Cigarette smoking and histologic type of lung cancer in men

Spinosad blocks CHRNA5 mediated EGFR signaling pathway activation to inhibit lung adenocarcinoma proliferation

Lung adenocarcinoma (LUAD) is the leading cause of cancer death worldwide, with high incidence and low survival rates. Nicotinic acetylcholine receptors play an important role in the progression of LUAD. In this study, a screening of 17 nicotinic acetylcholine receptor allosteric agents revealed that spinosad effectively suppressed the proliferation of LUAD cells. The experiments demonstrated that spinosad induced cell cycle arrest in the G1 phase and stimulated apoptosis, thereby impeding the growth of LUAD and enhancing the responsiveness to gefitinib in vitro and vivo. Mechanistic insights obtained through transcriptome sequencing, Co-IP, and protein immunoblots indicated that spinosad disrupted the interaction between CHRNA5 and EGFR, thereby inhibiting the formation of downstream complexes and activation of the EGFR signaling pathway. The supplementation of exogenous acetylcholine showed to mitigate the inhibition of LUAD cell proliferation induced by spinosad. This study elucidates the therapeutic effects and mechanisms of spinosad in LUAD, and offers a theoretical and experimental foundation for novel LUAD treatments.

Association between Airport Ultrafine Particles and Lung Cancer Risk: The Multiethnic Cohort Study

BACKGROUND

Ultrafine particles (UFP) are unregulated air pollutants abundant in aviation exhaust. Emerging evidence suggests that UFPs may impact lung health due to their high surface area-to-mass ratio and deep penetration into airways. This study aimed to assess long-term exposure to airport-related UFPs and lung cancer incidence in a multiethnic population in Los Angeles County.

METHODS

Within the California Multiethnic Cohort, we examined the association between long-term exposure to airport-related UFPs and lung cancer incidence. Multivariable Cox proportional hazards regression models were used to estimate the effect of UFP exposure on lung cancer incidence. Subgroup analyses by demographics, histology and smoking status were conducted.

RESULTS

Airport-related UFP exposure was not associated with lung cancer risk [per one IGR HR, 1.01; 95% confidence interval (CI), 0.97-1.05] overall and across race/ethnicity. A suggestive positive association was observed between a one IQR increase in UFP exposure and lung squamous cell carcinoma (SCC) risk (HR, 1.08; 95% CI, 1.00-1.17) with a Phet for histology = 0.05. Positive associations were observed in 5-year lag analysis for SCC (HR, 1.12; 95% CI, CI, 1.02-1.22) and large cell carcinoma risk (HR, 1.23; 95% CI, 1.01-1.49) with a Phet for histology = 0.01.

CONCLUSIONS

This large prospective cohort analysis suggests a potential association between airport-related UFP exposure and specific lung histologies. The findings align with research indicating that UFPs found in aviation exhaust may induce inflammatory and oxidative injury leading to SCC.

IMPACT

These results highlight the potential role of airport-related UFP exposure in the development of lung SCC.

Lung cancer, comorbidities, and medication: the infernal trio

Most patients with lung cancer are smokers and are of advanced age. They are therefore at high risk of having age- and lifestyle-related comorbidities. These comorbidities are subject to treatment or even polypharmacy. There is growing evidence of a link between lung cancer, comorbidities and medications. The relationships between these entities are complex. The presence of comorbidities and their treatments influence the time of cancer diagnosis, as well as the diagnostic and treatment strategy. On the other hand, cancer treatment may have an impact on the patient's comorbidities such as renal failure, pneumonitis or endocrinopathies. This review highlights how some comorbidities may have an impact on lung cancer presentation and may require treatment adjustments. Reciprocal influences between the treatment of comorbidities and anticancer therapy will also be discussed.

Frequency and functional characterization of fusion genes in squamous cell carcinoma of the lung

INTRODUCTION

In contrast to lung adenocarcinoma (LUAD), targetable genetic alterations are less frequently detected in squamous cell carcinoma of the lung (LUSC). Over the last years, gene fusions have become promising targets in many solid cancers. Here, we analysed a cohort of LUSC, identified recurrent fusion genes and functionally characterised these tumour genomes.

METHODS

A subset of 1608 squamous cell carcinomas of the lung was analysed by means of the FusionPlex® Lung Panel to identify potentially targetable gene fusions using targeted next-generation sequencing. Cases harbouring recurrent gene fusions were further analysed using FISH, Cytoscan HD arrays and cell culture experiments.

RESULTS

We found both, known and novel gene fusions in about 3 % of the cases. Known fusions occurring in lung cancer included ALK::EML4, EGFRvIII, EZR::ROS1 and FGFR3::TACC. We further identified recurrent gene fusions of currently unknown biological function, involving EGFR::VSTM2A and NSD3::FGFR1 and showed that the occurrence of the EGFR::VSTM2A fusion is accompanied by high-level amplification of EGFR. Our analyses further revealed that the genomes of these LUSC patients are chromosomally unstable, which leads us to believe that such non-actionable genomic rearrangements may be a result of "chromosomal chaos" most probably not representing exclusive cancer-driving genes in this cancer entity.

CONCLUSIONS

We emphasise that caution should be taken when novel fusions are found and that the appearance of new gene fusions should always be interpreted in the molecular context of the respective disease.

Lung cancer diagnosis and mortality beyond 15 years since quit in individuals with a 20+ pack-year history: A systematic review

Current US lung cancer screening recommendations limit eligibility to adults with a pack-year (PY) history of ≥20 years and the first 15 years since quit (YSQ). The authors conducted a systematic review to better understand lung cancer incidence, risk and mortality among otherwise eligible individuals in this population beyond 15 YSQ. The PubMed and Scopus databases were searched through February 14, 2023, and relevant articles were searched by hand. Included studies examined the relationship between adults with both a ≥20-PY history and ≥15 YSQ and lung cancer diagnosis, mortality, and screening ineligibility. One investigator abstracted data and a second confirmed. Two investigators independently assessed study quality and certainty of evidence (COE) and resolved discordance through consensus. From 2636 titles, 22 studies in 26 articles were included. Three studies provided low COE of elevated lung cancer incidence beyond 15 YSQ, as compared with people who never smoked, and six studies provided moderate COE that the risk of a lung cancer diagnosis after 15 YSQ declines gradually, but with no clinically significant difference just before and after 15 YSQ. Studies examining lung cancer-related disparities suggest that outcomes after 15 YSQ were similar between African American/Black and White participants; increasing YSQ would expand eligibility for African American/Black individuals, but for a significantly larger proportion of White individuals. The authors observed that the risk of lung cancer not only persists beyond 15 YSQ but that, compared with individuals who never smoked, the risk may remain significantly elevated for 2 or 3 decades. Future research of nationally representative samples with consistent reporting across studies is needed, as are better data from which to examine the effects on health disparities across different populations.

Mutational processes of tobacco smoking and APOBEC activity generate protein-truncating mutations in cancer genomes

Mutational signatures represent a genomic footprint of endogenous and exogenous mutational processes through tumor evolution. However, their functional impact on the proteome remains incompletely understood. We analyzed the protein-coding impact of single-base substitution (SBS) signatures in 12,341 cancer genomes from 18 cancer types. Stop-gain mutations (SGMs) (i.e., nonsense mutations) were strongly enriched in SBS signatures of tobacco smoking, APOBEC cytidine deaminases, and reactive oxygen species. These mutational processes alter specific trinucleotide contexts and thereby substitute serines and glutamic acids with stop codons. SGMs frequently affect cancer hallmark pathways and tumor suppressors such as TP53, FAT1, and APC. Tobacco-driven SGMs in lung cancer correlate with smoking history and highlight a preventable determinant of these harmful mutations. APOBEC-driven SGMs are enriched in YTCA motifs and associate with APOBEC3A expression. Our study exposes SGM expansion as a genetic mechanism by which endogenous and carcinogenic mutational processes directly contribute to protein loss of function, oncogenesis, and tumor heterogeneity.

