E-cigarette use among us ever-smoking cancer survivors and its implications on lung cancer screening

E-cigarettes are increasingly used as a perceived safe alternative for smoking cessation, despite evidence of increased lung cancer risk. Young cancer survivors (<40 years old) use e-cigarettes 1.5 times more than their non-cancer survivor peers. Long-term cancer survivors have a higher risk of developing second primary lung cancer than the general population. However, lung cancer screening (LCS) guidelines that focus on cigarette smoking may overlook the cancer risk of using e-cigarettes. We aimed to study e-cigarette use in LCS-ineligible long-term cancer survivors. Smokers aged 50-79 years were obtained from the 2017-2018 & 2020-2021 US Behavioral Risk Factor Surveillance System Ineligibility for LCS was defined using the US Preventive Service Task Force (USPSTF) 2021 criteria: smokers with <20 pack-year smoking history or former smokers quit >15 years. The prevalence of current e-cigarette use in LCS-ineligible smokers was calculated and compared between long-term cancer survivors (cancer diagnosed > 5 years ago) and non-cancer survivors. All calculations were weighted. Out of 11,431,095 smokers, 62.6% were ineligible for LCS. Ineligible cancer survivors had a significantly lower prevalence of e-cigarette use than their peers without a history of cancer (p<0.01) (Table). E-cigarette use was comparable between cancer survivors and non-cancer survivors who were current, heavy, or recently quit smokers (p>0.05). Table: 1698MOE-cigarette use prevalence % (95%CI)LCS ineligible smokers (62.6%; N=7,159,703)Non-cancer survivors (95.2%)Long-term cancer survivors (4.8%)p-valueOverall9.7 (8.0-11.3)4.2 (1.1-7.3)<0.01GenderWomen11.8 (9.4-14.2)5.2 (0.1-10.3)0.02Men7.3 (5.0-9.5)3.0 (0.2-5.7)0.03Smoking statusCurrent15.4 (11.8-19.0)14.7 (0.5-28.9)0.93Former6.5 (4.9-8.1)1.9 (0.1-3.6)<0.001Pack-years<2010.6 (8.7-12.4)5.0 (1.2-8.8)0.01≥204.2 (1.4-7.0)1.3 (0.0-3.7)0.14Years since quitting (former smokers)>153.8 (2.3-5.3)1.6 (0.0-3.2)0.05≤1517.1 (12.1-22.1)4.7 (0.0-13.7)0.07 Open table in a new tab Nearly 0.8 million LCS-ineligible long-term cancer survivors currently use e-cigarettes in the US. While the overall prevalence of e-cigarette use among cancer survivors was relatively low, current/heavy smokers use e-cigarettes at rates comparable to non-cancer survivors. Given that cancer survivors already face an increased risk of lung cancer, the use of e-cigarettes may further heighten this risk. Future lung cancer risk assessment and screening studies may need to take e-cigarette use into consideration.