Lung Cancer In Never-smokers Research Articles

Abstract 5211: Somatic copy number variation as prognostic marker for recurrence in never-smokers with early-stage lung adenocarcinoma

Abstract Objective: Lung cancer in never-smokers has a distinct genomic profile with low tumor mutation burden, more tumor promotor mutations and fewer somatic copy number variations (CNV) than smokers. CNVs have shown to be associated with poor outcome in advanced stage disease. However, the relationship between CNV and clinicopathologic features on prognosis in early-stage lung cancer is undefined. To address this knowledge gap, we assessed the impact of CNV on recurrence in never-smokers who underwent curative resection for pathological stage I-II lung adenocarcinoma using an integrated genomic and clinicopathological analysis. Methods: We analyzed a cohort of 210 never-smokers with stage I-II lung adenocarcinoma treated from 2014 to 2022 who met the inclusion criteria (no neoadjuvant therapy, pathological stage I-II, complete resection, next-generation sequencing available). The patient cohort was stratified using unsupervised hierarchical clustering of arm-level CNVs. We assessed cumulative incidence of recurrence (CIR) between CNV groups using competing risk regression analysis, adjusting for SUVmax, pathologic stage, lymphovascular invasion, IASLC grade, and tumor mutation burden. Results: Of the 210 patients, 159 patients were female (76%), and patients were primarily from Caucasian (n=140, 67%) or Asian decent (n=50, 24%). Based on arm-level CNV clustering, the cohort was stratified into three groups: CNV low (n=86, 41%), CNV moderate (n=75, 36%) and CNV high (n=49, 23%). The CNV low tumors were characterized by a low CNV burden. Conversely, the CNV moderate tumors primarily exhibited gains in chromosomes 1q, 5p and 7p, along with loss of heterozygosity in chromosome 9p, 9q and 13. CNV high tumors were characterized by whole-genome doubling. Whole-genome doubling was significantly more common in CNV high tumors (n=33, 66%) compared to CNV low (n=2, 2.3%) and CNV moderate tumors (n=2, 2.7%) (p<.001). EGFR (n=145, 69%) and TP53 (n=61, 29%) were the most frequently altered genes, with EGFR alterations being significantly more prevalent in CNV high tumors (n=41, 84%) compared to CNV low tumors (n=46, 53%) (p<.001). In total, 42 patients (20%) developed recurrences. The CIR was lower in the CNV low group (5y-CIR, 14%, 95%CI: 6.5%-25%) compared to the CNV moderate (5y-CIR, 31%, 95%CI: 18%-44%) and CNV high group (5y-CIR, 48%, 95%CI: 27%-66%) (p=.004), with adjusted hazard ratios of 2.3 (95%CI: 0.93-5.71; p=0.074) and 2.65 (95%CI: 1.07-6.60; p=.037), respectively. The CIR for locoregional (n=11, 5%) and distant recurrence (n=31, 15%) remained lower in the CNV low group compared to the combined CNV moderate & high groups (Gray test p=.020 and p=.049, respectively). Conclusion: In never-smokers who underwent curative treatment of pathological stage I-II lung adenocarcinoma, copy number status seems a predictor of recurrence, with CNV low tumors associated with the best prognosis. Citation Format: Stijn Vanstraelen, Allison Reiner, Brooke H. Mastrogiacomo, Kay See Tan, Joseph Dycoco, Bernard J. Park, Prasad S. Adusumilli, Matthew J. Bott, David R. Jones, Gaetano Rocco. Somatic copy number variation as prognostic marker for recurrence in never-smokers with early-stage lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5211.