A Unique Case of Atrial Fibrillation Secondary to Squamous Cell Lung Carcinoma

Atrial fibrillation (AF) is widely considered to be the most prevalent cardiac arrhythmia with an incidence of roughly 1%-2% in the United States alone. The incidence of AF has been known to increase with advancing age and thus presents a significant burden on healthcare systems across the globe. AF arises as a result of several mechanisms including structural changes that occur in the heart over time. Here, we present a case in which a 63-year-old male with no past medical history except heavy tobacco use presented to the emergency department complaining of shortness of breath. He also endorsed having palpations and a productive cough for several weeks prior to presenting to the emergency department. An EKG revealed AF with a rapid ventricular response. His chest x-ray revealed an irregular opacification of the left lung; however, a chest computed tomography unveiled a left hilar mass extending to the left upper lobe. The mass was causing obstruction of the left upper lobe and encasement of the left main pulmonary artery and left atrium. This case highlights a rare etiology of AF. While many causes of AF have been elucidated, including hypertension and valvular heart disease, a much lesser-known cause includes lung carcinoma resulting in a mass effect on the heart. Representing almost 19% of all cancer deaths, lung cancer is the leading cause of cancer death. Although lung cancer screenings are recommended for certain populations, the majority of lung cancer cases present at an advanced stage, limiting treatment options. Our patient presents a unique case involving a lung mass causing AF due to the mass effect on the left heart. Although the patient had other risk factors for AF including advanced age and cigarette smoking, we propose that due to the anatomical location of his lung mass, his AF was a consequence of the squamous cell carcinoma of the lung. Although the mortality for lung cancer remains high, new treatments, including pembrolizumab, have the potential to drastically alter the way these cancers are treated.

Trends in the epidemiology of small-cell lung cancer: a Dutch nationwide population-based study over 1989-2020

INTRODUCTION

This study describes the evolving characteristics of patients with small-cell lung cancer (SCLC) from 1989 to 2020 in the Netherlands to analyse how the population of patients with SCLC has changed in the last decades, hypothesising that this might explain the little progress made in SCLC.

METHODS

Patients with SCLC diagnosed from 1989 to 2020 were selected from the Dutch cancer registry. Incidence, patient and disease characteristics, treatments, and overall survival (OS) were analysed. Joinpoint analyses were used to test annual percentage changes for statistical significance.

RESULTS

A total of 52,527 patients were diagnosed with SCLC. The absolute numbers of patients with SCLC remained equal over the years; however, the incidence rates decreased from 15.01 to 8.93 per 100,000 person-years. The proportion of women increased from 22% to 50%, and those aged ≥75 years increased from 20% to 25%. The latter coincided with a higher proportion receiving only the best supportive care (BSC) over the years (18-24%). The use of surgery in stage I increased from 2% to 37%. The proportion of patients diagnosed with stage IV increased from 46% to 70% due to better staging. The OS improved for all stages, with a 2-year OS rate for stage IV doubling from 3% to 6%.

CONCLUSION

The incidence of SCLC has significantly decreased over the last 30 years, with an increasing proportion of elderly and women. The male-female ratio became similar, and the OS improved. As a consequence of more elderly and probably more vulnerable patients, more patients received only the BSC.

Health effects associated with smoking: a Burden of Proof study

As a leading behavioral risk factor for numerous health outcomes, smoking is a major ongoing public health challenge. Although evidence on the health effects of smoking has been widely reported, few attempts have evaluated the dose-response relationship between smoking and a diverse range of health outcomes systematically and comprehensively. In the present study, we re-estimated the dose-response relationships between current smoking and 36 health outcomes by conducting systematic reviews up to 31 May 2022, employing a meta-analytic method that incorporates between-study heterogeneity into estimates of uncertainty. Among the 36 selected outcomes, 8 had strong-to-very-strong evidence of an association with smoking, 21 had weak-to-moderate evidence of association and 7 had no evidence of association. By overcoming many of the limitations of traditional meta-analyses, our approach provides comprehensive, up-to-date and easy-to-use estimates of the evidence on the health effects of smoking. These estimates provide important information for tobacco control advocates, policy makers, researchers, physicians, smokers and the public.

Identification of Potential Prognostic Biomarkers Associated with Monocyte Infiltration in Lung Squamous Cell Carcinoma

The five-year survival rate of lung squamous cell carcinoma is significantly lower than that of other cancer types. It is therefore urgent to discover novel prognosis biomarkers and therapeutic targets and understand their correction with infiltrating immune cells to improve the prognosis of patients with lung squamous cell carcinoma. In this study, we employed robust rank aggregation algorithms to overcome the shortcomings of small sizes and potential bias in each Gene Expression Omnibus dataset of lung squamous cell carcinoma and identified 513 robust differentially expressed genes including 220 upregulated and 293 downregulated genes from six microarray datasets. Functional enrichment analysis showed that these robust differentially expressed genes were obviously involved in the extracellular matrix and structure organization, epidermis development, cell adhesion molecule binding, p53 signaling pathway, and interleukin-17 signaling pathway to affect the progress of lung squamous cell carcinoma. We further identified six hub genes from 513 robust differentially expressed genes by protein-protein interaction network and 10 topological analyses. Moreover, the results of immune cell infiltration analysis from six integrated Gene Expression Omnibus datasets and our sequencing transcriptome data demonstrated that the abundance of monocytes was significantly lower in lung squamous cell carcinoma compared to controls. Immune correlation analysis and survival analysis of hub genes suggested that three hub genes, collagen alpha-1(VII) chain, mesothelin, and chordin-like protein 1, significantly correlated with tumor-infiltrating monocytes as well as may be potential prognostic biomarkers and therapy targets in lung squamous cell carcinoma. The investigation of the correlation of hub gene markers and infiltrating monocytes can also improve to well understand the molecular mechanisms of lung squamous cell carcinoma development.

Identification of lung cancer drivers by comparison of the observed and the expected numbers of missense and nonsense mutations in individual human genes

Largely, cancer development is driven by acquisition and positive selection of somatic mutations that increase proliferation and survival of tumor cells. As a result, genes related to cancer development tend to have an excess of somatic mutations in them. An excess of missense and/or nonsense mutations in a gene is an indicator of its cancer relevance. To identify genes with an excess of potentially functional missense or nonsense mutations one needs to compare the observed and expected numbers of mutations in the gene. We estimated the expected numbers of missense and nonsense mutations in individual human genes using (i) the number of potential sites for missense and nonsense mutations in individual transcripts and (ii) histology-specific nucleotide context-dependent mutation rates. To estimate mutation rates defined as the number of mutations per site per tumor we used silent mutations reported in the Catalog Of Somatic Mutations In Cancer (COSMIC). The estimates were nucleotide context dependent. We have identified 26 genes with an excess of missense and/or nonsense mutations for lung adenocarcinoma, 18 genes for small cell lung cancer, and 26 genes for squamous cell carcinoma of the lung. These genes include known genes and novel lung cancer gene candidates.

The Differentiation of Metastatic Mediastinal Lymph Nodes From Benign Hypermetabolic Lesions

Background

Anthracosis may cause a positron emission tomography/computed tomography (PET/CT) false positivity in mediastinal and hilar lymph nodes. We aimed to evaluate the radiological features and the maximum standardized uptake values (SUVmax) of the mediastinal lymph nodes with anthracosis or squamous cell lung cancer metastasized.

Methodology

Patients diagnosed with anthracosis or squamous cell lung cancer with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) between January 1, 2015, and November 15, 2020, in a tertiary hospital were enrolled. The squamous cell subtype of lung cancer was selected due to its association with tobacco use, biomass, and air pollution. Anthracosis may occur due to the same etiologic reasons.

