The study was published on March 30 in the journal Carcinogenesis. As part of the study, researchers analyzed findings from human, animal, and laboratory research to assess whether vaping may be carcinogenic, independent of traditional tobacco smoking.
Researchers at the University of New South Wales (UNSW) in Sydney led the review, which found consistent biological signals linked to cancer development—such as DNA damage, oxidative stress, and inflammation in oral and respiratory tissues.
"Nicotine-based e-cigarettes are likely to be carcinogenic to humans who use them causing an indeterminate burden of oral cancer and lung cancer,” states the study’s abstract.
Researchers reviewed studies from 2017 to 2025, focusing on the biomarkers of exposure and harm, animal testing, and mechanistic data.
The review found evidence of carcinogenic compounds in e-cigarette aerosols, including nicotine-derived nitrosamines, volatile organic compounds, and certain metals.
Laboratory studies included rodent bioassays that found mice exposed to e-cigarette aerosols developed lung adenocarcinomas, the paper said.
Study Raises Concerns
The study notes that while direct epidemiological data linking vaping to cancer in humans is limited, evidence from multiple scientific approaches raises concern.“Considering all the findings–from clinical monitoring, animal studies, and mechanistic data–e-cigarettes are likely to cause lung cancer and oral cancer,” Stewart said.
Researchers say concerns about vaping may mirror a historical pattern seen with smoking, when early warning signs were overlooked.
Professor Stewart and Associate Professor Ingrid Sitas noted it took decades—from the 1800s until the 1964 U.S. Surgeon General’s Report on Smoking and Health—before smoking was officially recognized as a cause of lung cancer.
During that time, early evidence linking smoking to diseases such as tuberculosis, cardiovascular disease, and stroke was often dismissed.
Researchers warn a similar delay could happen with vaping. “E-cigarettes were introduced about 20 years ago. We should not wait another 80 years to decide what to do,” said Sitas.
Along with being led by Adjunct Professor Bernard Stewart of UNSW Sydney, the study was conducted with contributions from The University of Queensland, Flinders University, The University of Sydney, and major hospitals including Royal North Shore, The Prince Charles, and Sunshine Coast University.