Meta-analysis of studies of passive smoking and lung cancer: effects of study type and continent

Socioeconomic Status, Smoking, and Lung Cancer: Mediation and Bias Analysis in the SYNERGY Study

BACKGROUND

Increased lung cancer risks for low socioeconomic status (SES) groups are only partially attributable to smoking habits. Little effort has been made to investigate the persistent risks related to low SES by quantification of potential biases.

METHODS

Based on 12 case-control studies, including 18 centers of the international SYNERGY project (16,550 cases, 20,147 controls), we estimated controlled direct effects (CDE) of SES on lung cancer via multiple logistic regression, adjusted for age, study center, and smoking habits and stratified by sex. We conducted mediation analysis by inverse odds ratio weighting to estimate natural direct effects and natural indirect effects via smoking habits. We considered misclassification of smoking status, selection bias, and unmeasured mediator-outcome confounding by genetic risk, both separately and by multiple quantitative bias analyses, using bootstrap to create 95% simulation intervals (SI).

RESULTS

Mediation analysis of lung cancer risks for SES estimated mean proportions of 43% in men and 33% in women attributable to smoking. Bias analyses decreased the direct effects of SES on lung cancer, with selection bias showing the strongest reduction in lung cancer risk in the multiple bias analysis. Lung cancer risks remained increased for lower SES groups, with higher risks in men (fourth vs. first [highest] SES quartile: CDE, 1.50 [SI, 1.32, 1.69]) than women (CDE: 1.20 [SI: 1.01, 1.45]). Natural direct effects were similar to CDE, particularly in men.

CONCLUSIONS

Bias adjustment lowered direct lung cancer risk estimates of lower SES groups. However, risks for low SES remained elevated, likely attributable to occupational hazards or other environmental exposures.

Secondhand smoke is associated with peptic ulcer disease and gastroesophageal reflux disease in non-smokers in a large Taiwanese population study

Background

Active smokers are known to be at an increased risk of both gastroesophageal reflux disease (GERD) and peptic ulcer disease (PUD), however the role of passive smoking remains unclear. In this study, we aimed to examine whether secondhand smoke (SHS) is associated with PUD and GERD.

Methods

In this population-based study, we conducted a large-scale analysis with 88,297 never-smokers (male: 18,595; female: 69,702; mean age 50.1 ± 11.0 years) from the Taiwan Biobank. The exposure group was comprised of those who had been exposed to SHS, and the no exposure group as those without SHS exposure. According to the frequency of exposure, we further divided the participants into "no exposure," "<1 h per week," and "≥1 h per week" groups. A cutoff point of 1 h per week was chosen according to the median exposure time in our participants. Associations between SHS and SHS frequency with PUD and GERD were assessed.

Results

Of the 88,297 enrolled participants, 11,909 (13.5%) had PUD and 76,388 (86.5%) did not. In addition, 11,758 (13.3%) had GERD and 76,539 (86.7%) did not. Multivariable analysis showed a significant association between SHS with PUD (odds ratio [OR] = 1.166; 95% confidence interval [CI] = 1.084-1.254; p < 0.001), and GERD (OR = 1.131; 95% CI = 1.053-1.216; p = 0.001). Furthermore, those exposed to SHS ≥ 1 h per week (vs. no exposure) were associated with higher risks of PUD (OR = 1.232; 95% CI = 1.121-1.355; p < 0.001) and GERD (OR = 1.200; 95% CI = 1.093-1.319; p < 0.001).

Conclusion

SHS was significantly associated with PUD and GERD. Furthermore, exposure to SHS ≥ 1 h per week (vs. no exposure) was associated with a 1.23-fold higher risk of PUD and 1.20-fold higher risk of GERD. This study represents the largest population-based investigation to explore the association between SHS with PUD and GERD in Taiwanese never-smokers.

Lung cancer caused by asbestos: What a reporting pathologist needs to know

Asbestos is a carcinogen that can cause lung cancer. The suspicion that a lung cancer diagnosis may be associated with exposure to asbestos has no bearing on treatment. However, attributing an individual's lung cancer to asbestos exposure has important medicolegal implications and may impact public health measures and policy. Simultaneous exposure(s) to other carcinogens (such as tobacco smoke, silica and many others) adds complexity while trying to answer the causation question. The Helsinki criteria were formulated to assist attributing lung cancer to previous asbestos exposure. Surrogate markers can be used and include signs of asbestosis and pleural plaques. The most widely used criterion for the presence of asbestosis is interstitial fibrosis in conjunction with 2 or more asbestos bodies/1 cm2 tissue section by light microscopy. Identification of asbestos bodies ty light pr electron microscopy provides an important element for asbestos diagnosis. However, fibrosis may be subtle, and the distribution of asbestos bodies is not uniform throughout the lungs, some types of asbestos fibres have low biopersistence, and not all types of asbestos readily form asbestos bodies. Additional criteria require knowledge of exposure history, which is often unknown to pathologists, but reliance on morphology in isolation may lead to mis-classification of interstitial lung disease as idiopathic. While a smoking-related lung cancer signature has emerged, an asbestos-related lung cancer signature has not yet been identified. In this review we will discuss practice points for the surgical pathologist.

Socioeconomic disparity in stage at cancer diagnosis among patients with type 2 diabetes in Dutch primary care: a cross-sectional study

Introduction

Disparities in cancer stage appear to exist by socioeconomic status (SES) in the Netherlands. We evaluated the association of SES and cancer stage among patients with type 2 diabetes (T2DM) treated in primary care.

Research design and methods

This cross-sectional study linked data from the primary care Zwolle Outpatient Diabetes Project Integrating Available Care database for T2DM (n=71 648, 1998-2019) to a cancer registry and personal records database in the Netherlands. Only cancers (excluding all skin cancers) diagnosed after the onset of diabetes were included and grouped by stages (III-IV or 0-II). SES was estimated as low, intermediate or high based on postal codes and Dutch social research status scores. Logistic regression was performed, with stratification by sex and correction for age, body mass index, smoking, diabetes duration, glycaemic control and metformin use. ORs and 95% CI are reported.

Results

Of the 5087 males and 4021 females with any cancer, 50.1% and 53.7% had low SES, respectively. Compared with patients with high SES, the ORs for diagnosing cancer at stages III-IV in patients with low SES were 1.00 (95% CI 0.84 to 1.19) for males and 1.32 (95% CI 1.06 to 1.67) for females. However, the ORs varied by cancer type: breast, 1.46 (95% CI 0.90 to 2.39); male colorectal, 1.00 (95% CI 0.70 to 1.43); female colorectal, 1.72 (95% CI 1.06 to 2.77); prostate, 0.81 (95% CI 0.57 to 1.15); male lung, 1.06 (95% CI 0.62 to 1.80) and female lung, 2.56 (95% CI 1.32 to 4.95).

