The Thoracic Oncology Group of Australasia (TOGA) congratulates the Clinical Oncology Society of Australia (COSA) on the release of its new report, E-cigarettes and Cancer: A Qualitative Risk Assessment.
This major qualitative risk assessment brings together years of growing research into the carcinogenic potential of vaping. The public conversation often starts with, “Is vaping safer than smoking?”;
but COSA’s report pushes us to ask a more urgent question:
“Is vaping harmful in its own right?”
And the emerging answer is clear:
E-cigarette use is not harmless — and is likely to cause cancer, especially lung and oral cancer.
Vaping has unintentionally exposed a new population to cancer risk, with limited evidence of broad population-level benefits in reducing tobacco smoking. While Australia introduced reforms in 2024, a significant number of people (especially young people) had already been exposed to the addictive effects of nicotine.
The ongoing intense debate about the role of e-cigarettes in smoking cessation, alarming youth uptake and industry interference warrants application of the growing science, evident in this research publication
E-cigarettes and cancer: What does the science say?
E-cigarettes work by heating a liquid (usually containing nicotine) into an aerosol, which is then inhaled. Despite sleek packaging and marketing, this aerosol carries a mix of known carcinogens and toxic chemicals.
COSA’s report highlights internal exposure to:
- Formaldehyde, acetaldehyde, acrolein, acrylonitrile
- Heavy metals: nickel, chromium, lead, manganese
- Nitroso-derivatives of nicotine
- Toxic by-products from heated flavouring agents
These substances don’t just exist in the vape liquid — they’ve been detected in the breath, blood, and urine of people who vape, confirming they are absorbed into the body.
Does vaping cause cancer?
The COSA report builds on years of studies across humans, animals, and molecular models, finding strong evidence for harm.
Key findings include:
- Tissue damage in the lungs and mouth of people who vape
- DNA damage, oxidative stress, and immune suppression in clinical and lab studies
- Animal studies: 25% of mice developed lung adenocarcinoma after long-term inhalation of e-cigarette aerosol
- Changes in gene expression and immune function, some similar to those seen in smokers, others unique to vapers
Although long-term population studies are still underway, the early warning signs are strong and consistent, with multiple individual case reports of oral cancer and serious lung damage linked to vaping.
Who is most likely to take up vaping?
Australia’s 2024 policy now restricts e-cigarette sales to pharmacies, but vapes remain largely accessible to a generation who had benefitted from anti-tobacco policy with limited uptake of tobacco smoking.
Before Australia introduced tighter rules on vaping, use of e-cigarettes had jumped significantly, peaking in 2023.
The people most likely to vape are different to those who still smoke traditional cigarettes. Daily vaping is especially common in younger adults — nearly 1 in 10 people aged 18–24, and around 1 in 15 people aged 25–29. Meanwhile, smoking cigarettes is most common in people aged 40–59.
There’s also a difference based on where people live. Smoking is more common in lower-income areas, while vaping is more common in wealthier.
Essentially, after years of successful anti-tobacco campaigns to decrease the risk of lung cancer, evidence is emerging that the introduction of vaping may have introduced a new and previously unexposed population to vaping-induced cancers.
In addition, research shows that people who’ve never smoked are about three times more likely to start smoking cigarettes if they use e-cigarettes, compared to those who don’t vape. This means that even without long-term studies on vaping and cancer risk, vaping could still raise someone’s risk of lung cancer indirectly by increasing the chances that they’ll go on to smoke tobacco.
Are there any benefits of e-cigarette use?
When evaluating vaping, it’s helpful to ask two distinct questions:
1. Does vaping cause harm in people who are not smokers?
Yes — absolutely.
If you’ve never smoked, vaping carries risk. Vapers are exposed to known carcinogens and experience:
- Inflammation and immune dysfunction
- Genetic changes linked to cancer development
- Increased risk of addiction, especially in young people
In Australia, one in three people aged 15–30 have used e-cigarettes, and many go on to take up smoking. From a public health perspective, vaping is now recognised as a gateway to tobacco use.
E-cigarettes are not harmless. And there is growing evidence that they may also contribute to lung cancer.
2. Are there benefits in using e-cigarettes to quit smoking?
Possibly — but with strong warnings.
Some studies suggest that switching entirely from cigarettes to e-cigarettes may reduce exposure to certain harmful substances. However:
- This only applies if you quit smoking completely (no dual use)
- There’s no strong evidence that switching reduces your risk of cancer
- Vaping may be more effective than existing quit aids, such as gums and lozenges, when used with accompanying text message support. More studies are needed to assess vaping comparison to nicotine patches and other medications for successful quitting.