Abstract 1467: Contribution of estrogen metabolites to never-smoking lung cancer

Abstract There has been a consistent rise in the incidence of non-small cell lung cancer (NSCLC) among individuals who have never smoked. Remarkably, over 50% of diagnosed female cases and 15-20% of male cases are never-smokers. Notably, NSCLC in never-smokers exhibits distinctive clinical and pathological features, notably a higher incidence of tumors with EGFR mutations, setting it apart from its counterpart in smokers. Despite the improved disease-free survival observed with EGFR-tyrosine kinase inhibitors, eventual relapse and limited responsiveness to immunotherapy are common, underscoring the urgency to comprehend the molecular mechanisms driving the escalating prevalence of NSCLC in never-smokers and develop targeted preventive and interceptive therapeutic strategies. The preponderance of females among NSCLC patients who never smoked has prompted an exploration into the potential contribution of estrogen to lung tumorigenesis. In contrast to prevailing research focused on estrogen receptor-mediated signaling, our investigations have yielded compelling evidence supporting the involvement of estrogen metabolism in lung carcinogenesis among never-smokers. This group is the first to report that estrogen is metabolized extensively in both mouse and human lungs, resulting in the generation of various derivatives, including the potential carcinogen 4-hydroxyestrogen (4-OHE). Notably, recent findings from our laboratory indicate that prolonged exposure of nonneoplastic human bronchial epithelial cells to 17β estradiol or 4-OHE, at concentrations approximating physiological levels, induces the accumulation of double-strand DNA breaks and cellular transformation. A comprehensive analysis was performed to further elucidate the mechanisms underlying the transformation process. Isolated transformed clones obtained after 9, 18, and 22 wks of exposure to 4-OHE were subjected to karyotyping, F.I.S.H., and RNA and exome sequencing. A longitudinal progression of aberrant chromosomal rearrangements and copy number alterations was observed, that increased with time of 4-OHE exposure. In addition, RNA-Seq analyses revealed the epithelial-mesenchymal transition pathway was highly enriched at the early timepoint (9 wks), while replicative stress-related signaling pathways were induced at all timepoints. To determine if the differentially expressed genes were also dysregulated in clinical lung cancer cases, TCGA lung adenocarcinoma (LUAD) data were examined. Interestingly, many of the genes upregulated after estrogen exposure were similarly overexpressed in the LUAD samples and often associated with a worse prognosis. In conclusion, our data support the role of estrogen metabolites in promoting lung cancer among never-smokers. (Supported by CA217161 and generous contributions from the Hellendall Family Foundation, Gregory G. Lawton and the Timothy and Aurora Hughes Cancer Research Fund.) Citation Format: Mitchell Cheung, Lisa A. Vanderveer, Daniel Krzizike, J. Nicholas Bodor, Joseph Treat, Joseph R. Testa, Margie L. Clapper. Contribution of estrogen metabolites to never-smoking lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1467.

Sex differences in the tumor promoting effects of tobacco smoke in a cRaf transgenic lung cancer disease model

Tobacco smoke (TS) is the leading cause for lung cancer (LC), and female smokers are at a greater risk for LC. Yet, the underlying causes are unknown. We performed whole genome scans in TS exposed wild type and histologically characterized tumor lesions of cRaf transgenic mice. We constructed miRNA-gene and transcription factor-miRNA/gene regulatory networks and determined sex-specific gene regulations by evaluating hormone receptor activities. We validated the findings from TS exposed cRaf mice in a large cohort of smoking and never-smoking LC patients. When compared to males, TS prompted a sevenfold increase in tumor multiplicity in cRaf females. Genome-wide scans of tumor lesions identified 161 and 53 genes and miRNAs, which code for EGFR/MAPK signaling, cell proliferation, oncomirs and oncogenes, and 50% of DEGs code for immune response and tumor evasion. Outstandingly, in transgenic males, TS elicited upregulation of 20 tumor suppressors, some of which are the targets of the androgen and estrogen receptor. Conversely, in females, 18 tumor suppressors were downregulated, and five were specifically repressed by the estrogen receptor. We found TS to perturb the circadian clock in a sex-specific manner and identified a female-specific regulatory loop that consisted of the estrogen receptor, miR-22-3p and circadian genes to support LC growth. Finally, we confirmed sex-dependent tumor promoting effects of TS in a large cohort of LC patients. Our study highlights the sex-dependent genomic responses to TS and the interplay of circadian clock genes and hormone receptors in the regulation of oncogenes and oncomirs in LC growth.

