Background:Genome-wide association studies (GWAS) have identified numerous lung cancer susceptibility loci based on single nucleotide polymorphisms (SNPs), yet a substantial proportion of heritability remains unexplained. We therefore evaluated germline copy number variants (CNVs) as an underexplored source of genetic susceptibility and potential contributors to genomic instability in lung cancer. Methods:We conducted a genome-wide analysis of germline CNVs using 19,342 cases and 15,917 controls from the Transdisciplinary Research in Cancer of the Lung (TRICL) consortium, with replication in two independent cohorts. High-confidence CNVs were identified by integrating two CNV callers including PennCNV and modSaRa2. Association analyses were performed using both gene-based and CNV region-based approaches. Polygenic risk scores (PRS) were constructed from top loci, and functional validation was conducted using siRNA-mediated knockdown in lung fibroblast cells. Results:We identified CNVs in four genomic regions (1p36.22, 2q31.2, 6p21.32, and 19q13.32) significantly associated with lung cancer risk. Two loci (1p36.22 and 2q31.2) were consistently supported across both analytical strategies. A CNV-based PRS constructed from key genes (CLCN6, NFE2L2, OPA3, and PSMB8) was significantly associated with lung cancer risk and replicated across independent datasets. Functional assays demonstrated that knockdown of NFE2L2 and OPA3 increased endogenous DNA damage, supporting a role in genomic stability. Conclusions:Germline CNVs contribute to lung cancer susceptibility and may influence carcinogenesis through mechanisms related to genomic instability. Impact:These findings expand the genetic architecture of lung cancer and highlight CNVs as potential biomarkers for improving risk stratification and informing precision prevention strategies.

Heterozygosity at human leukocyte antigen (HLA) loci may improve lung cancer immunosurveillance by increasing recognition of the tumor by the immune system. Previous studies utilizing data from population-level biobanks, such as the United Kingdom Biobank and FinnGen, have identified an association between germline HLA class II (HLA-II) heterozygosity and reduced lung cancer risk in smokers. In the present study, we evaluate the association between HLA heterozygosity and lung cancer in a large case-control study (15,302 cases and 14,580 controls) with imputed HLA allele-type information, comparing differences in HLA heterozygosity between smokers and non-smokers, among lung cancer subtypes, and at 2- and 4-digit HLA allele resolution. We identify a strong protective association of HLA-II heterozygosity in smokers compared to non-smokers, particularly at the HLA-DPB1 and HLA-DPA1 loci, and provide subtype-specific resolution. Finally, analysis of the additive effects of HLA allele heterozygosity in smokers identified significant associations with several 4-digit HLA alleles, including HLA-B∗08:01, HLA-A∗01:01, HLA-C∗07:01, HLA-DQA1∗05:01, HLA-DRB1∗03:01, and HLA-C∗03:04. Our study provides additional evidence, with added histologic subtype information, that germline HLA-II heterozygosity is inversely associated with lung cancer risk.

