Nicotine-based vapes, or e-cigarettes, are likely to cause cancers of the lung and oral cavity, according to a new study.
The team brought together experts from multiple disciplines, including pharmacists, epidemiologists, thoracic surgeons and public health researchers. The review is one of the most detailed attempts yet to determine whether vaping itself may cause cancer, independent of tobacco smoking. The analysis draws together clinical studies, animal experiments and laboratory research examining the chemicals produced by e-cigarettes.
In the study, published in Carcinogenesis, researchers identified numerous carcinogenic compounds in e-cigarette aerosols, including volatile organic chemicals and metals released from heating coils. They examined several types of evidence: biomarkers in people showing DNA damage, oxidative stress and tissue inflammation; experiments in mice that caused lung tumors; and laboratory studies showing cellular damage and disrupted biological pathways linked to cancer. Taken together, the researchers say the evidence points strongly in one direction.
Study co-author Freddy Sitas, associate professor at New South Wales, pointed out that although the consistency of findings across the disciplines was striking, the exact number of attributable cancer cases remains unclear.
“Our assessment is qualitative and does not involve a numerical estimate of cancer risk or burden. We’ll only be able to determine the precise risk once longer-term studies are available,” said Sitas.
The study authors traced parallels between the early scientific evidence linking smoking to disease and emerging concerns about vaping. It took nearly a century of scientific investigation—from the mid-1800s to the landmark U.S. Surgeon General’s report in 1964—before smoking was officially recognized as a cause of lung cancer. During that time, early warning signs were often dismissed or overlooked. For example, early reports linked smoking to infectious diseases such as tuberculosis, followed by cardiovascular disease, stroke and lung cancer.
Sitas says the same pattern may now be unfolding with vaping—and researchers should not repeat the delay that occurred with cigarettes.
“E-cigarettes were introduced about 20 years ago. We should not wait another 80 years to decide what to do,” concluded Sitas.
Data from University of New South Wales