The Role of Smoking Status in Making Risk-Informed Diagnostic Decisions in the Lung Cancer Pathway: A Qualitative Study of Health Care Professionals and Patients.

Lung cancer clinical guidelines and risk tools often rely on smoking history as a significant risk factor. However, never-smokers make up 14% of the lung cancer population, and this proportion is rising. Consequently, they are often perceived as low-risk and may experience diagnostic delays. This study aimed to explore how clinicians make risk-informed diagnostic decisions for never-smokers. Qualitative interviews were conducted with 10 lung cancer diagnosticians, supported by data from interviews with 20 never-smoker lung cancer patients. The data were analyzed using a framework analysis based on the Model of Pathways to Treatment framework and data-driven interpretations. Participants described 3 main strategies for making risk-informed decisions incorporating smoking status: guidelines, heuristics, and potential harms. Clinicians supplemented guidelines with their own heuristics for never-smokers, such as using higher thresholds for chest X-ray. Decisions were easier for patients with high-risk symptoms such as hemoptysis. Clinicians worried about overinvestigating never-smoker patients, particularly in terms of physical and psychological harms from invasive procedures or radiation. To minimize unnecessary anxiety about lung cancer risk, clinicians made efforts to downplay this. Conversely, some patients found that this caused process harms such as delays and miscommunications. Improved guidance and methods of risk differentiation for never-smokers are needed to avoid diagnostic delays, overreassurance, and clinical pessimism. This requires an improved evidence base and initiatives to increase awareness among clinicians of the incidence of lung cancer in never-smokers. As the proportion of never-smoker patients increases, this issue will become more urgent. Smoking status is the most common risk factor used by clinicians to guide decision making, and guidelines often focus on this factor.Some clinicians also use their own heuristics for never-smokers, and this becomes particularly relevant for patients with lower risk symptoms.Clinicians are also concerned about the potential harms and risks associated with deploying resources on diagnostics for never-smokers.Some patients find it difficult to decide whether or not to go ahead with certain procedures due to efforts made by clinicians to downplay the risk of lung cancer.Overall, the study highlights the complex interplay between smoking history, clinical decision making, and patient anxiety in the context of lung cancer diagnosis and treatment.

Lung Cancer in Ever- and Never-Smokers: Findings from Multi-Population GWAS Studies.

Clinical, molecular, and genetic epidemiology studies displayed remarkable differences between ever- and never-smoking lung cancer. We conducted a stratified multi-population (European, East Asian, and African descent) association study on 44,823 ever-smokers and 20,074 never-smokers to identify novel variants that were missed in the non-stratified analysis. Functional analysis including expression quantitative trait loci (eQTL) colocalization and DNA damage assays, and annotation studies were conducted to evaluate the functional roles of the variants. We further evaluated the impact of smoking quantity on lung cancer risk for the variants associated with ever-smoking lung cancer. Five novel independent loci, GABRA4, intergenic region 12q24.33, LRRC4C, LINC01088, and LCNL1 were identified with the association at two or three populations (P < 5 × 10-8). Further functional analysis provided multiple lines of evidence suggesting the variants affect lung cancer risk through excessive DNA damage (GABRA4) or cis-regulation of gene expression (LCNL1). The risk of variants from 12 independent regions, including the well-known CHRNA5, associated with ever-smoking lung cancer was evaluated for never-smokers, light-smokers (packyear ≤ 20), and moderate-to-heavy-smokers (packyear > 20). Different risk patterns were observed for the variants among the different groups by smoking behavior. We identified novel variants associated with lung cancer in only ever- or never-smoking groups that were missed by prior main-effect association studies. Our study highlights the genetic heterogeneity between ever- and never-smoking lung cancer and provides etiologic insights into the complicated genetic architecture of this deadly cancer.

Short-Term Exposure to Air Pollution May Drive Lung Cancer in Never-Smokers

Short-Term Exposure to Air Pollution May Drive Lung Cancer in Never-Smokers

Lung Cancer in Never Smokers: Delving into Epidemiology, Genomic and Immune Landscape, Prognosis, Treatment, and Screening.

