Efficacy of Electronic Cigarettes vs Varenicline and Nicotine Chewing Gum as an Aid to Stop Smoking: A Randomized Clinical Trial.

Importance: Electronic cigarettes (ECs) are often used by smokers as an aid to stopping smoking, but evidence is limited regarding their efficacy compared with nicotine replacement therapy (NRT), and no evidence is available on how their efficacy compares with that of varenicline. Objective: To evaluate whether ECs are superior to NRT and noninferior to varenicline in helping smokers quit. Design, Setting, and Participants: This was a randomized clinical trial conducted at 7 sites in China and including participants who were smoking at least 10 cigarettes per day and motivated to quit, not using stop-smoking medications or EC, and willing to use any of the study products. Participants were first recruited in May 2021, and data analysis was conducted in December 2022. Interventions: A cartridge-based EC (30 mg/mL nicotine salt for 2 weeks and 50 mg/mL after that), varenicline (0.5 mg, once a day for 3 days; 0.5 mg, twice a day for 4 days; and 1 mg, twice a day, after that), and 2 mg (for smokers of ≤20 cigarettes per day) or 4 mg (>20 cigarettes per day) nicotine chewing gum, all provided for 12 weeks and accompanied by minimal behavioral support (an invitation to join a self-help internet forum). Main Outcomes and Measures: The primary outcome was sustained abstinence from smoking at 6 months as validated by an expired-air carbon monoxide reading (<8 parts per million). Participants lost to follow-up were included as nonabstainers. Results: Of 1068 participants, 357 (33.5%) were female, and the mean (SD) age was 33.9 (3.1) years. A total of 409 (38.3%), 409 (38.3%), and 250 (23.4%) participants were randomized to the EC, varenicline, and NRT arms, respectively. The 6-month biochemically validated abstinence rates were 15.7% (n = 64), 14.2% (n = 58), and 8.8% (n = 22) in the EC, varenicline, and NRT study arms, respectively. The quit rate in the EC arm was noninferior to the varenicline arm (absolute risk reduction, 1.47%; 95% CI, -1.41% to 4.34%) and higher than in the NRT arm (odds ratio, 1.92; 95% CI, 1.15-3.21). Treatment adherence was similar in all study arms during the initial 3 months, but 257 participants (62.8%) in the EC arm were still using ECs at 6 months, with no further use in the 2 other study arms. The most common adverse reactions were throat irritation (32 [7.8%]) and mouth irritation (28 [6.9%]) in the EC arm, nausea (36 [8.8%]) in the varenicline arm, and throat irritation (20 [8.0%]) and mouth irritation (22 [8.8%]) in the NRT arm. No serious adverse events were recorded. Conclusions and Relevance: The results of this randomized clinical trial found that when all treatments were provided with minimal behavior support, the efficacy of EC was noninferior to varenicline and superior to nicotine chewing gum. Trial Registration: Chinese Clinical Trial Registry: ChiCTR2100048156.

Identification of heritable rare variants associated with early-stage lung adenocarcinoma risk.

Background: In East Asia, the number of patients with adenocarcinoma, especially those presenting with ground-glass nodules (GGNs), is gradually increasing. Family aggregation of pulmonary GGNs is not uncommon; however, genetic predisposition in these patients remains poorly understood and identification of genes involved in the cause of these early-stage lung cancers might contribute to understanding of the underlying mechanisms and potential prevention strategies. Methods: Fifty patients with early-stage lung adenocarcinoma (LUAD) presenting as GGNs and a first-degree family history of lung cancer (FHLC) from 34 independent families were enrolled into this study. Germline mutations of these patients were analyzed with whole exome sequencing (WES) and compared with age- and sex-matched 39 patients with sporadic lung cancer and 689 local healthy people. We used a stepwise variant filtering strategy, gene-based burden testing, and enrichment analysis to investigate rare but potentially pathogenic heritable mutations. Somatic tumor mutations were analyzed to consolidate germline findings. Results: In total, 1,571 single nucleotide variants (SNVs) and 238 frameshifts with a minor allele frequency (MAF) <0.01, which were rare, recurrent, and potentially damaging candidates, were finally identified through the filtering in the GGN cohort. Pathway analysis showed the extracellular matrix to be the top dysregulated pathway. Gene-based burden testing of these highly disruptive risk-conferring heritable variants showed that MSH5 [odds ratio (OR), 9.28, 95% confidence interval (CI): 2.49-35.87], MMP9 (OR, 8.11, 95% CI: 2.22-28.43), and CYP2D6 (OR, 8.09, 95% CI: 2.68-24.92) were significantly enriched in our cohort (P<0.05). The number of rare damaging germline variants in non-smoking patients was significantly higher than that of smoking-affected patients (Spearman's ρ=-0.39, P=0.02). Conclusions: Heritable, potentially deleterious, and rare candidate variants of MSH5, MMP9 and CYP2D6 were significantly associated with early-stage LUAD presenting with GGNs. Nonsmoking patients likely have a higher genetic predisposition to this type of cancer than smoking-affected patients. These results have extended our understanding of the underlying mechanisms of early-stage LUAD.

