Australian Researchers Uncover Strongest Evidence Linking Vaping to Lung and Oral Cancer

Australian Universities Lead Groundbreaking Review on Vaping Risks

Researchers from the University of New South Wales (UNSW Sydney), in collaboration with experts from the University of Queensland, Flinders University, and the University of Sydney, have published what they describe as the most definitive evidence to date linking nicotine-based electronic cigarettes, commonly known as vapes, to an increased risk of lung and oral cancers. This comprehensive qualitative risk assessment, appearing in the prestigious journal Carcinogenesis, shifts the conversation around vaping from a perceived safer alternative to traditional cigarettes to a product likely carcinogenic on its own merits.

Led by Adjunct Professor Bernard Stewart AM at UNSW Sydney's School of Population Health, the multidisciplinary team—including epidemiologists, pharmacists, thoracic surgeons, and public health specialists—analyzed peer-reviewed studies published between 2017 and mid-2025. Their work emphasizes vaping's independent cancer-causing potential, separate from any history of tobacco smoking, drawing parallels to the historical lag in recognizing cigarette dangers that spanned decades.

The Surge of Vaping Among Australian Youth and University Concerns

Australia has witnessed a sharp rise in vaping, particularly among young people affiliated with higher education environments. Recent data indicates that approximately 30 percent of secondary school students have tried vaping at least once, with 12.9 percent of 12- to 15-year-olds reporting use in the past month. Among 14- to 17-year-olds, ever-use has nearly tripled from 9.6 percent in 2019 to 28 percent by 2022-2023, a trend continuing into university-aged populations where about 1.5 million Australians, mostly young adults aged 18-24, report current use.

Universities like UNSW and the University of Sydney have expressed alarm over this trend, noting vapes as a gateway to nicotine addiction on campuses. Associate Professor Freddy Sitas from UNSW highlighted that many young vapers have never smoked, positioning vaping as a novel risk in academic settings where stress and social pressures amplify experimentation.

Methodology: A Rigorous Multi-Disciplinary Approach

The review employed a qualitative risk assessment framework akin to those used by the International Agency for Research on Cancer (IARC), evaluating evidence across five key domains: chemical composition of e-liquids and aerosols, absorption and biomarkers in humans, tissue alterations in the oral cavity and lungs, animal experimentation, and clinical observations. Unlike quantitative meta-analyses, this approach synthesized mechanistic, clinical, and epidemiological insights to classify vaping's carcinogenicity without relying on long-term incidence data, which is unavailable due to vaping's relatively recent emergence around 20 years ago.

Over 100 studies were scrutinized, revealing consistent patterns. For instance, laboratory analyses identified volatile organic compounds (VOCs) like formaldehyde and acrolein—known carcinogens found in herbicides and disinfectants—in vape aerosols. Heavy metals such as nickel, chromium, and lead leach from heating coils, while flavorings like cinnamaldehyde exhibit cytotoxic effects.

Key Evidence: Carcinogenic Compounds and Biological Mechanisms

At the core of the findings are the toxicants in nicotine vapes. E-liquids, when heated, produce aerosols containing nearly all ten IARC-defined key characteristics of carcinogens, including DNA reactivity, genotoxicity, and immune suppression. Human biomarker studies detected nicotine metabolites, carcinogenic metals, and organic compounds in the blood and urine of exclusive vapers, alongside DNA adducts and mutations in oral and lung epithelial cells.

Oxidative stress and chronic inflammation—precursors to cancer—were evident in biopsied tissues, observable via microscopy and molecular assays. Animal models provided compelling support: mice exposed to vape aerosols developed lung adenomas and hyperplasia, mirroring early tobacco-induced changes. Clinical case reports, including a 19-year-old non-smoker with oral squamous cell carcinoma attributed to heavy vaping, underscore real-world plausibility.

• DNA damage from aldehydes like formaldehyde, which binds to genetic material.
• Metal-induced oxidative stress disrupting cellular repair pathways.
• Flavoring agents impairing ciliary function in airways, promoting carcinogen retention.