Lung cancer in never smokers (LCINS) represents a growing and distinct entity within the broader landscape of lung malignancies. This review provides a comprehensive overview of LCINS, encompassing its epidemiologic trends, risk factors, distinct genomic alterations, clinical outcomes and the ongoing initiative aimed at formulating screening guidelines tailored to this unique population. As LCINS continues to gain prominence, understanding its intricate genomic landscape has become pivotal for tailoring effective therapeutic strategies. Moreover, LCINS does not meet the criteria for lung cancer screening as per the current guidelines. Hence, there is an urgent need to explore its heterogeneity in order to devise optimal screening guidelines conducive to early-stage detection. This review underscores the vital importance of detailed research to elucidate the multifaceted nature of LCINS, with the potential to shape future clinical management and screening recommendations for this unique and growing patient cohort.

Development and evaluation of a polygenic risk score for lung cancer in never-smoking women: A large-scale prospective Chinese cohort study.

The proportion of lung cancer in never smokers is rising, especially among Asian women, but there is no effective early detection tool. Here, we developed a polygenic risk score (PRS), which may help to identify the population with higher risk of lung cancer in never-smoking women. We first performed a large GWAS meta-analysis (8595 cases and 8275 controls) to systematically identify the susceptibility loci for lung cancer in never-smoking Asian women and then generated a PRS using GWAS datasets. Furthermore, we evaluated the utility and effectiveness of PRS in an independent Chinese prospective cohort comprising 55 266 individuals. The GWAS meta-analysis identified eight known loci and a novel locus (5q11.2) at the genome-wide statistical significance level of P < 5 × 10-8 . Based on the summary statistics of GWAS, we derived a polygenic risk score including 21 variants (PRS-21) for lung cancer in never-smoking women. Furthermore, PRS-21 had a hazard ratio (HR) per SD of 1.29 (95% CI = 1.18-1.41) in the prospective cohort. Compared with participants who had a low genetic risk, those with an intermediate (HR = 1.32, 95% CI: 1.00-1.72) and high (HR = 2.09, 95% CI: 1.56-2.80) genetic risk had a significantly higher risk of incident lung cancer. The addition of PRS-21 to the conventional risk model yielded a modest significant improvement in AUC (0.697 to 0.711) and net reclassification improvement (24.2%). The GWAS-derived PRS-21 significantly improves the risk stratification and prediction accuracy for incident lung cancer in never-smoking Asian women, demonstrating the potential for identification of high-risk individuals and early screening.

1285P Lung cancer in never smokers (LCINS): Clinicopathological characteristics and treatment outcomes from a university cancer centre in London

1285P Lung cancer in never smokers (LCINS): Clinicopathological characteristics and treatment outcomes from a university cancer centre in London

Biomarkers of lung cancer for screening and in never-smokers-a narrative review.

Lung cancer is the leading cause of cancer-related mortality worldwide, partially attributed to late-stage diagnoses. In order to mitigate this, lung cancer screening (LCS) of high-risk patients is performed using low dose computed tomography (CT) scans, however this method is burdened by high false-positive rates and radiation exposure for patients. Further, screening programs focus on individuals with heavy smoking histories, and as such, never-smokers who may otherwise be at risk of lung cancer are often overlooked. To resolve these limitations, biomarkers have been posited as potential supplements or replacements to low-dose CT, and as such, a large body of research in this area has been produced. However, comparatively little information exists on their clinical efficacy and how this compares to current LCS strategies. Here we conduct a search and narrative review of current literature surrounding biomarkers of lung cancer to supplement LCS, and biomarkers of lung cancer in never-smokers (LCINS). Many potential biomarkers of lung cancer have been identified with varying levels of sensitivity, specificity, clinical efficacy, and supporting evidence. Of the markers identified, multi-target panels of circulating microRNAs, lipids, and metabolites are likely the most clinically efficacious markers to aid current screening programs, as these provide the highest sensitivity and specificity for lung cancer detection. However, circulating lipid and metabolite levels are known to vary in numerous systemic pathologies, highlighting the need for further validation in large cohort randomised studies. Lung cancer biomarkers is a fast-expanding area of research and numerous biomarkers with potential clinical applications have been identified. However, in all cases the level of evidence supporting clinical efficacy is not yet at a level at which it can be translated to clinical practice. The priority now should be to validate existing candidate markers in appropriate clinical contexts and work to integrating these into clinical practice.

