A major scientific review has concluded that e-cigarettes are likely to cause cancer. The finding could reshape how governments, health bodies and the public think about vaping. Published in the journal Carcinogenesis on 31 March 2026, the study offers one of the most comprehensive assessments of the e-cigarette cancer risk to date. It raises serious questions about a product long marketed as a safer alternative to smoking.
What the Review Found About E-Cigarette Cancer Risk
Professor Bernard Stewart, a cancer researcher at the University of New South Wales (UNSW) in Sydney, led the review. His team examined a wide body of evidence including clinical data, animal studies and laboratory experiments. The central finding was stark: nicotine-based vapes are “likely to be carcinogenic to humans.”
“Considering all the findings, from clinical monitoring, animal studies and mechanistic data, e-cigarettes are likely to cause lung cancer and oral cancer,” Professor Stewart said during a media briefing.
Many previous studies evaluated vaping only by comparing it with cigarette smoking. This review assessed the e-cigarette cancer risk on its own terms. That distinction matters. For years, the harm reduction argument has driven public health policy on vaping. This research challenges that framing directly.
The Science Linking Vaping and Cancer
E-cigarettes have only been in widespread use for around 20 years. Long-term population studies simply do not exist yet. Rather than waiting decades for that data, researchers examined biomarkers, the early biological changes that signal cancer development.
Studies in the review show that people who vape absorb nicotine-related compounds, heavy metals and other chemicals. These substances damage DNA and trigger inflammation, both of which drive cancer.
Animal studies add further weight to the concern. In one experiment, mice exposed to e-cigarette aerosols developed lung tumours at significantly higher rates than control groups. They also showed bladder changes linked to cancer.
“There is no doubt that the cells and tissues of the oral cavity and the lungs are altered by inhalation from e-cigarettes,” Professor Stewart said.
Dual Use Is Compounding the Vaping and Cancer Threat
Researchers call it “dual use.” It describes the pattern where people use both e-cigarettes and traditional cigarettes rather than fully switching. More than half of users studied could not quit either habit.
Co-author Professor Freddy Sitas, an epidemiologist at UNSW, highlighted data from the United States. People who both vape and smoke face a fourfold increased risk of developing lung cancer compared with those who do neither.
The global vaping industry is worth an estimated $30 billion to $46 billion. Major tobacco companies including Altria Group, British American Tobacco and Imperial Brands have invested heavily in e-cigarettes. For those companies, these findings carry significant commercial and regulatory weight.
A Warning From History
The review draws an uncomfortable parallel with the history of tobacco research. Scientists took decades to prove conclusively that cigarette smoking causes lung cancer. Early warning signs existed long before the field reached consensus. The authors argue researchers should not repeat this mistake with vaping and cancer.
“We should not wait another 80 years to decide what to do,” Professor Sitas said.
The concern grows sharper given how quickly vaping has spread among young people. A generation is now growing up with the habit. The long-term consequences remain unknown.
What E-Cigarette Cancer Risk Means for Public Health
Countries including New Zealand and the United Kingdom have actively encouraged smokers to switch to vaping. The new analysis questions whether those approaches adequately account for the long-term vaping and cancer relationship.
Health experts involved in the study were clear on one point. Their findings should not push smokers back to cigarettes, which remain far more harmful.
“We have always assumed that vapes are safer than cigarettes, but what we are showing is that they might not be safe after all,” Professor Sitas said.
The assessment remains qualitative. Researchers have not yet produced a numerical estimate of cancer risk. Even so, reviews over the past decade have moved steadily from uncertainty toward serious concern about carcinogenic effects.
The Bottom Line
The e-cigarette cancer risk is real, even if scientists cannot yet put a precise number on it. The idea that vaping carries no meaningful health consequences has always rested more on a lack of evidence than on proof of safety.
This review brings the long-term consequences of vaping into sharper focus. Governments, regulators and individuals now face a clear question. Act on the evidence now, or wait for certainty that may arrive too late.
(Source: WRD News)