E-cigarette use among cancer survivors who are ineligible for lung cancer screening

Significance: Cancer survivors are at higher risk of developing lung cancer than the general population due to shared risk factors (e.g. cigarette smoking), treatment (e.g. prior chest irritation) and genetic susceptibilities. Though it has been widely promoted as a smoking cessation tool, preclinical studies have suggested that e-cigarettes contain carcinogens similar to those found in combustible cigarettes. Approximately 15% of cancer survivors reported life-time e-cigarette use. As current lung cancer screening (LCS) criteria primarily focuses on age and combustible smoking history, individuals who are never- or light-smokers but who use e-cigarettes may be excluded from screening. We aim to assess prevalence of e-cigarette use among LCS-ineligible cancer survivors and compare it to their non-cancer survivor peers. Methods: Data were extracted from Behavioral Risk Factor Surveillance System from 2022 to 2024. Individuals ineligible for LCS according to USPSTF 2021 guidelines (i.e. aged 50-80 years, smoked at least 20 pack years and quitted within past 15 years for former smokers) were included. Cancer survivors with history of lung cancer were excluded. Chi-square tests and multivariate logistic regressions were used to compare current e-cigarette use prevalence between cancer survivors and non-cancer survivors. All analyses were weighted. A p-value of <0.05 was considered statistically significant. Results: 694,576 patients (342,841,347 weighted) were included, of which 10.9% were cancer survivors. The average age was 68 (61-74) and 60 (50-69) for cancer survivors and non-cancer survivors, respectively. Overall, 2.6% and 3.6% of cancer survivors and non-cancer survivors reported currently using e-cigarettes, respectively (p<0.001). After adjusting for age, sex, race/ethnicity, education, income, marital status and combustible smoking status, cancer survivors were more likely to be current e-cigarette users (aOR=1.10, 95%CI: 0.99-1.23) than non-cancer survivors. Among individuals aged 40-49 years, cancer survivors were 21% more likely to report currently using e-cigarettes than non-cancer survivors (9.3% vs 7.2%, p<0.001; aOR=1.21; 95%CI: 1.02-1.44). In addition, male cancer survivors (aOR=1.22; 95%CI: 1.01-1.46), and cancer survivors who never smoked combustible cigarettes (aOR=1.52; 95%CI: 1.13-2.05) were more likely to report currently using e-cigarettes. Conclusion: Our results showed that among adults ineligible for LCS, cancer survivors were more likely to report currently using e-cigarettes, with the highest prevalence observed in younger individuals, men, and never-smokers. The findings are concerning as e-cigarette use may add to their pre-existing elevated risk profile. Future studies are needed to assess long-term risks of e-cigarette use in this population and to inform potential refinements to risk assessment and screening eligibility among cancer survivors.