Exposure to secondhand tobacco smoke and lung cancer by histological type: a pooled analysis of the International Lung Cancer Consortium (ILCCO)

Small cell lung cancer: emerging subtypes, signaling pathways, and therapeutic vulnerabilities

Small cell lung cancer (SCLC) is a recalcitrant cancer characterized by early metastasis, rapid tumor growth and poor prognosis. In recent decades, the epidemiology, initiation and mutation characteristics of SCLC, as well as abnormal signaling pathways contributing to its progression, have been widely studied. Despite extensive investigation, fewer drugs have been approved for SCLC. Recent advancements in multi-omics studies have revealed diverse classifications of SCLC that are featured by distinct characteristics and therapeutic vulnerabilities. With the accumulation of SCLC samples, different subtypes of SCLC and specific treatments for these subtypes were further explored. The identification of different molecular subtypes has opened up novel avenues for the treatment of SCLC; however, the inconsistent and uncertain classification of SCLC has hindered the translation from basic research to clinical applications. Therefore, a comprehensives review is essential to conclude these emerging subtypes and related drugs targeting specific therapeutic vulnerabilities within abnormal signaling pathways. In this current review, we summarized the epidemiology, risk factors, mutation characteristics of and classification, related molecular pathways and treatments for SCLC. We hope that this review will facilitate the translation of molecular subtyping of SCLC from theory to clinical application.

Plasma proteometabolome in lung cancer: exploring biomarkers through bidirectional Mendelian randomization and colocalization analysis

Unlike other cancers with widespread screening (breast, colorectal, cervical, prostate, and skin), lung nodule biopsies for positive screenings have higher morbidity with clinical complications. Development of non-invasive diagnostic biomarkers could thereby significantly enhance lung cancer management for at-risk patients. Here, we leverage Mendelian Randomization (MR) to investigate the plasma proteome and metabolome for potential biomarkers relevant to lung cancer. Utilizing bidirectional MR and co-localization analyses, we identify novel associations, highlighting inverse relationships between plasma proteins SFTPB and KDELC2 in lung adenocarcinoma (LUAD) and positive associations of TCL1A with lung squamous cell carcinoma (LUSC) and CNTN1 with small cell lung cancer (SCLC). Additionally, our work reveals significant negative correlations between metabolites such as theobromine and paraxanthine, along with paraxanthine-related ratios, in both LUAD and LUSC. Conversely, positive correlations are found in caffeine/paraxanthine and arachidonate (20:4n6)/paraxanthine ratios with these cancer types. Through single-cell sequencing data of normal lung tissue, we further explore the role of lung tissue-specific protein SFTPB in carcinogenesis. These findings offer new insights into lung cancer etiology, potentially guiding the development of diagnostic biomarkers and therapeutic approaches.

Exposure to second-hand smoke and risk of lung cancer among Iranian population: A multicenter case-control study

OBJECTIVE

Despite the implementation of the WHO Framework Convention on Tobacco Control (FCTC) program in Iran, the regulation of second-hand smoke (SHS) exposure-an often-overlooked hazard-, still requires improvement. We employed a multi-center case-control study to investigate the association between exposure to secondhand smoke (SHS) from various tobacco products (cigarettes, water-pipes, pipes, and chopogh), opium use, and the risk of lung cancer.

METHOD

We included 627 lung cancer cases and 3477 controls. Exposure to SHS tobacco and SHS opium was collected through a questionnaire. We used mixed-model logistic regressions to estimate odds ratios (ORs) and 95% confidence intervals (CI).

RESULT

Among the overall population exposed to second-hand tobacco smoke (SHTS), the odds ratio (OR) compared to those never exposed was 1.35 (95% CI: 1.08-1.71). Never smokers who were ever exposed to second-hand tobacco smoke (SHTS) had 1.69-fold risk of lung cancer compared to those who were never exposed (95% CI: 1.13-2.52). Exposure to SHTS between 2-3 per day (OR = 2.27, 95% CI: 1.13-4.53) and more than three hours per day (OR = 2.29, 95% CI: 1.20-4.37) can increase the risk of lung cancer compared with the no exposure group (P-trend <0.01). We did not observe any association between exposure to second-hand opium smoke (SHOS) and the risk of lung cancer, either in the overall population or among never-smokers.

CONCLUSION

Our study estimates the impact of second-hand tobacco smoke (SHTS) on lung cancer risk in both the overall population and never-smokers. Additional studies are required to evaluate the association between exposure to second-hand smoke from opium and other type of tobacco, including water-pipe and the risk of lung cancer.

Bioelectrical impedance analysis-derived phase angle (PhA) in lung cancer patients: a systematic review

BACKGROUND

Lung cancer is the second most diagnosed cancer in the world. Up to 84% of diagnosed patients have malnutrition, which can negatively affect quality of life and survival and may worsen with neoadjuvant treatment. Bioelectrical Impedance Analysis-Derived Phase Angle (PhA) in these patients could be a valid tool to assess the nutritional status in order to improve their condition.

METHODS

This review provides an update on PhA assessment in lung cancer patients over the past twenty years. We searched PubMed, Embase, Scopus, Web of Science, and Cochrane, for articles regarding the PhA obtained from Bioelectrical Impedance Analysis in lung cancer patients. The authors independently performed a literature search: sample size, patient population, study type, study dates, survival and interventions were evaluated. The final review included 11 studies from different countries.

RESULTS

Eight studies only considered patients with lung cancer, while three studies considered patients with different kind of cancer, including lung. Correlation data between PhA and age are conflicting. In patients undergoing clinical treatment and patients undergoing surgical treatment lower PhA was observed. A lower PhA is associated with a shorter survival. In three studies emerged a relationship between Karnofski Performance Status and Handgrip Strenght with PhA. From one study, univariate logistic regression analysis showed that higher PhA values represent a protective factor for sarcopenia.

CONCLUSION

Our research underlined interesting, but not conclusive, results on this topic; however more researches are needed to understand the clinical meaning of PhA.

Coffee Consumption and Risk of Lung Cancer: A Meta-Analysis of Prospective Cohort Studies

The association between coffee consumption and lung cancer risk remains inconsistent. To quantitatively assess this association, we conducted a meta-analysis of prospective cohort studies. We searched PubMed and Web of Science databases along with hand searches for eligible studies published up to July 2023. A total of 26 prospective studies, including 30,305 lung cancer cases and 1,795,158 participants, were included in the meta-analysis. The pooled RR for high vs. low coffee consumption was 1.30 (95% CI: 1.11-1.53) with significant heterogeneity (I2 = 72.0%, p < .001). For never smokers, however, the pooled RR was 1.18 (95% CI: 0.999-1.38) with no evidence of heterogeneity (I2 = 0.0%, p = .53). By adjustment for body mass index (BMI), there was no significant association between coffee consumption and lung cancer risk in studies that adjusted for BMI (RR = 1.06; 95% CI: 0.87-1.30) (Pdifference = .01). Further analysis of studies that adjusted for BMI in never smokers found that coffee consumption was not associated with lung cancer risk. In conclusion, the association of high coffee consumption with lung cancer risk was attenuated when the confounding effects caused by smoking and BMI were controlled. Our results, therefore, imply that coffee consumption does not seem to be a risk factor for lung cancer incidence.

Nomograms Predict PFS and OS for SCLC Patients After Standardized Treatment: A Real-World Study

Purpose

This study aims to investigate the process of small cell lung cancer (SCLC) patients from achieving optimal efficacy to experiencing disease progression until death. It examines the predictive value of the treatment response on progression free survival (PFS) and overall survival (OS) of SCLC patients.

Patients and Methods

We conducted a retrospective analysis on 136 SCLC patients diagnosed from 1992 to 2018. Important prognostic factors were identified to construct nomogram models. The predictive performance of the models was evaluated using the receiver operating characteristic curves and calibration curves. Survival differences between groups were compared using Kaplan-Meier survival curves. Subsequently, an independent cohort consisting of 106 SCLC patients diagnosed from 2014 to 2021 was used for validation.

