Sex differences in lung cancer susceptibility: A review

Lung cancer mortality trends and disparities: A cross-sectional analysis 1999-2020

BACKGROUND

Lung cancer remains a leading cause of morbidity and mortality in the United States. Given the importance of epidemiological insight on lung cancer outcomes as the foundation for targeted interventions, we aimed to examine lung cancer death trends in the United States in the recent 22-year period, exploring demographic disparities and yearly mortality shifts.

METHODS

Mortality information was obtained from the CDC Wide-ranging Online Data for Epidemiologic Research database from the years 1999-2020. Demographic information included age, sex, race or ethnicity, and area of residence. We performed log-linear regression models to assess temporal mortality shifts and calculated average annual percentage change (AAPC) and compared age-adjusted mortality rates (AAMR) across demographic subpopulations.

RESULTS

A total of 3,380,830 lung cancer deaths were identified. The AAMR decreased from 55.4 in 1999-31.8 in 2020 (p<0.001). Males (AAMR 57.6) and non-Hispanic (NH) (AAMR 47.5) populations were disproportionately impacted compared to females (AAMR 36.0) and Hispanic (AAMR 19.1) populations, respectively. NH Black populations had the highest AAMR (48.5) despite an overall reduction in lung cancer deaths (AAPC -3.3 %) over the study period. Although non-metropolitan regions were affected by higher mortality rates, the annual decrease in mortality among metropolitan regions (AAPC -2.8 %, p<0.001) was greater compared to non-metropolitan regions (AAPC -1.7 %, p<0.001). Individuals living in the Western US (AAPC -3.4 %, p<0.001) experienced the greatest decline in lung cancer mortality compared to other US census regions.

CONCLUSIONS

Our findings revealed lung cancer mortality inequalities in the US. By contextualizing these mortality shifts, we provide a larger framework of data-driven initiatives for societal and health policy changes for improving access to care, minimizing healthcare inequalities, and improving outcomes.

Reprint of: Smoking and pulmonary health in women: A narrative review and behavioral health perspective

OBJECTIVE

Cigarette smoking prevalence has declined slower among women than men, and smoking-related pulmonary disease (PD) has risen among women. Given these trends, there is a critical need to understand and mitigate PD risk among women who smoke. The purpose of this narrative review and commentary is to highlight important evidence from the literature on smoking and PD among women.

METHODS

This review focuses broadly on examining cigarette smoking and PD among women within six topic areas: (1) demographic characteristics and prevalence of smoking, (2) smoking behavior, (3) lung cancer, (4) obstructive PD, (5) diagnostic and treatment disparities, and (6) gaps in the literature and potential directions for future research and treatment.

RESULTS

Growing evidence indicates that compared to men, women are at increased risk for developing smoking-related PD and poorer PD outcomes. Gender disparities in smoking-related PD may be largely accounted for by genetic differences and sex hormones contributing to PD pathogenesis and presentation, smoking behavior, nicotine dependence, and pathogen/carcinogen clearance. Moreover, gender disparities in smoking-related PD may be exacerbated by important social determinants (e.g., women with less formal education and those from minoritized groups may be at especially high risk for poor PD outcomes due to higher rates of smoking).

CONCLUSION

Rising rates of smoking-related PD among women risk widening diagnostic and treatment disparities. Ongoing research is needed to explore potentially complex relationships between sex, gender, and smoking-related PD processes and outcomes, and to improve smoking-cessation and PD treatment for women.

Smoking and pulmonary health in women: A narrative review and behavioral health perspective

OBJECTIVE

Cigarette smoking prevalence has declined slower among women than men, and smoking-related pulmonary disease (PD) has risen among women. Given these trends, there is a critical need to understand and mitigate PD risk among women who smoke. The purpose of this narrative review and commentary is to highlight important evidence from the literature on smoking and PD among women.

METHODS

This review focuses broadly on examining cigarette smoking and PD among women within six topic areas: (1) demographic characteristics and prevalence of smoking, (2) smoking behavior, (3) lung cancer, (4) obstructive PD, (5) diagnostic and treatment disparities, and (6) gaps in the literature and potential directions for future research and treatment.

RESULTS

Growing evidence indicates that compared to men, women are at increased risk for developing smoking-related PD and poorer PD outcomes. Gender disparities in smoking-related PD may be largely accounted for by genetic differences and sex hormones contributing to PD pathogenesis and presentation, smoking behavior, nicotine dependence, and pathogen/carcinogen clearance. Moreover, gender disparities in smoking-related PD may be exacerbated by important social determinants (e.g., women with less formal education and those from minoritized groups may be at especially high risk for poor PD outcomes due to higher rates of smoking).

CONCLUSION

Rising rates of smoking-related PD among women risk widening diagnostic and treatment disparities. Ongoing research is needed to explore potentially complex relationships between sex, gender, and smoking-related PD processes and outcomes, and to improve smoking-cessation and PD treatment for women.

Sex-Specific Response to A1BG Loss Results in Female Dilated Cardiomyopathy

Background

Cardiac disease often manifests differently in terms of frequency and pathology between men and women. However, the mechanisms underlying these differences are not fully understood. The glycoprotein A1BG is necessary for proper cardiac function in females but not males. Despite this, the role of A1BG in the female heart remains poorly studied.

Methods

To determine the sex differential function of A1BG, we generated a novel conditional A1bg allele and a novel conditional A1bg Rosa26 knockin allele. Histology, electrocardiography, transcriptional profiling (RNA-seq), transmission electron microscopy, western blot analyses, mass spectrometry, and immunohistochemistry were used to assess cardiac structure and function.

Results

The study reveals that the absence of A1BG results in significant cardiac dysfunction in female but not male mice. Gene expression underscores that A1BG plays a critical role in metabolic processes and the integrity of intercalated discs in female cardiomyocytes. This dysfunction may be related to sex-specific A1BG cardiac interactomes and manifests as structural and functional alterations in the left ventricle indicative of dilated cardiomyopathy, thus suggesting a sex-specific requirement for A1BG in cardiac health.

Conclusion

The loss of A1BG in cardiomyocytes leads to dilated cardiomyopathy in females, not males.

Sex-related DNA methylation is associated with inflammation and gene expression in the lungs of healthy individuals

Lung cancer exhibits sex-biased molecular characteristics and epidemiological trends, suggesting a need for sex-specific approaches to understanding its etiology and treatment. DNA methylation alterations play critical roles in lung carcinogenesis and may serve as valuable biomarkers for precision medicine strategies. We employed the Infinium MethylationEPIC array to identify autosomal sex-related differentially methylated CpG sites (DM-CpGs) in lung epithelium of healthy individuals (32 females and 37 males) while controlling for age, BMI, and tobacco use. We correlated DM-CpGs with gene expression in lung epithelium and immune responses in bronchoalveolar lavage. We validated these DM-CpGs in lung tumors and adjacent normal tissue from The Cancer Genome Atlas (TCGA). Among 522 identified DM-CpGs, 61% were hypermethylated in females, predominantly located in promoter regions. These DM genes were implicated in cell-to-cell signaling, cellular function, transport, and lipid metabolism. Correlation analysis revealed sex-specific patterns between DM-CpGs and gene expression. Additionally, several DM-CpGs were correlated significantly with cytokines (IL-1β, IL-4, IL-12p70, and IFN-γ), macrophage, and lymphocyte counts. Also, some DM-CpGs were observed in TCGA lung adenocarcinoma, squamous cell carcinoma, and adjacent normal tissues. Our findings highlight sex-specific DNA methylation patterns in healthy lung epithelium and their associations with lung gene expression and lung immune biomarkers. These findings underscore the potential role of lung sex-related CpGs as epigenetic predispositions influencing sex disparities in lung cancer risk and outcomes, warranting further investigation for personalized lung cancer management strategies.

25-hydroxycholesterol promotes proliferation and metastasis of lung adenocarcinoma cells by regulating ERβ/TNFRSF17 axis

Lung adenocarcinoma is the main type of lung cancer in women. Our previous findings have evidenced that 25-hydroxycholesterol (25-HC) promotes migration and invasion of lung adenocarcinoma cells (LAC), during which LXR as a 25-HC receptor plays an important role. Estrogen receptor beta (ERβ) is a receptor of 27-hydroxycholesterol that is structurally analogous to 25-HC, but its role in the functional actions of 25-HC remained largely unknown. In this study, we demonstrated that 25-HC treatment triggered ERβ expression in LAC. Knockdown of ERβ inhibited 25-HC-mediated proliferation, migration and invasion, and reduced 25-HC-induced LAC metastasis in vivo. Further investigation revealed that ERβ knockdown restrained the expression of TNFRSF17 (BCMA). In vivo experiments also confirmed that ERβ knockdown blocked 25-HC-induced TNFRSF17 expression. TNFRSF17 knockdown also restrained 25-HC-induced proliferation, migration and invasion. Bioinformatic analysis showed that the levels of ERβ and TNFRSF17 were elevated in lung adenocarcinoma, and were closely related to tumor stages and nodal metastasis status. These results suggested that 25-HC promoted the proliferation and metastasis of LAC by regulating ERβ/TNFRSF17 axis.

