronic cigarette use with subsequent initiation of tobacco cigarettes in US youths. JAMA Network Open. 2019. Doi: 10.1001/jamanetworkopen.2018.7794.

• Hajek P, Phillips-Waller A, Przulj D, et al. A randomized trial of e-cigarettes versus nicotine-replacement therapy. New England Journal of Medicine. 2019. Doi: 10.1056/NEJMoa1808779