Results

We constructed two nomograms to predict first-line PFS (PFS1) and OS of SCLC. The area under the receiver operating characteristic curves for the PFS1 nomogram predicting PFS at 3-, 6-, and 12-months were 0.919 (95% CI: 0.867-0.970), 0.908 (95% CI: 0.860-0.956) and 0.878 (95% CI: 0.798-0.958), and for the OS nomogram predicting OS at 6-, 12-, and 24-months were 0.814 (95% CI: 0.736-0.892), 0.819 (95% CI: 0.749-0.889) and 0.809 (95% CI: 0.678-0.941), indicating those two models with a high discriminative ability. The calibration curves demonstrated the models had a high degree of consistency between predicted and observed values. According to the risk scores, patients were divided into high-risk and low-risk groups, showing a significant difference in survival rate. And these findings were validated in another independent validation cohort.

Conclusion

Based on the patients' treatment response after standardized treatment, we developed and validated two nomogram models to predict PFS1 and OS of SCLC. The models demonstrated good accuracy, reliability and clinical applicability by validating in an independent cohort.

Non-preventable cases of breast, prostate, lung, and colorectal cancer in 2050 in an elimination scenario of modifiable risk factors

Most Western countries have increasing number of new cancer cases per year. Cancer incidence is primarily influenced by basically avoidable risk factors and an aging population. Through hypothetical elimination scenarios of multiple major risk factors for cancer, we estimated the number of new cancer cases that are non-preventable in 2050. We compare numbers of new postmenopausal breast, prostate, lung, and colorectal cancer cases in 2021 to projected numbers of new cases in 2050 under prevention scenarios regarding smoking, overweight and obesity, and alcohol consumption: no intervention, 50%, and 100% instant reduction. Cancer incidence data were derived from NORDCAN, and risk factor prevalence data from the Danish National Health Survey. Cancer projections were calculated with the Prevent program. Hypothetical 100% instant elimination of major risk factors for cancer in Denmark in 2022 will result in unchanged numbers of new breast and colorectal cancers in 2050. The number of new prostate cancers will increase by 25% compared to 2021. Unchanged risk factor levels will result in noticeable increase in cancer burden. Increase in life expectancy and age will entail an increase in cancer incidence, despite maximum effect of preventive actions in the population. Our results are important when planning future health care.

Mortality attributable to secondhand smoke exposure in the autonomous communities of Spain

INTRODUCTION AND OBJECTIVES

Exposure to secondhand smoke (SHS) causes cardiovascular disease, respiratory disease, and cancer. The aim of this study was to estimate the mortality attributed to SHS in people aged ≥ 35 years in Spain and its autonomous communities (AC) by sex from 2016 to 2021.

METHODS

Estimates of SHS-attributable mortality were calculated by applying the prevalence-dependent method where SHS exposure was derived from the adjustment of small-area models and based on the calculation of population-attributed fractions. Sex, age group, AC, and cause of death (ischemic heart disease and lung cancer) were included. The estimates of attributed mortality are presented with their 95% confidence interval (95%CI). Crude and age-standardized rates were estimated for each sex and AC.

RESULTS

From 2016 to 2021, SHS exposure caused 4,970 (95%CI, 4,787-5,387) deaths, representing 1.6% of total mortality for ischemic heart disease and lung cancer. The burden of attributed mortality differed widely among the AC, with Andalusia having the highest burden of attributed mortality (crude rate: 46.6 deaths per 100 000 population in men and 17.0/100 000 in women). In all the AC, the main cause of death in both sexes was ischemic heart disease. The highest burden of mortality was observed in nonsmokers.

CONCLUSIONS

The burden of SHS-attributable mortality was high and varied geographically. The results of this study should be considered to advance tobacco control legislation in Spain.

Asthma prevalence among United States population insights from NHANES data analysis

Asthma is a prevalent respiratory condition that poses a substantial burden on public health in the United States. Understanding its prevalence and associated risk factors is vital for informed policymaking and public health interventions. This study aims to examine asthma prevalence and identify major risk factors in the U.S.

POPULATION

Our study utilized NHANES data between 1999 and 2020 to investigate asthma prevalence and associated risk factors within the U.S.

POPULATION

We analyzed a dataset of 64,222 participants, excluding those under 20 years old. We performed binary regression analysis to examine the relationship of demographic and health related covariates with the prevalence of asthma. The study found that asthma affected 8.7% of the U.S.

POPULATION

Gender emerged as a significant factor, with 36.0% of asthma patients being male and 64.0% female (p < 0.001). Individuals aged 60 and older having the highest asthma prevalence at 34.0%. Non-Hispanic whites had the highest prevalence at 46.4%, followed by non-hispanic blacks at 26.0%. In contrast, Mexican Americans and other hispanic individuals had lower rates, at 9.6% and 9.0%, respectively. Females were 1.76 times more likely to have asthma than males (p < 0.001). Obese individuals had a 1.74 times higher likelihood of current asthma compared to underweight individuals (p < 0.001). Notably, both Non-Hispanic Whites and Non-Hispanic Blacks showed higher odds of current asthma compared to Mexican Americans (with adjusted odds ratios of 2.084 and 2.096, respectively, p < 0.001). The research findings indicate that asthma is prevalent in 8.7% of the U.S.

POPULATION

Our study highlights that individuals who are female, have low income, are obese, and smoke have the highest likelihood of being affected by asthma. Therefore, public health policies should prioritize addressing these risk factors in their preventive strategies.

Ethnic differences in the characteristics of patients with newly diagnosed lung cancer in the Te Manawa Taki region of New Zealand

BACKGROUND

Māori have three times the mortality from lung cancer compared with non-Māori. The Te Manawa Taki region has a population of 900 000, of whom 30% are Māori. We have little understanding of the factors associated with developing and diagnosing lung cancer and ethnic differences in these characteristics.

AIMS

To explore the differences in the incidence and characteristics of patients with newly diagnosed lung cancer between Māori and non-Māori.

METHODS

Patients were identified from the regional register. Incidence rates were calculated based on population data from the 2013 and 2018 censuses. The patient and tumour characteristics of Māori and non-Māori were compared. The analysis used Χ2 tests and logistic models for categorical variables and Student t tests for continuous variables.

RESULTS

A total of 4933 patients were included, with 1575 Māori and 3358 non-Māori. The age-standardised incidence of Māori (236 per 100 000) was 3.3 times higher than that of non-Māori. Māori were 1.3 times more likely to have an advanced stage of disease and 1.97 times more likely to have small cell lung cancer. Māori were more likely to have comorbidities, chronic obstructive pulmonary disease, cardiovascular disease and diabetes. They also had higher levels of social deprivation and tended to be younger, female and current smokers.

CONCLUSIONS

The findings point to the need to address barriers to early diagnosis and the need for system change including the need to introduce a lung cancer screening focussing on Māori. There is also the need for preventive programmes to address comorbidities that impact lung cancer outcomes as well as a continued emphasis on creating a smoke-free New Zealand.

Dietary and supplementary vitamin C intake and the risk of lung cancer: A meta‑analysis of cohort studies

Previous cohort studies reported inconsistent findings regarding the association between dietary or supplementary vitamin C intake and lung cancer risk. These associations were investigated by conducting a meta-analysis of cohort studies. The PubMed and EMBASE databases were utilized, using keywords related to the topic from inception to April 15, 2022. Pooled effect sizes, such as relative risk (RR) or hazard ratio (HR) with 95% confidence intervals (CIs), were calculated using a random-effects model. A total of 20 cohort studies from 13 articles were included in the final analysis. In a meta-analysis of all studies, there was no significant association between dietary or supplementary vitamin C intake and lung cancer risk (RR/HR, 0.90; 95% CI, 0.80-1.01; I2=56.4%; n=20). In the subgroup meta-analysis by the source of vitamin C, dietary vitamin C intake decreased the risk of lung cancer (RR/HR, 0.82; 95% CI, 0.73-0.92; I2=42.5%; n=14), whereas there was no association between supplementary vitamin C intake and lung cancer risk (RR/HR, 1.01; 95% CI, 0.84-1.22; n=4). The present meta-analysis of cohort studies found that dietary vitamin C intake is beneficial for preventing lung cancer, whereas its supplementary intake does not have a beneficial effect.