Results

A total of 190 patients met the study enrollment criteria, of which 86 were diagnosed with anthracosis and 33 with squamous cell lung cancer lymph metastasis. Median values for short axis, long axis, SUVmax, shape features, and presence of calcification were found significantly different between the groups. In receiver operating characteristic (ROC) analysis, the SUVmax cut-off value was calculated as 6.61. With this cutoff value, the negative predictive value (NPV) was 92.5% and the positive predictive value (PPV) was 54% for differentiating anthracosis and malignant lymph nodes metastasis.

Conclusions

We conclude that the evaluation of the shape and metabolic activities of the anthracotic lymph nodes detected by PET/CT together with EBUS-TBNA granted a more accurate staging of the patients and more cancer patients will benefit from surgical treatment.

Molecular cytogenetic characterization of the urethane-induced murine lung cell line LA-4 as a model for human squamous cell lung cancer

The murine tumor cell line LA-4 (also known as LA4 or LA 4) has been extensively used in ~70 studies from 1975 to present. However, the genetic characteristics have not been comprehensively delineated, apart from a single solid-stain cytogenetic study, which reported an average of 116 chromosomes per cell. LA-4 was created via urethane induction in an A/He mouse and demonstrated characteristic features of lung adenoma cells. In the present study, multicolor banding-based molecular cytogenetics was combined with molecular karyotyping to characterize ploidy, copy number alterations and chromosomal breakpoints of LA-4. A hyper-tetraploid karyotype with 85-93 chromosomes per cell, three distinct (pseudo-) dicentric derivatives, two neocentrics, four unbalanced translocations, two chromosomes with terminal deletions and one chromosome with a balanced inversion were detected. The results were translated into the human genome and a comparison with the literature revealed that LA-4 is well-suited as a murine model for human squamous cell lung cancer.

Role of novel cancer gene SLITRK3 to activate NTRK3 in squamous cell lung cancer

The development of targeted therapies that inhibit cancer-driving oncogenes has improved outcomes of patients diagnosed with lung adenocarcinoma (LUAD). In contrast, patients diagnosed with lung squamous cell carcinoma (LUSC) suffer worse survival outcomes and lack effective targeted treatment options. Identification of molecular drivers of LUSC to support development of targeted treatments is urgently needed. Addressing this need, the current report introduces the novel cancer gene SLIT- and NTRK-like family member 3 (SLITRK3) and its role in activating the neurotrophic receptor tyrosine kinase 3 (NTRK3) in LUSC cells. Multiple genome-wide data sets from patient samples were produced by us or downloaded from public databases to analyze tumor gene copy number aberrations, mRNA expression and associated survival outcomes. An accompanying mechanistic study employed LUSC cell lines and multiple methods, including in situ immunofluorescence, sphere-formation assay, and fluorescence-activated cell sorting analysis of the CD133-positive cell fraction. Altogether, the results indicate that gene amplification and consequent high expression of SLITRK3 in LUSC is associated with worse outcomes and induces SLITRK3-dependent activation of NTRK3 to promote a cancer stem cell phenotype that is inhibited by existing NTRK-targeted inhibitors. Based on a recent literature search, this is the first report of a mechanistic role for SLITRK3 in cancer.

Risk of lung cancer among women in relation to lifetime history of tobacco smoking: a population-based case-control study in France (the WELCA study)

Background

This study aims to provide new insights on the role of smoking patterns and cigarette dependence in female lung cancer, and to examine differences by histological subtype.

Methods

We conducted a population-based case-control study in the great Paris area among women including 716 incident cases diagnosed between 2014 and 2017 and 757 age-matched controls. Detailed data on smoking history was collected during in-person interviews to assess intensity and duration of tobacco smoking, time since cessation, smoking habits (depth of smoke inhalation, use of filter, type of tobacco, and type of cigarettes) and Fagerström test for cigarette dependence. The comprehensive smoking index (CSI), a score modelling the combined effects of intensity, duration and time since quitting smoking was determined for each subject. Multivariable logistic regression models were fitted to calculate odds ratios (ORs) and their confidence intervals (95%CI) of lung cancer associated with smoking variables.

Results

Lung cancer risk increased linearly with intensity and duration of tobacco smoking while it decreased with time since cessation, to reach the risk in never-smokers after 20 years of abstinence. The combined effect of intensity and duration of tobacco smoking was more than multiplicative (p-interaction 0.012). The OR in the highest vs the lowest quartile of CSI was 12.64 (95%CI 8.50; 18.80) (p-trend < 0.001). The risk of small cell or squamous cell carcinomas increased with the CSI more sharply than the risk of adenocarcinomas. Deep smoke inhalation, dark vs blond tobacco, conventional vs light cigarettes, and unfiltered vs filtered cigarettes, as well as having mixed smoking habits, were found to be independent risk factors. Having high cigarette addiction behaviours also increased the risk after adjusting for CSI.

Conclusion

This study provides additional insights on the effects of tobacco smoking patterns on lung cancer risk among women.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08433-z.

Prospective Single-Arm Phase 1 and 2 Study: Ipilimumab and Nivolumab With Thoracic Radiation Therapy After Platinum Chemotherapy in Extensive-Stage Small Cell Lung Cancer

PURPOSE

Consolidative thoracic radiation therapy (TRT) has been shown to improve outcomes for patients with extensive stage small cell lung cancer. We hypothesized that the addition of ipilimumab (IPI) and nivolumab (NIVO) after TRT would improve outcomes for patients with extensive stage small cell lung cancer.

METHODS AND MATERIALS

Eligibility required stable disease or better after platinum doublet chemotherapy. Study therapy included consolidative TRT to 30 Gy in 10 fractions, targeting residual primary tumor and initially involved regional lymph nodes. Two weeks after TRT, patients received concurrent IPI (3 mg/kg) and NIVO (1 mg/kg) every 3 weeks for 4 doses followed by NIVO monotherapy (480 mg) every 4 weeks until progression or up to 1 year.

RESULTS

The study enrolled 21 patients, with 6-month progression-free survival (PFS) of 24% (90% confidence interval [CI], 11%-40%) and a median PFS of 4.5 months (95% CI, 2.7%-4.6%). The 12-month overall survival (OS) was 48% (95% CI, 29%-64%) with a median OS of 11.7 months (95% CI, 4.7%-16.0%). Fifty-two percent of patients had ≥1 possibly related grade 3 to 4 immune-related adverse event. Grade 3 pulmonary and gastrointestinal immune-related adverse events were recorded in 19% and 24% of patients, respectively. Exploratory analysis showed increased cytotoxic T cell (CD3+CD8+) tumor infiltration was associated with favorable PFS (P = .01) and OS (P = .02). Reduction in peripheral blood CD3+CD8+ from baseline to after first dose of IPI/NIVO was associated with improved PFS (P = .02) and OS (P = .02).

CONCLUSIONS

Consolidative IPI and NIVO after platinum-based chemotherapy and TRT demonstrated a toxicity profile consistent with the known adverse events attributable to IPI and NIVO. Although the study regimen did not significantly improve PFS, the OS was higher than historic expectations. CD3+CD8+ tumor infiltration and migration may identify patients most likely to have improved outcomes in small cell lung cancer.