PDF file - 836K, Supplemental Figure 1: Overview of the study design for the identification of candidate coding genes, development and validation of the four coding gene classifier using five independent datasets. Supplemental Figure 2: Technical validation of the microarray experiments showing Pearsons correlation between microarray expression values and qRT-PCR expression values for each gene across all tumors that were examined.Supplemental Figure 3: Kaplan-Meier survival curves according to tertiles of the four coding gene classifier in AJCC 6th edition stage I-II lung adenocarcinoma from five independent cohorts, including the Japan (n=199, relapse-free survival), US/Norway (n=92, cancer specific mortality), Directors (n=378, overall survival), Bhattacharjee (n=100, overall survival) and Tomida (n=92, overall survival) cohorts. P-values were estimated by log-rank test for trend. Supplemental Figure 4: For survival analysis, miR-21 expression values as measured by nCounter miRNA assays were normalized to the average of the 5 most highly expressed microRNAs in tumor tissue, excluding miR-21 itself. Supplemental Figure 5: In the Japan cohort, the four coding gene classifier and the non-coding miR-21 classifier are each significantly associated with relapse-free survival.Supplemental Figure 6: In the US/Norway cohort, the four coding gene classifier and the non-coding miR-21 classifier are each significantly associated with relapse-free survival. Supplemental Figure 7: Estimation of miR-21 copies per cell in lung adenocarcinoma tissue by PCR-based absolute quantification. Supplemental Figure 8: Total RNA content per lung tumor cell was estimated at approximately 20pg per cell based on a series of total RNA extraction from serially diluted cultured lung adenocarcinoma cell lines A549 and NCI-H23. Supplemental Figure 9: Prognostic significance of BRCA1 expression in multiple cancer types. Supplemental Table 1. Characteristics of study populations of patients from public database. Supplemental Table 2. Univariate Cox regression analysis in the Japan cohort using microarray data (AJCC TNM 6th, Stage I, n=148). Supplemental Table 3. Univariate Cox Regression analysis of the expression of six genes.

Abstract Background Aberrant Wnt signalling, regulating cell development and stemness, influences the development of many cancer types. The Aryl hydrocarbon receptor (AhR) mediates tumorigenesis of environmental pollutants. Complex interaction patterns of genes assigned to AhR/Wnt-signalling were recently associated with lung cancer susceptibility. Aim To assess the association and predictive ability of AhR/Wnt-genes with lung cancer in cases and controls of European descent. Methods Odds ratios (OR) were estimated for genomic variants assigned to the Wnt agonist and the antagonistic genes DKK2, DKK3, DKK4, FRZB, SFRP4 and Axin2. Logistic regression models with variable selection were trained, validated and tested to predict lung cancer, at which other previously identified SNPs that have been robustly associated with lung cancer risk could also enter the model. Furthermore, decision trees were created to investigate variant × variant interaction. All analyses were performed for overall lung cancer and for subgroups. Results No genome-wide significant association of AhR/Wnt-genes with overall lung cancer was observed, but within the subgroups of ever smokers (e.g., maker rs2722278 SFRP4; OR = 1.20; 95% CI 1.13–1.27; p = 5.6 × 10–10) and never smokers (e.g., maker rs1133683 Axin2; OR = 1.27; 95% CI 1.19–1.35; p = 1.0 × 10–12). Although predictability is poor, AhR/Wnt-variants are unexpectedly overrepresented in optimized prediction scores for overall lung cancer and for small cell lung cancer. Remarkably, the score for never-smokers contained solely two AhR/Wnt-variants. The optimal decision tree for never smokers consists of 7 AhR/Wnt-variants and only two lung cancer variants. Conclusions The role of variants belonging to Wnt/AhR-pathways in lung cancer susceptibility may be underrated in main-effects association analysis. Complex interaction patterns in individuals of European descent have moderate predictive capacity for lung cancer or subgroups thereof, especially in never smokers.