Conclusions

Among patients treated for T2DM in Dutch primary care, our data suggest the need to target females with low SES to decrease inequalities in the early detection of colorectal and lung cancer.

Knowledge, Attitude, and Perception of Passive Smoking Among Medical and Dental Students of Karachi: A Survey-Based Study

Background

Passive smoking, the involuntary inhalation of tobacco smoke, poses significant health risks; however, its prevalence and impact on medical and dental students in Karachi, Pakistan, remain understudied. Therefore, this research aims to understand the knowledge, attitudes, and practices (KAP) regarding passive smoking among medical and dental students and will help shed light on their awareness, perceptions, and behaviours regarding this public health concern.

Methods

A cross-sectional study was conducted over 3 months, involving 378 medical and dental students (303 medical and 75 dental students)from various universities in Karachi. Participants completed a questionnaire to gather information on demographics, awareness of passive smoking, perceptions of its health effects, and actions taken in response to exposure.

Results

The majority of participants demonstrated awareness of passive smoking 320 (84.7%) and believed that it was essentially linked to active smoking 320 (84.7%). Cigarette smoke was identified as the primary contributor to passive smoking 345 (91.3%). A significant proportion of participants believed that children and pregnant women exposed to passive smoking had elevated health risks. In areas where smoking is not permissible, less than half of the participants 173 (45.8%) reminded smokers about the smoking regulations, and a few even referred smokers for counselling 141 (37.3%). Males are usually indifferent to smokers around them, whereas females are found uncomfortable with smoking in their surroundings.

Conclusion

In conclusion, our study highlights the persistent prevalence of passive smoking among medical and dental students in Pakistan. Enforcing strict tobacco control policies, integrating passive smoking education into medical curricula, and improving communication strategies for smoking cessation interventions are crucial steps towards creating smoke-free environments and healthier lifestyles nationwide. Despite awareness among medical and dental students about the dangers of cigarette smoking, their reluctance to urge regular smokers to quit underscores the need for improved communication between smokers and non-smokers to foster a cleaner and hazard-free environment.

Characteristics of Singapore lung cancer patients who miss out on lung cancer screening recommendations

INTRODUCTION

The National Lung Screening Trial (NLST) identified individuals at high risk for lung cancer and showed that serial low-dose helical computed tomography could identify lung cancer at an earlier stage, leading to mortality reduction. However, there is little evidence regarding the effectiveness of the NLST criteria for the Asian population.

METHODS

We performed a retrospective audit in our hospital from January 2018 to December 2018, with the aim to describe the characteristics of patients diagnosed with lung cancer and to identify patients who would miss out on lung cancer screening when the NLST criteria was applied.

RESULTS

We found that only 38.1% of our cohort who were diagnosed with lung cancer met the NLST criteria strictly by age and smoking status. Patients who met the screening criteria would have derived significant benefits from it, as 85.4% of our patients had presented at an advanced stage and 54.6% died within 1 year. When the United States Preventive Services Task Force criteria was applied, it increased the sensitivity of lung cancer diagnosis to 58.7%. Only 15.5% of the female patients with lung cancer met the NLST criteria; their low smoking quantity was a significant contributing factor for exclusion.

CONCLUSION

The majority of Singapore patients diagnosed with lung cancer, especially females, would not have been identified with the NLST criteria. However, those who met the inclusion criteria would have benefited greatly from screening. Extending the screening age upper limit may yield benefits and improved sensitivity in the Singapore context.

The Clinical Significance and Involvement in Molecular Cancer Processes of Chemokine CXCL1 in Selected Tumors

Chemokines play a key role in cancer processes, with CXCL1 being a well-studied example. Due to the lack of a complete summary of CXCL1's role in cancer in the literature, in this study, we examine the significance of CXCL1 in various cancers such as bladder, glioblastoma, hemangioendothelioma, leukemias, Kaposi's sarcoma, lung, osteosarcoma, renal, and skin cancers (malignant melanoma, basal cell carcinoma, and squamous cell carcinoma), along with thyroid cancer. We focus on understanding how CXCL1 is involved in the cancer processes of these specific types of tumors. We look at how CXCL1 affects cancer cells, including their proliferation, migration, EMT, and metastasis. We also explore how CXCL1 influences other cells connected to tumors, like promoting angiogenesis, recruiting neutrophils, and affecting immune cell functions. Additionally, we discuss the clinical aspects by exploring how CXCL1 levels relate to cancer staging, lymph node metastasis, patient outcomes, chemoresistance, and radioresistance.

Extent of smoking at a Danish hospital with a smoke-free policy

AIM

One-fifth of the Danish population smoke and exposure to second-hand smoke has well-documented adverse health effects. The smoking policy at hospital level prohibits hospital staff from smoking on the hospital grounds while patients and visitors may smoke in outdoor smoking cabins. This study aimed to quantify smoking at a Danish hospital and document any policy breaches.

METHODS

In April 2020, we collected cigarette butts and observed smokers at the outdoor grounds to document smoking behaviour.

RESULTS

In total, 7152 cigarette butts were collected during one week and 368 people were observed smoking at the outdoor grounds during four observation days. Of all collected cigarette butts, 55% were collected outside the smoking cabins and 62% of all smokers were observed smoking outside the smoking cabins. In addition, 31 staff were observed smoking.

CONCLUSIONS

This study documents that smoking is prevalent at a smoke-free hospital and that the smoking policy is frequently violated. The frequency of smoking outside the cabins may at least partly be influenced by the COVID-19 pandemic. Smoking at a hospital can expose patients, visitors and staff to second-hand smoke with subsequent adverse health effects. Hospitals could play an exemplary role towards a smoke-free society (and not the exception), but the opportunity is not always seized.

Smoking and quality of life in lung cancer patients: systematic review

OBJECTIVES

Lung cancer (LC) accounts for the largest number of cancer deaths worldwide, with smoking being the leading cause for its development. While quality of life (QoL) is a crucial factor in the treatment of patients with LC, the impact of smoking status on QoL remains unclear. This systematic review aims to provide a comprehensive overview of available evidence on the relationship between smoking status and QoL among patients with LC.

METHODS

A systematic search of Embase, Medline and Web of Science was conducted. Studies reporting the impact of smoking status on QoL among patients with LC were eligible for inclusion. Two reviewers independently assessed the eligibility of studies, extracted data and evaluated the risk of bias using the Critical Appraisal Skills Programme appraisal tool for cohort studies. A descriptive synthesis was performed due to the heterogeneity of the studies.

RESULTS

A total of 23 studies met the inclusion criteria (17 studies providing cross-sectional and 6 longitudinal data). The studies included a total of 10 251 participants. The results suggested a tendency towards lower QoL among smokers compared with non-smokers. The effect of smoking cessation on QoL was insufficiently investigated in the included studies and therefore remains inconclusive.