Low-Dose Nicotine Activates EGFR Signaling via α5-nAChR and Promotes Lung Adenocarcinoma Progression

Nicotine in tobacco smoke is considered carcinogenic in several malignancies including lung cancer. The high incidence of lung adenocarcinoma (LAC) in non-smokers, however, remains unexplained. Although LAC has long been less associated with smoking behavior based on previous epidemiological correlation studies, the effect of environmental smoke contributing to low-dose nicotine exposure in non-smoking population could be underestimated. Here we provide experimental evidence of how low-dose nicotine promotes LAC growth in vitro and in vivo. Screening of nicotinic acetylcholine receptor subunits in lung cancer cell lines demonstrated a particularly high expression level of nicotinic acetylcholine receptor subunit α5 (α 5-nAChR) in LAC cell lines. Clinical specimen analysis revealed up-regulation of α 5-nAChR in LAC tumor tissues compared to non-tumor counterparts. In LAC cell lines α 5-nAChR interacts with epidermal growth factor receptor (EGFR), positively regulates EGFR pathway, enhances the expression of epithelial-mesenchymal transition markers, and is essential for low-dose nicotine-induced EGFR phosphorylation. Functionally, low-dose nicotine requires α 5-nAChR to enhance cell migration, invasion, and proliferation. Knockdown of α 5-nAChR inhibits the xenograft tumor growth of LAC. Clinical analysis indicated that high level of tumor α 5-nAChR is correlated with poor survival rates of LAC patients, particularly in those expressing wild-type EGFR. Our data identified α 5-nAChR as an essential mediator for low-dose nicotine-dependent LAC progression possibly through signaling crosstalk with EGFR, supporting the involvement of environmental smoke in tumor progression in LAC patients.

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.

Changes in Black-White Difference in Lung Cancer Incidence among Young Adults

Background

We previously reported that lung cancer incidence between Blacks and Whites younger than 40 years of age converged in women and approached convergence in men. Whether this pattern has continued in contemporary young birth cohorts is unclear.

Methods

We examined 5-year age-specific lung cancer incidence in Blacks and Whites younger than 55 years of age by sex and calculated the Black-to-White incidence rate ratios (IRRs) and smoking prevalence ratios by birth cohort using nationwide incidence data from 1997 to 2016 and smoking data from 1970 to 2016 from the National Health Interview Survey.

Results

Five-year age-specific incidence decreased in successive Black and White men born since circa 1947 and women born since circa 1957, with the declines steeper in Blacks than Whites. Consequently, the Black-to-White IRRs became unity in men born 1967-1972 and reversed in women born since circa 1967. For example, the Black-to-White IRRs in ages 40-44 years born between 1957 and 1972 declined from 1.92 (95% confidence interval [CI] = 1.82 to 2.03) to 1.03 (95% CI = 0.93 to 1.13) in men and from 1.32 (95% CI = 1.24 to 1.40) to 0.71 (95% CI = 0.64 to 0.78) in women. Similarly, the historically higher sex-specific smoking prevalence in Blacks than Whites disappeared in men and reversed in women born since circa 1965. The exception to these patterns is that the incidence became higher in Black men than White men born circa 1977-1982.

Conclusions

The historically higher lung cancer incidence in young Blacks than young Whites in the United States has disappeared in men and reversed in women, coinciding with smoking patterns, though incidence again became higher in Black men than White men born circa 1977-1982.

Cytochrome P450 2A6 whole-gene deletion (CYP2A6*4) polymorphism reduces risk of lung cancer: A meta-analysis

INTRODUCTION

Lung cancer is the most commonly diagnosed cancer worldwide and is the leading cause of cancer death. Smoking is a major contributor to the pathogenesis of lung cancer. Cytochrome P450 2A6 (CYP2A6) is responsible for the metabolic activation of most tobacco carcinogens. CYP2A6 genetic polymorphism can cause variations in the human metabolism of xenobiotics. We performed this meta-analysis to determine the association between whole-gene CYP2A6 deletion polymorphism (CYP2A6*4) and lung cancer risk.

METHODS

The PubMed, SAGE, Science Direct, the Cochrane Library and Ovid databases were searched for observational studies before October 2018. Methodological quality was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOS).

RESULTS

Nine case-control studies involving 4385 lung cancer cases and 4142 controls were included in the analysis. The random-effects model was used to combine results from individual studies. The pooled odds ratio was 0.39 (95% CI: 0.27-0.56). There was no heterogeneity across studies (χ2=2.49, p=0.96, I2=0%).

CONCLUSIONS

Current evidence from the case-control studies suggests that the CYP2A6 whole-gene deletion polymorphism decreases the risk of lung cancer. Further research is needed to identify any potential confounding factors that may impact this association.

EGFR mutation exists in squamous cell lung carcinoma

Whether EGFR mutation occurs in lung squamous cell carcinoma (SCC) remains a controversial issue. Although numerous trials have shown positive response to tyrosine kinase inhibitors in SCC, these observations have not been well correlated with presence or absence of EGFR mutation. A complicating issue is that adenosquamous carcinoma, a mimic of SCC, frequently harbours EGFR mutations. We evaluated the EGFR mutation status of 191 cases initially diagnosed as SCC of lung origin in years 2000-2011, and performed a panel of markers including p40, p63, CK5/6, TTF-1, mucicarmine on the tissue microarray or tissue blocks from each case, to ascertain the squamous differentiation of each case. Four cases were found to have EGFR mutations, with three showing typical squamous morphological features and immunohistochemical profile on all available tumour blocks, and one reclassified as adenosquamous carcinoma. Mixed responses were noted for two of the patients with EGFR-mutated SCC treated with tyrosine kinase inhibitors. In conclusion, we report that a small subset of rigorously proven SCC harbours EGFR mutation. It also appears in our cohort that EGFR-mutated tumours, in the context of SCC, may have relatively poor response to tyrosine kinase inhibitors.

A Strong Decrease in TIMP3 Expression Mediated by the Presence of miR-17 and 20a Enables Extracellular Matrix Remodeling in the NSCLC Lesion Surroundings

Background: Lung cancer is one of the most common causes of death worldwide with a relatively high fatality rate and a mean 5-years survival of about 18%. One of the hallmarks of cancer is the extracellular matrix (ECM) remodeling, which is crucial for metastasis. This process may be regulated by miRs targeting metalloproteinases (MMPs) associated with the ECM breakdown and metastatic process or blocking the action of tissue inhibitors of metalloproteinases (TIMPs). Search for early biomarkers is essential in detecting non-small cell lung cancer (NSCLC) and distinguishing its subtypes: Adenocarcinoma (AC) from Squamous Cell Carcinoma (SCC), enabling targeted chemotherapy.

Methods:MiR-17 and miR-20a targeting MMP2 and TIMP3 were selected by TCGA data analysis with further validation using miRTarBase and literature. The study group comprised 47 patients with primary NSCLC (AC and SCC subtypes). RNA was isolated from the tumor and normal-looking neighboring tissue (NLNT) free of cancer cells. MiRs from peripheral blood exosomes were extracted on admission and 5–7 days after surgery. Gene and miRs expression were assessed in qPCR using TaqMan probes.

Results: The MMP2 has been expressed on a similar level in NLNT, as in cancer. While, TIMP3 expression was decreased both in cancer tissue and NLNT, with significantly lower expression in cancer. TIMP3 downregulation in NLNT and in SCC subtype correlated negatively with miR-20a. The preoperative miR-17 expression was significantly higher among patients with SCC compared to AC. Receiver operating characteristic (ROC) analysis of miR-17 as AC subtype classifier revealed 90% specificity and 48% sensitivity in optimal cut-off point with area under ROC curve (AUC): 0.71 (95%CI: 0.55–0.87). Within NSCLC subtypes: a strong negative correlation between pack-years (PY) and TIMP3 expression was observed for NLNT in the SCC group.

Conclusion: The TIMP3 silencing observed in the NLNT and its negative correlation with presurgical expression of miR-20a (from serum exosomes), suggest that miRs can influence ECM remodeling at a distance from the center of the lesion. The miRs expression pattern in serum obtained before surgery significantly differs between AC and SCC subtypes. Moreover, decreased TIMP3 expression in NLNT (in SCC group) negatively correlates with the amount of tobacco smoked in a lifetime in PY.

