Effect of Time Since Smoking Cessation on Lung Cancer Incidence: An Occupational Cohort With 27 Follow-Up Years

Risk prediction models for lung cancer in people who have never smoked: a protocol of a systematic review

BACKGROUND

Lung cancer is one of the most commonly diagnosed cancers and the leading cause of cancer-related death worldwide. Although smoking is the primary cause of the cancer, lung cancer is also commonly diagnosed in people who have never smoked. Currently, the proportion of people who have never smoked diagnosed with lung cancer is increasing. Despite this alarming trend, this population is ineligible for lung screening. With the increasing proportion of people who have never smoked among lung cancer cases, there is a pressing need to develop prediction models to identify high-risk people who have never smoked and include them in lung cancer screening programs. Thus, our systematic review is intended to provide a comprehensive summary of the evidence on existing risk prediction models for lung cancer in people who have never smoked.

METHODS

Electronic searches will be conducted in MEDLINE (Ovid), Embase (Ovid), Web of Science Core Collection (Clarivate Analytics), Scopus, and Europe PMC and Open-Access Theses and Dissertations databases. Two reviewers will independently perform title and abstract screening, full-text review, and data extraction using the Covidence review platform. Data extraction will be performed based on the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modeling Studies (CHARMS). The risk of bias will be evaluated independently by two reviewers using the Prediction model Risk-of-Bias Assessment Tool (PROBAST) tool. If a sufficient number of studies are identified to have externally validated the same prediction model, we will combine model performance measures to evaluate the model's average predictive accuracy (e.g., calibration, discrimination) across diverse settings and populations and explore sources of heterogeneity.

DISCUSSION

The results of the review will identify risk prediction models for lung cancer in people who have never smoked. These will be useful for researchers planning to develop novel prediction models, and for clinical practitioners and policy makers seeking guidance for clinical decision-making and the formulation of future lung cancer screening strategies for people who have never smoked.

SYSTEMATIC REVIEW REGISTRATION

This protocol has been registered in PROSPERO under the registration number CRD42023483824.

Public Attitudes Towards Lung Cancer Screening in Saudi Arabia: A Cross-Sectional Study

Objective

Lung cancer is one of the leading causes of death worldwide, and it is ranked as the first cause of death in more than 100 countries around the world. The aim of this study was to explore the knowledge and attitude of the general population in Saudi Arabia toward lung cancer screening.

Methods

A cross-sectional study employing an online survey was conducted between November 2021 and February 2022 in Saudi Arabia. This study utilized a previously developed questionnaire instrument. Logistic regression was used to identify predictors of positive attitude toward lung cancer screening.

Results

A total of 473 participants were involved in this study. The majority of the study participants (74.6%) reported that they are current smokers. Almost 31.5% of the study participants reported that if lung cancer is detected early, the person's chance of surviving is poor to very poor. The majority of the study participants reported that they would be willing to do tests to diagnose lung cancer if you were invited by the Ministry of Health or their doctor. Males, participants aged (24-34 years), and current smokers were more likely to have positive attitude towards lung cancer screening (p ≤ 0.05). On the other hand, patients aged 46 years and over and those with higher education had less positive attitude towards lung cancer screening (p ≤ 0.05).

Conclusion

This is the first study to look into the general public's attitudes toward lung cancer screening in Saudi Arabia. According to our findings, the majority of people believe that early detection of lung cancer can lead to improved results and have a favourable attitude toward lung cancer screening if it is indicated. Thus, incorporating lung cancer screening into the local guidelines in at-risk population is highly recommended and considering the launch of nation-wide lung cancer screening program is advised.

Mendelian randomization to explore the direct or mediating associations between socioeconomic status and lung cancer

Objective

The purpose of this study was to verify whether there are direct or mediated causal associations between socioeconomic status and lung cancer.

Methods

Pooled statistics were obtained from corresponding genome-wide association studies. The inverse-variance weighted, weighted median, MR-Egger, MR-PRESSO and contamination-mixture methods were used as supplements to Mendelian randomization (MR) statistical analysis. Cochrane's Q value and the MR-Egger intercept were used for sensitivity analysis.

Results

In the univariate MR analysis, household income and education had protective effects on overall lung cancer (income: P = 5.46×10^-4; education: P = 4.79×10^-7) and squamous cell lung cancer (income: P = 2.67×10^-3; education: P = 1.42×10^-10). Smoking and BMI had adverse effects on overall lung cancer (smoking: P = 2.10×10^-7; BMI: P = 5.67×10^-4) and squamous cell lung cancer (smoking: P = 5.02×10^-6; BMI: P = 2.03×10^-7). Multivariate MR analysis found that smoking and education were independent risk factors for overall lung cancer (smoking: P = 1.96×10^-7; education: P = 3.11×10^-3), while smoking was an independent risk factor for squamous cell lung cancer (P = 2.35×10^-6). Smoking, education, and household income mediate the effect of BMI on overall lung cancer (smoking 50.0%, education 49.2%, income 25.3%) and squamous cell lung cancer (smoking 34.8%, education 30.8%, income 21.2%). Smoking, education, and BMI mediate the effect of income on overall lung cancer (smoking 13.9%, education 54.8%, BMI 9.4%) and squamous cell lung cancer (smoking 12.6%, education 63.3%, BMI 11.6%). Smoking, BMI, and income mediate the effect of education on squamous cell lung cancer (smoking 24.0%, BMI 6.2%, income 19.4%).