Differentiating Benign Pulmonary Lesions from Suspected Lung Cancer in Never Smokers: Based on a Comprehensive Questionnaire

Differentiating Benign Pulmonary Lesions from Suspected Lung Cancer in Never Smokers: Based on a Comprehensive Questionnaire

A Functional Genomics Review of Non-Small-Cell Lung Cancer in Never Smokers.

There is currently a dearth of information regarding lung cancer in never smokers (LCINS). Additionally, there is a difference in somatic mutations, tumour mutational burden, and chromosomal aberrations between smokers and never smokers (NS), insinuating a different disease entity in LCINS. A better understanding of actionable driver alterations prevalent in LCINS and the genomic landscape will contribute to identifying new molecular targets of relevance for NS that will drastically improve outcomes. Differences in treatment outcomes between NS and smokers, as well as sexes, with NSCLC suggest unique tumour characteristics. Epidermal growth factor receptor (EGFR) tyrosine kinase mutations and echinoderm microtubule-associated protein-like 4 anaplastic lymphoma kinase (EML4-ALK) gene rearrangements are more common in NS and have been associated with chemotherapy resistance. Moreover, NS are less likely to benefit from immune mediators including PD-L1. Unravelling the genomic and epigenomic underpinnings of LCINS will aid in the development of not only novel targeted therapies but also more refined approaches. This review encompasses driver genes and pathways involved in the pathogenesis of LCINS and a deeper exploration of the genomic landscape and tumour microenvironment. We highlight the dire need to define the genetic and environmental aspects entailing the development of lung cancer in NS.

Identification of a novel survival predictor, CSF2RB, for female lung cancer in never smokers (LCNS) by a bioinformatics analysis.

Lung cancer in never smokers (LCNS) has been considered as a separate disease and the 7th cause of cancer-related death worldwide. However, limited research has focused on "female" cohorts, which have presented a higher incidence rate. In this study, the microarray data of lung cancer tissues derived from 54 female lung cancer patients, consisting of 43 nonsmokers and 11 smokers, were selected from GSE2109 dataset. A total of 249 differentially expressed genes (DEGs) including 102 up- and 147 down-regulated genes were identified and further analyzed for gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment. By constructing protein-protein interaction (PPI) network and calculating key modules, 10 hub genes were screened out. The module analysis of the PPI network presented that the progression of female LCNS was significantly associated with immune response as chemokine activity and lipopolysaccharide response, and these biological processes (BP) might be mediated by chemokine signaling pathway and cytokine-cytokine receptor interaction. Then, survival analysis by Kaplan-Meier (K-M) Plotter online platform presented down-regulated gene colony stimulating factor 2 receptor beta common subunit (CSF2RB) of female LCNS might be involved in poor clinical outcome. Female LCNS with high expression of CSF2RB might be relevant with relative risk reduction of mortality, longer median survival time and higher 5-year survival rate, while female LCNS with low expression of CSF2RB might be implicated in a poor clinical outcome. In short, our results support CSF2RB to be a candidate survival predictor for female LCNS.

Distinct immune microenvironment of lung adenocarcinoma in never-smokers from smokers

Lung cancer in never-smokers (LCINS) presents clinicopathological and molecular features distinct from that in smokers. Tumor microenvironment (TME) plays important roles in cancer progression and therapeutic response. To decipher the difference in TME between never-smoker and smoker lung cancers, we conduct single-cell RNA sequencing on 165,753 cells from 22 treatment-naive lung adenocarcinoma (LUAD) patients. We find that the dysfunction of alveolar cells induced by cigarette smoking contributes more to the aggressiveness of smoker LUADs, while the immunosuppressive microenvironment exerts more effects on never-smoker LUADs' aggressiveness. Moreover, the SPP1hi pro macrophage is identified to be another independent source of monocyte-derived macrophage. Importantly, higher expression of immune checkpoint CD47 and lower expression of major histocompatibility complex (MHC)-I in cancer cells of never-smoker LUADs imply that CD47 may be a better immunotherapy target for LCINS. Therefore, this study reveals the difference of tumorigenesis between never-smoker and smoker LUADs and provides a potential immunotherapy strategy for LCINS.