Clinical insights into small cell lung cancer: Tumor heterogeneity, diagnosis, therapy, and future directions

Small cell lung cancer (SCLC) is characterized by rapid growth and high metastatic capacity. It has strong epidemiologic and biologic links to tobacco carcinogens. Although the majority of SCLCs exhibit neuroendocrine features, an important subset of tumors lacks these properties. Genomic profiling of SCLC reveals genetic instability, almost universal inactivation of the tumor suppressor genes TP53 and RB1, and a high mutation burden. Because of early metastasis, only a small fraction of patients are amenable to curative-intent lung resection, and these individuals require adjuvant platinum-etoposide chemotherapy. Therefore, the vast majority of patients are currently being treated with chemoradiation with or without immunotherapy. In patients with disease confined to the chest, standard therapy includes thoracic radiotherapy and concurrent platinum-etoposide chemotherapy. Patients with metastatic (extensive-stage) disease are treated with a combination of platinum-etoposide chemotherapy plus immunotherapy with an anti-programmed death-ligand 1 monoclonal antibody. Although SCLC is initially very responsive to platinum-based chemotherapy, these responses are transient because of the development of drug resistance. In recent years, the authors have witnessed an accelerating pace of biologic insights into the disease, leading to the redefinition of the SCLC classification scheme. This emerging knowledge of SCLC molecular subtypes has the potential to define unique therapeutic vulnerabilities. Synthesizing these new discoveries with the current knowledge of SCLC biology and clinical management may lead to unprecedented advances in SCLC patient care. Here, the authors present an overview of multimodal clinical approaches in SCLC, with a special focus on illuminating how recent advancements in SCLC research could accelerate clinical development.

Latin America and the Caribbean Code Against Cancer 1st edition: Tobacco and nicotine-related products, secondhand smoke, and alcohol and cancer

Tobacco, secondhand smoke (SHS), and alcohol, all carcinogens, are leading preventable cancer risk factors in Latin America and the Caribbean (LAC). Since 2000, smoking and SHS exposure have significantly decreased in the region. Yet alcohol consumption remains high. The entry of nicotine-related products such as electronic cigarettes (e-cigs) threatens achievements made in tobacco control and chronic diseases prevention, including cancer. E-cigs use is likely associated with smoking initiation among adolescents who had never smoked and dual use with combustible tobacco products. Therefore, the LAC Code Against Cancer recommends to the public actions they can take to reduce their risk of cancer: 1. Don't smoke or use any type of tobacco. If you do, quitting is possible, with professional help if needed. Don't use e-cigarettes either, as they lead to tobacco use. 2. Make your home a smoke-free place. Respect and promote laws that ensure smoke-free spaces to protect our health. and 3. Avoid drinking alcoholic beverages. This helps prevent several types of cancer. The Code recommends to policymakers a package of cost-effective policies based on the MPOWER and SAFER to prevent cancer at the population level. It also recommends that primary care health professionals: 1. Ask all their patients and their families whether they smoke or vape, inform them about the harms of smoking and vaping, and promote tobacco and nicotine related products cessation strategies among users. 2. Inform about the harms of exposure to SHS, especially among children, and promote smoke-free environments, and 3. Prevent alcohol use by their patients and their families, use tools to assess use, intensity, and frequency, and apply brief counseling intervention to support alcohol abstinence in primary care.

Lung cancer associated with combustion particles and fine particulate matter (PM2.5) - The roles of polycyclic aromatic hydrocarbons (PAHs) and the aryl hydrocarbon receptor (AhR)

Air pollution is the leading cause of lung cancer after tobacco smoking, contributing to 20% of all lung cancer deaths. Increased risk associated with living near trafficked roads, occupational exposure to diesel exhaust, indoor coal combustion and cigarette smoking, suggest that combustion components in ambient fine particulate matter (PM2.5), such as polycyclic aromatic hydrocarbons (PAHs), may be central drivers of lung cancer. Activation of the aryl hydrocarbon receptor (AhR) induces expression of xenobiotic-metabolizing enzymes (XMEs) and increase PAH metabolism, formation of reactive metabolites, oxidative stress, DNA damage and mutagenesis. Lung cancer tissues from smokers and workers exposed to high combustion PM levels contain mutagenic signatures derived from PAHs. However, recent findings suggest that ambient air PM2.5 exposure primarily induces lung cancer development through tumor promotion of cells harboring naturally acquired oncogenic mutations, thus lacking typical PAH-induced mutations. On this background, we discuss the role of AhR and PAHs in lung cancer development caused by air pollution focusing on the tumor promoting properties including metabolism, immune system, cell proliferation and survival, tumor microenvironment, cell-to-cell communication, tumor growth and metastasis. We suggest that the dichotomy in lung cancer patterns observed between smoking and outdoor air PM2.5 represent the two ends of a dose-response continuum of combustion PM exposure, where tumor promotion in the peripheral lung appears to be the driving factor at the relatively low-dose exposures from ambient air PM2.5, whereas genotoxicity in the central airways becomes increasingly more important at the higher combustion PM levels encountered through smoking and occupational exposure.

Association of secondhand smoke exposure and health-related lifestyle behaviors among male university employees in Japan

Secondhand smoke (SHS) exposure causes various health problems associated with an unhealthy lifestyle. However, the lifestyles of individuals exposed to SHS have not been characterized extensively. Therefore, this cross-sectional study aimed to investigate the association between SHS exposure and lifestyle behaviors. The participants were 2379 healthy male employees at Osaka University who underwent health examinations. Physical and biochemical parameters and lifestyle behavior data were obtained from all the participants. Participants with SHS exposure had significantly higher body mass index, waist circumference, and serum levels of triglycerides and uric acid than that of those without SHS exposure. SHS exposure was significantly correlated with several lifestyle behaviors, including TV time, frequency of breakfast consumption and fried food consumption, vegetable and fruit intake, alcohol consumption frequency and daily alcohol intake, and smoking status. Thus, SHS exposure may be associated with an unhealthy lifestyle. The lifestyle behaviors of the smoke-excluded population were assessed further; however, SHS exposure was still associated with dietary and drinking habits. Since participants with SHS exposure are likely to have an unhealthy life and combined unhealthy lifestyle behaviors, the confounding effect of these factors should be considered when assessing the impact of SHS exposure on health.

Breathing in danger: how particulate matter pollution is putting the public at risk of lung cancer†

We are constantly exposed to chemicals and other agents in our environment that can influence our risk of tumorigenesis, but exactly how these factors contribute to cancer development is largely unknown. Fine particulate matter measuring ≤2.5 μm (PM2.5 ) from air pollution can accumulate in alveoli, contributing to inflammation and tissue damage. Despite prior correlative studies highlighting the mortality risk, there has been a historical reluctance to lower national standards for safe PM2.5 exposure. A recent publication further highlights the attributable risk of PM2.5 exposure with lung cancer - particularly in 'never-smokers' with EGFR-driven non-small cell lung cancer. Importantly, it also elucidates a mechanistic link between PM2.5 exposure and tumorigenesis using in vivo models of EGFR non-small cell lung cancer. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

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.