Sex gaps in perception of tobacco conversations between adult patients who now smoke cigarettes and oral health care providers: National Health and Nutrition Examination Survey 2017-March 2020 prepandemic

BACKGROUND

Smoking cessation is difficult. A potential gap based on sex exists in the tobacco cessation aid that dental care professionals provide to patients. The purpose of this research was to examine whether there is a sex difference in dental patients' reports of having a direct conversation about the benefits of giving up cigarettes or other types of tobacco products with their oral health care provider.

METHODS

National Health and Nutrition Examination Survey 2017-March 2020 prepandemic data were used in this cross-sectional study for participants 18 years and older who reported that they "now smoke cigarettes," had a dental visit within the previous year, self-reported their sex, and responded whether their oral health care provider had a direct conversation about the benefits of giving up cigarettes or other types of tobacco products to improve dental health at their last visit (n = 582). Multivariable logistic regression analysis was conducted to compare data according to sex.

RESULTS

Overall, 50.7% of patients (59.2% of men, 42.9% of women; P = .0037) reported having a conversation about tobacco cessation at their dental visit. The odds of women reporting having no such discussion were twice those of men (odds ratio, 2.17; 95% CI, 1.10 to 4.28; P = .0270).

CONCLUSIONS

One-half of the participants reported having no tobacco cessation conversation about the benefits of giving up cigarettes or other types of tobacco with their dental care provider. Women were twice as likely to report no such discussion.

PRACTICAL IMPLICATIONS

Oral health care providers need to ensure that primary and secondary prevention information and intervention programs about the benefits of giving up cigarettes or other types of tobacco products are provided equitably to all patients.

Gender differences in weight gain during attempted and successful smoking cessation on dulaglutide treatment: a predefined secondary analysis of a randomised trial

Background

Women seem to have more difficulty quitting smoking than men. This is particularly concerning as smoking puts women at a higher risk of developing smoking-associated diseases. Greater concerns about postcessation weight gain in women have been postulated as a possible explanation.

Methods

Predefined secondary analysis of a placebo-controlled, double-blind, parallel-group, superiority randomised trial including 255 adults who smoke daily (155 women, 100 men). Participants received weekly dulaglutide (1.5 mg) or placebo (0.9% sodium chloride) in addition to standardised smoking cessation care (varenicline 2 mg/day plus behavioural counselling) over 12 weeks. We aimed to investigate gender differences in weight change after dulaglutide-assisted smoking cessation. Weight change between baseline and week 12 was analysed as absolute and revative weight change and as substantial weight gain (defined as >6% increase).

Results

No gender differences were observed in absolute or relative weight change neither on dulaglutide nor placebo treatment. However, substantial weight gain (defined as >6% increase) in the placebo group was almost five times more frequent in females than males (24% vs 5%). Female patients were less likely to have substantial weight gain on dulaglutide compared with placebo (1% (n=1/83) vs 24% (n=17/72); p<0.001), while this dulaglutide effect was less pronounced in males (0% (n=0/44) vs 5% (n=3/56); p=0.333).

Conclusion

Dulaglutide reduced postcessation weight gain in both genders and was very effective in preventing substantial weight gain, which seems to be a specific observation in females.

Trial registration number

NCT03204396.

Discovery adductomics provides a comprehensive portrait of tissue-, age- and sex-specific DNA modifications in rodents and humans

DNA damage causes genomic instability underlying many diseases, with traditional analytical approaches providing minimal insight into the spectrum of DNA lesions in vivo. Here we used untargeted chromatography-coupled tandem mass spectrometry-based adductomics (LC-MS/MS) to begin to define the landscape of DNA modifications in rat and human tissues. A basis set of 114 putative DNA adducts was identified in heart, liver, brain, and kidney in 1-26-month-old rats and 111 in human heart and brain by 'stepped MRM' LC-MS/MS. Subsequent targeted analysis of these species revealed species-, tissue-, age- and sex-biases. Structural characterization of 10 selected adductomic signals as known DNA modifications validated the method and established confidence in the DNA origins of the signals. Along with strong tissue biases, we observed significant age-dependence for 36 adducts, including N2-CMdG, 5-HMdC and 8-Oxo-dG in rats and 1,N6-ϵdA in human heart, as well as sex biases for 67 adducts in rat tissues. These results demonstrate the potential of adductomics for discovering the true spectrum of disease-driving DNA adducts. Our dataset of 114 putative adducts serves as a resource for characterizing dozens of new forms of DNA damage, defining mechanisms of their formation and repair, and developing them as biomarkers of aging and disease.

Role of geographic characteristics in the spatial cluster detection of cancer: Evidence in South Korea, 1999-2013

BACKGROUND

Identification of high-risk areas of cancer, referred to as spatial clusters, can inform targeted policies for cancer control. Although cancer cluster detection could be affected by various geographic characteristics including sociodemographic and environmental factors which impacts could also vary over time, studies accounting for such influence remain limited. This study aims to assess the role of geographic characteristics in the spatial cluster detection for lung and stomach cancer over an extended period.

METHODS

We obtained sex-specific age-standardized incidence and mortality rates of lung and stomach cancer as well as geographic characteristics across 233 districts in South Korea for three five-year periods between 1999 and 2013. We classified geographic characteristics of each district into four categories: demography, socioeconomic status, behaviors, and physical environments. Specifically, we quantified physical environments using measures of greenness, concentrations of particulate matter and nitrogen dioxide, and air pollution emissions. Finally, we conducted cluster detection analyses using weighted normal spatial scan statistics with the residuals from multiple regression analyses performed with the four progressive sets of geographic attributes.

RESULTS

We found that the size of clusters reduced as we progressively adjusted for geographic covariates. Among the four categories, physical environments had the greatest impact on the reduction or disappearance of clusters particularly for lung cancer consistently over time. Whereas older population affected a decrease of lung cancer clusters in the early period, the contribution of education was large in the recent period. The impact was less clear in stomach cancer than lung cancer.

CONCLUSION

Our findings highlight the importance of geographic characteristics in explaining the existing cancer clusters and identifying new clusters, which jointly provides practical guidance to cancer control.

The prognostic impact of KRAS, TP53, STK11 and KEAP1 mutations and their influence on the NLR in NSCLC patients treated with immunotherapy

BACKGROUND

PD-L1 expression is used to predict NSCLC response to ICIs, but its performance is suboptimal. The impact of KRAS mutations in these patients is unclear. Studies evaluating co-mutations in TP53, STK11 and KEAP1 as well as the NLR showed that they may predict the benefit of ICIs.

PATIENTS & METHODS

This is a retrospective study of patients with NSCLC treated with ICIs at the CHUM between July 2015 and June 2020. OS and PFS were compared using Kaplan-Meier and logrank methods. Co-mutations in TP53, STK11 and KEAP1 as well as the NLR were accounted for. ORR and safety were compared using Wald method.

RESULTS

From 100 patients with known KRAS status, 50 were mutated (KRASMut). Mutation in TP53, STK11 and KEAP1 were present, and their status known in, respectively, 19/40 (47.5 %), 8/39 (20.5 %) and 4/38 (10.5 %) patients. STK11Mut and KEAP1Mut were associated with shorter overall survival when compared with wild type tumors (respectively median OS of 3.3 vs 20.4, p = 0.0001 and 10.1 vs 17.7, p = 0.24). When KRAS status was compounded with STK11/KEAP1, KRASMut trended to a better prognosis in STK11+KEAP1WT tumors (median OS 21.1 vs 15.8 for KRASWT, p = 0.15), but not for STK11+/-KEAP1Mut tumors. The NLR was strongly impacted by STK11 (6.0Mutvs 3.6WT, p = 0.014) and TP53 (3.2Mutvs 4.8WT, p = 0.048), but not by KEAP1 or KRAS mutations.

CONCLUSION

STK11Mut and KEAP1Mut are adverse predictors of ICI therapy benefit. The NLR is strongly impacted by STK11Mut but not by KEAP1Mut, suggesting differences in their resistance mechanism. In STK11-KEAP1WT tumors, KRASMut seem associated with improved survival in NSCLC patients treated with ICIs.

MICROABSTRACT

Response of NSCLC to immunotherapy is not easily predictable. We conducted a retrospective study in 100 patients with NSCLC and a known KRAS status. By accounting for different co-mutations, KRAS mutation was found to be associated with a better median overall survival in STK11 and KEAP1 wild-type tumors (21.1 vs 15.8, p = 0.15). NLR was impacted by STK11, but not KEAP1 mutation, suggesting a difference in their resistance mechanism.

Sex effects in predictors of smoking abstinence and neuropsychiatric adverse events in the EAGLES trial

Significance There are sex effects in abstinence outcomes across all smoking cessation medications, but there is limited information regarding sex effects on cessation-related neuropsychiatric adverse events (NPSAEs) or interactions with psychiatric status.

METHODS

Secondary analysis of data from EAGLES of 8144 adults who smoke cigarettes randomized to varenicline, bupropion, nicotine patch or placebo. Design characteristics included region (within/outside US), psychiatric cohort (absent/present), and treatment. Baseline variables included demographics, smoking history, prior use of study treatments, lifetime suicide-related history, and prior psychiatric co-morbidities and medication use. Design characteristics were forced into logistic regressions models, and then interactions among sex, design elements, and baseline characteristics were evaluated for NPSAEs and 6-month cessation outcomes.