Spatiotemporal Analysis of Lung Cancer Histological Types in Kentucky, 1995-2014

Recent metabolic and genetic research has demonstrated that risk for specific histological types of lung cancer varies in relation to cigarette smoking and obesity. This study investigated the spatial and temporal distribution of lung cancer histological types in Kentucky, a largely rural state with high rates of smoking and obesity, to discern population-level trends that might reflect variation in these and other risk factors. The Kentucky Cancer Registry provided residential geographic coordinates for lung cancer cases diagnosed from 1995 through 2014. We used multinomial and discrete Poisson spatiotemporal scan statistics, adjusted for age, gender, and race, to characterize risk for specific histological types—small cell, adenocarcinoma, squamous cell, and other types—throughout Kentucky and compared to maps of risk factors. Toward the end of the study period, adenocarcinoma was more common among all population subgroups in north-central Kentucky, where smoking and obesity are less prevalent. During the same time frame, squamous cell, small cell, and other types were more common in rural Appalachia, where smoking and obesity are more prevalent, and in some high poverty urban areas. Spatial and temporal patterns in the distribution of histological types of lung cancer are likely related to regional variation in multiple risk factors. High smoking and obesity rates in the Appalachian region, and likely in high poverty urban areas, appeared to coincide with high rates of squamous cell and small cell lung cancer. In north-central Kentucky, environmental exposures might have resulted in higher risk for adenocarcinoma specifically.

Impact of low-dose computed tomography screening on lung cancer mortality among asbestos-exposed workers

Background

We previously showed that low-dose computed tomography (LDCT) screening in asbestos-exposed workers is effective in detecting lung cancer (LC) at an early stage. Here, we evaluate whether LDCT screening could reduce mortality from LC in such a high-risk population.

Methods

Within a cohort of 2433 asbestos-exposed men enrolled in an Occupational Health surveillance programme, we compared mortality between the participants in the ATOM002 study (LDCT-P, N  =  926) and contemporary non-participants (LDCT-NP, N  =  1507). We estimated standardized mortality ratios for the LDCT-P and LDCT-NP populations using regional and national rates (SMR_FVG and SMR_ITA, respectively). We compared survival for all causes, all neoplasms, LC and malignant neoplasm of pleura (MNP) between LDCT-P and LDCT-NP using Cox proportional hazard models adjusted for age, smoking history, asbestos exposure level and comorbidities.

Results

A reduction in mortality from LC was observed in the LDCT-P group compared with regional and national figures (SMR_FVG  =  0.55, 95% confidence interval (CI) 0.24-1.09; SMR_ITA  =  0.51, 95% CI 0.22-1.01); this was not the case for the LDCT-NP group (SMR_FVG  =  2.07, 95% CI 1.53-2.73; SMR_ITA  =  1.98, 95% CI 1.47-2.61). A strong reduction in LC mortality was observed for the LDCT-P compared with the LDCT-NP [hazard ratio (HR)  =  0.41, 95% CI 0.17-0.96]. Mortality was also reduced for all causes (HR  =  0.61, 95% CI 0.44-0.84), but not for all neoplasms (HR  =  0.97, 95% CI 0.62-1.50) and MNP (HR  =  0.86, 95% CI 0.31-2.41) within the LDCT-P population.

Conclusions

In our cohort, participation in the LDCT screening study was associated with reduced mortality from LC. This finding supports the use of LDCT in surveillance programmes for asbestos-exposed workers.

Can CT radiomic analysis in NSCLC predict histology and EGFR mutation status?

To assess the role of radiomic features in distinguishing squamous and adenocarcinoma subtypes of nonsmall cell lung cancers (NSCLC) and predict EGFR mutations.Institution Review Board-approved study included chest CT scans of 93 consecutive patients (43 men, 50 women, mean age 60 ± 11 years) with biopsy-proven squamous and adenocarcinoma lung cancers greater than 1 cm. All cancers were evaluated for epidermal growth factor receptor (EGFR) mutation. The clinical parameters such as age, sex, and smoking history and standard morphology-based CT imaging features such as target lesion longest diameter (LD), longest perpendicular diameter (LPD), density, and presence of cavity were recorded. The radiomics data was obtained using commercial CT texture analysis (CTTA) software. The CTTA was performed on a single image of the dominant lung lesion. The predictive value of clinical history, standard imaging features, and radiomics was assessed with multivariable logistic regression and receiver operating characteristic (ROC) analyses.Between adenocarcinoma and squamous cell carcinomas, ROC analysis showed significant difference in 3/11 radiomic features (entropy, normalized SD, total) [AUC 0.686-0.744, P = .006 to <.0001], 1/3 clinical features (smoking) [AUC 0.732, P = .001], and 2/3 imaging features (LD and LPD) [AUC 0.646-0658, P = .020 to .032]. ROC analysis for probability variables showed higher values for radiomics (AUC 0.800, P < .0001) than clinical (AUC 0.676, P = .017) and standard imaging (AUC 0.708, P < .0001). Between EGFR mutant and wild-type adenocarcinoma, ROC analysis showed significant difference in 2/11 radiomic features (kurtosis, K2) [AUC 0.656-0.713, P = .03 to .003], 1/3 clinical features (smoking) [AUC 0.758, P < .0001]. The combined probability variable for radiomics, clinical and imaging features was higher (AUC 0.890, P < .0001) than independent probability variables.The radiomics evaluation adds incremental value to clinical history and standard imaging features in predicting histology and EGFR mutations.

Cancer incidence in a cohort of asbestos-exposed workers undergoing health surveillance

OBJECTIVES

To compare a local cohort of 2488 men occupationally exposed to asbestos and enrolled in a public health surveillance program with the 1995-2009 cancer incidence of the general population of Friuli Venezia Giulia (FVG) region, Northeast Italy, we conducted a historical cohort study.

METHODS

Standardized incidence ratios (SIRs), with 95% confidence interval (95% CI), for specific cancer sites were estimated in the cohort and in subgroups of workers employed in shipbuilding between 1974 and 1994. For internal comparisons, we calculated incidence rate ratios (IRRs) for all cancers, lung cancer and mesothelioma, by level of exposure to asbestos and sector of employment adjusted for smoking habits and age at start of follow-up.

RESULTS

Among cohort members the SIR was 8.82 (95% CI 5.95-12.61) for mesothelioma and 1.61 (95% CI 1.26-2.04) for lung cancer. In subgroup analyses, the SIR for lung cancer in subjects hired in shipbuilding between 1974 and 1984 was 2.09 (95% CI 1.32-3.13). In the overall cohort, a borderline increased incidence was also found for stomach cancer (SIR = 1.53 95% CI 0.96-2.31). Internal comparisons within the cohort show that among men with high asbestos exposure level the relative risk was almost threefold for lung cancer (IRR = 2.94 95% CI 1.01-8.57).

CONCLUSIONS

This cohort experienced an excess in the incidence of both mesothelioma and lung cancer, showing increasing incidence rates at higher level of asbestos exposure. For lung cancer, the relative incidence was highest among workers hired in shipbuilding between 1974 and 1984.

Detection of Lung Cancer: Concomitant Volatile Organic Compounds and Metabolomic Profiling of Six Cancer Cell Lines of Different Histological Origins

In recent years, there has been an extensive search for a non-invasive screening technique for early detection of lung cancer. Volatile organic compound (VOC) analysis in exhaled breath is one such promising technique. This approach is based on the fact that tumor growth is accompanied by unique oncogenesis, leading to detectable changes in VOC emitting profile. Here, we conducted a comprehensive profiling of VOCs and metabolites from six different lung cancer cell lines and one normal lung cell line using mass spectrometry. The concomitant VOCs and metabolite profiling allowed significant discrimination between lung cancer and normal cell, nonsmall cell lung cancer (NSCLC) and small cell lung cancer (SCLC), as well as between different subtypes of NSCLC. It was found that a combination of benzaldehyde, 2-ethylhexanol, and 2,4-decadien-1-ol could serve as potential volatile biomarkers for lung cancer. A detailed correlation between nonvolatile metabolites and VOCs can demonstrate possible biochemical pathways for VOC production by the cancer cells, thus enabling further optimization of VOCs as biomarkers. These findings could eventually lead to noninvasive early detection of lung cancer and differential diagnosis of lung cancer subtypes, thus revolutionizing lung cancer treatment.