Incidence trends and spatial distributions of lung adenocarcinoma and squamous cell carcinoma in Taiwan

Lung cancer is the second most common cancer in Taiwan. After Taiwan implemented the Tobacco Hazards Prevention Act in 1997, smoking rates declined. However, the incidence rates of lung cancer for both sexes are still increasing, possibly due to risk factors other than smoking. We used age-period-cohort analysis to examine the secular trends of lung cancer incidence rates by histological type in Taiwan. A stabilized kriging method was employed to map these lung cancer incidence rates. Lung adenocarcinoma incidence rates increased, but lung squamous cell carcinoma incidence rates decreased, for both the sexes in recent birth cohorts, particularly in women. In Taiwan, the hotspots of lung adenocarcinoma incidence rates were in the northern, northeastern, and western coastal areas; the incidence rates increased rapidly in the western and southern coastal regions and southern mountainous regions. The high incidence rates of lung squamous cell carcinoma in men were in the southwestern and northeastern coastal areas. The incidence rates rapidly increased in the central and southern coastal and mountainous regions. For both sexes in Taiwan, lung squamous cell carcinoma incidence rates declined from 1997 to 2017, but lung adenocarcinoma increased. The increased incidence rates of lung adenocarcinoma may be related to indoor and outdoor air pollution. Some areas in Taiwan have increasing lung cancer incidence rates, including the northwestern and southern coasts and mountains, and warrant particular attention.

SCLC: Epidemiology, Risk Factors, Genetic Susceptibility, Molecular Pathology, Screening, and Early Detection

We review research regarding the epidemiology, risk factors, genetic susceptibility, molecular pathology, and early detection of SCLC, a deadly tumor that accounts for 14% of lung cancers. We first summarize the changing incidences of SCLC globally and in the United States among males and females. We then review the established risk factor (i.e., tobacco smoking) and suspected nonsmoking-related risk factors for SCLC, and emphasize the importance of continued effort in tobacco control worldwide. Review of genetic susceptibility and molecular pathology suggests different molecular pathways in SCLC development compared with other types of lung cancer. Last, we comment on the limited utility of low-dose computed tomography screening in SCLC and on several promising blood-based molecular biomarkers as potential tools in SCLC early detection.

Determining Association between Lung Cancer Mortality Worldwide and Risk Factors Using Fuzzy Inference Modeling and Random Forest Modeling

Lung cancer remains the leading cause for cancer mortality worldwide. While it is well-known that smoking is an avoidable high-risk factor for lung cancer, it is necessary to identify the extent to which other modified risk factors might further affect the cell's genetic predisposition for lung cancer susceptibility, and the spreading of carcinogens in various geographical zones. This study aims to examine the association between lung cancer mortality (LCM) and major risk factors. We used Fuzzy Inference Modeling (FIM) and Random Forest Modeling (RFM) approaches to analyze LCM and its possible links to 30 risk factors in 100 countries over the period from 2006 to 2016. Analysis results suggest that in addition to smoking, low physical activity, child wasting, low birth weight due to short gestation, iron deficiency, diet low in nuts and seeds, vitamin A deficiency, low bone mineral density, air pollution, and a diet high in sodium are potential risk factors associated with LCM. This study demonstrates the usefulness of two approaches for multi-factor analysis of determining risk factors associated with cancer mortality.

Public Health Burden of Secondhand Smoking: Case Reports of Lung Cancer and a Literature Review

Secondhand smoke (SHS), composed of mainstream and sidestream smoke, is a known human carcinogen. It contains a variety of harmful substances at even higher concentrations than mainstream smoke itself, which is inhaled during firsthand smoking. Exposure to SHS, affecting more than a third of the worldwide population, increases the likelihood of lung cancer by roughly 30%, with specific contributions depending on the histological type of cancer. This study aimed to present the harmful potential of SHS through case reports and describe the burden of SHS via a literature review. From a collection of lung cancer case reports occurring in never smokers from the Olomouc district over the last 10 years, 2 cases with no risk factors for lung cancer except for significant exposure to SHS were identified. Both cases were of young women who lived in households where their parents smoked during childhood. They suffered from rarer histological types of lung cancer in which the association with SHS has not yet been analyzed. As the literature confirms, SHS has the most adverse effects in individuals exposed during childhood. It is necessary to both take measures to reduce the prevalence of SHS, especially among children in households and pay due attention to the smoking history of patients, including current and previous exposure to SHS, when obtaining anamnestic data. Furthermore, the effect of SHS on rarer histological types of lung cancer should be studied.

Exposure to Secondhand Smoke and a Tobacco-Specific Carcinogen in Non-Smokers

Background: The International Agency for Research on Cancer classifies 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) as a known carcinogen. This study aimed to investigate the association between exposure to secondhand smoke (SHS) and NNAL concentrations in non-smokers.Methods: This was a cross-sectional study based on data from the 2016 to 2018 Korea National Health and Nutrition Examination Survey. Urine NNAL concentrations were categorized into tertiles of 3,615 study participants who were non-smokers. All sampling and weight variables were stratified, and analyses to account for the complex sampling design were conducted.Results: The overall, male, and female percentages of SHS exposure among non-smokers were 22.4%, 29.2%, and 20.4%, respectively. The geometric means of urine NNAL concentrations were 1.896±0.098 pg/mL and 1.094±0.028 pg/mL in the SHS exposure and non-exposure groups, respectively. After adjusting for confounding variables, in the total group, the geometric mean of urine NNAL concentrations was significantly higher in the SHS exposure group than in the SHS non-exposure group (adjusted P-value <0.001). Compared with the non-exposure group, the adjusted odds ratios (95% confidence intervals) for the highest NNAL tertile group of overall SHS exposure in the total, men, and women groups were 2.44 (1.95–3.05), 1.65 (1.08–2.53), and 2.73 (2.11–3.52), respectively, after full adjustment.Conclusion: The urine NNAL concentration in the SHS exposure group was significantly higher than that in the non-exposure group. Exposure to SHS was associated with a higher risk of elevated urine NNAL concentrations in non-smokers.

Lung cancer mortality trends in Mexico, 1998-2018: the impact of the General Law on Tobacco Control

OBJECTIVE

The aim of this study was to describe trends in lung cancer (LC) mortality and trends in tobacco use.

METHODS

This is an ecological time-series study to determine mortality trends due to lung cancer resulting from tobacco consumption, based on secondary open-access sources, such as the National Surveys. Smoking prevalence, tobacco use trends, mortality rates, and percentage were determined by LC. The mortality trend from LC was calculated, and a linear regression analysis was performed to evaluate the impact of the General Law for Tobacco Control.

RESULTS

The prevalence of tobacco use decreased steadily between 1988 and 2015, particularly in men. Mortality rates and percentage decreased between 1998 and 2018. During this period, the mortality rate decreased from 6.3 to 5.4 per 100,000 population (-0.032/100,000 each year, p<0.001), with a net decrease of 0.9 per 100,000. We observe increases in mortality in women in the central and southeastern regions. Of 32 states, 18 showed a tendency to loss (p<0.005). The rate of change for men was -0.24, with a total reduction of 2.17 before the introduction of the laws and -0.32 after their introduction, a total reduction of 3.24 (p<0.005). Women showed no reduction.

CONCLUSIONS

Mortality rates showed a limited decrease. Strategies need to be strengthened, mainly in the central and southeastern regions, and to focus on the control of tobacco use by women.

Influence of Psychological Factors in Breast and Lung Cancer Risk - A Systematic Review

Introduction: In 2020, according to the Global Cancer Observatory, nearly 10 million people died of cancer. Amongst all cancers, breast cancer had the highest number of new cases and lung cancer had the highest number of deaths. Even though the literatures suggest a possible connection between psychological factors and cancer risk, their association throughout studies remains inconclusive. The present systematic review studied the connection between psychological factors and the risk of breast and lung cancer, prior to a cancer diagnosis. The psychological factors of trauma, grief, and depression were studied. Methods: The current systematic review was carried out across multiple databases in two phases, an initial exploratory research in June 2020, refined with a second electronic research in December 2020. The inclusion criteria included studies describing the association between trauma, posttraumatic stress disorder (PTSD), grief, and depression with breast and lung cancer risk. The psychological data collection must have been carried out prior to a confirmed breast or lung cancer diagnosis, and accessed through self-report measures, questionnaires, clinical interviews, or clinical diagnoses. Study reports had to contain information about the incidence of cancer and effect size. The exclusion criteria were studies in which psychological factors were collected after cancer diagnosis. Results and Conclusion: A total of 26 studies were included. Although non-consensual, the findings from the present systematic review suggest that, in addition to the known risk factors, psychological factors may play an important role in the etiology of both breast and lung cancer. To include psychological factors as a variable that affects cancer development may be fundamental to opening new avenues for prevention and intervention. Systematic Review Registration: [www.ClinicalTrials.gov], identifier [CRD42020209161].