RESULTS

Findings demonstrated a significant interaction of sex and race (p < 0.02); Black women were more likely to report NPSAEs than Black men. For cessation outcomes, there were no significant interactions with psychiatric cohort and sex. Women vs men with higher baseline levels of smoking had lower odds of continuous abstinence. Women vs men who used varenicline previously had lower odds of continuous abstinence. For 6-month point prevalence, sex interacted with baseline cigarettes per day (p < 0.01) similar to the interaction for continuous abstinence. Sex interacted with medication (p < 0.03), such that women vs men had relatively greater success at achieving point prevalence abstinence on varenicline.

CONCLUSIONS

Overall, results demonstrated important sex and racial differences in the incidence of NPSAEs, but psychiatric status did not interact with sex on cessation outcomes. Findings did support prior work demonstrating relative increased efficacy of varenicline for women.

Calcium Intake and Lung Cancer Risk: A Pooled Analysis of 12 Prospective Cohort Studies

BACKGROUND

Previous studies on calcium intake and lung cancer risk reported inconsistent associations, possibly due to the differences in intake amounts and contributing sources of calcium and smoking prevalence.

OBJECTIVES

We investigated the associations of lung cancer risk with intake of calcium from foods and/or supplements and major calcium-rich foods in 12 studies.

METHODS

Data from 12 prospective cohort studies conducted in the United States, Europe, and Asia were pooled and harmonized. We applied the DRI to categorize calcium intake based on the recommendations and quintile distribution to categorize calcium-rich food intake. We ran multivariable Cox regression by each cohort and pooled risk estimates to compute overall HR (95% CI).

RESULTS

Among 1,624,244 adult men and women, 21,513 incident lung cancer cases were ascertained during a mean follow-up of 9.9 y. Overall, the dietary calcium intake was not significantly associated with lung cancer risk; the HRs (95% CI) were 1.08 (0.98-1.18) for higher (>1.5 RDA) and 1.01 (0.95-1.07) for lower intake (<0.5 RDA) comparing with recommended intake (EAR to RDA). Milk and soy food intake were positively or inversely associated with lung cancer risk [HR (95% CI) = 1.07 (1.02-1.12) and 0.92 (0.84-1.00)], respectively. The positive association with milk intake was significant only in European and North American studies (P-interaction for region = 0.04). No significant association was observed for calcium supplements.

CONCLUSIONS

In this largest prospective investigation, overall, calcium intake was not associated with risk of lung cancer, but milk intake was associated with a higher risk. Our findings underscore the importance of considering food sources of calcium in studies of calcium intake.

Gender Differences in Oxidative Stress in Relation to Cancer Susceptibility and Survival

Genetic, developmental, biochemical, and environmental variables interact intricately to produce sex differences. The significance of sex differences in cancer susceptibility is being clarified by numerous studies. Epidemiological research and cancer registries have revealed over the past few years that there are definite sex variations in cancer incidence, progression, and survival. However, oxidative stress and mitochondrial dysfunction also have a significant impact on the response to treatment of neoplastic diseases. Young women may be more protected from cancer than men because most of the proteins implicated in the regulation of redox state and mitochondrial function are under the control of sexual hormones. In this review, we describe how sexual hormones control the activity of antioxidant enzymes and mitochondria, as well as how they affect several neoplastic diseases. The molecular pathways that underlie the gender-related discrepancies in cancer that have been identified may be better understood, which may lead to more effective precision medicine and vital information on treatment options for both males and females with neoplastic illnesses.

Sex/Gender Differences in the Time-Course for the Development of Substance Use Disorder: A Focus on the Telescoping Effect

Sex/gender effects have been demonstrated for multiple aspects of addiction, with one of the most commonly cited examples being the "telescoping effect" where women meet criteria and/or seek treatment of substance use disorder (SUD) after fewer years of drug use as compared with men. This phenomenon has been reported for multiple drug classes including opioids, psychostimulants, alcohol, and cannabis, as well as nonpharmacological addictions, such as gambling. However, there are some inconsistent reports that show either no difference between men and women or opposite effects and a faster course to addiction in men than women. Thus, the goals of this review are to evaluate evidence for and against the telescoping effect in women and to determine the conditions/populations for which the telescoping effect is most relevant. We also discuss evidence from preclinical studies, which strongly support the validity of the telescoping effect and show that female animals develop addiction-like features (e.g., compulsive drug use, an enhanced motivation for the drug, and enhanced drug-craving/vulnerability to relapse) more readily than male animals. We also discuss biologic factors that may contribute to the telescoping effect, such as ovarian hormones, and its neurobiological basis focusing on the mesolimbic dopamine reward pathway and the corticomesolimbic glutamatergic pathway considering the critical roles these pathways play in the rewarding/reinforcing effects of addictive drugs and SUD. We conclude with future research directions, including intervention strategies to prevent the development of SUD in women. SIGNIFICANCE STATEMENT: One of the most widely cited gender/sex differences in substance use disorder (SUD) is the "telescoping effect," which reflects an accelerated course in women versus men for the development and/or seeking treatment for SUD. This review evaluates evidence for and against a telescoping effect drawing upon data from both clinical and preclinical studies. We also discuss the contribution of biological factors and underlying neurobiological mechanisms and highlight potential targets to prevent the development of SUD in women.

Daily adherence to nicotine replacement therapy in low-income smokers: The role of gender, negative mood, motivation, and self-efficacy

BACKGROUND

Low-income smokers may benefit from interventions promoting nicotine replacement therapies (NRTs), particularly for women, as women have worse smoking cessation outcomes than men. Little is known about factors that affect daily NRT adherence, such as negative mood, motivation, and self-efficacy, and whether gender moderates these associations.

METHODS

Secondary analysis of a randomized controlled trial comparing a novel, in session sampling of short-acting combination NRT intervention (In Vivo) to standard care smoking cessation behavioral counseling was performed. Low-income smokers (n = 62; Mage = 47.4; 42 % female; 61 % non-White) completed daily surveys using the Insight™ mHealth platform for 55 consecutive days. Three types of NRT adherence were examined: dose amount of short-acting NRT, nicotine patch wear time, and combination NRT (cNRT) (combined nicotine patch and short-acting NRT).

RESULTS

Generalized multilevel models report same-day negative mood was associated with greater likelihood of nicotine patch adherence in men, but unrelated to women's nicotine patch adherence. Same-day negative mood was associated with greater likelihood of cNRT adherence in men, but less likelihood in women. The relationship between same-day motivation and use of short-acting NRT varied by gender, but simple slope analyses revealed that motivation was unrelated to short-acting NRT use within either group. Same-day self-efficacy was related to an increased likelihood of nicotine patch adherence and cNRT adherence in women but unrelated to men's adherence of either type.

CONCLUSIONS

Future research should focus on gender differences in low-income smokers' same-day negative mood, motivation, and self-efficacy processes on NRT adherence during smoking cessation interventions.

Biological and Genetic Mechanisms of COPD, Its Diagnosis, Treatment, and Relationship with Lung Cancer

Chronic obstructive pulmonary disease (COPD) is one of the most prevalent chronic adult diseases, with significant worldwide morbidity and mortality. Although long-term tobacco smoking is a critical risk factor for this global health problem, its molecular mechanisms remain unclear. Several phenomena are thought to be involved in the evolution of emphysema, including airway inflammation, proteinase/anti-proteinase imbalance, oxidative stress, and genetic/epigenetic modifications. Furthermore, COPD is one main risk for lung cancer (LC), the deadliest form of human tumor; formation and chronic inflammation accompanying COPD can be a potential driver of malignancy maturation (0.8-1.7% of COPD cases develop cancer/per year). Recently, the development of more research based on COPD and lung cancer molecular analysis has provided new light for understanding their pathogenesis, improving the diagnosis and treatments, and elucidating many connections between these diseases. Our review emphasizes the biological factors involved in COPD and lung cancer, the advances in their molecular mechanisms' research, and the state of the art of diagnosis and treatments. This work combines many biological and genetic elements into a single whole and strongly links COPD with lung tumor features.

Mechanisms Contributing to the Comorbidity of COPD and Lung Cancer

Lung cancer and chronic obstructive pulmonary disease (COPD) often co-occur, and individuals with COPD are at a higher risk of developing lung cancer. While the underlying mechanism for this risk is not well understood, its major contributing factors have been proposed to include genomic, immune, and microenvironment dysregulation. Here, we review the evidence and significant studies that explore the mechanisms underlying the heightened lung cancer risk in people with COPD. Genetic and epigenetic changes, as well as the aberrant expression of non-coding RNAs, predispose the lung epithelium to carcinogenesis by altering the expression of cancer- and immune-related genes. Oxidative stress generated by tobacco smoking plays a role in reducing genomic integrity, promoting epithelial-mesenchymal-transition, and generating a chronic inflammatory environment. This leads to abnormal immune responses that promote cancer development, though not all smokers develop lung cancer. Sex differences in the metabolism of tobacco smoke predispose females to developing COPD and accumulating damage from oxidative stress that poses a risk for the development of lung cancer. Dysregulation of the lung microenvironment and microbiome contributes to chronic inflammation, which is observed in COPD and known to facilitate cancer initiation in various tumor types. Further, there is a need to better characterize and identify the proportion of individuals with COPD who are at a high risk for developing lung cancer. We evaluate possible novel and individualized screening strategies, including biomarkers identified in genetic studies and exhaled breath condensate analysis. We also discuss the use of corticosteroids and statins as chemopreventive agents to prevent lung cancer. It is crucial that we optimize the current methods for the early detection and management of lung cancer and COPD in order to improve the health outcomes for a large affected population.