CONCLUSIONS

The findings of this review suggest that current smokers may experience worse QoL than former and never smokers. The results of this systematic review should, however, be viewed in the context of the difficulty of data collection in this patient group given the low survival rates and low performance status, among other factors and in light of the large variety of different QoL measures used. Future research requires uniform QoL measures, a holistic representation of all patients with LC as well as a comprehensive consideration of all potential determinants of QoL. The potential benefits of smoking cessation on QoL among patients with LC require investigation.

A Bibliometric Analysis of Comorbidity of COPD and Lung Cancer: Research Status and Future Directions

Objective

Although studies on the association between COPD and lung cancer are of great significance, no bibliometric analysis has been conducted in the field of their comorbidity. This bibliometric analysis explores the current situation and frontier trends in the field of COPD and lung cancer comorbidity, and to lay a new direction for subsequent research.

Methods

Articles in the field of COPD and cancer comorbidity were retrieved from Web of Science Core Collections (WoSCC) from 2004 to 2023, and analyzed by VOSviewer, CiteSpace, Biblimatrix and WPS Office.

Results

In total, 3330 publications were included. The USA was the leading country with the most publications and great influence. The University of Groningen was the most productive institution. Edwin Kepner Silverman was the most influential scholar in this field. PLOS One was found to be the most prolific journal. Mechanisms and risk factors were of vital importance in this research field. Environmental pollution and pulmonary fibrosis may be future research prospects.

Conclusion

This bibliometric analysis provided new guidance for the development of the field of COPD and lung cancer comorbidity by visualizing current research hotspots, and predicting possible hot research directions in the future.

Secondhand and thirdhand smoke: a review on chemical contents, exposure routes, and protective strategies

Secondhand smoke (SHS: a mixture of sidestream and mainstream smoke) and thirdhand smoke (THS: made up of the pollutants that settle indoors after smoking in closed environments) are a significant public health concern. SHS and THS contain various chemicals which can be released into the air or settle on surfaces. At present, the hazards of SHS and THS are not as well documented. In this review, we describe the chemical contents of THS and SHS, exposure routes, vulnerable groups, health effects, and protective strategies. The literature search was conducted for published papers on September 2022 in Scopus, Web of Science, PubMed, and Google Scholar databases. This review could provide a comprehensive understanding of the chemical contents of THS and SHS, exposure routes, vulnerable groups, health effects, protective strategies, and future researches on environmental tobacco smoke.

How Does Environmental and Occupational Exposure Contribute to Carcinogenesis in Genitourinary and Lung Cancers?

Environmental and occupational exposures have been associated with an increased risk of different types of cancers, although the exact mechanisms of higher carcinogenesis risk are not always well understood. Lung cancer is the leading cause of global cancer mortality, and, also, genitourinary neoplasms are among the main causes of cancer-related deaths in Western countries. The purpose of this review is to describe the main environmental and occupational factors that increase the risk of developing lung and genitourinary cancers and to investigate carcinogenesis mechanisms that link these agents to cancer onset. Further objectives are to identify methods for the prevention or the early detection of carcinogenic agents and, therefore, to reduce the risk of developing these cancers or to detect them at earlier stages.

Regulation of Autophagy via Carbohydrate and Lipid Metabolism in Cancer

Metabolic changes are an important component of tumor cell progression. Tumor cells adapt to environmental stresses via changes to carbohydrate and lipid metabolism. Autophagy, a physiological process in mammalian cells that digests damaged organelles and misfolded proteins via lysosomal degradation, is closely associated with metabolism in mammalian cells, acting as a meter of cellular ATP levels. In this review, we discuss the changes in glycolytic and lipid biosynthetic pathways in mammalian cells and their impact on carcinogenesis via the autophagy pathway. In addition, we discuss the impact of these metabolic pathways on autophagy in lung cancer.

Smoking and passive smoking increases mortality through mediation effect of cadmium exposure in the United States

Cigarette smoking is one of the leading causes of preventable and premature death worldwide. Even worse, many people are generally exposed to passive smoking, which leads to several respiratory diseases and related mortalities. Considering, more than 7000 compounds are included in cigarettes, their combustion results intoxicants that have deleterious effects on health. However, there is a lack of research analyzing the effects of smoking and passive smoking on all-cause and disease-specific mortality through its chemical compounds including heavy metals. Thus, this study aimed to evaluate the effect of smoking and passive smoking on all-cause and disease-specific mortality mediated by cadmium, one of the representative smoking-related heavy metals using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 in the United States. We found that current smoking and passive smoking was related to increased risk of all-cause, CVD-related, and cancer-related mortality. Notably, passive smoking showed a synergistic effect with smoking status on the risk of mortality. In particular, current smokers with passive smoking had the highest risk of all-cause and disease-specific deaths. In addition, the accumulation of cadmium in the blood due to smoking and passive smoking mediates the increased risk of all-cause mortality. Further studies are needed to monitor and treat cadmium toxicity to improve smoking-related mortality rates.

Glycomic, Glycoproteomic, and Proteomic Profiling of Philippine Lung Cancer and Peritumoral Tissues: Case Series Study of Patients Stages I-III

Lung cancer is the leading cause of cancer death and non-small cell lung carcinoma (NSCLC) accounting for majority of lung cancers. Thus, it is important to find potential biomarkers, such as glycans and glycoproteins, which can be used as diagnostic tools against NSCLC. Here, the N-glycome, proteome, and N-glycosylation distribution maps of tumor and peritumoral tissues of Filipino lung cancer patients (n = 5) were characterized. We present several case studies with varying stages of cancer development (I-III), mutation status (EGFR, ALK), and biomarker expression based on a three-gene panel (CD133, KRT19, and MUC1). Although the profiles of each patient were unique, specific trends arose that correlated with the role of aberrant glycosylation in cancer progression. Specifically, we observed a general increase in the relative abundance of high-mannose and sialofucosylated N-glycans in tumor samples. Analysis of the glycan distribution per glycosite revealed that these sialofucosylated N-glycans were specifically attached to glycoproteins involved in key cellular processes, including metabolism, cell adhesion, and regulatory pathways. Protein expression profiles showed significant enrichment of dysregulated proteins involved in metabolism, adhesion, cell-ECM interactions, and N-linked glycosylation, supporting the protein glycosylation results. The present case series study provides the first demonstration of a multi-platform mass-spectrometric analysis specifically for Filipino lung cancer patients.

Secondhand smoke is positively associated with pre-frailty and frailty in non-smoking older adults

Introduction

Either exposure to secondhand smoke (SHS) or frailty has been linked to adverse health outcomes in nonsmoking adults. However, their relationship is rarely studied. The purpose of this study is to examine the association between serum cotinine level and frailty status among non-smoking older adults.