Trends in the incidence rate of lung cancer by histological type and gender in Sichuan, China, 1995-2015: A single-center retrospective study

BACKGROUND

In recent years, lung cancer incidence has been increasing; however the impact of different histological types of lung cancer is not yet clear.

METHODS

Trends in the lung cancer incidence rate by histological type were examined based on data of 36 658 primary lung cancer patients from West China Hospital between 1995 and 2015.

RESULTS

The most common histological type of lung cancer in our hospital was adenocarcinoma (ADC) in both genders, followed by squamous cell carcinoma (SQCC), and small cell carcinoma (SCLC), which is consistent with general worldwide trends. The proportion of young patients with SCLC showed a downward trend. In the overall population with lung cancer, the number of elderly patients with lung cancer increased significantly, while the proportion of elderly patients increased gradually. The mean age at diagnosis also increased. The number of women with ADC increased sharply in recent years, especially in young patients, and the incidence rate in women is now greater than in men.

CONCLUSION

Significant increases in the number of patients with ADC and the rate of lung cancer in women over recent years were observed, indicating that research on the pathogenesis of disease in these patients is urgent.

Birth in winter can reduce the risk of lung cancer: A retrospective study of the birth season of patients with lung cancer in Beijing area, China

The season of birth is an important risk factor for several diseases. We explored the relationship between birth season and lung cancer. In this population-based retrospective study, we focused on patients with lung cancer who had registered at the Beijing Institute for Cancer Research from 2003 to 2012. In total, 33,025 patients were divided into five subgroups based on their histologic classification, and these five subgroups were compared with the general population (i.e., the permanent resident population of Beijing in 2013). A binary logistic regression method with sex and age as control factors was used to evaluate the relationship between birth season and lung cancer; P < 0.01 was statistically significant. Taking winter as a reference in our analysis of the relationship between season of birth and lung cancer, we found that people who were born in other seasons had a higher probability of developing lung cancer (spring: odds ratio [OR] = 1.06, 95% confidence interval [CI] = 1.03-1.09; summer: OR = 1.07, 95% CI = 1.04-1.10; autumn: OR = 1.06, 95% CI = 1.03-1.09) (P < 0.01). Among the five subgroups, persons with squamous cell carcinoma who were born in summer were more likely to develop lung cancer than those who were born in winter (OR = 1.09, 95% CI = 1.02-1.15, P = 0.006). The other subgroups showed no correlation with season of birth (P > 0.01). This study demonstrates that for people born in winter, the risks of developing lung cancer and squamous cell carcinoma are comparatively lower than those for people born in other seasons. Differences in immune function and the maternal nutrition status during pregnancy of people born in different seasons may explain this finding.

The Use of Deceased Controls in Epidemiologic Research: A Systematic Review

Scholarly debate on the use of deceased controls in epidemiologic research continues. This systematic review examined published epidemiologic research using deceased persons as a control group. A systematic search of 5 major biomedical literature databases (MEDLINE, CINAHL, PsycINFO, Scopus, and EMBASE) was conducted, using variations of the search terms "deceased" and "controls" to identify relevant peer-reviewed journal articles. Information was sought on study design, rationale for using deceased controls, application of theoretical principles of control selection, and discussion of the use of deceased controls. The review identified 134 studies using deceased controls published in English between 1978 and 2015. Common health outcomes under investigation included cancer (n = 31; 23.1%), nervous system diseases (n = 26; 19.4%), and injury and other external causes (n = 22; 16.4%). The majority of studies used deceased controls for comparison with deceased cases (n = 95; 70.9%). Investigators rarely presented their rationale for control selection (n = 25/134; 18.7%); however, common reasons included comparability of information on exposures, lack of appropriate controls from other sources, and counteracting bias associated with living controls. Comparable accuracy was the most frequently observed principle of control selection (n = 92; 68.7%). This review highlights the breadth of research using deceased controls and indicates their appropriateness in studies using deceased cases.

Treatment of advanced squamous cell carcinoma of the lung: a review

Lung cancer remains the single deadliest cancer both in the US and worldwide. The great majority of squamous cell carcinoma (SCC) is attributed to cigarette smoking, which fortunately is declining alongside cancer incidence. While we have been at a therapeutic plateau for advanced squamous cell lung cancer patients for several decades, recent observations suggest that we are on the verge of seeing incremental survival improvements for this relatively large group of patients. Current studies have confirmed an expanding role for immunotherapy [including programmed cell death-1 (PD-1)/programmed cell death ligand 1 (PD-L1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibition], a potential opportunity for VEGFR inhibition, and even future targets in fibroblast growth factor receptor (FGFR) and PI3K-AKT that collectively should improve survival as well as quality of life for those affected by squamous cell lung cancer over the next decade.

Residence in Proximity of an Iron Foundry and Risk of Lung Cancer in the Municipality of Trieste, Italy, 1995-2009

We assessed the risk of lung cancer in people living near the iron foundry located within the city of Trieste, Northeastern Italy. Between 1995 and 2009, all incident cases of lung cancer and corresponding population were considered. A deposition model of the foundry-specific emissions of SO2 defined: "nearby", "urban", and "outlying" areas. Rate ratios (RRs) and annual percent changes (APCs) were computed. Among nearby residents, significantly increased risks of lung cancer were noted in men below age 75 years (RR = 1.35 vs. urban area; 95% CI: 1.03-1.77). In women, and in men aged 75 years or older, no significant RRs were observed. Conversely, people living in the outlying area appeared to be at lower risk than residents in the urban area- in all age groups, in men (RR = 0.87; 95% CI: 0.78-0.98) and in women (RR = 0.74; 95% CI: 0.62-0.88). Negative statistically significant APC was recorded in men living in urban areas (-2.6%), whereas in women APC significantly increased among those living in the urban area (+2.3%). Multiple interpretations for this observation are plausible, since several factors might have modified and/or confounded the risk of lung cancer, including air pollution from other sources and road traffic, occupational and smoking patterns.

Using the Negative Exponential Model to Describe Changes in Risk of Smoking-Related Diseases following Changes in Exposure to Tobacco

Recently published analyses for four smoking-related diseases show that the declining excess relative risk by time quit is well fitted by the negative exponential model. These analyses estimated the half-life of this excess, that is, the time after quitting when the excess relative risk reaches half that for continuing smokers. We describe extensions of the simple model. One quantifies the decline following an exposure reduction. We show that this extension satisfactorily predicts results from studies investigating the effect of reducing cigarette consumption. It may also be relevant to exposure reductions following product-switching. Another extension predicts changes in excess relative risk occurring following multiple exposure changes over time. Suitable published epidemiological data are unavailable to test this, and we recommend its validity to be investigated using large studies with data recorded on smoking habits at multiple time points in life. The basic formulae described assume that the excess relative risk for a continuing smoker is linearly related to exposure and that the half-life is invariant of age. We describe model adaptations to allow for nonlinear dose-response and for age-dependence of the half-life. The negative exponential model, though relatively simple, appears to have many potential uses in epidemiological research for summarizing variations in risk with exposure changes.