The association of BTLA gene polymorphisms with non-small lung cancer risk in smokers and never-smokers

Introduction

Lung cancer is the predominant cause of death among cancer patients and non-small cell lung cancer (NSCLC) is the most common type. Cigarette smoking is the prevailing risk factor for NSCLC, nevertheless, this cancer is also diagnosed in never-smokers. B and T lymphocyte attenuator (BTLA) belongs to immunological checkpoints which are key regulatory molecules of the immune response. A growing body of evidence highlights the important role of BTLA in cancer. In our previous studies, we showed a significant association between BTLA gene variants and susceptibility to chronic lymphoblastic leukemia and renal cell carcinoma in the Polish population. The present study aimed to analyze the impact of BTLA polymorphic variants on the susceptibility to NSCLC and NSCLC patients' overall survival (OS).

Methods

Using TaqMan probes we genotyped seven BTLA single-nucleotide polymorphisms (SNPs): rs2705511, rs1982809, rs9288952, rs9288953, rs1844089, rs11921669 and rs2633582 with the use of ViiA 7 Real-Time PCR System.

Results

We found that rs1982809 within BTLA is associated with NSCLC risk, where carriers of rs1982809G allele (AG+GG genotypes) were more frequent in patients compared to controls. In subgroup analyses, we also noticed that rs1982809G carriers are significantly overrepresented in never-smokers, but not in smokers compared to controls. Additionally, the global distribution of the haplotypes differed between the never-smokers and smokers, where haplotypes A G G C A, C G A C G, and C G A T G were more frequent in never-smoking patients. Furthermore, the presence rs1982809G (AG+GG genotypes) allele as well as the presence of rs9288953T allele (CT+TT genotypes) increased NSCLC risk in females' patients. After stratification by histological type, we noticed that rs1982809G and rs2705511C carriers were more frequent among adenocarcinoma patients. Moreover, rs1982809G and rs2705511C correlated with the more advanced stages of NSCLC (stage II and III), but not with stage IV. Furthermore, we showed that rs2705511 and rs1982809 significantly modified OS, while rs9288952 tend to be associated with patients' survival.

Conclusion

Our results indicate that BTLA polymorphic variants may be considered low penetrating risk factors for NSCLC especially in never-smokers, and in females, and are associated with OS of NSCLC patients.

Genetic differences between smokers and never-smokers with lung cancer

Smoking is a major risk factor for lung cancer, therefore lung cancer epidemiological trends reflect the past trends of cigarette smoking to a great extent. The geographic patterns in mortality closely follow those in incidence. Although lung cancer is strongly associated with cigarette smoking, only about 15% of smokers get lung cancer, and also some never-smokers develop this malignancy. Although less frequent, lung cancer in never smokers is the seventh leading cause of cancer deaths in both sexes worldwide. Lung cancer in smokers and never-smokers differs in many aspects: in histological types, environmental factors representing a risk, and in genes associated with this disease. In this review, we will focus on the genetic differences between lung cancer in smokers versus never-smokers: gene expression, germ-line polymorphisms, gene mutations, as well as ethnic and gender differences. Finally, treatment options for smokers and never-smokers will be briefly reviewed.

Multivariate analysis of prognostic factors in patients with lung cancer

Objective

Lung cancer is the leading cause of cancer-related mortality in China. The purpose of this study was to determine the effect of non-therapeutic and therapeutic factors of patients with lung cancer on survival rate.

Methods

In this retrospective study, a total of 458 patients diagnosed as lung cancer at the Department of Thoracic Surgery, the Fourth Affiliated Hospital of Hebei Medical University from September 2008 to October 2013 were enrolled. The COX proportional hazards model was used to analyze the possible factors affecting the survival of patients. Model variables included age, sex, family history, smoking, tumor location, pathological type, stage, chemotherapy, radiotherapy, operation, and targeted therapy.

Results

The median survival time (MST) was 32.0 months (95% CI: 29.0-34.0 months), while the 1-, 3-, and 5-year survival rates were 70.74%, 36.90%, and 30.13%, respectively. The univariate analysis showed that stage, chemotherapy, radiotherapy, and operation significantly affected the median survival time of patients. Multivariate cox regression analysis suggested that sex (female vs male, 2.096, 95% CI: 1.606-2.736), stage (stage I vs IV, 0.111, 95% CI: 0.039-0.314; stage II vs IV, 0.218, 95%CI: 0.089-0.535), chemotherapy (no vs yes, 0.469, 95% CI: 0.297-0.742), and operation (no vs yes, 2.667, 95% CI: 1.174-6.055) were independently associated with the survival of patients with lung cancer.

Conclusion

Our study showed that male, early stage, operation were protective factors for the survival of patients, while female, advanced stage, chemotherapy were risk factors for the survival of patients. Larger studies are required to address the usefulness of these prognostic factors in defining the management of patients with lung cancer.

Gender Differences Among Out-of-School Korean Adolescents in a Counselor-Visiting Smoking Cessation Program

ABSTRACT

The purpose of this study was to explore the determinants of self-reported smoking cessation among out-of-school Korean adolescents who participated in a counselor-visiting smoking cessation program. This retrospective descriptive study analyzed data from the Korea Health Promotion Institute. Participants were enrolled between June 1, 2015, and December 31, 2017, at a regional smoking cessation center in a counselor-visiting smoking cessation program for out-of-school adolescents. Participants consisted of 807 adolescents (70.3% male) with a mean age of 16.9 ± 1.2 years. Multiple logistic regression analysis showed that female gender (OR = 1.54-1.92), cohort year 2016 (OR = 1.69-1.90), smoking more than half a pack a day (OR = 0.44-0.50), strong motivation to quit (OR = 1.44), and number of counseling in person (OR = 1.97-2.10) were statistically significant independent contributors to quitting, based on follow-up assessments at 4 weeks, 12 weeks, and 6 months. This study explored smoking cessation outcomes of a government-driven smoking cessation program that targeted out-of-school adolescents and identified several risk factors that affect a successful outcome. More research is necessary to evaluate the efficacy of such smoking cessation programs for marginalized or understudied populations.

Controversies and challenges in lung cancer screening

Two large randomized controlled trials have shown mortality benefit from lung cancer screening (LCS) in high-risk groups. Updated guidelines by the United State Preventative Service Task Force in 2020 will allow for inclusion of more patients who are at high risk of developing lung cancer and benefit from screening. As medical clinics and lung cancer screening programs around the country continue to work on perfecting the LCS workflow, it is important to understand some controversial issues surrounding LCS that should be addressed. In this article, we identify some of these issues, including false positive rates of low-dose CT, over-diagnosis, cost expenditure, LCS disparities in minorities, and utility of biomarkers. We hope to provide clarity, potential solutions, and future directions on how to address these controversies.

New Implications of Patients’ Sex in Today’s Lung Cancer Management

Simple Summary

We aim to raise awareness that sex is an important factor to take into account in modern-day thoracic oncology practice. Summarized, women should be specifically targeted in smoking cessation campaigns and sex-specific barriers should be addressed. Women present more often with adenocarcinoma histology and EGFR/ALK alterations, as lung cancer in never-smokers is more common in women compared to men. Lung cancer in female patients may show a poorer response to immune checkpoint inhibition; therefore, the addition of chemotherapy should be considered. On the other hand, women experience more benefits from targeted therapy against EGFR. In general, prognosis for women is better compared to that in men. Lung cancer screening trials report that women derive more benefit from screening, although they have not been designed for women. Future trial designs should take this into account and encourage participation of women.

Abstract

This paper describes where and how sex matters in today’s management of lung cancer. We consecutively describe the differences between males and females in lung cancer demographics; sex-based differences in the immune system (including the poorer outcomes in women who are treated with immunotherapy but no chemotherapy); the presence of oncogenic drivers and the response to targeted therapies according to sex; the greater benefit women derive from lung cancer screening and why they get screened less; and finally, the barriers to smoking cessation that women experience. We conclude that sex is an important but often overlooked factor in modern-day thoracic oncology practice.

Gender, Tobacco Control Policies, and Persistent Smoking Among Older Adults: A Longitudinal Analysis of 11 European Countries

INTRODUCTION

Little is known about sociodemographic and macro-level predictors of persistent smoking when one has developed a health condition that is likely caused by smoking.

AIMS AND METHODS

We investigate the impact of gender, education, and tobacco control policies (TCPs) on persistent smoking among older Europeans. Respondents (aged 50 +) with a smoking history and at least one smoking-related health condition were pooled from the Survey of Health, Aging and Retirement in Europe (SHARE) and the English Longitudinal Study of Ageing (ELSA) from four waves from 2004 to 2013. We fitted gender-specific logistic regression models with two-way fixed effects (country and year) and tested interaction terms between gender, education, and TCPs.