The characteristics and patterns of e-cigarette use and its association with cigarette cessation intention in a Chinese smoking population: A mediation analysis.

INTRODUCTION: The use of e-cigarettes has become more common in China, but the research on e-cigarettes in China, while growing, is still limited. This study examined the characteristics and patterns of e-cigarette use, and analyzed the possible mediators between cigarette cessation intention and e-cigarette use in a Chinese smoking population. METHODS: This was a cross-sectional study conducted in mainland China. By convenience sampling method, the participants were recruited from 85 major commercial streets of several large cities in China. The study interviewers completed face-to-face interviews and uploaded the completed questionnaires into the online survey platform. The participants were contacted for clarification if any problems were detected. Logistic regression yielded adjusted odds ratios (ORs) for ever use of e-cigarettes. We further conducted a mediation analysis to estimate the effect of possible mediators. RESULTS: From July to August 2020, a total of 738 smokers were invited to participate in this study; 613 smokers were identified as eligible and 609 smokers were included in this analysis. Of them, 24 (3.94%) participants were currently using e-cigarettes, and 165 (27.09%) participants have ever used e-cigarettes. The participants with younger age were more likely to have ever used e-cigarettes, ranging from 37.5% in the 18-29 years age group to 6.5% in the 60-69 years age group. After controlling for demographic characteristics and nicotine dependence, the ever use of e-cigarettes was significantly associated with younger age, higher education level, higher monthly income, previous smoking cessation attempts and quitting intention. With the mediation analysis, the education level is confirmed as a mediating factor, and approximately 42.86% of the effects were mediated through the channel of higher socioeconomic status. CONCLUSIONS: This is the first study to examine the possible mediators between cigarette cessation intention and e-cigarette use in a Chinese smoking population. The findings revealed that high socioeconomic status, particularly higher education level, was a major mediating factor.

The Effects of Smoke-Free Workplace Policies on Individual Smoking Behaviors in China.

OBJECTIVE: Studies have shown that smoke-free (SF) workplace policies can create an SF environment, but most of them have focused only on reducing secondhand smoke (SHS) exposure or changing smoking behavior. Our study aims to explore the effects of SF workplace policies and the pathway between workplace SF policies and SHS exposure. METHOD: 14 195 employees from 79 companies in China participated in this survey. Binary logistic regression is used to examine the direct effects of SF workplace policies. Structured Equation Modeling approach is used to test other indirect effects. The Sobel test is used to estimate the mediation effect. RESULTS: Working in a company with SF policies was associated with lower SHS exposure (odds ratio = 0.56; 95% confidence interval = 0.51 to 0.60). Such policy were associated with lower smoking prevalence (Coef. = -0.05, p < .05) and positively associated with smoking harm awareness (Coef. = 0.07, p < .05) and SHS harm awareness (Coef. = 0.05, p < .05). Sobel test suggests that approximately 16.3% of the effects on SHS exposure reduction are mediated through the channel of lower smoking prevalence for males. For smokers, we did not identify a direct effect of such policies on quitting intentions, but a significant indirect effect via increased smoking harm awareness (Coef. = 0.07, p < .05) and lower smoking consumption (Coef. = -0.10, p < .05) were found. CONCLUSION: This study finds that SF workplace policies are not only associated with lower SHS exposure but also related to some indirect effects. Further mediation analyses for males confirmed that the effect on SHS exposure reduction is mediated through the channel of lower smoking prevalence. IMPLICATIONS: This study joins the debate in recent years on the effects of workplace SF policies and provides evidence with more comprehensive data from Asia Best Workplace Mainland China program. It shows that SF workplace policies not only can reduce SHS exposure but also are associated with lower smoking prevalence, fewer cigarettes smoked, and higher smoking harm-related awareness. These findings provide valuable evidence to promote such policies in all workplaces and underline the need for more stringent SF policies to be enacted in all countries.