Race, insurance type, and stage of presentation among lung cancer patients

The purpose of this study was to determine whether African-American lung cancer patients are diagnosed at a later stage than white patients, regardless of insurance type. The relationship between race and stage at diagnosis by insurance type was assessed using a Poisson regression model, with relative risk as the measure of association. The setting of the study was a large tertiary care cancer center located in the southeastern United States. Patients who were diagnosed with lung cancer between 2001 and 2010 were included in the study. A total of 717 (31%) African-American and 1,634 (69%) white lung cancer patients were treated at our facility during the study period. Adjusting for age, sex, and smoking-related histology, African-American patients were diagnosed at a statistically significant later stage (III/IV versus I/II) than whites for all insurance types, with the exception of Medicaid. Our results suggest that equivalent insurance coverage may not ensure equal presentation of stage between African-American and white lung cancer patients. Future research is needed to determine whether other factors such as treatment delays, suboptimal preventive care, inappropriate specialist referral, community segregation, and a lack of patient trust in health care providers may explain the continuing racial disparities observed in the current study.

Circulating biomarkers of tryptophan and the kynurenine pathway and lung cancer risk

BACKGROUND

Imbalances in tryptophan metabolism have been linked to cancer-related immune escape and implicated in several cancers, including lung cancer.

METHODS

We conducted a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC) that included 893 incident lung cancer cases and 1,748 matched controls. Circulating levels of tryptophan and six of its metabolites were measured and evaluated in relation to lung cancer risk.

RESULTS

Tryptophan (Ptrend = 2 × 10(-5)) and the kynurenine/tryptophan ratio (KTR; Ptrend = 4 × 10(-5)) were associated with lung cancer risk overall after adjusting for established risk factors. The ORs comparing the fifth and first quintiles (OR5th vs. 1st) were 0.52 [95% confidence interval (CI), 0.37-0.74] for tryptophan and 1.74 (95% CI, 1.24-2.45) for KTR. After adjusting for plasma methionine (available from previous work, which was strongly correlated with tryptophan), the associations of tryptophan (adjusted Ptrend = 0.13) and KTR (Ptrend = 0.009) were substantially attenuated. KTR was positively associated with squamous cell carcinoma, the OR5th vs. 1st being 2.83 (95% CI, 1.62-4.94, Ptrend = 3 × 10(-5)) that was only marginally affected by adjusting for methionine.

CONCLUSIONS

This study indicates that biomarkers of tryptophan metabolism are associated with subsequent lung cancer risk. Although this result would seem consistent with the immune system having a role in lung cancer development, the overall associations were dependent on methionine, and further studies are warranted to further elucidate the importance of these metabolites in lung cancer etiology.

IMPACT

This is the first prospective study investigating the tryptophan pathway in relation to lung cancer risk.

Increased serum S-TRAIL level in newly diagnosed stage-IV lung adenocarcinoma but not squamous cell carcinoma is correlated with age and smoking

BACKGROUND

Lung cancer is the leading cause of cancer mortality in the world. Many factors can protect against or facilitate its development. A TNF family member TRAIL, has a complex physiological role beyond that of merely activating the apoptotic pathway in cancer cells. Vitamin D is converted to its active form locally in the lung, and is also thought to play an important role in lung health. Our goal was to investigate the possible clinical significance of serum sTRAIL and 1,25-dihydroxyvitamin D(3) levels in patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Totals of 18 consecutive adenocarcinoma and 22 squamous cell carcinoma patients with stage-IV non-small cell lung cancer referred to our institute were included in this study. There were 12 men and 6 women, with ages ranging from 38 to 97 (mean 60.5) years with adenocarcinoma, and 20 men and 2 women, with ages ranging from 46 to 80 (mean 65) years with squamous cell carcinoma. Serum levels of sTRAIL and 1,25-dihydroxyvitamin D(3) were measured in all samples at the time of diagnosis.

RESULTS

sTRAIL levels in NSCLC patients were higher than in the control group. Although there was no correlation between patient survival and sTRAIL levels, the highest sTRAIL levels were correlated with age and cigarette smoking in the adenocarcinoma patients. sTRAIL level in healthy individuals were correlated with serum 1,25-dihydroxyvitamin D(3).

CONCLUSIONS

Serum sTRAIL concentrations were increased in NSCLC patients, and correlated with age and smoking history, but not with overall survival.

Systematic review with meta-analysis of the epidemiological evidence in the 1900s relating smoking to lung cancer

BACKGROUND

Smoking is a known lung cancer cause, but no detailed quantitative systematic review exists. We summarize evidence for various indices.

METHODS

Papers published before 2000 describing epidemiological studies involving 100+ lung cancer cases were obtained from Medline and other sources. Studies were classified as principal, or subsidiary where cases overlapped with principal studies. Data were extracted on design, exposures, histological types and confounder adjustment. RRs/ORs and 95% CIs were extracted for ever, current and ex smoking of cigarettes, pipes and cigars and indices of cigarette type and dose-response. Meta-analyses and meta-regressions investigated how relationships varied by study and RR characteristics, mainly for outcomes exactly or closely equivalent to all lung cancer, squamous cell carcinoma ("squamous") and adenocarcinoma ("adeno").

RESULTS

287 studies (20 subsidiary) were identified. Although RR estimates were markedly heterogeneous, the meta-analyses demonstrated a relationship of smoking with lung cancer risk, clearly seen for ever smoking (random-effects RR 5.50, CI 5.07-5.96) current smoking (8.43, 7.63-9.31), ex smoking (4.30, 3.93-4.71) and pipe/cigar only smoking (2.92, 2.38-3.57). It was stronger for squamous (current smoking RR 16.91, 13.14-21.76) than adeno (4.21, 3.32-5.34), and evident in both sexes (RRs somewhat higher in males), all continents (RRs highest for North America and lowest for Asia, particularly China), and both study types (RRs higher for prospective studies). Relationships were somewhat stronger in later starting and larger studies. RR estimates were similar in cigarette only and mixed smokers, and similar in smokers of pipes/cigars only, pipes only and cigars only. Exceptionally no increase in adeno risk was seen for pipe/cigar only smokers (0.93, 0.62-1.40). RRs were unrelated to mentholation, and higher for non-filter and handrolled cigarettes. RRs increased with amount smoked, duration, earlier starting age, tar level and fraction smoked and decreased with time quit. Relationships were strongest for small and squamous cell, intermediate for large cell and weakest for adenocarcinoma. Covariate-adjustment little affected RR estimates.

CONCLUSIONS

The association of lung cancer with smoking is strong, evident for all lung cancer types, dose-related and insensitive to covariate-adjustment. This emphasises the causal nature of the relationship. Our results quantify the relationships more precisely than previously.

Relationship between paradoxical breathing and pleural diseases in dyspneic dogs and cats: 389 cases (2001-2009)

OBJECTIVE

To determine the strength of the relationship between paradoxical breathing (PB) and spontaneous pleural diseases in dyspneic dogs and cats.

DESIGN

Cross-sectional study.

ANIMALS

Dogs (n = 195) and cats (194) with a recorded diagnosis of dyspnea examined at the National Veterinary Schools of Alfort and Toulouse (France) between January 2001 and October 2009.

PROCEDURES

Dogs and cats were divided into 2 groups according to the presence or absence of PB. Stratified analysis by species was performed. Signalment of affected animals and occurrence of PB were recorded. The relationship between PB and pleural diseases among dyspneic dogs and cats was analyzed.