RESULTS

Although women are less likely to smoke than men, they were more likely to smoke persistently. The effects of education and general TCPs on persistent smoking were significant for women only. Compared to women with low levels of education, those with moderate education (odds ratio [OR] = .63; .49-.82) and high education (OR = .57; .34-.98) are less likely to be persistent smokers. TCPs are associated with a reduced risk of women's persistent smoking (OR = .70; .51-.95) and the association is stronger for those having less education.

CONCLUSIONS

Older women, particularly those with low levels of education, are vulnerable to persistent smoking. TCPs might be effective in reducing persistent smoking for older women, with greater effects for less-educated women. Future studies are needed to understand mechanisms that explain gender differences in responsiveness to TCPs.

IMPLICATIONS

Persistent smoking is a particularly harmful smoking behavior as it is associated with greater risks of comorbidity and mortality. By employing the framework of the multilevel social determinants of health, this study examined the behavior of persistent smoking among older adults in European countries. Women, especially women with low levels of education are vulnerable to persistent smoking. Moreover, TCPs, in general, are significantly related to a reduction in persistent smoking among older women only and the negative association is stronger for those having less education, indicating gender and socioeconomic differences in responsiveness to TCPs.

Consideration of sex and gender differences in addiction medication response

Substance use continues to contribute to significant morbidity and mortality in the United States, for both women and men, more so than another other preventable health condition. To reduce the public health burden attributable to substances, the National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism have identified that medication development for substance use disorder is a high priority research area. Furthermore, both Institutes have stated that research on sex and gender differences in substance use medication development is a critical area. The purpose of the current narrative review is to highlight how sex and gender have been considered (or not) in medication trials for substance use disorders to clarify and summarize what is known regarding sex and gender differences in efficacy and to provide direction to the field to advance medication development that is consistent with current NIH 'sex as a biological variable' (SABV) policy. To that end, we reviewed major classes of abused substances (nicotine, alcohol, cocaine, cannabis, opioids) demonstrating that, sex and gender have not been well-considered in addiction medication development research. However, when adequate data on sex and gender differences have been evaluated (i.e., in tobacco cessation), clinically significant differences in response have been identified between women and men. Across the other drugs of abuse reviewed, data also suggest sex and gender may be predictive of outcome for some agents, although the relatively low representation of women in clinical research samples limits making definitive conclusions. We recommend the incorporation of sex and gender into clinical care guidelines and improved access to publicly available sex-stratified data from medication development investigations.

The association between hormonal contraceptive use and smoking, negative affect, and cessation attempts in college females

Exogenous and endogenous female hormones influence nicotine use and cessation, potentially through mechanisms such as anxiety and negative affect. In the present study, college females using all types of hormonal contraceptives (HC) were compared to those not using HC to determine the potential influence on current smoking, negative affect, and current and past cessation attempts. Differences between progestin-only and combination HC were also examined. Of the 1,431 participants, 53.2% (n = 761) reported current HC use, and 12.3% (n = 176) of participants endorsed current smoking. Women currently using HC were significantly more likely to smoke (13.5%; n = 103) compared to women not using HC (10.9%; n = 73), p = .04. There was a significant main effect of HC use being associated with lower anxiety levels (p = .005), as well as a significant HC use by smoking status interaction, such that women who smoke using HC reported the lowest levels of anxiety among participants (p = .01). Participants using HC were more likely to be making a current attempt to quit smoking than those not using HC (p = .04) and were more likely to have made past quit attempts (p = .04). No significant differences were observed across women using progestin-only, combined estrogen and progestin, and women not using HC. These findings provide evidence that exogenous hormones may be an advantageous treatment target and that they warrant additional study.

Real-World longitudinal practice patterns in the use of PD-1 and PD-L1 inhibitors as First-Line therapy in patients with Non-Small cell lung cancer in the United States

Background

Immune checkpoint inhibitors targeting the programmed cell death protein‐1 (PD‐1) and programmed death ligand‐1 (PD‐L1) axis (collectively referred to as PD[L]1i) have demonstrated clinical benefits in non‐small cell lung cancer (NSCLC) patients. The purpose of this United States‐based real‐world study is to examine changes in the landscape of first‐line therapies for NSCLC since the introduction of PD(L)1i.

Methods

Patients with NSCLC initiating first‐line treatment between May 1, 2017, and October 31, 2020, were identified in the IBM MarketScan® database. Patients were assigned groups based on first‐line therapy: PD(L)1i monotherapy, chemotherapy alone, PD(L)1i with chemotherapy, or targeted therapy for patients with actionable driver mutations.

Results

A total of 5431 patients with NSCLC starting first‐line treatment were identified: chemotherapy alone 2568 (47%), PD(L)1i with chemotherapy 1364 (25%), PD(L)1i monotherapy 790 (15%), and targeted therapy 709 (13%). The use of PD(L)1i monotherapy and targeted therapy remained consistent, while the percentage of patients receiving PD(L)1i with chemotherapy more than doubled. Over a third of patients in 2019 and 2020 received chemotherapy alone. Patients aged ≥65 years (odds ratio [OR]: 0.80; 95% confidence interval [CI]: 0.68–0.95), females (OR: 0.86; 95% CI: 0.74–0.98), and those with respiratory (OR: 0.82; 95% CI: 0.71–0.94) or kidney (OR: 0.56; 95% CI: 0.40–0.77) disease were less likely to have received PD(L)1i with chemotherapy than patients that received chemotherapy alone.

Conclusions

Since the approval of PD(L)1i for NSCLC, their use has significantly increased for first‐line treatment, especially when used in combination with chemotherapy. A significant proportion of patients received chemotherapy alone.

Gender and tobacco epidemic in South Korea: implications from age-period-cohort analysis and the DPSEEA framework

OBJECTIVES

To understand a 20-year trend of gender-specific smoking prevalence among adults in South Korea.

DESIGN

Age-period-cohort analysis using the intrinsic estimator method was applied to examine the separate contribution of age, period and cohort effect on smoking prevalence. The Driving Force-Pressure-State-Exposure-Effect-Action (DPSEEA) framework was used to explain the observed smoking trends by mapping potential determinants and to address policy implications.

SETTING

General adult population in South Korea.

PARTICIPANTS

34 828 men and 43 632 women who aged 19-78 years, were not currently pregnant and were without a prior diagnosis of cardiovascular disease or cancer.

OUTCOME MEASURES

Gender-specific current smoking prevalence using the 1998-2017 Korea National Health and Nutrition Examination Survey.

RESULTS

Our results showed gender-specific age and birth cohort effects. More specifically, the smoking prevalence peaked at their mid-20s (prevalence rate ratio (PRR): 1.54, 95% CI: 1.49 to 1.59) and cohort born in 1959-1963 (PRR: 1.63, 95% CI: 1.57 to 1.70) and then decreased in men. On the other hand, in women, the smoking prevalence consistently increased until their mid-40s (PRR: 1.53, 95% CI: 1.27 to 1.84) and in recent birth cohort groups (PRR in 1994-1998 cohort: 1.55, 95% CI: 1.13 to 2.13). The period effects declined from 1998-2002 to 2003-2007, following increasing fluctuations in both genders. The smoking-DPSEEA framework showed the absence of policy actions to target female smokers and emphasised a proactive approach that tackles the upstream causes for smoking in women.

CONCLUSIONS

Men and women are clearly in different phases of the smoking epidemic in Korean population, and gender-tailored policies should be implemented.

Machine learning application in personalised lung cancer recurrence and survivability prediction

Machine learning is an important artificial intelligence technique that is widely applied in cancer diagnosis and detection. More recently, with the rise of personalised and precision medicine, there is a growing trend towards machine learning applications for prognosis prediction. However, to date, building reliable prediction models of cancer outcomes in everyday clinical practice is still a hurdle. In this work, we integrate genomic, clinical and demographic data of lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) patients from The Cancer Genome Atlas (TCGA) and introduce copy number variation (CNV) and mutation information of 15 selected genes to generate predictive models for recurrence and survivability. We compare the accuracy and benefits of three well-established machine learning algorithms: decision tree methods, neural networks and support vector machines. Although the accuracy of predictive models using the decision tree method has no significant advantage, the tree models reveal the most important predictors among genomic information (e.g. KRAS, EGFR, TP53), clinical status (e.g. TNM stage and radiotherapy) and demographics (e.g. age and gender) and how they influence the prediction of recurrence and survivability for both early stage LUAD and LUSC. The machine learning models have the potential to help clinicians to make personalised decisions on aspects such as follow-up timeline and to assist with personalised planning of future social care needs.

Effect of smoking reduction, cessation, and resumption on cancer risk: A nationwide cohort study

BACKGROUND

The objective of this study was to investigate the effects of reduction, cessation, and resumption of smoking on cancer development.

METHODS

The authors identified 893,582 participants who currently smoked, had undergone a health screening in 2009, and had a follow-up screening in 2011. Among them, 682,996 participated in a third screening in 2013. Participants were categorized as quitters, reducers I (≥50% reduction), reducers II (<50% reduction), sustainers (referent), or increasers (≥20% increase). Outcome data were obtained through December 31, 2018.