Background Aberrant Wnt signalling, regulating cell development and stemness, influences the development of many cancer types. The Aryl hydrocarbon receptor ( AhR ) mediates tumorigenesis of environmental pollutants. Complex interaction patterns of genes assigned to AhR / Wnt -signalling were recently associated with lung cancer susceptibility. Aim To assess the association and predictive ability of AhR / Wnt -genes with lung cancer in cases and controls of European descent. Methods Odds ratios (OR) were estimated for genomic variants assigned to the Wnt agonist and the antagonistic genes DKK2 , DKK3 , DKK4 , FRZB , SFRP4 and Axin2 . Logistic regression models with variable selection were trained, validated and tested to predict lung cancer, at which other previously identified SNPs that have been robustly associated with lung cancer risk could also enter the model. Furthermore, decision trees were created to investigate variant × variant interaction. All analyses were performed for overall lung cancer and for subgroups. Results No genome-wide significant association of AhR / Wnt -genes with overall lung cancer was observed, but within the subgroups of ever smokers (e.g., maker rs2722278 SFRP4 ; OR = 1.20; 95% CI 1.13–1.27; p = 5.6 × 10 –10 ) and never smokers (e.g., maker rs1133683 Axin2 ; OR = 1.27; 95% CI 1.19–1.35; p = 1.0 × 10 –12 ). Although predictability is poor, AhR / Wnt-variants are unexpectedly overrepresented in optimized prediction scores for overall lung cancer and for small cell lung cancer. Remarkably, the score for never-smokers contained solely two AhR / Wnt-variants . The optimal decision tree for never smokers consists of 7 AhR / Wnt-variants and only two lung cancer variants. Conclusions The role of variants belonging to Wnt / AhR- pathways in lung cancer susceptibility may be underrated in main-effects association analysis. Complex interaction patterns in individuals of European descent have moderate predictive capacity for lung cancer or subgroups thereof, especially in never smokers.

Clinical trial results have recently demonstrated that inhibiting inflammation by targeting the interleukin-1 beta pathway can offer a significant reduction in lung cancer incidence and mortality, highlighting a pressing and unmet need to understand the benefits of inflammation-focused lung cancer therapies at the genetic level. While numerous genome-wide association studies (GWAS) have explored the genetic etiology of lung cancer, there remains a large gap between the type of information that may be gleaned from an association study and the depth of understanding necessary to explain and drive translational findings. Thus, in this study we jointly model and integrate extensive multiomics data sources, utilizing a total of 40 genome-wide functional annotations that augment previously published results from the International Lung Cancer Consortium (ILCCO) GWAS, to prioritize and characterize single nucleotide polymorphisms (SNPs) that increase risk of squamous cell lung cancer through the inflammatory and immune responses. Our work bridges the gap between correlative analysis and translational follow-up research, refining GWAS association measures in an interpretable and systematic manner. In particular, reanalysis of the ILCCO data highlights the impact of highly associated SNPs from nuclear factor-kappa B signaling pathway genes as well as major histocompatibility complex mediated variation in immune responses. One consequence of prioritizing likely functional SNPs is the pruning of variants that might be selected for follow-up work by over an order of magnitude, from potentially tens of thousands to hundreds. The strategies we introduce provide informative and interpretable approaches for incorporating extensive genome-wide annotation data in analysis of genetic association studies.

Impaired lung function is often caused by cigarette smoking, making it challenging to disentangle its role in lung cancer susceptibility. Investigation of the shared genetic basis of these phenotypes in the UK Biobank and International Lung Cancer Consortium (29,266 cases, 56,450 controls) shows that lung cancer is genetically correlated with reduced forced expiratory volume in one second (FEV 1 : r g = 0.098, p = 2.3 × 10 −8 ) and the ratio of FEV 1 to forced vital capacity (FEV 1 /FVC: r g = 0.137, p = 2.0 × 10 −12 ). Mendelian randomization analyses demonstrate that reduced FEV 1 increases squamous cell carcinoma risk (odds ratio (OR) = 1.51, 95% confidence intervals: 1.21–1.88), while reduced FEV 1 /FVC increases the risk of adenocarcinoma (OR = 1.17, 1.01–1.35) and lung cancer in never smokers (OR = 1.56, 1.05–2.30). These findings support a causal role of pulmonary impairment in lung cancer etiology. Integrative analyses reveal that pulmonary function instruments, including 73 novel variants, influence lung tissue gene expression and implicate immune-related pathways in mediating the observed effects on lung carcinogenesis.