Lung cancer metabolomics: A pooled analysis in the cancer prevention studies.

10508 Background: Lung cancer is a heterogeneous disease, often diagnosed at advanced stages, with low overall survival rate. To better understand the lung cancer etiology and discover screening and early detection biomarkers, we performed a nested case-control study to examine the metabolic perturbation related to lung cancer. Methods: This study included 741 case-control pairs (mean age = 67 years) from the ongoing Cancer Prevention Study (CPS) cohorts. Participants completed a comprehensive exposure and health questionnaire at enrollment. Pre-diagnosis blood samples were collected between 1998-2001 in CPS-II and 2006-2013 in CPS-3. Cases and controls were 1:1 matched on date of birth, blood draw date, gender, and race/ethnicity. All eligible controls were cancer-free at the time of case diagnosis. Odds ratios (ORs) per standard deviation and 95% confidence intervals (CIs) were estimated using conditional logistic regression, controlling for potential confounders including body mass index, fruit and vegetable consumption, smoking status, and hormone use. We further performed stratified analyses by smoking status (never/former/current) and follow-up time (i.e., within 3 years/ beyond 3 years between blood draw and diagnosis). Statistical significance was determined as false discovery rate (FDR) &lt; 0.2. Results: Sphingomyelin (d18:0/22:0), a bioactive sphingolipid of cell membranes, was associated with lung cancer risk (OR:1.32, 95% CI: [1.15, 1.53], FDR = 0.12). When stratified by follow-up time, participants diagnosed within 3 years of blood draw had a 59% higher risk of lung cancer per standard deviation increase in sphingomyelin (d18:0/22:0) (OR:1.58, 95% CI: 1.16, 2.15, p = 0.004) and 25% higher risk for those diagnosed beyond 3 years (OR:1.27, 95% CI: 1.08, 1.50, p = 0.005). Metabolites associated with lung cancer at raw p-value &lt; 0.05 indicated the perturbation mostly in lipid, amino acid, and xenobiotics metabolism. We observed variants in perturbed metabolic pathways between never-smoker lung cancer cases and current-smoker lung cancer cases. Conclusions: This is the largest prospective study examining lung cancer risk and metabolic response using an untargeted metabolomics platform. These findings provide preliminary support for sphingomyelin (d18:0/22:0) as a potential screening and early detection biomarker for lung cancer. Results also highlight that lipid metabolism including sphingolipid and bile acid metabolism may play an important role in lung cancer etiology.

Early immune pressure initiated by tissue-resident memory Tcells sculpts tumor evolution in non-small cell lung cancer.

Tissue-resident memory T (TRM) cells provide immune defense against local infection and can inhibit cancer progression. However, it is unclear to what extent chronic inflammation impacts TRM activation and whether TRM cells existing in tissues before tumor onset influence cancer evolution in humans. We performed deep profiling of healthy lungs and lung cancers in never-smokers (NSs) and ever-smokers (ESs), finding evidence of enhanced immunosurveillance by cells with a TRM-like phenotype in ES lungs. In preclinical models, tumor-specific or bystander TRM-like cells present prior to tumor onset boosted immune cell recruitment, causing tumor immune evasion through loss of MHC class I protein expression and resistance to immune checkpoint inhibitors. In humans, only tumors arising in ES patients underwent clonal immune evasion, unrelated to tobacco-associatedmutagenic signatures or oncogenic drivers. These data demonstrate that enhanced TRM-like activity prior to tumor development shapes the evolution of tumor immunogenicity and can impact immunotherapy outcomes.

Lung Cancer Incidence by Detailed Race-Ethnicity.