RESULTS

Reducers I exhibited a decreased risk of all cancers (adjusted hazard ratio [aHR], 0.96; 95% confidence interval [CI], 0.93-0.99), smoking-related cancers (aHR, 0.95; 95% CI, 0.92-0.99), and lung cancer (aHR, 0.83; 95% CI, 0.77-0.88). Quitters had the lowest risk of all cancers (aHR, 0.94; 95% CI, 0.92-0.96), smoking-related cancers (aHR, 0.91; 95% CI, 0.89-0.93), and lung cancer (aHR, 0.79; 95% CI, 0.76-0.83). In further analysis with 3 consecutive screenings, additional smoking reduction (from reducers II to reducers I) lowered the risk of lung cancer (aHR, 0.74; 95% CI, 0.58-0.94) in comparison with sustainers. Quitting among reducers I further decreased the risk of all cancers (aHR, 0.90; 95% CI, 0.80-1.00), smoking-related cancers (aHR, 0.81; 95% CI, 0.81-0.92), and lung cancer (aHR, 0.66; 95% CI, 0.52-0.84) in comparison with sustainers. Smoking resumption after quitting, even at a lower level, increased the risk of smoking-related cancers (aHR, 1.19; 95% CI, 1.06-1.33) and lung cancer (aHR, 1.48; 95% CI, 1.21-1.80) in comparison with sustained quitting.

CONCLUSIONS

Smoking cessation and, to a lesser extent, smoking reduction decreased the risks of cancer. Smoking resumption increased cancer risks in comparison with sustained quitting.

LAY SUMMARY

Worldwide, tobacco use is the single leading preventable risk factor for cancer and cancer death. This study examined the effects of reduction, cessation, and resumption of smoking on cancer development by measuring smoking behavior repetitively. Although smoking reduction has a substantial cancer prevention benefit for those who cannot quit, cessation should be encouraged whenever possible. Quitters should be monitored to ensure that they do not resume smoking.

Sex differences in lung cancer treatment and outcomes at a large hybrid academic-community practice

Introduction

Methods

Results

Conclusions

Nomogram to predict cause-specific mortality of patients with rectal adenocarcinoma undergoing surgery: a competing risk analysis

BACKGROUND

Rectal adenocarcinoma is one of major public health problems, severely threatening people's health and life. Cox proportional hazard models have been applied in previous studies widely to analyze survival data. However, such models ignore competing risks and treat them as censored, resulting in excessive statistical errors. Therefore, a competing-risk model was applied with the aim of decreasing risk of bias and thereby obtaining more-accurate results and establishing a competing-risk nomogram for better guiding clinical practice.

METHODS

A total of 22,879 rectal adenocarcinoma cases who underwent primary-site surgical resection were collected from the SEER (Surveillance, Epidemiology, and End Results) database. Death due to rectal adenocarcinoma (DRA) and death due to other causes (DOC) were two competing endpoint events in the competing-risk regression analysis. The cumulative incidence function for DRA and DOC at each time point was calculated. Gray's test was applied in the univariate analysis and Gray's proportional subdistribution hazard model was adopted in the multivariable analysis to recognize significant differences among groups and obtain significant factors that could affect patients' prognosis. Next, A competing-risk nomogram was established predicting the cause-specific outcome of rectal adenocarcinoma cases. Finally, we plotted calibration curve and calculated concordance indexes (c-index) to evaluate the model performance.

RESULTS

22,879 patients were included finally. The results showed that age, race, marital status, chemotherapy, AJCC stage, tumor size, and number of metastasis lymph nodes were significant prognostic factors for postoperative rectal adenocarcinoma patients. We further successfully constructed a competing-risk nomogram to predict the 1-year, 3-year, and 5-year cause-specific mortality of rectal adenocarcinoma patients. The calibration curve and C-index indicated that the competing-risk nomogram model had satisfactory prognostic ability.

CONCLUSION

Competing-risk analysis could help us obtain more-accurate results for rectal adenocarcinoma patients who had undergone surgery, which could definitely help clinicians obtain accurate prediction of the prognosis of patients and make better clinical decisions.

Modulation of chemoimmunotherapy efficacy in non-small cell lung cancer by sex and histology: a real-world, patient-level analysis

Background

It has been postulated that patient’s sex impacts response to immunotherapy. Sex modulation of immunotherapy benefit, however, has not yet been explored using patient-level data, where potential confounders, as well as histologic type, can be accounted for. Here we investigated the association between sex and chemoimmunotherapy efficacy for non-small cell lung cancer (NSCLC) using a large, nation-wide dataset.

Patients & methods

Stage IV NSCLC patients diagnosed in 2015 were identified in the National Cancer Database (NCDB). Patients were treated with either chemoimmunotherapy or chemotherapy alone. The efficacy of the addition of immunotherapy treatment by sex was investigated using both an adjusted Cox proportional hazards model and propensity-score matching, in both the overall cohort and stratified by histological subtype.

Results

2064 (16%) patients received chemoimmunotherapy and10,733 (84%) received chemotherapy alone. Adjusted survival analysis in the overall cohort showed that both males (hazards ratio (HR)_adj: 0.80, 95% CI: 0.74–0.87) and females (HR_adj: 0.83, 95% CI: 0.76–0.90) had better OS when treated with chemoimmunotherapy than chemotherapy alone, with no statistically significant interaction between sex and receipt of immunotherapy (p = 0.63). Propensity matching confirmed these results. However, for those with squamous cell histology, male patients derived more benefit from chemoimmunotherapy treatment than females (HR_adj: 0.73, 95% CI: 0.58–0.91 vs HR_adj: 1.03, 95% CI: 0.76–1.38; p for interaction = 0.07).

Conclusion

Male patients with squamous cell carcinoma may derive more benefit from chemoimmunotherapy treatment. Histology likely plays an important role in how sex modulates immunotherapy efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09187-y.

Lung Cancer in Women

BACKGROUND

Lung cancer is the leading cause of cancer-related death for women in the United States. Clinical characteristics, histology, epidemiology, and treatment responses are unique for women with lung cancer.

METHODS

Literature search of MEDLINE publications from 1989 to 2021 was conducted for lung cancer in women. Subsequent narrative review focused on identified differences in risk factors, diagnosis, and treatment of importance to the surgical care of these patients.

RESULTS

Studies investigating lung cancer, in which sex-differences are explored, demonstrated differences in risk factors, histology, and treatment response among women, with a significant post-surgical survival advantage over men (41.8 months vs 26.8 months, p=0.007) and greater clinical benefit from anti-PD1 combined with chemotherapy (HR=0.44, 95% CI: 0.25-0.76) compared with men (HR=0.76, 95% CI: 0.64-0.91). Smoking remains a dominant risk factor and multiple clinical trials suggest lung cancer screening provides greater benefit for women. However, young non-smoking patients with lung cancer are 2-fold more likely to be female, advocating for broader sex-based screening criteria. Potential roles of genetic mutations, estrogen signaling, and infectious elements in sex-based differences in presentation, histology, prognosis and treatment response are explored.

CONCLUSIONS

Overall, much remains unknown regarding how sex influences lung cancer risk, treatment decisions and outcomes. However, evidence of specific differences in presentation, environmental risk, molecular drivers, and mutational burden support the need to better leverage these sex-associated differences to further improve detection, diagnosis, surgical outcomes and systemic regimens in order to advance the overall care strategy for women with lung cancer.

Role of sex hormones in lung cancer

Lung cancer represents the world's leading cause of cancer deaths. Sex differences in the incidence and mortality rates for various types of lung cancers have been identified, but the biological and endocrine mechanisms implicated in these disparities have not yet been determined. While some cancers such as lung adenocarcinoma are more commonly found among women than men, others like squamous cell carcinoma display the opposite pattern or show no sex differences. Associations of tobacco product use rates, susceptibility to carcinogens, occupational exposures, and indoor and outdoor air pollution have also been linked to differential rates of lung cancer occurrence and mortality between sexes. While roles for sex hormones in other types of cancers affecting women or men have been identified and described, little is known about the influence of sex hormones in lung cancer. One potential mechanism identified to date is the synergism between estrogen and some tobacco compounds, and oncogene mutations, in inducing the expression of metabolic enzymes, leading to enhanced formation of reactive oxygen species and DNA adducts, and subsequent lung carcinogenesis. In this review, we present the literature available regarding sex differences in cancer rates, associations of male and female sex hormones with lung cancer, the influence of exogenous hormone therapy in women, and potential mechanisms mediated by male and female sex hormone receptors in lung carcinogenesis. The influence of biological sex on lung disease has recently been established, thus new research incorporating this variable will shed light on the mechanisms behind the observed disparities in lung cancer rates, and potentially lead to the development of new therapeutics to treat this devastating disease.