- Long-term safety of e-cigarettes is still unknown
According to Australian guidance on the use of e-cigarettes to manage nicotine dependence, e-cigarette products that contain nicotine may improve quit rates for smoking cigarettes; however, there is currently not enough evidence for it to be prescribed as a first-line treatment. Moreover, studies do not conclusively demonstrate cessation from e-cigarette products that contain nicotine and may be just a ‘switch’ from tobacco products.
For people undergoing cancer treatment, it’s well established that quitting tobacco improves treatment outcomes and tolerability to treatment. COSA’s report notes a lack of clinical guidance on whether switching to e-cigarettes offers any benefit at all for cancer patients or survivors.
Quitting smoking or vaping
Talk to your GP or QUITLine if you would like to quit smoking or vaping. Supports are available to manage nicotine withdrawal and are best used in conjunction with behavioural interventions such is QUITLine.
If you are a healthcare professional wanting to know more about smoking cessation, TOGA has previously produced a podcast featuring Dr Henry Marshall, Prof Christine Paul and Dr Matt Steliga providing practical advice on how to start the conversations using variations on the “Ask, Advise, Help” model and emphasising the brief advice and referral that can be conducted by any healthcare professional.
Conclusion: A critical moment for cancer prevention
COSA’s landmark report reaffirms what many experts have suspected:
Nicotine-based e-cigarettes are likely to be carcinogenic to humans who use them.
Yet uptake of vaping in a previously smoking naïve population has already occurred, rising steadily until 2023 before significantly declining for the first time in 2024 among the overall population aged 14+ years.
Broadly supported reforms were introduced in Australia in 2024, with the most relevant to decrease uptake of vaping in the general population described below
- From 1 July 2024, vapes, including those containing no nicotine, have only been able to be legally sold at pharmacies.
- From 1 October 2024, people 18 years or over have only been able to purchase nicotine vapes with 20 mg/mL or less from a pharmacist without a prescription subject to certain conditions. A prescription from a medical or nurse practitioner is required for nicotine concentrations greater than 20 mg/mL.
- People under 18 years of age will continue to require a prescription to access vapes, where state and territory laws allow.
These reforms mark a critical opportunity to curb a new wave of nicotine dependence and reduce future cancer risk, particularly among young people. Ongoing monitoring will be essential to determine their impact on vaping uptake, alongside further research to further support the long-term link between vaping and lung cancer, and behavioural research on differences in quitting vaping and traditional smoking cessation advice.
Further reading and references
- Australian Institute of Health and Welfare (2024) Electronic cigarette use (vaping) in Australia in 2022–2023, AIHW, Australian Government
- Australian Institute of Health and Welfare (2024) Vaping and e-cigarette use in the NDSHS, AIHW, Australian Government
- Banks et al (2023) Electronic cigarettes and health outcomes: umbrella and systematic review of the global evidence Med J Aust; 218: 267
- Caini et al (2022). Quitting Smoking At or Around Diagnosis Improves the Overall Survival of Lung Cancer Patients: A Systematic Review and Meta-Analysis Journal of Thoracic Oncology, 17:623
- Clinical Oncology Society of Australia Smoking Cessation Working Group. (2020) Smoking Cessation in Cancer Patients: Embedding Smoking Cessation Care in Australian Oncology Health Services. Clinical Oncology Society of Australia; Sydney.
- Department of Health Disability and Ageing (2025) About vaping and e-cigarettes Australian Government
- Royal Australian College of General Practice (2024) Supporting smoking & vaping cessation: A guide for health professionals Guidance on smoking and vaping cessation support related to changes to Australia’s vaping regulation
- Sanchez et al (2021) Is vaping cessation like smoking cessation? A qualitative study exploring the responses of youth and young adults who vape e-cigarettes Addictive Behaviours 113: 106687
- Stewart B. (2025) E-cigarettes and Cancer: A Qualitative Risk Assessment. Clinical Oncology Society of Australia; Sydney.
- Stewart B et al. (2026) The carcinogenicity of e-cigarettes: a qualitative risk assessment Carcinogenesis. 47: bgag015
- Tabbakh et al. (2025) Current vaping and current smoking in the Australian population aged 14+ years: 2018 – 2024 Centre for Behavioural Research in Cancer Cancer Council Victoria Prepared for: Department of Health, Disability and Ageing.
- Courtney, et al. (2025) Vaporized Nicotine Products for Smoking Cessation Among People Experiencing Social Disadvantage: A Randomized Clinical Trial. Ann Intern Med. [Epub 15 July 2025]. doi:10.7326/ANNALS-24-03531
- 13QUIT for telephone advice
- QUIT online referral form
