UNSW Review Finds Vaping Likely Causes

UNSW Review Finds Vaping Likely Causes Lung and Oral Cancer

By kevin Li Updated Aug 24, 2026 3 min read

A comprehensive new review led by researchers at UNSW Sydney has concluded that nicotine-based e-cigarettes are likely to cause cancers of the lung and oral cavity. Published June 21 in the journal Carcinogenesis, the review evaluated evidence across clinical monitoring, animal studies, and laboratory investigations. The findings were reported by ScienceDaily and the original study is indexed on PubMed (Stewart et al., Carcinogenesis 2026, 47(1)).

What the Review Found

The research team, which included specialists from pharmacy, epidemiology, thoracic surgery, and public health at institutions including the University of Queensland, Flinders University, and Royal North Shore Hospital, examined multiple lines of evidence:

Chemical analysis: E-cigarette aerosols contain known carcinogens including volatile organic compounds and metals released by heating coils.
Biomarker evidence: Vapers show biomarkers indicating DNA damage, oxidative stress, and tissue inflammation — the same biological signals seen in smokers.
Animal studies: Mouse studies have produced lung tumors following e-cigarette aerosol exposure.
Cell-level damage: Laboratory experiments show cellular injury and disruptions to biological processes linked to cancer development.

“To our knowledge, this review is the most definitive determination that those who vape are at increased risk of cancer compared to those who don’t,” said Professor Bernard Stewart, the lead author.

The review explicitly addresses a question many vapers ask: is vaping safer than smoking? The answer is more nuanced than a simple yes or no.

Vaping exposes users to fewer total toxins than combustible cigarettes. But “fewer toxins” does not mean “no risk.” The review found that the evidence for carcinogenicity was consistent across every research method examined — clinical, animal, and mechanistic.

Co-author Associate Professor Freddy Sitas noted that e-cigarettes are “known to be a gateway to smoking and hence cancer,” but added that the review focused on whether vaping could cause cancer independently of smoking. The evidence suggests it can.

What the Review Does Not Say

The authors were careful to note limitations. The assessment is qualitative — it does not estimate the exact number of cancer cases attributable to vaping. “We’ll only be able to determine the precise risk once longer-term studies are available,” Professor Stewart said.

This matters because e-cigarettes have only been widely available since the early 2000s. Lung cancer typically takes decades to develop. The review’s conclusion is based on mechanistic and animal evidence, not on long-term human epidemiology, which will take another 10-20 years to accumulate.

Context: Other Recent Studies

This review arrives alongside a wave of new research on vaping health risks:

A Nature Medicine study published June 8 found that using e-cigarettes after quitting smoking was associated with a 23% higher lung cancer risk compared to quitting nicotine entirely. A separate Nature review on vaping and erectile dysfunction identified biological mechanisms linking e-cigarette use to vascular damage.

Research on cooling agents WS-3 and WS-23 used in “ice” vape flavors has also raised concerns about cardiovascular effects.

If you vape to quit smoking, the harm reduction calculus still applies: switching from cigarettes to vaping reduces exposure to the thousands of chemicals in tobacco smoke. But this review makes clear that vaping is not risk-free, and long-term use carries cancer concerns that are still being quantified.

For non-smokers, especially young people, the message is clearer: there is no known safe level of exposure to carcinogenic compounds, and starting vaping introduces cancer risk where none existed before.

If you are using vaping as a cessation tool, work toward a plan to eventually stop nicotine use entirely. The evidence increasingly suggests that long-term vaping carries real health risks, even if those risks are lower than smoking.