Lung cancer (LC) incidence rates and tumor characteristics among (non-Hispanic) Black and Hispanic detailed groups, normally characterized in aggregate, have been overlooked in the US. We used LC data from the Florida state cancer registry, 2012-2018, to compute LC age-adjusted incidence rates (AAIR) for US-born Black, Caribbean-born Black, Mexican, Puerto Rican, Cuban, Dominican, and Central and South American populations. We analyzed 120,550 total LC cases. Among Hispanics, Cuban males had the highest AAIR (65.6 per 100,000; 95%CI: 63.6-67.6), only 8% [Incidence Rate Ratio (IRR): 0.92; 95%CI: 0.89-0.95] lower than Whites, but 2.7 (IRR 95%CI: 2.31-3.19) times higher than Central Americans. Among Blacks, the AAIR for US-born Black males was over three times that of those Caribbean-born (IRR: 3.12; 95%CI: 2.80-3.40) and 14% higher than White males (IRR: 1.14; 95%CI: 1.11-1.18). Among women, US-born Blacks (46.4 per 100,000) and foreign-born Mexicans (12.2 per 100,000) had the highest and lowest rates. Aggregation of non-Hispanic Blacks or Hispanics obscures inherent disparities within groups. Understanding the distinct LC rates in US populations is crucial for targeting public health measures for LC diagnosis, prevention, and treatment. Further LC research exploring detailed race-ethnicity regarding LC in never-smokers is necessary, particularly among females and considering pertinent environmental factors.

Abstract 2088: gCNV-Seeker: A comprehensive germline CNV calling pipeline based on whole genome sequencing data

Abstract Germline Copy Number Variation (gCNV) is a type of genomic structural alteration including deletion or duplication of small genomic regions (50bp to 1MB) and can have an important role into cancer etiology. Whole genome sequencing (WGS) has been considered to be the most effective technology for genome-wide identification of gCNVs. However, an easy-to-use gCNV calling pipeline based on WGS data is still lacking. Here, we present the gCNV-Seeker, a user-friendly, rigorous computational pipeline to detect gCNV events based on WGS with standardized quality control and data visualization features. gCNV-Seeker initially adopts GATK probabilistic algorithms to detect a set of raw gCNV events and subsequently applies Binary Segmentation and Pruned Exact Linear Time (PELT) algorithms for re-segmentation and boundary revision of the gCNV candidates, respectively. In addition, gCNV-Seeker is built with several functionalities, including quality control, filtration, annotation and visualization to identify the gCNV regions (gCNVRs) of interest. We applied gCNV-Seeker to the WGS data from 872 lung cancers in never smokers from the Sherlock-Lung study and 3202 WGS data from the 1000 Genomes Project (1KGP) (reference) and identified CNVRs associated with lung cancer risk in never smokers. For example, in comparison to WGS data from 1KGP, we identified several CNVR candidates overlapping with known LC susceptible genes, e.g., the GSTM1/2 homozygous deletion (OR = 1.64, 95% CI=1.43-1.88, P &amp;lt; 0.01) and CYP2A6/7 homozygous or heterozygous deletion (OR = 1.59, 95% CI=1.24-2.03, P &amp;lt; 0.01). To evaluate its performance, we also carried out a comprehensive comparison of gCNV calling results between gCNV-Seeker and the 1KGP structural variant calling pipelines (PMID: 36055201) for common gCNVRs in the 1KGP WGS data. gCNV-Seeker showed a significant improvement on specificity and sensitivity for gCNVR detection compared with the 1KGP pipeline. In terms of specificity, 1315 out of 2692 (HGSV_9692) GSTM1/2 heterozygous deletion events (48.85%) originally identified by 1KGP were detected as homozygous deletions by gCNV-Seeker. These results were further confirmed by manual check. In terms of sensitivity, gCNV-Seeker detected total 299 deletion events in CYP2A6/7 regions, which were also manually confirmed. This corresponds to an increase of 48.02% compared to the 202 deletion events (HGSV_232739 &amp; HGSV_232740) originally identified by the 1KGP pipeline. gCNV-Seeker will be a publicly available cross-platform (Linux and IOS) pipeline accessible in GitHub. Citation Format: Jian Sang, Tongwu Zhang, David Wedge, Maria Teresa Landi. gCNV-Seeker: A comprehensive germline CNV calling pipeline based on whole genome sequencing data [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2088.