Method

The study population consisted of 2,703 older adults aged ≥60 from the National Health and Nutrition Examination Survey 2011-2014. Non-smokers were included based on (1) a serum cotinine level ≤ 10 ng/mL and 2) a response of "no" to the question, "Do you currently smoke?" Frailty status was measured based on the Fried Phenotype and had three groups- robust, pre-frailty, and frailty. Multinomial logistic regression models were constructed to examine the association between serum cotinine level quartile and frailty status, controlling for age, sex, race/ethnicity, education, depressive symptoms, alcohol use, and systolic blood pressure.

Results

About half of the participants (median age 70.0 years, range 64-78) were female (53.6%), non-Hispanic White (48.3%), and completed some college and above (50.1%). Multinomial logistic regression with a reference group being those in the 1st quantile (the lowest) of serum cotinine level showed that participants in the 4th quartile (the highest) of serum cotinine level had increased odds of pre-frailty vs. robust (OR 1.522, 95% confidence interval [CI] 1.060, 2.185, P = 0.023) as well as increased odds of frailty vs. robust (OR 2.349, 95% CI 1.081, 5.107, P = 0.031).

Conclusions

Higher serum cotinine level is associated with increased risk of pre-frailty and frailty versus robust in non-smoking older adults. Prevention and reduction of SHS in older adults may help protect them from developing pre-frailty or frailty.

Construction and case study of a novel lung cancer risk index

PURPOSE

This study constructs a lung cancer risk index (LCRI) that incorporates many modifiable risk factors using an easily reproducible and adaptable method that relies on publicly available data.

METHODS

We used meta-analysis followed by Analytic Hierarchy Process (AHP) to generate a lung cancer risk index (LCRI) that incorporates seven modifiable risk factors (active smoking, indoor air pollution, occupational exposure, alcohol consumption, secondhand smoke exposure, outdoor air pollution, and radon exposure) for lung cancer. Using county-level population data, we then performed a case study in which we tailored the LCRI for use in the state of Illinois (LCRI_IL).

RESULTS

For both the LCRI and the LCRI_IL, active smoking had the highest weights (46.1% and 70%, respectively), whereas radon had the lowest weights (3.0% and 5.7%, respectively). The weights for alcohol consumption were 7.8% and 14.7% for the LCRI and the LCRI_IL, respectively, and were 3.8% and 0.95% for outdoor air pollution. Three variables were only included in the LCRI: indoor air pollution (18.5%), occupational exposure (13.2%), and secondhand smoke exposure (7.6%). The Consistency Ratio (CR) was well below the 0.1 cut point. The LCRI_IL was moderate though significantly correlated with age-adjusted lung cancer incidence (r = 0.449, P < 0.05) and mortality rates (r = 0.495, P < 0.05).

CONCLUSION

This study presents an index that incorporates multiple modifiable risk factors for lung cancer into one composite score. Since the LCRI allows data comprising the composite score to vary based on the location of interest, this measurement tool can be used for any geographic location where population-based data for individual risk factors exist. Researchers, policymakers, and public health professionals may utilize this framework to determine areas that are most in need of lung cancer-related interventions and resources.

Etiology of lung cancer: Evidence from epidemiologic studies

Lung cancer is one of the leading causes of cancer incidence and mortality worldwide. While smoking, radon, air pollution, as well as occupational exposure to asbestos, diesel fumes, arsenic, beryllium, cadmium, chromium, nickel, and silica are well-established risk factors, many lung cancer cases cannot be explained by these known risk factors. Over the last two decades the incidence of adenocarcinoma has risen, and it now surpasses squamous cell carcinoma as the most common histologic subtype. This increase warrants new efforts to identify additional risk factors for specific lung cancer subtypes as well as a comprehensive review of current evidence from epidemiologic studies to inform future studies. Given the myriad exposures individuals experience in real-world settings, it is essential to investigate mixture effects from complex exposures and gene-environment interactions in relation to lung cancer and its subtypes.

N-Glycan and Glycopeptide Serum Biomarkers in Philippine Lung Cancer Patients Identified Using Liquid Chromatography-Tandem Mass Spectrometry

Aberrant glycosylation has been extensively reported in cancer, with fundamental changes in the glycosylation patterns of cell-surface and secreted proteins largely occurring during cancer progression. As such, serum glycan and glycopeptide biomarkers have been discovered using mass spectrometry and proposed for cancer detection. Here, we report for the first time potential serum N-glycan and glycopeptide biomarkers for Philippine lung cancer patients. The N-glycan and glycoprotein profiles of a cohort (n = 26 patients, n = 22 age- and gender-matched) of lung cancer patients were analyzed and compared to identify potential N-glycan and glycopeptide serum biomarkers using nano-QToF-MS/MS and ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry dynamic multiple monitoring methods, respectively. Statistical analyses identified differential N-glycan and glycopeptide abundances. The N-glycans were mostly sialylated and sialofucosylated branched structures. The glycopeptides involved proteins in complement and coagulation cascades (p _adj = 6.418 × 10^-4), innate immunity (p _adj = 6.094 × 10^-3), acute inflammatory response (p _adj = 6.404 × 10^-5), defense response (p _adj = 2.082 × 10^-4), complement activation pathways (p _adj = 1.895 × 10^-2), and immunoglobulin-mediated immune response pathways (p _adj = 4.818 × 10^-2). Biomarker models were constructed using serum N-glycans [area under the curve (AUC) = 0.775; 95% CI: 0.617-0.931] and glycopeptides (AUC = 0.959; 95% CI: 0.85-1.0), with glycopeptides having higher accuracies than N-glycans. The results suggest that in the Philippine lung cancer patient sera, specific N-glycans and site-specific glycans are differentially expressed between cases and controls. This report represents the first serum glycan and glycopeptide biomarkers of Philippine lung cancer patients, further demonstrating the utility of mass spectrometry-based glycomic and glycoproteomic methods.

Solid Fuel, Secondhand Smoke, and Lung Cancer Mortality: A Prospective Cohort of 323,794 Chinese Never-Smokers

Rationale: Household air pollution and secondhand tobacco smoke are known carcinogens for lung cancer, but large-scale estimates of the relationship with lung cancer mortality are lacking. Objectives: Using the large-scale cohort China Kadoorie Biobank, we prospectively investigated associations between these two risk factors and lung cancer death among never-smokers. Methods: The Biobank recruited 512,715 adults aged 30-79 years from 10 regions in China during 2004-2008. Self-reported never-smoking participants were followed up to December 31, 2016, with linkage to mortality data. Total duration of exposure to household air pollution was calculated from self-reported domestic solid fuel use. Exposure to secondhand tobacco smoke was ascertained using exposure at home and/or other places. Hazard ratios and 95% confidence intervals for associations between these two exposures and lung cancer death were estimated using Cox regression, adjusting for key confounders. Measurements and Main Results: There were 979 lung cancer deaths among 323,794 never-smoking participants without a previous cancer diagnosis during 10.2 years of follow-up. There was a log-linear positive association between exposure to household air pollution and lung cancer death, with a 4% increased risk per 5-year increment of exposure (hazard ratio = 1.04; 95% confidence interval = 1.01-1.06; P trend = 0.0034), and participants with 40.1-50.0 years of exposure had the highest risk compared with the never-exposed (hazard ratio = 1.53; 95% confidence interval = 1.13-2.07). The association was largely consistent across various subgroups. No significant association was found between secondhand smoke and lung cancer death. Conclusions: This cohort study provides new prospective evidence suggesting that domestic solid fuel use is associated with lung cancer death among never-smokers.