BackgroundEvidence from observational studies of telomere length (TL) has been conflicting regarding its direction of association with cancer risk. We investigated the causal relevance of TL for lung and head and neck cancers using Mendelian Randomization (MR) and mediation analyses.MethodsWe developed a novel genetic instrument for TL in chromosome 5p15.33, using variants identified through deep-sequencing, that were genotyped in 2051 cancer-free subjects. Next, we conducted an MR analysis of lung (16 396 cases, 13 013 controls) and head and neck cancer (4415 cases, 5013 controls) using eight genetic instruments for TL. Lastly, the 5p15.33 instrument and distinct 5p15.33 lung cancer risk loci were evaluated using two-sample mediation analysis, to quantify their direct and indirect, telomere-mediated, effects.ResultsThe multi-allelic 5p15.33 instrument explained 1.49-2.00% of TL variation in our data (p = 2.6 × 10-9). The MR analysis estimated that a 1000 base-pair increase in TL increases risk of lung cancer [odds ratio (OR) = 1.41, 95% confidence interval (CI): 1.20-1.65] and lung adenocarcinoma (OR = 1.92, 95% CI: 1.51-2.22), but not squamous lung carcinoma (OR = 1.04, 95% CI: 0.83-1.29) or head and neck cancers (OR = 0.90, 95% CI: 0.70-1.05). Mediation analysis of the 5p15.33 instrument indicated an absence of direct effects on lung cancer risk (OR = 1.00, 95% CI: 0.95-1.04). Analysis of distinct 5p15.33 susceptibility variants estimated that TL mediates up to 40% of the observed associations with lung cancer risk.ConclusionsOur findings support a causal role for long telomeres in lung cancer aetiology, particularly for adenocarcinoma, and demonstrate that telomere maintenance partially mediates the lung cancer susceptibility conferred by 5p15.33 loci.

Background: Platelets are a critical element in coagulation and inflammation, and activated platelets are linked to cancer risk through diverse mechanisms. However, a causal relationship between platelets and risk of lung cancer remains unclear. Methods: We performed single and combined multiple instrumental variable Mendelian randomization analysis by an inverse-weighted method, in addition to a series of sensitivity analyses. Summary data for associations between SNPs and platelet count are from a recent publication that included 48,666 Caucasian Europeans, and the International Lung Cancer Consortium and Transdisciplinary Research in Cancer of the Lung data consisting of 29,266 cases and 56,450 controls to analyze associations between candidate SNPs and lung cancer risk. Results: Multiple instrumental variable analysis incorporating six SNPs showed a 62% increased risk of overall nonsmall cell lung cancer [NSCLC; OR, 1.62; 95% confidence interval (CI), 1.15-2.27; P = 0.005] and a 200% increased risk for small-cell lung cancer (OR, 3.00; 95% CI, 1.27-7.06; P = 0.01). Results showed only a trending association with NSCLC histologic subtypes, which may be due to insufficient sample size and/or weak effect size. A series of sensitivity analysis retained these findings. Conclusions: Our findings suggest a causal relationship between elevated platelet count and increased risk of lung cancer and provide evidence of possible antiplatelet interventions for lung cancer prevention. Impact: These findings provide a better understanding of lung cancer etiology and potential evidence for antiplatelet interventions for lung cancer prevention.

INTRODUCTION:Inherited susceptibility to lung cancer risk in never-smokers is poorly understood. The major reason for this gap in knowledge is that this disease is relatively uncommon (except in Asians), making it difficult to assemble an adequate study sample. In this study we conducted a genome-wide association study on the largest, to date, set of European-descent never-smokers with lung cancer. METHODS:We conducted a two-phase (discovery and replication) genome-wide association study in never-smokers of European descent. We further augmented the sample by performing a meta-analysis with never-smokers from the recent OncoArray study, which resulted in a total of 3636 cases and 6295 controls. We also compare our findings with those in smokers with lung cancer. RESULTS:We detected three genome-wide statistically significant single nucleotide polymorphisms rs31490 (odds ratio [OR]: 0.769, 95% confidence interval [CI]: 0.722-0.820; p value 5.31 × 10-16), rs380286 (OR: 0.770, 95% CI: 0.723-0.820; p value 4.32 × 10-16), and rs4975616 (OR: 0.778, 95% CI: 0.730-0.829; p value 1.04 × 10-14). All three mapped to Chromosome 5 CLPTM1L-TERT region, previously shown to be associated with lung cancer risk in smokers and in never-smoker Asian women, and risk of other cancers including breast, ovarian, colorectal, and prostate. CONCLUSIONS:We found that genetic susceptibility to lung cancer in never-smokers is associated to genetic variants with pan-cancer risk effects. The comparison with smokers shows that top variants previously shown to be associated with lung cancer risk only confer risk in the presence of tobacco exposure, underscoring the importance of gene-environment interactions in the etiology of this disease.