Abstract 6056: A nested case-control study of untargeted plasma metabolomics and lung cancer risk among never-smoking women in the prospective Shanghai Women’s Health Study

Abstract Background: The etiology of lung cancer among never-smokers is unclear despite 15% of cases in men and 53% in women worldwide are not smoking-related. Metabolomics provides a snapshot of dynamic biochemical activities, including those found to be driving tumor formation and progression. This study used untargeted metabolomics with network analysis to agnostically identify network modules and independent metabolites in pre-diagnostic blood samples among never-smokers to further understand the pathogenesis of lung cancer. Methods: Within the prospective Shanghai Women’s Health Study, we conducted a nested case-control study of 395 never-smoking incident lung cancer cases and 395 never-smoking controls matched on age. We performed liquid chromatography high-resolution mass spectrometry to quantify 20,348 unique metabolic features in plasma. Because metabolic features are expected to be highly correlated and more likely to be involved in biological processes as a network of intertwined features than individually, we agnostically constructed 28 network modules using a weighted correlation network analysis approach. The associations between metabolite network modules and individual metabolites with lung cancer were assessed using conditional logistic regression models, adjusting for age, body mass index, and exposure to environmental tobacco smoke. We accounted for multiple testing using a false discovery rate (FDR) &amp;lt; 0.20. Results: We identified a network module of 122 metabolic features enriched in lysophosphatidylethanolamines that was associated with all lung cancer combined (p = 0.001, FDR = 0.028) and lung adenocarcinoma (p = 0.002, FDR = 0.056) and another network module of 440 metabolic features that was associated with lung adenocarcinoma (p = 0.014, FDR = 0.196). Metabolic features were enriched in pathways associated with cell growth and proliferation, including oxidative stress, bile acid biosynthesis, and metabolism of nucleic acids, carbohydrates, and amino acids, including 1-carbon compounds. Conclusions: Our prospective study suggests that untargeted plasma metabolomics in pre-diagnostic samples could provide new insights into the etiology of lung cancer in never-smokers. Replication and further characterization of these associations are warranted. Citation Format: Mohammad L. Rahman, Xiao-Ou Shu, Douglas Walker, Dean P. Jones, Wei Hu, Bu-tian Ji, Batel Blechter, Jason YY Wong, Qiuyin Cai, Gong Yang, Tu-Tang Gao, Wei Zheng, Nathaniel Rothman, Qing Lan. A nested case-control study of untargeted plasma metabolomics and lung cancer risk among never-smoking women in the prospective Shanghai Women’s Health Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6056.

Abstract 861: Modelling the role of EGFR mutation in the initiation of never-smoker lung cancer

Abstract Genetic mutations associated with never-smoker lung cancer frequently appear in normal lung tissue, in both cancer and non-cancer patients. It is unclear what circumstances are required for a mutation to fix in healthy tissue and eventually lead to a tumor. To investigate this, alveolar type-II murine cells were grown in a 3D nutrient system, forming spheroidal clusters. The volumes of these clusters were measured at 7 and 14 days and a mathematical model was devised to describe their growth. In the absence of an EGFR mutation, variations in growth between clusters can be explained by a skew-normal distribution of initial division rates. These rates decline exponentially as the clusters age, and the decline rate is the same across clusters. When cells possess an epidermal growth factor receptor (EGFR) mutation or are grown in the presence of interleukin-1 beta (il-1b) growth factor, clusters form more complex shapes, which we believe may be driven by branching processes and cell-cell interactions. Accordingly, more complex models are needed to explain their development. This work lays the groundwork for new, parameterized models of mutational spread in lung tissue, and a deeper understanding of the role of mutation in carcinogenesis. Citation Format: Helena M. Coggan, Clare E. