According to a presentation at the recent American Thoracic Society International Conference, switching to e-cigarettes use after conventional smoking cessation was correlated with a greater risk of developing lung cancer and related mortality compared with those who did not use e-cigarettes.

The authors noted that e-cigarettes and heating elements have been shown to contain carbonyl compounds and toxic metals, which are known to be carcinogenic and are also found in conventional cigarettes.

In a press release, corresponding author Yeon Wook Kim, MD, assistant professor, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea, stated, “This is the first large population-based study to demonstrate the increased risk of lung cancer in e-cigarette users after smoking cessation.”

The authors wrote, “Electronic cigarettes (e-cigarettes) have gained popularity as a less harmful alternative to conventional cigarette smoking. However, whether switching to e-cigarette use after conventional smoking cessation affects future lung cancer risk remains unclear.”

The researchers conducted a nationwide, population-based study to ascertain the risk of lung cancer and related mortality associated with smoking habit changes to e-cigarette use among those who smoked conventional cigarettes, further graded by the length of smoking cessation.

The study included 4,329,288 individuals with a conventional smoking history who participated in the National Health Screening Program between 2012 and 2014 and in 2018, with follow-up through December 2021.

The researchers classified participants into six groups according to their smoking history and habit change to e-cigarette use as follows: ex-smokers ≥5 years since quitting (YSQ) without e-cigarette use, ≥5 YSQ with e-cigarette use, <5 YSQ without e-cigarette use, <5 YSQ with e-cigarette use, and current smokers without and with e-cigarette use.

Employing Cox-proportional hazards models with adjustments for potential confounders, the risk of lung cancer and lung cancer–specific death (LCSD) were evaluated. Using the U.S. Preventive Services Task Force 2021 criteria and the 2023 American Cancer Society guidelines, researchers performed stratified analysis for high-risk individuals aged 50 to 80 years with ≥20 pack-years (PYs) smoking history, likely recommended for lung cancer screening.

The results revealed that during the follow-up, 53,354 individuals developed lung cancer and 6,351 LCSD events occurred. Compared with ex-smokers ≥5 YSQ without e-cigarette use, ex-smokers ≥5 YSQ with e-cigarette use demonstrated an augmented risk of LCSD. The results also revealed that ex-smokers <5 YSQ with e-cigarette use demonstrated a higher risk of lung cancer development and LCSD than those <5 YSQ without e-cigarette use.

The authors wrote, “Stratified analysis for individuals aged 50-80 with a smoking history of ≥20 PY revealed that ex-smokers ≥5 YSQ with e-cigarette use reported a higher risk of lung cancer (aHR [adjusted hazard ratio] = 1.65, 95% CI = 1.05-2.58) and LCSD (aHR = 4.46, 95% CI = 1.85-10.75) than those ≥5 YSQ without e-cigarette use, respectively. Similarly, ex-smokers <5 YSQ with e-cigarette use reported a higher risk of lung cancer (aHR = 1.26, 95% CI = 1.03-1.54) than those <5 YSQ without e-cigarette use.”

Based on their findings, the authors concluded that switching to e-cigarette use after conventional smoking cessation was correlated with a greater risk of lung cancer and related mortality, especially in high-risk individuals who are likely to be recommended for low-dose CT-based screening.

Finally, the authors noted that when implementing smoking cessation interventions to diminish the risk of lung cancer, clinicians must also emphasize the potentially detrimental effects of alternative e-cigarette use.

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.