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DNase I hypersensitive sites (DHS) are abundant in regulatory elements, such as promoter, enhancer and transcription factor binding sites. Many studies have revealed that disease-associated variants were concentrated in DHS-related regions. However, limited studies are available on the roles of DHS-related variants in lung cancer. In this study, we performed a large-scale case-control study with 20 871 lung cancer cases and 15 971 controls to evaluate the associations between regulatory genetic variants in DHS and lung cancer susceptibility. The expression quantitative trait loci (eQTL) analysis and pathway-enrichment analysis were performed to identify the possible target genes and pathways. In addition, we performed motif-based analysis to explore the lung-cancer-related motifs using sequence kernel association test. Two novel variants, rs186332 in 20q13.3 (C>T, odds ratio [OR] = 1.17, 95% confidence interval [95% CI]: 1.10-1.24, P = 8.45 x 10(-7)) and rs4839323 in 1p13.2 (T>C, OR = 0.92, 95% CI: 0.89-0.95, P = 1.02 x 10(-6)) showed significant association with lung cancer risk. The eQTL analysis suggested that these two SNPs might regulate the expression of MRGBP and SLC16A1, respectively. What's more, the expression of both MRGBP and SLC16A1 was aberrantly elevated in lung tumor tissues. The motif-based analysis identified 10 motifs related to the risk of lung cancer (P < 1.71 x 10(-4)). Our findings suggested that variants in DHS might modify lung cancer susceptibility through regulating the expression of surrounding genes. This study provided us a deeper insight into the roles of DHS-related genetic variants for lung cancer.

Lung cancer has several genetic associations identified within the major histocompatibility complex (MHC); although the basis for these associations remains elusive. Here, we analyze MHC genetic variation among 26,044 lung cancer patients and 20,836 controls densely genotyped across the MHC, using the Illumina Illumina OncoArray or Illumina 660W SNP microarray. We impute sequence variation in classical HLA genes, fine-map MHC associations for lung cancer risk with major histologies and compare results between ethnicities. Independent and novel associations within HLA genes are identified in Europeans including amino acids in the HLA-B*0801 peptide binding groove and an independent HLA-DQB1*06 loci group. In Asians, associations are driven by two independent HLA allele sets that both increase risk in HLA-DQB1*0401 and HLA-DRB1*0701; the latter better represented by the amino acid Ala-104. These results implicate several HLA-tumor peptide interactions as the major MHC factor modulating lung cancer susceptibility.

Occupational exposure to diesel exhaust may cause lung cancer in humans. Mechanisms include DNA-damage and inflammatory responses. Here, the potential of NIST SRM2975 diesel exhaust particles (DEP) to transform human bronchial epithelial cells (HBEC3) in vitro was investigated. Long-term exposure of HBEC3 to DEP led to increased colony growth in soft agar. Several DEP-transformed cell lines were established and based on the expression of epithelial-to-mesenchymal-transition (EMT) marker genes, one of them (T2-HBEC3) was further characterized. T2-HBEC3 showed a mesenchymal/fibroblast-like morphology, reduced expression of CDH1, and induction of CDH2 and VIM. T2-HBEC3 had reduced migration potential compared with HBEC3 and little invasion capacity. Gene expression profiling showed baseline differences between HBEC3 and T2-HBEC3 linked to lung carcinogenesis. Next, to assess differences in sensitivity to DEP between parental HBEC3 and T2-HBEC3, gene expression profiling was carried out after DEP short-term exposure. Results revealed changes in genes involved in metabolism of xenobiotics and lipids, as well as inflammation. HBEC3 displayed a higher steady state of IL1B gene expression and release of IL-1β compared with T2-HBEC3. HBEC3 and T2-HBEC3 showed similar susceptibility towards DEP-induced genotoxic effects. Liquid-chromatography-tandem-mass-spectrometry was used to measure secretion of eicosanoids. Generally, major prostaglandin species were released in higher concentrations from T2-HBEC3 than from HBEC3 and several analytes were altered after DEP-exposure. In conclusion, long-term exposure to DEP-transformed human bronchial epithelial cells in vitro. Differences between HBEC3 and T2-HBEC3 regarding baseline levels and DEP-induced changes of particularly CYP1A1, IL-1β, PGE2, and PGF2α may have implications for acute inflammation and carcinogenesis.

Radon is a risk factor for lung cancer and uranium miners are more exposed than the general population. A genome-wide interaction analysis was carried out to identify genomic loci, genes or gene sets that modify the susceptibility to lung cancer given occupational exposure to the radioactive gas radon.

Genome-wide association studies (GWAS) identified the chromosome 15q25.1 locus as a leading susceptibility region for lung cancer. However, the pathogenic pathways, through which susceptibility SNPs within chromosome 15q25.1 affects lung cancer risk, have not been explored. We analyzed three cohorts with GWAS data consisting 42,901 individuals and lung expression quantitative trait loci (eQTL) data on 409 individuals to identify and validate the underlying pathways and to investigate the combined effect of genes from the identified susceptibility pathways. The KEGG neuroactive ligand receptor interaction pathway, two Reactome pathways, and 22 Gene Ontology terms were identified and replicated to be significantly associated with lung cancer risk, with P values less than 0.05 and FDR less than 0.1. Functional annotation of eQTL analysis results showed that the neuroactive ligand receptor interaction pathway and gated channel activity were involved in lung cancer risk. These pathways provide important insights for the etiology of lung cancer.

Objectives This study aimed to assess the biological impact of occupational exposure to diesel exhaust (DE) including DE particles (DEP) from heavy-duty diesel-powered equipment in Norwegian tunnel finishing workers (TFW). Methods TFW (n=69) and referents (n=69) were investigated for bulky DNA adducts (by 32P-postlabelling) and expression of microRNAs (miRNAs) (by small RNA sequencing) in peripheral blood mononuclear cells (PBMC), as well as circulating free arachidonic acid (AA) and eicosanoid profiles in plasma (by liquid chromatography–tandem mass spectrometry). Results PBMC from TFW showed significantly higher levels of DNA adducts compared with referents. Levels of DNA adducts were also related to smoking habits. Seventeen miRNAs were significantly deregulated in TFW. Several of these miRNAs are related to carcinogenesis, apoptosis and antioxidant effects. Analysis of putative miRNA-gene targets revealed deregulation of pathways associated with cancer, alterations in lipid molecules, steroid biosynthesis and cell cycle. Plasma profiles showed higher levels of free AA and 15-hydroxyeicosatetraenoic acid, and lower levels of prostaglandin D2 and 9-hydroxyoctadecadienoic acid in TFW compared with referents. Conclusion Occupational exposure to DE/DEP is associated with biological alterations in TFW potentially affecting lung homoeostasis, carcinogenesis, inflammation status and the cardiovascular system. Of particular importance is the finding that tunnel finishing work is associated with an increased level of DNA adducts formation in PBMC.