Conclusion

Income, education, BMI, and smoking are causally associated with both overall lung cancer and squamous cell lung cancer. Smoking and education are independent association factors for overall lung cancer, while smoking is an independent association factor for squamous cell lung cancer. Smoking and education also play important mediating roles in overall lung cancer and squamous cell lung cancer. No causal relationship was found between multiple risk factors associated with socioeconomic status and lung adenocarcinoma.

Synergy of arsenic with smoking in causing cardiovascular disease mortality: A cohort study with 27 follow-up years in China

Background

To explore the patterns of the exposure-response relationship between arsenic exposure and cardiovascular disease (CVD) mortality and investigate the effect of cigarette smoking on the association.

Methods

Seven thousand seven hundred thirty-five tin miners with at least 10 years of arsenic exposure were enrolled since 1992 and followed up for 27 years. Each individual's air arsenic exposure at workplace was calculated by time weighted average arsenic concentration × exposure months. Detailed information on smoking was collected at baseline, and information on smoking status was collected for five consecutive years from 1992 to 1996. Hazard ratio (HR) and 95% confidence interval (CI) for the risk of CVD were estimated using Cox proportional hazards models.

Results

A total of 1,046 CVD deaths occurred in this cohort over 142,287.7 person-years of follow up. We firstly reported that for equal cumulative exposure, participants exposed to higher concentrations over shorter duration had a higher risk of CVD mortality than those exposed to lower concentration over longer duration. The HR and 95% CI were 1.38 (95%CI: 1.03-1.85) in participants exposed to arsenic concentration (45.5-99.5 mg/m³), 1.29 (95%CI: 1.02-1.67) in 99.5-361.0 mg/m³. Further, participants with age at first exposure <18 years had a significantly higher risk of morality from CVD, cerebrovascular and heart diseases than those with ≥18 years. Finally, all synergy indices were greater than 1 (range, 1.11-2.39), indicating that the joint effect of arsenic exposure and cigarette smoking on CVD mortality was greater than the sum of their individual effect.

Conclusions

Exposure to air arsenic at workplace is adversely associated with mortality from CVD, especially among smokers younger than 18 years and smokers.

Cost-Effectiveness Analysis of Smoking Cessation Interventions With Behavioral Support: A Study Based on the Benefits of Smoking Cessation on Outcomes (BENESCO) Model

INTRODUCTION

Few studies have compared cost-effectiveness of different smoking cessation interventions (SCIs) that include behavioral support, considering smoking-related diseases. Therefore, we compare the cost-effectiveness of SCIs with behavioral support in South Korea using the Benefits of Smoking Cessation on Outcomes (BENESCO) model.

AIMS AND METHODS

We used the BENESCO model to estimate the cost and utility of the SCIs with behavioral support, including pharmacist counseling with nicotine replacement therapy (pharmacist+NRT), expert counseling with NRT (expert+NRT), and expert counseling with varenicline (expert+varenicline). The target population was adult smokers who wanted to cease smoking within 1 month. We applied transitional probabilities and epidemiological data from the literature. Medical costs and utilities were calculated using claims and national survey data, respectively. Cost-effectiveness was evaluated within the threshold (17 926 USD per quality-adjusted life years [QALYs]) by incremental cost-effectiveness ratio (ICER).

RESULTS

The model cohort included 1 219 390 male and 298 511 female smokers. The pharmacist+NRT group had 32 842 more QALYs gained and 26 689 958 USD less expended than the expert+NRT group. The ICER for the expert+varenicline group versus the pharmacist+NRT and expert+NRT groups was 27 247 and 4074 USD per QALY, respectively. The robustness of the results was confirmed by sensitivity analyses, except for the discount rate and cost of the expert+varenicline group.

CONCLUSIONS

In Korea, pharmacist counseling with NRT showed higher QALY gains and lower costs than expert counseling with NRT. Expert counseling with varenicline was more effective for smoking cessation and more cost-effective than expert counseling with NRT but was not cost-effective compared with pharmacist counseling with NRT.

IMPLICATIONS

This study provides evidence for decision-making on smoking cessation programs by evaluating the cost-effectiveness of SCIs. Furthermore, we attempted to use the BENESCO model to compare and evaluate the cost-effectiveness of SCIs with behavioral support. It is meaningful because this study showed the availability of using the BENESCO model in the future cost-effectiveness analysis of various SCIs.