Molecular insights and therapeutic implications of nanoengineered dietary polyphenols for targeting lung carcinoma: part I

Lung cancer is the second leading cause of cancer-related mortality globally, and non-small-cell lung cancer accounts for most lung cancer cases. Nanotechnology-based drug-delivery systems have exhibited immense potential in lung cancer therapy due to their fascinating physicochemical characteristics, in vivo stability, bioavailability, prolonged and targeted delivery, gastrointestinal absorption and therapeutic efficiency of their numerous chemotherapeutic agents. However, traditional chemotherapeutics have systemic toxicity issues; therefore, dietary polyphenols might potentially replace them in lung cancer treatment. Polyphenol-based targeted nanotherapeutics have demonstrated interaction with a multitude of protein targets and cellular signaling pathways that affect major cellular processes. This review summarizes the various molecular mechanisms and targeted therapeutic potentials of nanoengineered dietary polyphenols in the effective management of lung cancer.

Explainable Machine Learning Solution for Observing Optimal Surgery Timings in Thoracic Cancer Diagnosis

In this paper, we introduce an AI-based procedure to estimate and assist in choosing the optimal surgery timing, in the case of a thoracic cancer diagnostic, based on an explainable machine learning model trained on a knowledge base. This decision is usually taken by the surgeon after examining a set of clinical parameters and their evolution in time. Therefore, it is sometimes subjective, it depends heavily on the previous experience of the surgeon, and it might not be confirmed by the histopathological exam. Therefore, we propose a pipeline of automatic processing steps with the purpose of inferring the prospective result of the histopathologic exam, generating an explanation of why this inference holds, and finally, evaluating it against the conclusive opinion of an experienced surgeon. To obtain an accurate practical result, the training dataset is labeled manually by the thoracic surgeon, creating a training knowledge base that is not biased towards clinical practice. The resulting intelligent system benefits from both the precision of a classical expert system and the flexibility of deep neural networks, and it is supposed to avoid, at maximum, any possible human misinterpretations and provide a factual estimate for the proper timing for surgical intervention. Overall, the experiments showed a 7% improvement on the test set compared with the medical opinion alone. To enable the reproducibility of the AI system, complete handling of a case study is presented from both the medical and technical aspects.

Evaluating risk factors for lung cancer among never-smoking individuals using two Australian studies

PURPOSE

Lung cancer (LC) in never-smoking individuals would rank as Australia's eighth most deadly cancer, yet risk factors remain uncertain. We investigated demographic, lifestyle and health-related exposures for LC among never-smoking Australians.

METHODS

Using the prospective 45 and Up Study with 267,153 New South Wales (NSW) residents aged ≥ 45 years at recruitment (2006-2009), we quantified the relationship of 20 potential exposures with LC among cancer-free participants at baseline who self-reported never smoking. Adjusted hazard ratios (HR) and 95% confidence intervals (CI) for incident LC were estimated using Cox regression. The NSW Cancer, Lifestyle and Evaluation of Risk (CLEAR) Study, a case-control study including 10,781 NSW residents aged ≥ 18 years (2006-2014), was used to examine 16 potential LC exposures among cancer-free never-smoking participants. Adjusted odds ratios (OR) and 95% CI of LC were estimated using logistic regression.

RESULTS

There were 226 LC cases among 132,354 cancer-free 45 and Up Study participants who reported never smoking, with a median follow-up of 5.41 years. The CLEAR Study had 58 LC cases and 1316 cancer-free controls who had never smoked. Analyses of both datasets showed that Asian-born participants had a higher risk of LC than those born elsewhere: cohort, adjusted HR = 2.83 (95% CI 1.64-4.89) and case-control, adjusted OR = 3.78 (1.19-12.05). No significant association with LC was found for other exposures.

CONCLUSION

Our findings support the growing evidence that never-smoking, Asian-born individuals are at higher risk of developing LC than those born elsewhere. Ethnicity could be considered when assessing potential LC risk among never-smoking individuals.

Introducing a Novel Chemotherapeutic Drug for the Treatment of Lung Adenocarcinoma: Silver Nanoparticles Green-formulated by Cinnamomum verum

In this study we report the green synthesis of nontoxic, stable, and small size silver nanoparticle by Cinnamomum verum with reducing/capping ability without any toxic reducing agents. The in situ prepared AgNPs were characterized by advanced physicochemical techniques like FE-SEM, TEM, and UV-Vis study. It has been established that AgNPs have a spherical shape with a mean diameter from 10 to 45 nm. In the antioxidant test, the IC50 of AgNPs and BHT against DPPH free radicals were 191 and 242 µg/mL, respectively. In the cellular and molecular part of the recent study, the treated cells with AgNPs were assessed by MTT assay for 48 h about the cytotoxicity and anti-human lung adenocarcinoma properties on normal (HUVEC) and lung adenocarcinoma cell lines i.e. PC-14, LC-2/ad, and HLC-1. The IC50 of AgNPs were 259, 291, and 395 µg/mL against PC-14, LC-2/ad, and HLC-1 cell lines, respectively. The viability of malignant lung cell line reduced dose-dependently in the presence of AgNPs.

Anti-human Glioma Cancer Potentials of Neobavaisoflavone as Natural Antioxidant Compound and Its Inhibition Profiles for Acetylcholinesterase and Butyrylcholinesterase Enzymes with Molecular Modeling and Spin Density Distributions Studies

In this study, the carcinogenic potential of Neobavaisoflavone as a natural antioxidant compound and the inhibitory profiles of acetylcholinesterase and butyrylcholinesterase were investigated by molecular modeling and spin density distribution studies. To evaluate the antioxidant properties of neobavaisoflavone, DPPH test was performed in the presence of butyl hydroxytoluene as a control. Neobavaisoflavone cell viability was low compared to normal human glioma cancer cell lines, namely LN-229, U-87 and A-172 cell lines, without any effect of cytotoxicity on normal cell line. Neobavaisoflavone inhibited half of DPPH at 125 μg/mL. The best effects of Neobavaisoflavone antihypertensive glioma against the above cell lines were in the LN-229 cell line. In addition, the significant anti-cancer potential of human glioma Neobavaisoflavone against the popular human glioma cancer cell lines is related in this study. IC₅₀ values were calculated by Neobavaisoflavone diagrams, 63.87 nM for AChE and 112.98 nM for BuChE, % Activity- [Inhibitor]. According to the above results, Neobavaisoflavone can be used to treat a variety of human glioma cancers in humans. In addition, molecular modeling calculations were performed to compare the biochemical activities of the Neobavaisoflavone molecule with enzymes. After molecular insertion calculations, ADME/T analysis was performed to investigate the properties of the neobavaisoflavone molecule, which will be used as a drug in the future. Then, different parameters for the antioxidant activity of the neobavaisoflavone molecule were calculated.