Occupational exposure to diesel exhaust may cause lung cancer in humans. Mechanisms include DNA-damage and inflammatory responses. Here, the potential of NIST SRM2975 diesel exhaust particles (DEP) to transform human bronchial epithelial cells (HBEC3) in vitro was investigated. Long-term exposure of HBEC3 to DEP led to increased colony growth in soft agar. Several DEP-transformed cell lines were established and based on the expression of epithelial-to-mesenchymaltransition (EMT) marker genes, one of them (T2-HBEC3) was further characterized. T2-HBEC3 showed a mesenchymal/ fibroblast-like morphology, reduced expression of CDH1, and induction of CDH2 and VIM. T2-HBEC3 had reduced migration potential compared with HBEC3 and little invasion capacity. Gene expression profiling showed baseline differences between HBEC3 and T2-HBEC3 linked to lung carcinogenesis. Next, to assess differences in sensitivity to DEP between parental HBEC3 and T2-HBEC3, gene expression profiling was carried out after DEP short-term exposure. Results revealed changes in genes involved in metabolism of xenobiotics and lipids, as well as inflammation. HBEC3 displayed a higher steady state of IL1B gene expression and release of IL-1b compared with T2-HBEC3. HBEC3 and T2-HBEC3 showed similar susceptibility towards DEP-induced genotoxic effects. Liquid-chromatography-tandem-mass-spectrometry was used to measure secretion of eicosanoids. Generally, major prostaglandin species were released in higher concentrations from T2HBEC3 than from HBEC3 and several analytes were altered after DEP-exposure. In conclusion, long-term exposure to DEPtransformed human bronchial epithelial cells in vitro. Differences between HBEC3 and T2-HBEC3 regarding baseline levels and DEP-induced changes of particularly CYP1A1, IL-1b, PGE2, and PGF2a may have implications for acute inflammation and carcinogenesis. VC The Author(s) 2018. Published by Oxford University Press on behalf of the Society of Toxicology. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/ licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com 51 TOXICOLOGICAL SCIENCES, 166(1), 2018, 51–64 doi: 10.1093/toxsci/kfy183 Advance Access Publication Date: July 16, 2018

Introduction: There are no validated molecular methods that prospectively identify patients with surgically resected lung squamous cell carcinoma (SCC) at high risk for recurrence. By focusing on the expression of genes with known functions in development of lung SCC and prognosis, we sought to develop a robust prognostic classifier of early stage lung SCC.Methods: The expression of 253 genes selected by literature search was evaluated in microarrays from 107 stage I/II tumors. Associations with survival were evaluated by Cox regression and Kaplan-Meier survival analyses in two independent cohorts of 121 and 91 patients with SCC, respectively. A classifier score based on multivariable Cox regression was derived and exam fined in six additional publicly available data sets of stage I/II lung SCC expression profiles (n = 358). The prognostic value of this classifier was evaluated in meta analysis of patients with stage I/II (n = 479) and stage I (n = 326) lung SCC.Results: Dual specificity phosphatase 6 gene (DUSP6) and actinin alpha 4 gene (ACTN4) were associated with prognostic outcome in two independent patient cohorts. Their expression values were utilized to develop a classifier that identified patients with stage I/II lung SCC at high risk for recurrence (hazard ratio [HR] = 4.7, p = 0.018) or cancer-specific mortality (HR = 3.5, p = 0.016). This classifier also identified patients at high risk for recurrence (HR = 2.7, p = 0.008) or death (HR = 2.2, p = 0.001) in publicly available data sets of stage I/II and in meta analysis of stage I patients.Conclusions: We have established and validated a prognostic classifier to inform clinical management of patients with lung SCC after surgical resection. Published by Elsevier Inc. on behalf of International Association for the Study of Lung Cancer.

