Despite being seen as a safer alternative to tobacco, a new review of more than 100 studies concluded that e-cigarettes are also associated with an increased risk of lung and mouth cancer.
An important scientific review of more than 100 studies concluded that the use of e-cigarettes with nicotine is likely to cause lung and mouth cancer.
The research, in the journal Carcinogenesis, analyzed studies published since 2017 to assess the independent risk of cancer associated with e-cigarettes. Unlike previous research, the review excluded studies focused on dual usersreferring to those who smoke both traditional and electronic cigarettes, thus examining the effects of vapes in isolation.
Across multiple lines of evidence, results consistently indicated harmful potential. Human studies have revealed biomarkers linked to key processes in cancer development, such as DNA damage, oxidative stress and inflammation.
Experiments on rats showed the formation of lung tumors after exposure to e-cigarette aerosols, while laboratory analyzes have identified harmful pathways triggered by chemicals in e-cigarette liquids, including known carcinogens.
The review also highlighted clinical case reports of frequent e-cigarette users who developed aggressive oral cancerssometimes in younger individuals without traditional risk factors, such as smoking or viral infections, explains .
Although long-term population data is still lacking, researchers argue that existing evidence is strong enough to justify precaution. They draw parallels with the history of tobacco, where it took decades to establish a conclusive link between smoking and cancer. “We must not repeat this delay”, warn the authors.
The use of e-cigarettes, introduced in the early 2000s as a supposedly safer alternative to tobacco, has rapidly grown in popularity. Although some evidence suggests that it may help smokers quit smoking in the short termthere are still concerns about real-world usage patterns.
Many users continue to smoke conventional cigarettes alongside using e-cigarettes, a combination associated with significantly greater health risks. A recent study found that users of both products face a up to four times greater risk of lung cancer compared to smokers who only use conventional cigarettes.
The authors say their findings should guide government regulation and public health policy. While more research is needed to quantify long-term risks, early biological evidence already provides a clear warning.
“E-cigarettes were introduced about 20 years ago,” said co-author Freedy Sitas. “We shouldn’t wait decades to decide how to react.”