Sex-specific normal values and determinants of infrarenal abdominal aortic diameter among non-aneurysmal elderly population

To establish age- and sex-specific distribution of the infrarenal abdominal aortic diameters (IAD) among non-aneurysmal elderly population and to investigate the associations between traditional cardiovascular risk factors and IAD in men and women. We included 4032 participants (mean age 67.2 years; 60.4% women) from the population-based Rotterdam Study, free of cardiovascular disease, who underwent IAD ultrasound assessment between 2009-2014. Linear regression analysis was used to identify determinants of IAD. The medians (inter-quartile range) of absolute IAD and body surface area (BSA)-adjusted IAD were 17.0 (15.0-18.0) mm and 9.3 (8.5-10.2) mm for women and 19.0 (18.0-21.0) mm and 9.4 (8.6-10.3) mm for men, respectively. There was a non-linear relationship between age and IAD. IAD increased steeply with advancing age and up to 70 years. After around 75 years of age, the diameter values reached a plateau. Waist circumference and diastolic blood pressure were associated with larger diameters in both sexes. Body mass index [Effect estimate (95% CI): 0.04 (0.00 to 0.08)], systolic blood pressure [- 0.01(- 0.02 to 0.00)], current smoking [0.35 (0.06 to 0.65)], total cholesterol levels [- 0.21 (- 0.31 to - 0.11)], and lipid-lowering medication [- 0.43 (- 0.67 to - 0.19)] were significantly associated with IAD in women. Sex differences in IAD values diminished after taking BSA into account. The increase in diameters was attenuated after 70 years. Differences were observed in the associations of several cardiovascular risk factors with IAD among men and women.

Sex Differences in the Association of Cigarette Craving With Insula Structure

BACKGROUND

Cigarette craving, which can negatively impact smoking cessation, is reportedly stronger in women than in men when they initiate abstinence from smoking. Identifying approaches to counteract craving in people of different sexes may facilitate the development of personalized treatments for Tobacco Use Disorder, which disproportionately affects women. Because cigarette craving is associated with nicotine dependence and structure of the insula, this study addressed whether a person's sex influences these associations.

METHODS

The research participants (n = 99, 48 women) reported daily cigarette smoking and provided self-reports of nicotine dependence. After overnight abstinence from smoking, they underwent structural magnetic resonance imaging scanning to determine cortical thickness of the left and right anterior circular insular sulcus, and self-rated their cigarette craving before and after their first cigarette of the day.

RESULTS

Women reported stronger craving than men irrespective of smoking condition (i.e., pre- and post-smoking) (P = .048), and smoking reduced craving irrespective of sex (P < .001). A 3-way interaction of sex, smoking condition, and right anterior circular insular sulcus thickness on craving (P = .033) reflected a negative association of cortical thickness with pre-smoking craving in women only (P = .012). No effects of cortical thickness in the left anterior circular insular sulcus were detected. Nicotine dependence was positively associated with craving (P < .001) across groups and sessions, with no sex differences in this association.

CONCLUSIONS

A negative association of right anterior insula thickness with craving in women only suggests that this region may be a relevant therapeutic target for brain-based smoking cessation interventions in women.

Combined effects of lung disease history, environmental exposures, and family history of lung cancer to susceptibility of lung cancer in Chinese non-smokers

Background

Although cigarette smoking is a major risk factor for lung cancer, the incidence rate of lung cancer among non-smokers is notable. The etiology and potential mechanism of non-smoker lung cancer are worthy of further research. This study was designed to explore the collective effects of environmental factors and the relationship between environmental exposure index (EEI) and lung cancer among non-smokers by evaluating the joint effects among lung disease history, environmental factors, and family history of lung cancer without smoking confounders.

Methods

A total of 767 never-smoked lung cancer cases and 767 sex- and age-matched controls were selected from the department of Thoracic Surgery and Respiratory Medicine of three hospitals in Fujian, China. We used two methods to develop the EEI according to 12 statistically significant environmental risk factors. Restricted cubic spline (RCS) was applied to analyze the non-linear relationship between EEI and lung cancer in non-smokers. Combined effects, additive interaction, and multiplicative interaction were assessed among lung disease history, EEI, and family history of lung cancer to estimate susceptibility to develop lung cancer.

Results

Lung disease history, especially asthma, was significantly associated with an increased risk of lung cancer with an odds ratio (OR) for asthma history of 14.720 (95% CI: 1.877–115.449). Family history of lung cancer was related to susceptibility of lung cancer (OR = 3.347, 95% CI: 1.930–5.806). According to type of relatives and cancer, a parental or children’s history and a sibling’s history of lung cancer were significantly associated with an increased risk of lung cancer. The positive association between EEI and lung cancer was apparently stronger in those with lung disease history or family lung cancer history. Furthermore, there was a addictive interaction between EEI and lung disease history, and a possibly addictive interaction between EEI and family lung cancer history on development of lung cancer.

Conclusions

There were combined effects among lung disease history, environmental exposures, and family history of lung cancer toward susceptibility to lung cancer in Chinese non-smokers. Non-smokers who had a family history of lung cancer were at higher risk of lung cancer than non-smokers who had lung disease history. Non-smokers with family cancer history may obtain benefits from removal of environmental exposures and active treatment of lung disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01802-z.

Relationship between Lung Carcinogenesis and Chronic Inflammation in Rodents

Simple Summary

Lung cancer is the most common cause of cancer-related deaths worldwide. There are various risk factors for lung cancer, including tobacco smoking, inhalation of dust particles, chronic inflammation, and genetic factors. Chronic inflammation has been considered a key factor that promotes tumor progression via production of cytokines, chemokines, cytotoxic mediators, and reactive oxygen species by inflammatory cells. Here, we review rodent models of lung tumor induced by tobacco, tobacco-related products, and pro-inflammatory materials as well as genetic modifications, and discuss the relationship between chronic inflammation and lung tumor. Through this review, we hope to clarify the effects of chronic inflammation on lung carcinogenesis and help develop new treatments for lung cancer.

Abstract

Lung cancer remains the leading cause of cancer-related deaths, with an estimated 1.76 million deaths reported in 2018. Numerous studies have focused on the prevention and treatment of lung cancer using rodent models. Various chemicals, including tobacco-derived agents induce lung cancer and pre-cancerous lesions in rodents. In recent years, transgenic engineered rodents, in particular, those generated with a focus on the well-known gene mutations in human lung cancer (KRAS, EGFR, and p53 mutations) have been widely studied. Animal studies have revealed that chronic inflammation significantly enhances lung carcinogenesis, and inhibition of inflammation suppresses cancer progression. Moreover, the reduction in tumor size by suppression of inflammation in animal experiments suggests that chronic inflammation influences the promotion of tumorigenesis. Here, we review rodent lung tumor models induced by various chemical carcinogens, including tobacco-related carcinogens, and transgenics, and discuss the roles of chronic inflammation in lung carcinogenesis.

Socioeconomic inequalities in tobacco smoking in women aged 15-54 in Iran: a multilevel model

Significant evidence suggests an inverse relationship between socioeconomic status and tobacco smoking, where inequality is visible among different social and economic strata. The aim of this study was to investigate the prevalence and economic and social inequalities in tobacco smoking in women aged 15-54 in Iran. This study is a cross-sectional study. Sampling in this study was a randomized clustered multistage sampling with equal clusters. A total of 35,305 women aged 15-55 enrolled in the study. Data analysis was in two stages. In the first stage, the social and economic inequalities were investigated using the concentration index and concentration curve method, and in the second method, and multilevel method was used to identify the determinants. The prevalence of tobacco smoking in women was 12.24%. The concentration index for smoking was CI = -0.07 [95% CI (-0.09, -0.05)], which represents smoking in people with low socioeconomic status. The results of the multilevel analysis indicated that the marital status of people over the age of 35 and the economic class was related to smoking in women. Inequality in tobacco smoking in women is to the interest of the well-off group, and this inequality varies in different provinces. Marital status, place of residence, age and socioeconomic status of women are factors influencing the prevalence of tobacco smoking in women, and these issues should be noticed to reduce inequalities.

Urinary biomarkers of polycyclic aromatic hydrocarbons and their associations with liver function in adolescents

Associations between polycyclic aromatic hydrocarbons (PAHs) and respiratory diseases have been widely studied, but the effects of PAH on liver toxicity in adolescents are unclear. Here, 3194 adolescents with NHANES data from 2003 to 2016 were selected. PAH exposure was assessed by measuring PAH metabolites in urine. The outcome variables were the levels of alanine aminotransferase (ALT), aspartate amino transferase (AST) and gamma-glutamyl transpeptidase (GGT). The association between PAH exposure and liver function was evaluated by the weighted quantile sum (WQS) and logistic regression, and the associations between PAHs and inflammation and blood lipids were evaluated by linear regression. Covariates were adjusted for age, ethnicity, BMI, physical activity, family income, cotinine, and urinary creatinine. The results showed that for females, mixed PAH exposure was related to an increased ALT level (OR = 2.33, 95% CI 1.15, 4.72), and 2-fluorene contributed the most (38.6%). Urinary 2-fluorene was positively associated with an elevated ALT level (OR = 2.19 95% 1.12, 4.27, p for trend = 0.004). Mechanistically, 2-fluorene can cause a 3.56% increase in the white blood cell count, a 6.99% increase in the triglyceride level, and 1.70% increase in the total cholesterol level. PAHs may have toxic effects, possibly mediated by inflammation and blood lipids, on the adolescent female liver. Additional confirmatory studies are needed.