Abstract Background: Impaired lung function (LF) is strongly associated with increased lung cancer risk. However, since airflow obstruction is a diagnostic criterion for obstructive lung disease, and a consequence of tobacco smoking, isolating the causal relationship between LF and lung cancer has remained a challenge. Methods: We investigated 3 standardized (mean=0, standard deviation=1) LF metrics: forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC. To evaluate the causal relevance of LF in lung cancer etiology we conducted: i) survival analyses in the UK Biobank cohort (UKB); and ii) Mendelian Randomization (MR) analyses using genetic instrumental variables (IVs) developed in UKB and tested using individual-level data from the OncoArray, a genome-wide array with in-depth coverage for common cancers. Results: 702 incident lung cancers were diagnosed in 484,194 UKB participants during follow-up. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI), adjusted for age, sex, smoking status, socioeconomic status, and assessment center. Adjustment for other smoking metrics yielded similar results. Lung cancer risk increased per 1 unit decrease in FEV1 (HR=1.80, 95% CI: 1.64-1.98, p=3.3×10-34), FVC (HR=1.45, 1.30-1.60, p=2.3×10-12), and FEV1/FVC (HR=1.39, 1.33-1.46, p=1.3×10-38). This pattern was observed for adenocarcinoma (n=300): FEV1 (HR=1.77, p=6.0×10-12), FVC (HR=1.48, p=1.4×10-5), FEV1/FVC (HR=1.34, p=8.3×10-11); and squamous cell carcinoma (n=166): FEV1 (HR=1.97, p=9.9×10-10), FVC (HR=1.60, p=1.0×10-4), FEV1/FVC (HR=1.38, p=5.9×10-8). Next, a genome-wide association study of 67,708 UKB participants and 12.6 million variants was carried out to develop genetic IVs for LF. Results were filtered to retain independent variants (R2<0.2) associated with each LF phenotype (p<5×10-8). The following IVs were developed: FEV1 (n=28 variants, 0.72% of variation explained), FVC (n=44, 1.08%), and FEV1/FVC (n=45, 1.85%). Odds ratios (OR) for each IV and lung cancer were estimated for 18,686 cases 15,190 controls (>80% European ancestry) from 23 studies. Effect estimates were combined using maximum-likelihood MR models to estimate causal ORs. MR results indicate that genetic scores associated with improved airflow are unrelated to lung cancer risk: FEV1 (OR=1.00, 95% CI: 0.96-1.03, p=0.86), FVC (OR=1.00, 0.97-1.03, p=0.93) and FEV1/FVC (OR=1.00, 0.91-1.10, p=0.95). The null association observed for the genetic determinants of FEV1, FVC and FEV1/FVC was not modified by tumor histology or smoking status. Conclusions: LF is a robust predictor of lung cancer risk, however, our findings do not support the existence of causal pathways that are independent of obstructive lung disease or smoking. This apparent lack of a causal relationship should be interpreted with caution since pleiotropic effects of LF loci cannot be ruled out. Citation Format: Linda Kachuri, Mattias Johansson, Paul Brennan, Phillip Haycock, Geoffrey Liu, Maria Teresa Landi, David C. Christiani, Neil E. Caporaso, Xifeng Wu, Melinda C. Aldrich, Demetrius Albanes, Adonina Tardón, Gad Rennert, Chu Chen, Gary E. Goodman, Jennifer A. Doherty, Heike Bickeböller, Dawn Teare, Lambertus A. Kiemeney, Stig E. Bojesen, John K. Field, Aage Haugen, Stephen Lam, Loic Le Marchand, Matthew B. Schabath, Angeline S. Andrew, Jonas Manjer, Philip Lazarus, Susanne M. Arnold, Valérie Gaborieau, Richard Martin, Caroline Relton, George Davey Smith, Christopher I. Amos, James D. McKay, Rayjean J. Hung. Lung function and lung cancer risk: a Mendelian randomization study of UK Biobank cohort and the International Lung Cancer Consortium [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2292. doi:10.1158/1538-7445.AM2017-2292