A Pre-clinical Trial Study: Anti-human Colon Cancer Effect of Thalassiolin B in vitro with Enzymes Inhibition Effects and Molecular Docking Studies

In this study, it is recorded the inhibition effect of Thalassiolin B on aldose reductase, alpha-glucosidase and alpha-amylase enzymes. In the next step, the molecular docking method was used to compare the biological activities of the Thalassiolin B molecule against enzymes formed from the assembly of proteins. In these calculations, the enzymes used are Aldose reductase, Alpha-Amylase, and Alpha-Glucosidase, respectively. After the docking method, ADME/T analysis of Thalassiolin B molecule was performed to be used as a drug in the pharmaceutical industry. In the MTT assay, the anti-human colon cancer properties of Thalassiolin B against EB, LS1034, and SW480 cell lines were investigated. The cell viability of Thalassiolin B was very low against human colon cancer cell lines without any cytotoxicity on the human normal (HUVEC) cell line. The IC₅₀ of the Thalassiolin B against EB, LS1034, and SW480 were 483, 252, and 236 µg/mL, respectively. Thereby, the best cytotoxicity results and anti-human colon cancer potentials of our Thalassiolin B were observed in the case of the SW480 cell line. Maybe the anti-human colon cancer properties of Thalassiolin B are related to their antioxidant effects.

Mortality of Enlisted Men Who Served on Nuclear-Powered Submarines in the United States Navy

OBJECTIVE

To describe the long-term mortality experience of a cohort of enlisted men who served on nuclear-powered submarines in the United States Navy and breathed recirculated filtered air for extended periods of time.

METHODS

In this historical cohort study we estimated standardized mortality ratios (SMRs) and used within-cohort Poisson regression analyses to address healthy worker biases.

RESULTS

Three thousand two hundred sixty three deaths occurred among 85,498 men during 1,926,875 person-years of follow-up from 1969 to 1995. SMRs were reduced for most cause-of-death categories, prostate cancer had a twofold elevation. In within-cohort comparisons, prostate cancer mortality did not increase with duration of submarine service, but ischemic heart disease mortality increased 26% per 5 years of submarine service.

CONCLUSIONS

Long periods of submarine service do not increase mortality in most cause-of-death categories. Increased mortality from ischemic heart disease likely reflects the effects of tobacco smoke.

Correlation of serum electrolytes with serial miRNA in advanced stage non-small cell lung cancer (NSCLC) in Indonesia

Objective

This study aims to evaluate the correlation between electrolytes and serial miRNAs from our previous study. We want to prove that there is the molecular basis that underlying electrolytes disturbances as the predictive indicator to the outcome in NSCLC patients.

Results

There were positive correlation between potassium level with miR-34 (p  = 0.008, r  = 0.366), miR-148 (p  = 0.004, r  = 0.394) and miR-155 (p  = 0.031, r  = 0.300).

Lung cancer risk in never-smokers: An overview of environmental and genetic factors

Lung cancer is the leading cause of cancer-related mortality globally, accounting for 1.8 million deaths in 2020. While the vast majority are caused by tobacco smoking, 15%-25% of all lung cancer cases occur in lifelong never-smokers. The International Agency for Research on Cancer (IARC) has classified multiple agents with sufficient evidence for lung carcinogenesis in humans, which include tobacco smoking, as well as several environmental exposures such as radon, second-hand tobacco smoke, outdoor air pollution, household combustion of coal and several occupational hazards. However, the IARC evaluation had not been stratified based on smoking status, and notably lung cancer in never-smokers (LCINS) has different epidemiological, clinicopathologic and molecular characteristics from lung cancer in ever-smokers. Among several risk factors proposed for the development of LCINS, environmental factors have the most available evidence for their association with LCINS and their roles cannot be overemphasized. Additionally, while initial genetic studies largely focused on lung cancer as a whole, recent studies have also identified genetic risk factors for LCINS. This article presents an overview of several environmental factors associated with LCINS, and some of the emerging evidence for genetic factors associated with LCINS. An increased understanding of the risk factors associated with LCINS not only helps to evaluate a never-smoker's personal risk for lung cancer, but also has important public health implications for the prevention and early detection of the disease. Conclusive evidence on causal associations could inform longer-term policy reform in a range of areas including occupational health and safety, urban design, energy use and particle emissions, and the importance of considering the impacts of second-hand smoke in tobacco control policy.

Tobacco use disorder and the lungs

This narrative review provides a summary of the impact of tobacco smoking on the respiratory system and the benefits of smoking cessation. Tobacco smoking is one of the leading preventable causes of death world-wide and a major risk factor for lung cancer and chronic obstructive pulmonary disease. Smoking is also associated with an increased risk of respiratory infections and appears to be related to poorer outcomes among those with COVID-19. Non-smokers with second-hand smoke exposure also experience significant adverse respiratory effects. Smoking imposes enormous health- and non-health-related costs to societies. The benefits of smoking cessation, in both prevention and management of respiratory disease, have been known for decades and, to this day, cessation support remains one of the most important cost-effective interventions that health professionals can provide to people who smoke. Cessation at any age confers substantial health benefits, even in smokers with established morbidities. As other treatments for chronic respiratory disease advance and survival rates increase, smoking cessation treatment will become even more relevant. While smoking cessation interventions are available, the offer of these by clinicians and uptake by patients remain limited.

Interactions between Prepregnancy Overweight and Passive Smoking for Macrosomia and Large for Gestational Age in Chinese Pregnant Women

INTRODUCTION

Previous analysis showed that passive smoking and overweight were associated with an increased risk of gestational diabetes mellitus (GDM) in a synergistic manner, while GDM increased the risk of macrosomia/large for gestational age (LGA). This study aimed to examine any interactive effects between passive smoking and overweight/obesity on risk of macrosomia/LGA.