Genome-Wide Analysis of Sex Disparities in the Genetic Architecture of Lung and Colorectal Cancers

Almost all complex disorders have manifested epidemiological and clinical sex disparities which might partially arise from sex-specific genetic mechanisms. Addressing such differences can be important from a precision medicine perspective which aims to make medical interventions more personalized and effective. We investigated sex-specific genetic associations with colorectal (CRCa) and lung (LCa) cancers using genome-wide single-nucleotide polymorphisms (SNPs) data from three independent datasets. The genome-wide association analyses revealed that 33 SNPs were associated with CRCa/LCa at P < 5.0 × 10⁻⁶ neither males or females. Of these, 26 SNPs had sex-specific effects as their effect sizes were statistically different between the two sexes at a Bonferroni-adjusted significance level of 0.0015. None had proxy SNPs within their ±1 Mb regions and the closest genes to 32 SNPs were not previously associated with the corresponding cancers. The pathway enrichment analyses demonstrated the associations of 35 pathways with CRCa or LCa which were mostly implicated in immune system responses, cell cycle, and chromosome stability. The significant pathways were mostly enriched in either males or females. Our findings provided novel insights into the potential sex-specific genetic heterogeneity of CRCa and LCa at SNP and pathway levels.

Interplay between estrogen and Stat3/NF-κB-driven immunomodulation in lung cancer

K-ras mutant lung adenocarcinoma (LUAD) is the most common type of lung cancer, displays abysmal prognosis and is tightly linked to tumor-promoting inflammation, which is increasingly recognized as a target for therapeutic intervention. We have recently shown a gender-specific role for epithelial Stat3 signaling in the pathogenesis of K-ras mutant LUAD. The absence of epithelial Stat3 in male K-ras mutant mice (LR/Stat3Δ/Δ mice) promoted tumorigenesis and induced a nuclear factor-kappaB (NF-κB)-driven pro-tumor immune response while reducing tumorigenesis and enhancing anti-tumor immunity in female counterparts. In the present study, we manipulated estrogen and NF-κB signaling to study the mechanisms underlying this intriguing gender-disparity. In LR/Stat3Δ/Δ females, estrogen deprivation by bilateral oophorectomy resulted in higher tumor burden, an induction of NF-κB-driven immunosuppressive response, and reduced anti-tumor cytotoxicity, whereas estrogen replacement reversed these changes. On the other hand, exogenous estrogen in males successfully inhibited tumorigenesis, attenuated NF-κB-driven immunosuppression and boosted anti-tumor immunity. Mechanistically, genetic targeting of epithelial NF-κB activity resulted in reduced tumorigenesis and enhanced the anti-tumor immune response in LR/Stat3Δ/Δ males, but not females. Our data suggest that estrogen exerts a context-specific anti-tumor effect through inhibiting NF-κB-driven tumor-promoting inflammation and provide insights into developing novel personalized therapeutic strategies for K-ras mutant LUAD.

Polycyclic Aromatic Hydrocarbon-induced Pulmonary Carcinogenesis in Cytochrome P450 (CYP)1A1- and 1A2-Null Mice: Roles of CYP1A1 and CYP1A2

In 2019, lung cancer was estimated to be the leading cause of cancer deaths in humans. Polycyclic aromatic hydrocarbons (PAHs) are known to increase the risk of lung cancer. PAHs are metabolized by the cytochrome P450 (CYP)1A subfamily, comprised of the CYP1A1 and 1A2 monooxygenases. These enzymes bioactivate PAHs into reactive metabolites that induce mutagenic DNA adducts, which can lead to cancer. Past studies have investigated the role of CYP1A1 in PAH bioactivation; however, the individual roles of each CYP1A enzyme are still unknown. In this investigation, we tested the hypothesis that mice lacking the genes for Cyp1a1 or Cyp1a2 will display altered susceptibilities to PAH-induced pulmonary carcinogenesis. Wild-type, Cyp1a1-null (Cyp1a1-/-), and Cyp1a2-null (Cyp1a2-/-) male and female mice were treated with 3-methylcholanthrene for cancer initiation and tumor formation studies. In wild-type mice, CYP1A1 and 1A2 expression was induced by 3-methylcholanthrene. Cyp1a1-/- and Cyp1a2-/- mice treated with PAHs displayed a compensatory pattern, where knocking out 1 Cyp1a gene led to increased expression of the other. Cyp1a1-/- mice were resistant to DNA adduct and tumor formation, whereas Cyp1a2-/- mice displayed increased levels of both. UALCAN analysis revealed that lung adenocarcinoma patients with high levels of CYP1A2 expression survive significantly better than patients with low/medium expression. In conclusion, Cyp1a1-/- mice were less susceptible to PAH-induced pulmonary carcinogenesis, whereas Cyp1a2-/- mice were more susceptible. In addition, high CYP1A2 expression was found to be protective for lung adenocarcinoma patients. These results support the need to develop novel CYP1A1 inhibitors to mitigate human lung cancer.

Androgen and Androgen Receptors as Regulators of Monocyte and Macrophage Biology in the Healthy and Diseased Lung

Androgens, the predominant male sex hormones, drive the development and maintenance of male characteristics by binding to androgen receptor (AR). As androgens are systemically distributed throughout the whole organism, they affect many tissues and cell types in addition to those in male sexual organs. It is now clear that the immune system is a target of androgen action. In the lungs, many immune cells express ARs and are responsive to androgens. In this review, we describe the effects of androgens and ARs on lung myeloid immune cells-monocytes and macrophages-as they relate to health and disease. In particular, we highlight the effect of androgens on lung diseases, such as asthma, chronic obstructive pulmonary disease and lung fibrosis. We also discuss the therapeutic use of androgens and how circulating androgens correlate with lung disease. In addition to human studies, we also discuss how mouse models have helped to uncover the effect of androgens on monocytes and macrophages in lung disease. Although the role of estrogen and other female hormones has been broadly analyzed in the literature, we focus on the new perspectives of androgens as modulators of the immune system that target myeloid cells during lung inflammation.

Lung cancer incidence in young women vs. young men: A systematic analysis in 40 countries

Previous studies have reported converging lung cancer rates between sexes. We examine lung cancer incidence rates in young women vs. young men in 40 countries across five continents. Lung and bronchial cancer cases by 5-year age group (ages 30-64) and 5-year calendar period (1993-2012) were extracted from Cancer Incidence in Five Continents. Female-to-male incidence rate ratios (IRRs) and 95% confidence intervals (95%CIs) were calculated by age group and birth cohort. Among men, age-specific lung cancer incidence rates generally decreased in all countries, while in women the rates varied across countries with the trends in most countries stable or declining, albeit at a slower pace compared to those in men. As a result, the female-to-male IRRs increased among recent birth cohorts, with IRRs significantly greater than unity in Canada, Denmark, Germany, New Zealand, the Netherlands and the United States. For example, the IRRs in ages 45-49 year in the Netherlands increased from 0.7 (95% CI: 0.6-0.8) to 1.5 (95% CI: 1.4-1.7) in those born circa 1948 and 1963, respectively. Similar patterns, though nonsignificant, were found in 23 additional countries. These crossovers were largely driven by increasing adenocarcinoma incidence rates in women. For those countries with historical smoking data, smoking prevalence in women approached, but rarely exceeded, those of men. In conclusion, the emerging higher lung cancer incidence rates in young women compared to young men is widespread and not fully explained by sex differences in smoking patterns. Future studies are needed to identify reasons for the elevated incidence of lung cancer among young women.

Smoking Across the Menopausal Transition in a 10-Year Longitudinal Sample: The Role of Sex Hormones and Depressive Symptoms

INTRODUCTION

Current cigarette smoking rates among older women remain problematic, especially given that this population experiences increased smoking-related health consequences. Despite these increased health concerns, little research to date has explored smoking patterns across the menopausal transition (pre-, early-peri-, late-peri-, and postmenopausal) or the effect of unique factors such as sex hormones and depression during this transition.

METHODS

This study used 10 yearly waves of data from the Study of Women's Health Across the Nation, a longitudinal dataset. Data included 1397 women endorsing ever smoking regularly at baseline. Random-effects logistic regression models were used to examine smoking transitions.

RESULTS

Although there were no associations between menopausal transition stage and smoking behavior, increased estradiol was associated with an increased likelihood of quitting regular smoking (eg, transitioning from regular smoking to non-regular or no smoking; odds ratio [OR] = 1.28), whereas increased testosterone was associated with an increased likelihood of relapsing to regular smoking (eg, transitioning from former or nonregular smoking to regular smoking OR = 2.56). Depression was associated with increased likelihood of continued smoking (OR = 0.97) and relapse (OR = 1.03).

CONCLUSIONS

The results emphasize the need to develop interventions to target initiated or continued smoking among women across the menopausal transition and specifically highlight the importance of developing treatments that target depressive symptoms in this population. In addition, although singular hormone measures were associated with smoking behavior, there is a need for future study of dynamic changes in hormones, as well as the impact of progesterone on smoking behaviors across the menopausal transition.

IMPLICATIONS

To date, no studies have examined smoking behaviors across the menopausal transition. In this study, although menopausal transition status was not significantly related to transitions in smoking behavior, important relationships between sex hormones and depression were observed. Increased estradiol was associated with an increased likelihood of quitting regular smoking, whereas increased testosterone was associated with an increased likelihood of relapsing to regular smoking behavior. Higher depression scores were related to continued smoking and relapse to regular smoking behavior. These results highlight the need to develop interventions to target smoking cessation among women across the menopausal transition.