Link Between E-Cigarette Use After Quitting Smoking and Lung Cancer Risk

A recent study involving over 4.5 million participants reveals that smokers who vape after quitting cigarettes have a 50% higher risk of developing lung cancer compared to those who quit entirely. Nevertheless, the research indicates that utilizing e-cigarettes as a cessation tool is safer than ongoing smoking.

According to Dr. Becky Freeman from the University of Sydney, who was not associated with the study, “This study contributes to a growing body of evidence suggesting that e-cigarettes may pose greater health risks than previously thought.” She advises individuals aiming to quit smoking to prioritize safer methods initially, opting for e-cigarettes only when other methods fail.

In the UK, over 40% of smokers who quit are expected to use e-cigarettes in 2024, with 20% of ex-smokers still vaping a year after quitting. While some advocate for e-cigarettes as an effective smoking cessation strategy, studies link them to airway inflammation, decreased lung function, and even lung cancer in animal models.

Researchers from Seoul National University, including Kim Young Wook, followed 4.5 million adult smokers during South Korea’s National Health Checkup Program from 2018 to 2023. Participants were classified as current smokers, short-term quitters (stopped since 2018), or long-term quitters (stopped since 2014). Within the timeframe, 35,887 participants developed lung cancer, leading to 12,807 fatalities.

Analysis of this data indicated that ex-smokers who vaped had a notably elevated risk of dying from lung cancer compared to those refraining from e-cigarettes post-quitting. “Vapers had a 56% increased risk compared to those who completely quit smoking,” explained Kim.

While long-term research is essential, some chemicals in e-cigarettes are associated with DNA damage, alongside links to oxidative stress, epigenetic alterations, and inflammation in respiratory and oral tissues.

However, Kim and his colleagues emphasize that they cannot definitively assert that e-cigarettes directly cause lung cancer, highlighting the necessity for further studies beyond South Korea.

The research also found that ex-smokers who used e-cigarettes had a significantly lower mortality risk than current smokers, underscoring the profound health benefits of quitting altogether.

Dr. Nicole Lee from Curtin University in Australia remarked that the findings suggest that quitting both smoking and vaping is more effective in preventing lung cancer than continuing to vape after quitting smoking. “This study delivers critical insights for individuals who have stopped smoking,” she noted.

“Our guidance is clear: quitting entirely is the safest option. However, if quitting is not feasible without e-cigarettes, transitioning to vaping can be a safer alternative,” Lee concluded, highlighting it as a harm reduction strategy preferable to ongoing smoking.

Professor Bernard Stewart from the University of New South Wales in Sydney cautioned the need for more research before implementing public health initiatives that impose further restrictions on e-cigarettes.