An analysis of more than 4.5 million South Korean adults found a 56% higher incidence of lung cancer and a 91% higher lung cancer death rate among former smokers who vaped.
TBS Report
24 October, 2026, 07:10 pm
Last modified: 24 October, 2026, 07:18 pm
Former smokers who use vapes or e-cigarettes face a higher risk of developing and dying from lung cancer than those who quit smoking entirely, according to a study published in Nature Medicine.
Researchers from Seoul National University analysed health data from more than 4.5 million South Korean adults to examine the association between vaping and lung cancer among people with a history of smoking.
The participants were divided into three groups: current smokers, short-term quitters and long-term quitters. Researchers also assessed whether they used vapes daily during health screenings conducted in 2018, adjusting for factors including age, sex and previous health conditions.
The analysis found that former smokers who used vapes had a 56% higher incidence of lung cancer than those who had quit smoking without vaping.
The lung cancer death rate among vape users was also 91% higher than among those who did not vape, the study found.
However, the research did not establish whether vaping directly caused the increased risk. As an observational study, it identified an association rather than proving a causal relationship.
The researchers noted that evidence linking e-cigarettes to lung cancer remains limited, despite findings from epidemiological and biological studies suggesting associations between e-cigarette use and various respiratory disorders.
"Although epidemiological and biological studies support the association between e-cigarettes and various respiratory disorders, evidence regarding the relationship between e-cigarettes and lung cancer risk remains limited," the researchers wrote.
The study focused on people with a history of smoking and does not establish the long-term lung cancer risk among people who vape without ever having smoked conventional cigarettes.
The researchers said further studies are needed to determine whether vaping directly contributes to lung cancer risk.