The potential risks and benefits of electronic cigarettes to older smokers at high risk for lung cancer

PROJECT SUMMARY Older smokers suffer disproportionately from smoking-related disease, particularly lung cancer, and smoking prevalence among older smokers has not declined as steeply as that of younger smokers. The majority of risk results from the chronic inhalation of combusted cigarette (CC) smoke. However, older smokers are often more unwilling or unable to quit smoking than younger smokers, which suggests that they might benefit from switching to potentially less harmful nicotine products. Recent studies, as well as statements from the FDA, suggest that electronic cigarettes (ECs), may be less harmful than CCs. However, it is unknown how ECs would be used in this population, in a real-world setting, and whether or not such use would provide a safer alternative to CC smoking. This project will evaluate changes in product use, acceptability, reinforcement, symptoms of nicotine dependence, and biomarkers of inflammation, oxidative stress, and metabolism in smokers at high risk of lung cancer as they switch from CCs to ECs. Participants (n=330) will be smokers who meet criteria for high risk of lung cancer, who are uninterested in quitting smoking, but who are interested trying ECs and changing CC consumption. Participants will be randomly assigned to one of 2 conditions, EC or usual brand (UB) CC, for 6 months (26 weeks). Those assigned to the EC condition will sample and choose from among 4 EC flavors. All participants will be strongly encouraged to quit CC smoking at the end of the study if they have not already, and will be offered free standard treatment (NRT and counseling) in our clinic, if interested. We will address the following specific aims: (1) To characterize the effects of switching from CCs to ECs on product use, product acceptability, and reinforcement among adult daily CC smokers at high risk for lung cancer; (2) To characterize the effects of switching from CCs to ECs on biomarkers of inflammation and oxidative stress among adult daily CC smokers at high risk for lung cancer; (3) To characterize metabolomic changes that result from switching from CCs to ECs among CC smokers at high risk for lung cancer; (4) To characterize which factors moderate or mediate the effects of switching from CCs to ECs among CC smokers at high risk for lung cancer. This project is significant because it will inform regulatory science and public health policy about the potential harms and benefits of switching from CCs to ECs in older adult smokers at greatest risk for lung cancer who are uninterested in quitting CC smoking. This project is innovative because it will be among the first to focus exclusively on this high risk group and to evaluate the harms and benefits the effect of switching from CCs to ECs using a prospective clinical trial, that accesses the risks and benefits of switching across multiple domains, including behavior, addiction, and health outcomes.