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 1^st quantile (the lowest) of serum cotinine level showed that participants in the 4^th 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.

Phytoestrogens and lung cancer risk: a nested case-control study in never-smoking Chinese women

BACKGROUND

Since several lines of evidence suggest that estrogens may be involved in lung carcinogenesis, it has been hypothesized that intake of phytoestrogens, similar in molecular structure to mammalian estrogens, may be associated with lung cancer development.

OBJECTIVE

The aim was to prospectively evaluate the association between phytoestrogen exposure and lung cancer risk in never-smoking women.

METHODS

We conducted a nested case-control study within a population-based prospective cohort study of women. A total of 478 incident lung cancer cases and their individually matched controls were identified among never-smoking women after a mean follow-up of 15.6 years. Habitual intake of and internal exposure to phytoestrogens were assessed by repeated dietary surveys and urinary biomarkers, respectively. ORs and 95% CIs for lung cancer were estimated in conditional logistic regression models.

RESULTS

After adjustment for potential confounders, a moderate intake of dietary isoflavones was inversely associated with lung cancer risk in never-smoking women, with the OR for the second quartile vs. the lowest quartile of intake being 0.52 (95% CI: 0.35, 0.76). Further increasing intake did not convey additional benefits, with ORs (95% CI) for the third and fourth quartiles of 0.53 (0.36, 0.78) and 0.47 (0.31, 0.72), respectively (P-overall < 0.001 and P-nonlinearity = 0.006). A similar association was seen when exposure to isoflavones was assessed by urinary biomarkers. ORs (95% CI) for the second, third, and fourth quartiles compared with the lowest quartile of urinary isoflavone excretion were 0.57 (0.39, 0.83), 0.64 (0.44, 0.92), and 0.60 (0.41, 0.86), respectively. The inverse association reached a plateau beyond the second quartile, with P-overall = 0.04 and P-nonlinearity = 0.15. Urinary excretion of gut-microbiota-derived metabolites of lignans was not related to lung cancer risk.

CONCLUSIONS

This study suggests that moderately increasing intake of isoflavone-rich foods is associated with lower risk of lung cancer in never-smoking women.

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.

Benzo[a]pyrene diol epoxide-induced transformed cells identify the significance of hsa_circ_0051488, a ERCC1-derived circular RNA in pulmonary squamous cell carcinoma

ERCC1 is a gene for repairing DNA damage whose function is related to carcinogenic-induced tumorigenesis and the effectiveness of platinum therapies. Circular RNAs (circRNAs) are products of posttranscriptional regulation with pleiotropic effects on the pathogenesis of lung cancer. We aim to identify that specific circRNAs derived from ERCC1 can regulate key biological processes involved in the development of lung cancer. We performed bioinformatics analysis, in vitro experiments, and analyzed clinical samples, to determine the biological features of a certain ERCC1-derived circRNA termed as hsa_circ_0051488 in benzo[a]pyrene diol epoxide-induced malignant transformed cell and lung cancer cell. The well-established model of transformed cells provided an ideal platform for analyzing the molecular characteristics of this circRNA in the malignant transformation of lung epithelial cell, which supports that hsa_circ_0051488 functions in the onset and growth of lung squamous cell carcinoma (LUSC). Further analysis indicates that the absence of hsa_circ_0051488 promoted the proliferation of cells with the malignant phenotype. Extensive experiments confirm that hsa_circ_0051488 is present in the cytoplasm and functioned as a competing endogenous RNA. In particular, hsa_circ_0051488 binds to mir-6717-5p, thereby modulating the expression of SATB2 gene, a lung cancer suppressor. Furthermore, our in silico experiments indicate that SATB2 can inhibit multiple tumor pathways and its expression positively correlated with the tumor suppressor gene CRMP1. These findings suggest a possible regulatory mechanism of hsa_circ_0051488 in LUSC, and that the newly discovered hsa_circ_0051488/miR-6717-5p/SATB2 axis may be a potential route for therapeutic intervention of LUSC.

Tracing Lung Cancer Risk Factors Through Mutational Signatures in Never-Smokers

Epidemiologic studies often rely on questionnaire data, exposure measurement tools, and/or biomarkers to identify risk factors and the underlying carcinogenic processes. An emerging and promising complementary approach to investigate cancer etiology is the study of somatic "mutational signatures" that endogenous and exogenous processes imprint on the cellular genome. These signatures can be identified from a complex web of somatic mutations thanks to advances in DNA sequencing technology and analytical algorithms. This approach is at the core of the Sherlock-Lung study (2018-ongoing), a retrospective case-only study of over 2,000 lung cancers in never-smokers (LCINS), using different patterns of mutations observed within LCINS tumors to trace back possible exposures or endogenous processes. Whole genome and transcriptome sequencing, genome-wide methylation, microbiome, and other analyses are integrated with data from histological and radiological imaging, lifestyle, demographic characteristics, environmental and occupational exposures, and medical records to classify LCINS into subtypes that could reveal distinct risk factors. To date, we have received samples and data from 1,370 LCINS cases from 17 study sites worldwide and whole-genome sequencing has been completed on 1,257 samples. Here, we present the Sherlock-Lung study design and analytical strategy, also illustrating some empirical challenges and the potential for this approach in future epidemiologic studies.

Modelling tool to support decision-making in the NHS Health Check programme: workshops, systematic review and co-production with users

BACKGROUND

Local authorities in England commission the NHS Health Check programme to invite everyone aged 40-74 years without pre-existing conditions for risk assessment and eventual intervention, if needed. However, the programme's effectiveness, cost-effectiveness and equity impact remain uncertain.

AIM

To develop a validated open-access flexible web-based model that enables local commissioners to quantify the cost-effectiveness and potential for equitable population health gain of the NHS Health Check programme.

OBJECTIVES

The objectives were as follows: (1) co-produce with stakeholders the desirable features of the user-friendly model; (2) update the evidence base to support model and scenario development; (3) further develop our computational model to allow for developments and changes to the NHS Health Check programme and the diseases it addresses; (4) assess the effectiveness, cost-effectiveness and equity of alternative strategies for implementation to illustrate the use of the tool; and (5) propose a sustainability and implementation plan to deploy our user-friendly computational model at the local level.

DESIGN

Co-production workshops surveying the best-performing local authorities and a systematic literature review of strategies to increase uptake of screening programmes informed model use and development. We then co-produced the workHORSE (working Health Outcomes Research Simulation Environment) model to estimate the health, economic and equity impact of different NHS Health Check programme implementations, using illustrative-use cases.

SETTING

Local authorities in England.

PARTICIPANTS

Stakeholders from local authorities, Public Health England, the NHS, the British Heart Foundation, academia and other organisations participated in the workshops. For the local authorities survey, we invited 16 of the best-performing local authorities in England.

INTERVENTIONS

The user interface allows users to vary key parameters that represent programme activities (i.e. invitation, uptake, prescriptions and referrals). Scenarios can be compared with each other.

MAIN OUTCOME MEASURES

Disease cases and case-years prevented or postponed, incremental cost-effectiveness ratios, net monetary benefit and change in slope index of inequality.