RESULTS

A strong relationship between PB and pleural diseases was highlighted in multivariate analysis (dogs, OR = 12.6 and 95% confidence interval = 4.6 to 31.2; cats, OR = 14.1 and 95% confidence interval = 6.0 to 33.5). Paradoxical breathing prevalence among dyspneic dogs and cats was 27% and 64%, respectively. Occurrence of pleural diseases in dyspneic animals with and without PB was 49% and 9% in dogs and 66% and 13% in cats, respectively. The sensitivity and specificity of PB as a predictor of pleural diseases were 0.67 and 0.83 in dyspneic dogs and 0.90 and 0.58 in dyspneic cats, respectively. The positive and negative predictive values of PB were 0.49 and 0.91 in dyspneic dogs and 0.66 and 0.87 in dyspneic cats, respectively. Age, sex, feline breeds, and canine morphotypes in patients with PB were not significantly different from those of other dyspneic animals.

CONCLUSIONS AND CLINICAL RELEVANCE

PB was strongly associated with pleural diseases in dyspneic dogs and cats. The presence of this clinical sign should prompt small animal practitioners to implement appropriate emergency procedures and guide their diagnostic strategy.

Loss of special AT-rich binding protein 1 expression is a marker of poor survival in lung cancer

INTRODUCTION

Lung cancer is the leading cause of cancer-related mortality and requires more effective molecular markers of prognosis and therapeutic responsiveness. Special AT-rich binding protein 1 (SATB1) is a global genome organizer that recruits chromatin remodeling proteins to epigenetically regulate hundreds of genes in a tissue-specific manner. Initial studies suggest that SATB1 overexpression is a predictor of poor prognosis in breast cancer, but the prognostic significance of SATB1 expression has not been evaluated in lung cancer.

METHODS

A cohort of 257 lung cancers was evaluated by immunohistochemistry. Epigenetic silencing of SATB1 was examined in cell lines by 5-Aza 2-deoxycytidine and trichostatin A treatment, and chromatin immunoprecipitation.

RESULTS

Significant loss of SATB1 expression was found in squamous preinvasive lesions (p < 0.04) and in non-small cell lung cancers (p < 0.001) compared with matched normal bronchial epithelium. Loss of SATB1 independently predicted poor cancer-specific survival in squamous cell carcinomas (SCCs; hazard ratio: 2.06, 95% confidence interval: 1.2-3.7, p = 0.016). Treatment of lung cancer cell lines with the histone deacetylase inhibitor trichostatin A resulted in up-regulation of SATB1. SATB1 was associated with a decrease in the active chromatin mark acetylated histone H3K9 and an increase in the repressive polycomb mark trimethylated H3K27 in a SCC cell line relative to a normal bronchial epithelial cell line.

CONCLUSIONS

This is the first study showing that SATB1 expression is lost in early preinvasive squamous lesions and that loss of SATB1 is associated with poor prognosis in lung SCC. We hypothesize that the SATB1 gene is epigenetically silenced through histone modifications.

Classification of lung cancer histology by gold nanoparticle sensors

We propose a nanomedical device for the classification of lung cancer (LC) histology. The device profiles volatile organic compounds (VOCs) in the headspace of (subtypes of) LC cells, using gold nanoparticle (GNP) sensors that are suitable for detecting LC-specific patterns of VOC profiles, as determined by gas chromatography-mass spectrometry analysis. Analyzing the GNP sensing signals by support vector machine allowed significant discrimination between (i) LC and healthy cells; (ii) small cell LC and non-small cell LC; and between (iii) two subtypes of non-small cell LC: adenocarcinoma and squamous cell carcinoma. The discriminative power of the GNP sensors was then linked with the chemical nature and composition of the headspace VOCs of each LC state. These proof-of-concept findings could totally revolutionize LC screening and diagnosis, and might eventually allow early and differential diagnosis of LC subtypes with detectable or unreachable lung nodules.

FROM THE CLINICAL EDITOR

In this study, a nanomedical device that profiles volatile organic compounds (VOCs) in lung cancer cells is investigated, using a matrix of gold nanoparticle (GNP) sensors that are suitable for detecting lung cancer (LC) specific patterns of VOC profiles. This device might eventually allow early differential diagnosis of LC subtypes including unreachable lung nodules.

High prevalence of lung cancer in a surgical cohort of lung cancer patients a decade after smoking cessation

Background

This study was designed to assess the prevalence of smoking at time of lung cancer diagnosis in a surgical patient cohort referred for cardiothoracic surgery.

Methods

Retrospective study of lung cancer patients (n = 626) referred to three cardiothoracic surgeons at a tertiary care medical center in Southern California from January 2006 to December 2008. Relationships among years of smoking cessation, smoking status, and tumor histology were analyzed with Chi-square tests.

Results

Seventy-seven percent (482) had a smoking history while 11.3% (71) were current smokers. The length of smoking cessation to cancer diagnosis was <1 year for 56 (13.6%), 1-10 years for 110 (26.8%), 11-20 years for 87 (21.2%), 21-30 years for 66 (16.1%), 31-40 years for 44 (10.7%), 41-50 years for 40 (9.7%) and 51-60 years for 8 (1.9%). The mean cessation was 18.1 ± 15.7 years (n = 411 former smokers). Fifty-nine percent had stage 1 disease and 68.0% had adenocarcinoma. Squamous cell carcinoma was more prevalent in smokers (15.6% vs. 8.3%, p = 0.028); adenocarcinoma was more prevalent in never-smokers (79.9% versus 64.3%, p = 0.0004). The prevalence of adenocarcinoma varied inversely with pack year (p < 0.0001) and directly with years of smoking cessation (p = 0.0005).

Conclusions

In a surgical lung cancer cohort, the majority of patients were smoking abstinent greater than one decade before the diagnosis of lung cancer.

Exposure to environmental tobacco smoke in childhood and incidence of cancer in adulthood in never smokers in the European Prospective Investigation into Cancer and Nutrition

The association between childhood environmental tobacco smoke (ETS) exposure and adult cancer risk is controversial; we examined this relationship in never smokers within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Over an average of 10 years, 8,372 cases of cancer were diagnosed in 112,430 never smokers in EPIC. Childhood ETS was self-reported by participants at baseline, along with other lifestyle factors. Hazard ratios (HR) for ETS exposure in childhood and their 95% confidence intervals (CI) were estimated by Cox proportional hazards models stratified by age, sex, and study center and adjusted for education, alcohol drinking, body mass index, physical activity, non-alcoholic energy intake, fruit and vegetable intake, and adulthood ETS exposure. Models were further adjusted for reproductive factors for female cancers, for meat intake for digestive system cancers, and for diabetes status for pancreatic cancer. No association was observed between childhood ETS exposure and overall cancer risks (HR = 0.97, 95% CI = 0.92-1.02), and for selected sites. The only exception was pancreatic cancer, as previously reported by Vrieling et al., among those who had been exposed daily in childhood (overall HR = 2.09, 95% CI = 1.14-3.84). In conclusion, childhood ETS exposure might not be a major risk factor for common cancers in adulthood.

Association between insulin-like growth factor binding protein-3 promoter polymorphism of -1590 C>A and lung cancer susceptibility in a Chinese Han population

Recent studies have identified a negative correlation between serum levels of insulin-like growth factor binding protein-3 (IGFBP-3) and the risk of lung cancer. In this study, polymorphisms present at the -1590 site of the IGFBP-3 promoter were evaluated in relation to lung cancer risk in a Chinese Han population. A total of 248 nonsmall cell lung cancer (NSCLC) cases and 29 small cell lung cancer cases were compared with 252 matched, healthy controls. Polymerase chain reaction-based restriction fragment length polymorphism assays were used to detect polymorphisms present. The A/A genotype and an A allele were both associated with an increased risk of NSCLC after being adjusted for age and gender (adjusted odds ratio = 2.296, 95% confidence interval = 1.133-4.655; and adjusted odds ratio = 1.390, 95% confidence interval = 1.042-1.854, respectively). In conclusion, the A/A genotype and A allele of the IGFBP-3 promoter -1590 site may represent a genetic risk factor for NSCLC, with the A/A genotype being associated with a higher risk for squamous cell carcinoma than adenocarcinoma.