METHODS

From 2010 to 2012, 22,302 pregnant women registered for pregnancy at a primary hospital in Tianjin, China. Data were collected longitudinally; that is, from their first antenatal care visit, at the glucose challenge test (GCT) time (24-28 weeks of gestation) and at delivery. Passive smoking was self-reported. Macrosomia was defined as birth weight ≥4,000 g. Binary logistic regression was used to obtain odds ratios (ORs) and 95% confidence intervals (CIs). Additive interaction was used to test the synergistic effect.

RESULTS

Passive smokers accounted for 57.4% of women (n = 8,230). Using nonpassive smoking and prepregnancy body mass index (BMI) <24.0 kg/m2 as the reference, the adjusted ORs of overweight alone and passive smoking alone for macrosomia were 2.39 (95% CI: 2.11-2.71) and 1.17 (95% CI: 1.04-1.32). Copresence of passive smoking and prepregnancy BMI ≥24.0 kg/m2 increased the OR to 2.70 (95% CI: 2.28-3.20), with a significant additive interaction. After further adjustment for GDM or GCT, the OR of copresence of both risk factors was slightly attenuated to 2.52 (2.13-3.00) and 2.51 (2.11-2.98), with significant additive interaction. However, the additive interaction between prepregnancy overweight/obesity and passive smoking for LGA was nonsignificant.

CONCLUSIONS

Prepregnancy overweight/obesity was associated with an increased risk of macrosomia in Chinese women synergistically with passive smoking during pregnancy, and most of the association was not modified by hyperglycemia during pregnancy.

In situ decorated Au NPs on pectin-modified Fe3O4 NPs as a novel magnetic nanocomposite (Fe3O4/Pectin/Au) for catalytic reduction of nitroarenes and investigation of its anti-human lung cancer activities

In recent days, the green synthesized nanomagnetic biocomposites have been evolved with tremendous potential as the future catalysts. This has encouraged us to design and synthesis of a novel Au NPs immobilized pectin modified magnetic nanoparticles (Fe₃O₄/Pectin/Au). It was meticulously characterized using advanced analytical techniques like FT-IR, FESEM, TEM, EDX, XPS, VSM, XRD and ICP-OES. We investigated the chemical applications of the material in the catalytic reduction of nitroarenes using N₂H₄.H₂O as the reducing agent in the EtOH/H₂O solvent without any promoters or ligands. Due to strong paramagnetism, the catalyst was easily recovered and reused in 11 cycles without considerable leaching or loss in reactivity. The green protocol involves several advantages like mild conditions, easy workup, high yields, and reusability of the catalyst. Furthermore, the desired nanocomposite was employed in biological studies like anti-oxidant assay by DPPH radical scavenging test. Subsequently, on exhibiting a good IC₅₀ value in the DPPH assay, we extended the bio-application of the Fe₃O₄/Pectin/Au in the anticancer study of adenocarcinoma cells of human lungs using three cancer cell lines, PC-14, LC-2/ad and HLC-1 and a normal cell line HUVEC. The best result was accomplished in PC-14 cell lines with the lowest IC₅₀ values.

Cancer cases and deaths attributable to lifestyle risk factors in Chile

Background

To identify modifiable risk factors that contribute to cancer holds important public health relevance for setting up prevention strategies. Therefore, the aim of this study was to estimate the proportion of cancer cases and deaths attributable to alcohol consumption, high body mass index (BMI), low fruits and vegetables consumption, lack of physical activity, tobacco smoking, and passive smoking in Chile in 2018.

Methods

We retrieved data from a national representative survey to describe the distribution of six lifestyle risk factors. Relative risks of each risk factor-cancer pair were obtained from published meta-analysis and pooled cohort studies. Cancer cases and deaths were obtained from the GLOBOCAN 2018.

Results

Nearly 30% of all cancer cases (15,097 out of 50,320 cases) and 36% of all cancer deaths (10,155 out of 28,010 deaths) in Chile in 2018 were attributable to lifestyle risk factors. Smoking and high BMI accounted for most of the cancer cases (9232 and 4394, respectively) and deaths (6868 and 2572). The cancer burden of other lifestyle risk factors varied by sex. In men, the proportion of all cancer cases attributed to alcohol were 3.7% compare to 2.0% for women. Cancers cases and deaths of the larynx, lung, oral/cavity, esophagus and bladder could be at least halved if lifestyle risk factors were eliminated.

Conclusion

Smoking and high BMI were the leading causes of preventable cancer cases and deaths within the six lifestyles factors considered. Cancer prevention strategies should consider evidence-based interventions and public policies to encourage the adoption of a healthier lifestyle.

Addictions Causing Head-and-Neck Cancers

Head-and-neck cancers pose a serious economic burden, with most countries investing significant resources to reduce the incidence, primarily focusing on understanding addictive etiologies. The traditional literature focused on tobacco and alcohol use, with few studies on contemporary factors such as e-cigarette, waterpipe smoking, and human papillomavirus. This article attempts to collate and present an update on the globally identified etiologic factors.

The aim of this study was to identify and review the addictive etiologic factors causing head-and-neck cancers.

An electronic search was performed on Medline, Embase, and Google Scholar to identify the etiologies causing head-and-neck cancers and narrowed down on those driven by addiction. Further, we identified their constituents, mechanism of action, and the risks attributable to various forms of products.

Substances identified included smoked and chewed tobacco, alcohol, mate, marijuana, areca nut and betel quid, and viruses. An alarming majority of youth are now utilizing these substances. Furthermore, migrant movements have led to the spread of traditional practices across the regions, especially from the Asian subcontinent.

Ironically, despite modern advances and technology, we still see that a large proportion of population succumb to these cancers, emphasizing the need for more effective and targeted policies to combat this menace at the grassroots level.

Estimation of lifetime cumulative mortality risk of lung cancer by smoking status in Japan

The main objective of this study was to estimate the cumulative mortality risk for lung cancer according to smoking status and exposure to secondhand smoke (SHS) in Japan. We applied a life-table method to estimate the cumulative risk. Estimated lifetime cumulative risk for 20-year-old non-smokers, former, and current smokers was 3.2%, 7.6%, and 14.9% for men and 1.9%, 5.6%, and 7.2% for women, respectively. For males, the estimated risk was 3.2% for non-smokers not exposed to SHS and 4.1% for non-smokers exposed to SHS. For females, the estimated risk was 1.9% for non-smokers not exposed to SHS and 2.4% for non-smokers exposed to SHS. Lifetime cumulative mortality risk differed greatly according to smoking status. Moreover, SHS exposure resulted in observable differences in lifetime mortality risk. This study may be useful for the development of tailored prevention programs.

Dose-related effect of secondhand smoke on cardiovascular disease in nonsmokers: Systematic review and meta-analysis

BACKGROUND

Despite the positive association between secondhand smoke (SHS) and cardiovascular diseases (CVD), no comprehensive assessment on the dose-response relationship between SHS and CVD has yet been reported. Therefore, a meta-analysis was conducted to update the binary association, and to elucidate the dose-response relationship of both self-reported and objectively measured SHS exposure with CVD.