RESULTS

The survey of best-performing local authorities revealed a diversity of effective approaches to maximise the coverage and uptake of NHS Health Check programme, with no distinct 'best buy'. The umbrella literature review identified a range of effective single interventions. However, these generally need to be combined to maximally improve uptake and health gains. A validated dynamic, stochastic microsimulation model, built on robust epidemiology, enabled service options analysis. Analyses of three contrasting illustrative cases estimated the health, economic and equity impact of optimising the Health Checks, and the added value of obtaining detailed local data. Optimising the programme in Liverpool can become cost-effective and equitable, but simply changing the invitation method will require other programme changes to improve its performance. Detailed data inputs can benefit local analysis.

LIMITATIONS

Although the approach is extremely flexible, it is complex and requires substantial amounts of data, alongside expertise to both maintain and run.

CONCLUSIONS

Our project showed that the workHORSE model could be used to estimate the health, economic and equity impact comprehensively at local authority level. It has the potential for further development as a commissioning tool and to stimulate broader discussions on the role of these tools in real-world decision-making.

FUTURE WORK

Future work should focus on improving user interactions with the model, modelling simulation standards, and adapting workHORSE for evaluation, design and implementation support.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42019132087.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 35. See the NIHR Journals Library website for further project information.

Lung cancer incidence differences in migrant men in Belgium, 2004-2013: histology-specific analyses

BACKGROUND

Immigrants make up an important share of European populations which has led to a growing interest in research on migrants' health. Many studies have assessed migrants' cancer mortality patterns, yet few have studied incidence differences. This paper will probe into histology-specific lung cancer incidence by migrant origin aiming to enhance the knowledge on lung cancer aetiology and different risk patterns among population groups.

METHODS

We used data on all lung cancer diagnoses during 2004-2013 delivered by the Belgian Cancer Registry individually linked with the 2001 Belgian Census and the Crossroads Bank for Social Security. Absolute and relative inequalities in overall and histology-specific lung cancer incidence have been calculated for first-generation Italian, Turkish and Moroccan migrant men aged 50-74 years compared to native Belgian men.

RESULTS

Moroccan men seemed to be the most advantaged group. Both in absolute and relative terms they consistently had lower overall and histology-specific lung cancer incidence rates compared with native Belgian men, albeit less clear for adenocarcinoma. Turkish men only showed lower overall lung cancer incidence when adjusting for education. On the contrary, Italian men had higher incidence for overall lung cancer and squamous cell carcinoma, which was explained by adjusting for education.

CONCLUSIONS

Smoking habits are likely to explain the results for Moroccan men who had lower incidence for smoking-related histologies. The full aetiology for adenocarcinoma is still unknown, yet the higher incidence among Italian men could point to differences in occupational exposures, e.g. to carcinogenic radon while working in the mines.

Environmental Risk Factors and Health: An Umbrella Review of Meta-Analyses

Background: Environmental health is a growing area of knowledge, continually increasing and updating the body of evidence linking the environment to human health. Aim: This study summarizes the epidemiological evidence on environmental risk factors from meta-analyses through an umbrella review. Methods: An umbrella review was conducted on meta-analyses of cohort, case-control, case-crossover, and time-series studies that evaluated the associations between environmental risk factors and health outcomes defined as incidence, prevalence, and mortality. The specific search strategy was designed in PubMed using free text and Medical Subject Headings (MeSH) terms related to risk factors, environment, health outcomes, observational studies, and meta-analysis. The search was limited to English, Spanish, and French published articles and studies on humans. The search was conducted on September 20, 2020. Risk factors were defined as any attribute, characteristic, or exposure of an individual that increases the likelihood of developing a disease or death. The environment was defined as the external elements and conditions that surround, influence, and affect a human organism or population’s life and development. The environment definition included the physical environment such as nature, built environment, or pollution, but not the social environment. We excluded occupational exposures, microorganisms, water, sanitation and hygiene (WASH), behavioral risk factors, and no-natural disasters. Results: This umbrella review found 197 associations among 69 environmental exposures and 83 diseases and death causes reported in 103 publications. The environmental factors found in this review were air pollution, environmental tobacco smoke, heavy metals, chemicals, ambient temperature, noise, radiation, and urban residential surroundings. Among these, we identified 65 environmental exposures defined as risk factors and 4 environmental protective factors. In terms of study design, 57 included cohort and/or case-control studies, and 46 included time-series and/or case-crossover studies. In terms of the study population, 21 included children, and the rest included adult population and both sexes. In this review, the largest body of evidence was found in air pollution (91 associations among 14 air pollution definitions and 34 diseases and mortality diagnoses), followed by environmental tobacco smoke with 24 associations. Chemicals (including pesticides) were the third larger group of environmental exposures found among the meta-analyses included, with 19 associations. Conclusion: Environmental exposures are an important health determinant. This review provides an overview of an evolving research area and should be used as a complementary tool to understand the connections between the environment and human health. The evidence presented by this review should help to design public health interventions and the implementation of health in all policies approach aiming to improve populational health.

Environmental tobacco smoke and cancer risk, a prospective cohort study in a Chinese population

Few prospective cohort studies have investigated associations between environmental tobacco smoke (ETS) and other cancer sites, in addition to lung cancer. We assessed these associations in a population-based prospective cohort study started from 2008 to 2011 with average of 9.1 years of follow-up, in Minhang district, Shanghai, China. The study included a total of 23,415 participants (8388 men, 15,027 women) and 205,515 person-years. Epidemiological data were collected by a standardized questionnaire including ETS exposure. Newly diagnosed patients with primary cancers and deaths were identified by record linkage system with the Shanghai Cancer Registry and Shanghai Vital Statistics. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression models, adjusting for potential confounders. During the study period, a total of 1462 patients with diagnoses of primary cancers were identified. Among all participants and non-smokers, ETS was associated with an increased risk of all smoking-related cancers (all: adjusted HR: 1.23, 95% CI: 1.05-1.43 and non-smokers: 1.24, 1.02-1.49), lung cancer (1.29, 0.98-1.71 and 1.27, 0.91-1.77), and stomach cancer (1.86, 1.21-2.85 and 1.75, 1.05-2.91), respectively. Furthermore, associations for lung and stomach cancers were the strongest among non-smoking females. The joint effects of both ETS and active smoking were strongest for all cancers, all smoking-related cancers, lung cancer, and stomach cancer. No clear interactions were observed. These results suggest that ETS exposure may increase the risk of smoking-related cancers in a Chinese population. Further studies on the relationship between ETS exposure and specific cancer sites are warranted to replicate our findings.

An Uncommon Lung Neoplasm in a Young Patient: Diagnostic Challenges

Patient: Female, 29-year-old

Final Diagnosis: Lung adenosquamous carcinoma

Symptoms: Cough • Low back pain • night sweats • thoracic pain • weight loss

Medication: —

Clinical Procedure: Chemotherapy • CT-scan • fiberoptic bronchoscopy • radiotherapy • transbronchial biopsy

Specialty: Oncology • Pulmonology

Non-Small Cell Lung Cancer in Young Patients: An Analysis of Clinical, Pathologic and TNM Stage Characteristics Compared to the Elderly

Purpose

To compare clinicopathologic factors including tumor-node-metastasis (TNM) stage between young and elderly patients with non-small cell lung cancer (NSCLC).

Methods

This retrospective study compared the following characteristics between 52 young patients with NSCLC (<50 years of age) and 67 elderly patients with NSCLC (>60 years): duration of symptoms before medical consultation, smoking index, family history of cancer, Ki-67 index, and pTNM stage. A binary logistic regression analysis was used to identify factors predictive of greater stage NSCLC (stage III/IV compared to stage I/II) within each age group.