Independence from Smoking: Dual-Use Risks Amplified

Crucially, the review disentangles vaping from smoking. While dual-users face a four-fold elevated lung cancer risk compared to smokers alone (per a 2024 U.S. study), exclusive vapers show biomarker profiles akin to moderate smokers. Professor Stewart noted, "This review is the most definitive determination that those who vape are at increased risk of cancer compared to those who don’t." Nicotine-free vapes fare no better, harboring the same irritants and metals.

UNSW's detailed announcement elaborates on these distinctions, urging academic institutions to prioritize vaping cessation programs.

Australia's Evolving Vaping Regulations and Academic Advocacy

Australia's policy landscape has tightened progressively. Since October 2021, nicotine vapes require a prescription; from 2024, sales shifted to pharmacies exclusively for therapeutic use in quitting smoking, with disposable bans and nicotine caps at 20mg/mL. Yet, a thriving black market—fueled by illicit imports with hidden nicotine and incomplete labeling—undermines these measures, prompting $345 million in enforcement since 2024.

University researchers advocate fuller enforcement, likening delays to the 80-year tobacco lag before the 1964 U.S. Surgeon General's report. Becky Freeman from the University of Sydney emphasized, "Our laws would be the best in the world if enforced," calling for campus-wide education.

Stakeholder Perspectives: From Researchers to Regulators

Diverse voices converge on caution. Alexander Larcombe from Curtin University warns of black market perils, while Richard Edwards from Flinders University advises, "If you don't smoke, don't start vaping." Cancer organizations like Cancer Institute NSW reinforce that vapes deliver toxins akin to cigarettes, albeit potentially lower doses initially.

Academics stress multidisciplinary collaboration, as seen in this UNSW-led effort spanning public health, oncology, and epidemiology departments.

Implications for Higher Education and Campus Health

Universities face a dual challenge: protecting student health while advancing research. This study exemplifies higher education's pivotal role in evidence-based policy, with UNSW's integration of clinical and lab data setting a benchmark. Campuses report rising vaping-related queries in health services, prompting initiatives like peer-led workshops and integration with mental health support, given nicotine's anxiogenic effects.

Future academic research priorities include longitudinal cohorts tracking exclusive vapers, vital for quantifying risks in populations like university students.

Solutions and Actionable Insights for Vapers and Institutions

• Seek pharmacy-sourced vapes only under professional guidance for quitting.
• Utilize evidence-based cessation aids like nicotine replacement therapy (NRT) or behavioral counseling.
• Universities: Implement vape-free policies, akin to January 2026 school bans, and fund biomarker screening pilots.
• Monitor for early signs: persistent oral lesions or cough warranting dental/medical review.

Professor Stewart urges immediate action: "We should not wait another 80 years."

For deeper insights, explore the review's explanatory article.

Global Context and Future Research Directions

While Australia leads in regulation, global vaping surges, with similar youth trends. This review informs IARC classifications, potentially elevating vapes to Group 1 or 2A carcinogens. Ongoing trials at Australian universities probe mitigation strategies, like safer e-liquid formulations, though experts prioritize prevention.

Prospects include AI-driven cohort analysis accelerating timelines, ensuring higher education remains at the vanguard of public health innovation.

Stakeholders anticipate policy ripples, with calls for international harmonization. As Associate Professor Sitas notes, "The evidence was remarkably consistent... dictating an unequivocal finding now."

Photo by Jametlene Reskp on Unsplash

Broader Public Health Ramifications

Beyond cancer, vaping links to cardiovascular strain, respiratory diseases, and youth brain development impacts. Economic burdens—from treatment to lost productivity—mirror early tobacco costs. Universities, training future health professionals, integrate these findings into curricula, fostering informed generations.

In summary, this UNSW-led breakthrough underscores academia's responsibility in translating science to safeguards, potentially averting an epidemic through timely vigilance.