METHODS

PubMed and Embase databases were searched for articles published up to November 12, 2019. Random-effects models were used to assess the summary odds ratios (ORs) of CVD with SHS exposure. Restricted cubic splines were used to fit the dose-response relationship.

RESULTS

Fifty-five eligible observational studies were included in this meta-analysis to investigate the association between SHS exposure and CVD. Based on the meta-analysis, the pooled OR of CVD was 1.22 (95% CI 1.17-1.28) for the self-reported SHS individuals as comparing to the non-exposed group. The result of restricted cubic splines showed a risk plateau of SHS exposure at 15 cigarettes per day (P_{non-linearity} = 0.042), while other characteristics s of SHS exposure (amount, daily and cumulative duration, and cotinine) were in linear relationships with CVD (P_{non-linearity} >0.05). In addition, an estimated of 6.77% (95% CI: 5.31%-8.46%) of all CVD cases in men and 7.15% (95% CI: 5.62%-8.93%) in women might be attributed to SHS exposure worldwide.

CONCLUSIONS

Exposure to SHS is associated with an increased risk of CVD regardless of the modes. And thus, well-enforced smoke-free laws could possibly reduce a substantial risk of CVD caused by SHS.

Molecular Insights into Potential Contributions of Natural Polyphenols to Lung Cancer Treatment

Naturally occurring polyphenols are believed to have beneficial effects in the prevention and treatment of a myriad of disorders due to their anti-inflammatory, antioxidant, antineoplastic, cytotoxic, and immunomodulatory activities documented in a large body of literature. In the era of molecular medicine and targeted therapy, there is a growing interest in characterizing the molecular mechanisms by which polyphenol compounds interact with multiple protein targets and signaling pathways that regulate key cellular processes under both normal and pathological conditions. Numerous studies suggest that natural polyphenols have chemopreventive and/or chemotherapeutic properties against different types of cancer by acting through different molecular mechanisms. The present review summarizes recent preclinical studies on the applications of bioactive polyphenols in lung cancer therapy, with an emphasis on the molecular mechanisms that underlie the therapeutic effects of major polyphenols on lung cancer. We also discuss the potential of the polyphenol-based combination therapy as an attractive therapeutic strategy against lung cancer.

Media Use Is Linked to Lower Psychological Well-Being: Evidence from Three Datasets

Adolescents spend a substantial and increasing amount of time using digital media (smartphones, computers, social media, gaming, Internet), but existing studies do not agree on whether time spent on digital media is associated with lower psychological well-being (including happiness, general well-being, and indicators of low well-being such as depression, suicidal ideation, and suicide attempts). Across three large surveys of adolescents in two countries (n = 221,096), light users (<1 h a day) of digital media reported substantially higher psychological well-being than heavy users (5+ hours a day). Datasets initially presented as supporting opposite conclusions produced similar effect sizes when analyzed using the same strategy. Heavy users (vs. light) of digital media were 48% to 171% more likely to be unhappy, to be in low in well-being, or to have suicide risk factors such as depression, suicidal ideation, or past suicide attempts. Heavy users (vs. light) were twice as likely to report having attempted suicide. Light users (rather than non- or moderate users) were highest in well-being, and for most digital media use the largest drop in well-being occurred between moderate use and heavy use. The limitations of using percent variance explained as a gauge of practical impact are discussed.

Low-dose computed tomography for lung cancer screening in high-risk populations: a systematic review and economic evaluation

BACKGROUND

Diagnosis of lung cancer frequently occurs in its later stages. Low-dose computed tomography (LDCT) could detect lung cancer early.

OBJECTIVES

To estimate the clinical effectiveness and cost-effectiveness of LDCT lung cancer screening in high-risk populations.

DATA SOURCES

Bibliographic sources included MEDLINE, EMBASE, Web of Science and The Cochrane Library.

METHODS

Clinical effectiveness - a systematic review of randomised controlled trials (RCTs) comparing LDCT screening programmes with usual care (no screening) or other imaging screening programmes [such as chest X-ray (CXR)] was conducted. Bibliographic sources included MEDLINE, EMBASE, Web of Science and The Cochrane Library. Meta-analyses, including network meta-analyses, were performed. Cost-effectiveness - an independent economic model employing discrete event simulation and using a natural history model calibrated to results from a large RCT was developed. There were 12 different population eligibility criteria and four intervention frequencies [(1) single screen, (2) triple screen, (3) annual screening and (4) biennial screening] and a no-screening control arm.

RESULTS

Clinical effectiveness - 12 RCTs were included, four of which currently contribute evidence on mortality. Meta-analysis of these demonstrated that LDCT, with ≤ 9.80 years of follow-up, was associated with a non-statistically significant decrease in lung cancer mortality (pooled relative risk 0.94, 95% confidence interval 0.74 to 1.19). The findings also showed that LDCT screening demonstrated a non-statistically significant increase in all-cause mortality. Given the considerable heterogeneity detected between studies for both outcomes, the results should be treated with caution. Network meta-analysis, including six RCTs, was performed to assess the relative clinical effectiveness of LDCT, CXR and usual care. The results showed that LDCT was ranked as the best screening strategy in terms of lung cancer mortality reduction. CXR had a 99.7% probability of being the worst intervention and usual care was ranked second. Cost-effectiveness - screening programmes are predicted to be more effective than no screening, reduce lung cancer mortality and result in more lung cancer diagnoses. Screening programmes also increase costs. Screening for lung cancer is unlikely to be cost-effective at a threshold of £20,000/quality-adjusted life-year (QALY), but may be cost-effective at a threshold of £30,000/QALY. The incremental cost-effectiveness ratio for a single screen in smokers aged 60-75 years with at least a 3% risk of lung cancer is £28,169 per QALY. Sensitivity and scenario analyses were conducted. Screening was only cost-effective at a threshold of £20,000/QALY in only a minority of analyses.

LIMITATIONS

Clinical effectiveness - the largest of the included RCTs compared LDCT with CXR screening rather than no screening. Cost-effectiveness - a representative cost to the NHS of lung cancer has not been recently estimated according to key variables such as stage at diagnosis. Certain costs associated with running a screening programme have not been included.

CONCLUSIONS

LDCT screening may be clinically effective in reducing lung cancer mortality, but there is considerable uncertainty. There is evidence that a single round of screening could be considered cost-effective at conventional thresholds, but there is significant uncertainty about the effect on costs and the magnitude of benefits.

FUTURE WORK

Clinical effectiveness and cost-effectiveness estimates should be updated with the anticipated results from several ongoing RCTs [particularly the NEderlands Leuvens Longkanker Screenings ONderzoek (NELSON) screening trial].

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016048530.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.