Results

The incidence of adenocarcinoma was higher in the young than in the elderly (P=0.006). Smoking index (P=0.002) and Ki-67 index (P<0.001) were lower in the young than in the elderly. In young patients with NSCLC, delayed treatment (greater duration from symptoms to medical consultation, P=0.050) and active tumor proliferation (higher Ki-67 index, P=0.003) were predictive of more advanced cancer stage (III/IV), with only symptom duration being predictive of stage III/IV NSCLC among elderly patients. Among young patients, cough (P=0.021) and chest congestion (P=0.040) were the most significant warning symptoms of advanced-stage NSCLC.

Conclusion

High tumor proliferation and delayed treatment are predictive of advanced NSCLC on presentation among young individuals. Early diagnosis by imaging, such as with the use of low dose computed tomography (LDCT), for young individuals with coughing and chest congestion over 1 month might be effectiveto improve prognosis and outcomes.

Quantifying the association of low-intensity and late initiation of tobacco smoking with total and cause-specific mortality in Asia

BACKGROUND

Little is known about the health harms associated with low-intensity smoking in Asians who, on average, smoke fewer cigarettes and start smoking at a later age than their Western counterparts.

METHODS

In this pooled analysis of 738 013 Asians from 16 prospective cohorts, we quantified the associations of low-intensity (<5 cigarettes/day) and late initiation (≥35 years) of smoking with mortality outcomes. HRs and 95% CIs were estimated for each cohort by Cox regression. Cohort-specific HRs were pooled using random-effects meta-analysis.

FINDINGS

During a mean follow-up of 11.3 years, 92 068 deaths were ascertained. Compared with never smokers, current smokers who consumed <5 cigarettes/day or started smoking after age 35 years had a 16%-41% increased risk of all-cause, cardiovascular disease (CVD), respiratory disease mortality and a >twofold risk of lung cancer mortality. Furthermore, current smokers who started smoking after age 35 and smoked <5 cigarettes/day had significantly elevated risks of all-cause (HRs (95% CIs)=1.14 (1.05 to 1.23)), CVD (1.27 (1.08 to 1.49)) and respiratory disease (1.54 (1.17 to 2.01)) mortality. Even smokers who smoked <5 cigarettes/day but quit smoking before the age of 45 years had a 16% elevated risk of all-cause mortality; however, the risk declined further with increasing duration of abstinence.

CONCLUSIONS

Our study showed that smokers who smoked a small number of cigarettes or started smoking later in life also experienced significantly elevated all-cause and major cause-specific mortality but benefited from cessation. There is no safe way to smoke-not smoking is always the best choice.

Japanese Legacy Cohorts: Six-Prefecture Cohort Study (Hirayama Cohort Study)

Late Dr Takeshi Hirayama and his colleagues conducted a mortality follow-up of a large-scale cohort in six prefectures in Japan. This study is called the six-prefecture cohort study or Hirayama Cohort Study. The study subjects were residents aged 40 years or older at the baseline survey in 1965, which covered 94.8% of residents identified in the study area by the National Census conducted on October 1, 1965. The mortality of 264,118 cohort members was followed until the end of 1982. One of the most important findings made by this study was an association between second-hand smoke exposure and lung cancer. This finding is the origin of the worldwide spread of smoking ban in indoor public venues and workplaces. Other major findings obtained from the study are also briefly described in this article.

Prevalence of cancers diagnosed in Jamhuriyat Hospital, Kabul, Afghanistan

BACKGROUNDS

Throughout the world, there exists a clear need for the maintenance of cancer statistics, forming an essential part of any rational programme of cancer control, health-care planning, etiological research, primary and secondary prevention, benefiting both individuals and society. The present work reports only on the prevalence of cancers in the Oncology Department of Jamhuriyat Hospital, Kabul, Afghanistan following several decades of war.

MATERIALS AND METHODS

A quantitative retrospective cross-sectional study was conducted using the medical records of patients diagnosed and treated from October 2015 to December 2017. Data includes information on gender, age, economic status, address and types of cancer diagnosed. The data was transferred to a customized form and analysed using Microsoft Excel program to classify cancer types.

RESULTS

The total number of patients with completed documents were 1025. Of these, 403 (39.3%) were male and 622 (60.7%) female. Most of the patients were in the age range of 20-70 years old. The most common cancers in women were breast cancer (45.8%), followed by oesophagus (12.5%), colorectal (4.8%), Non-Hodgkin Lymphoma (4.7%), sarcoma (4.7%), ovary (3.8%), both stomach and liver (2.6%) and cervix uteri (1.9%). Contrarily to men, esophageal cancer was highest (21.8%), followed by stomach (12.2%), Non-Hodgkin Lymphoma (9.4%), sarcoma (8.9%), gastroesophageal junction (8.9%), colorectal (8.6%), Hodgkin lymphoma (4.7%), testis (4.2%), liver (3.2%), lung (2.7%) and Nonmelanoma skin squamous cell carcinoma 9 (2.2%).

CONCLUSION

Results showed that the most frequent cancers among Afghans were breast and oesophagus. The most common cancer in men was oesophagus and stomach at the age range of 50-70 years while in women, breast and oesophagus cancers were common and within the age range of 25-65 years old.

Lung cancer risk and do-it-yourself activities. A neglected risk factor for lung cancer

BACKGROUND

The aim of this study was to assess the relationship between do-it-yourself activities entailing the exposure to carcinogenic substances and the risk of lung cancer.

METHODS

We pooled individual data from different case-control studies conducted in Northwestern Spain which investigated residential radon and lung cancer. Cases had an anatomopathologically confirmed primary lung cancer and controls were selected at the pre-surgery unit with uncomplicated surgeries. Both cases and controls were older than 30 years with no previous cancer history. All participants were interviewed face-to-face using a specific questionnaire. Painting, model building, furniture refinishing and woodworking or home carpentry were the do-it-yourself activities considered risky due to exposure to carcinogenic agents.

RESULTS

We included 1528 cases and 1457 controls. Practicing do-it-yourself risk activities was more frequent among cases: 16.0% were exposed to carcinogenic exposures during leisure time, compared to 11.8% for controls. The overall adjusted OR for lung cancer risk among individuals who practiced do-it-yourself risk activities, was 1.77 (95% CI: 1.36-2.31); this was 2.17 (95% CI: 1.51-3.11) when the analysis was restricted to individuals who performed these activities for at least 10 years. These risks were greater when the analyses were carried out exclusively among never-smokers, with the respective ORs being 2.04 (95% CI: 1.38-3.01) and 3.10 (95% CI: 1.78-5.40).

CONCLUSION

These results support the hypothesis that do-it-yourself activities involving exposure to certain carcinogens are associated with an increased risk of lung cancer, both in ever and never-smokers.

Burden of disease attributable to second-hand smoke exposure: A systematic review

Our aim was to provide a systematic review of studies on the burden of disease due to second-hand smoke (SHS) exposure, reviewing methods, exposure assessment, diseases causally linked to SHS, health outcomes, and estimates available to date. A literature review of studies on the burden of disease from SHS exposure, available in PubMed and SCOPUS, published 2007-2018 in English language, was carried out following the PRISMA recommendations. Overall, 588 studies were first identified, and 94 were eligible. Seventy-two studies were included in the systematic review. Most of them were based on the comparative risk assessment approach, assessing SHS exposure using mainly surveys on exposure at home/workplaces. Diseases more frequently studied were: lung cancer, ischemic heart disease, stroke, chronic obstructive pulmonary disease, asthma and breast cancer in adults; lower respiratory tract infection, otitis media, asthma, sudden infant death syndrome and low birth weight in children. The SHS exposure assessment and the reported population attributable fractions (PAF) were largely heterogeneous. As an example, the PAF from lung cancer varied between 0.6% and 20.5%. Moreover, PAF were estimated applying relative risks and SHS exposures with no consistent definitions or with different age classes. The research gap on the SHS exposure burden is shrinking. However, estimates are not yet available for a number of countries, particularly the Middle Eastern and African countries, and not all diseases with the strongest evidence of causation, such as sudden infant death syndrome, have been explored. Moreover, in some cases the applied methodology revealed relatively low quality of data.

Crosstalk between let-7a-5p and BCL-xL in the Initiation of Toxic Autophagy in Lung Cancer

Autophagy is essential for cellular metabolism and plays pivotal roles in carcinogenesis, while excessive autophagy induces toxicity and cell death. Our previous studies have suggested that let-7a-5p/BCL-xL might regulate autophagy in lung cancer, but the regulatory mechanism is unclear. The central goal of the study was to figure out the role of let-7a-5p/BCL-xL in the initiation of autophagy and its effect on the migration, invasion, and proliferation of A549 cells as well as its therapeutic potential in lung cancer. Based on the genome-wide expression profiles of lung cancer, BCL-xL and let-7a-5p were found to be dysregulated and negatively correlated in lung adenocarcinoma, which was associated with the survival of lung cancer. The crosstalk between BCL-xL and let-7a-5p was then investigated using dual-luciferase reporter assay, and it was found to suppress the migration and invasion of A549 cells. Further, we found that the crosstalk between BCL-xL and let-7a-5p could lead to toxic autophagy and cell death through activating the PI3K-signaling pathway, which was independent of apoptosis or pyroptosis. These findings indicate that let-7a-5p is a sensitive initiator for toxic autophagy in A549 lung cancer cells and is an appealing target for lung cancer therapy.

The impact of smoking and the influence of other factors on lung cancer

Introduction: Smoking is the main preventable cause of lung cancer. This review summarizes preclinical and clinical data on the mechanisms of smoking-associated cancer development of the major histological lung cancer types small cell lung carcinoma squamous cell carcinoma and pulmonary adenocarcinoma (PAC) and the impact of several factors other than smoking on this process. Areas covered: The role of intracellular signaling induced by nicotinic receptors and beta-adrenergic receptors, the resulting increase in intracellular cyclic adenosine monophosphate (cAMP) as a key driver of PAC and the promoting effects of respiratory tract diseases and their therapeutics, psychological stress and global warming. Expert opinion: Smoking has deleterious effects on the regulation of lung epithelia by neurotransmitter receptors that are further enhanced by gene mutations. Sensitization of the alpha-7 nicotinic receptor (α7nAChR) by COPD enhances the carcinogenic effects of smoking and turns nicotine into a carcinogen. Nicotine vaping may, therefore, cause cancer in individuals with chronic obstructive pulmonary disease. The opposing effects of cAMP on the major lung cancer types indicate that patients with PAC of Clara cell phenotype (PAC-Cl) will benefit from treatment with cAMP reducers and suggest that global warming-induced respiratory tract diseases and their therapeutics cause the global increase in the incidence of PAC.

Lung Cancer Mortality Trends in a Brazilian City with a Long History of Asbestos Consumption

There are scarce epidemiological studies on lung cancer mortality in areas exposed to asbestos in developing countries. We compared the rates and trends in mortality from lung cancer between 1980 and 2016 in a municipality that made extensive use of asbestos, Osasco, with rates from a referent municipality with lower asbestos exposure and with the rates for the State of São Paulo. We retrieved death records for cases of lung cancer (ICD-9 C162) (ICD-10 C33 C34) from 1980 to 2016 in adults aged 60 years and older. The join point regression and age-period-cohort models were fitted to the data. Among men, there was an increasing trend in lung cancer mortality in Osasco of 0.7% (CI: 0.1; 1.3) in contrast to a mean annual decrease for Sorocaba of -1.5% (CI: -2.4; -0.6) and a stable average trend for São Paulo of -0.1 (IC: -0.3; 0.1). Similar increasing trends were seen in women. The age-period-cohort model showed an increase in the risk of death from 1996 in Osasco and a reduction for Sorocaba and São Paulo State during the same period. Our results point to a need for a special monitoring regarding lung cancer incidence and mortality in areas with higher asbestos exposure.

Lung cancer and residential radon in never-smokers: A pooling study in the Northwest of Spain

BACKGROUND

Using a pooled case-control study design, including only never-smokers, we have assessed the association of residential radon exposure with the subsequent occurrence of lung cancer. We also investigated whether residential radon poses a different risk specifically for adenocarcinoma.

METHODS

We pooled individual data from different case-control studies conducted in recent years in Northwestern Spain which investigated residential radon and lung cancer. All participants were never-smokers. Cases had a confirmed biopsy of primary lung cancer. Hospital controls were selected at pre-surgery units, presenting for non-complex surgical procedures. They were interviewed using a standardized instrument. Residential radon was measured using alpha track detectors at the Galician Radon Laboratory at the University of Santiago de Compostela.

RESULTS

A total of 1415 individuals, 523 cases and 892 controls were included. We observed an odds ratio of 1.73 (95%CI: 1.27-2.35) for individuals exposed to ≥ 200 Bq/m³ compared with those exposed to ≤100 Bq/m³. Lung cancer risk for adenocarcinoma was 1.52 (95%CI: 1.14-2.02) using the same categories for radon exposure.

CONCLUSIONS

Residential radon is a clear risk factor for lung cancer in never-smokers. Our data suggest that radon exposure is associated with all histological types of lung cancer and also with adenocarcinoma, which is currently the most frequent histological type for this disease.

Estimates of the current and future burden of cancer attributable to active and passive tobacco smoking in Canada

Although previous studies have examined the burden of cancer attributable to tobacco smoking, updated estimates are needed given the dramatic changes in smoking behaviours over the last 20 years. In this study, we estimate the proportion of cancer cases in 2015 attributable to past tobacco smoking and passive exposure in Canada and the proportion of cancers in the future that could be prevented through the implementation of interventions targeted at reducing tobacco use. Data from the Canadian Community Health Survey (2003) were used to estimate the prevalence of active tobacco smoking and passive exposure. Population attributable risk estimates were employed to estimate the proportion of cancers attributable to tobacco in 2015. The prevalence of active tobacco smoking and passive exposure was projected to 2032 and cancer incidence was projected from 2016 to 2042 to estimate the future burden of cancer attributable to tobacco. In 2003, 30% and 24% of Canadians were former and current smoker, respectively and 24% had been exposed to tobacco smoke in the past. We estimated that 17.5% (32,655 cases; 95% CI: 31,253-34,034) of cancers were attributable to active tobacco smoking and 0.8% (1408 cases; 95% CI: 1048-1781) to passive tobacco exposure in never smokers. Between 41,191 and 50,696 cases of cancer could be prevented by 2042 under various prevention scenarios. By decreasing passive tobacco exposure by 10-50%, between 730 and 3650 cancer cases could be prevented by 2042. Strategies focused on reducing the prevalence of tobacco smoking are crucial for cancer control in Canada.

Tobacco Smoking Modifies the Association between Hormonal Factors and Lung Cancer Occurrence among Post-Menopausal Chinese Women

Inconsistent evidence has been reported on the role of female hormonal factors in the development of lung cancer. This population-based case–control study evaluated the main effect of menstrual/reproductive factors on the risk of lung cancer, and the effect modification by smoking status. Multivariable unconditional logistic regression models were applied adjusted for age, income, education, county of residence, body mass index, smoking status, pack-years of smoking, and family history of lung cancer. Among 680 lung cancer cases and 1,808 controls, later menopause (at >54 vs. <46 years old) was associated with increased risk of lung cancer (SBOR, semi-Bayes adjusted odds ratio = 1.61, 95% PI, posterior interval = 1.10–2.36). More pregnancies (2 or 3 vs. 0 or 1) was associated with decreased risk (SBOR = 0.71, 95% PI = 0.53, 0.95). Ever being a smoker and having two or fewer pregnancies in one's lifetime could jointly increase the odds of lung cancer (RERI, relative excess risk due to interaction = 1.71, 95% CI = 0.03, 3.38). An increased number of ovulatory cycles was associated with increased risk of lung cancer (SBOR for 13 ovulatory cycles = 1.02, 95% CI = 1.00+, 1.04).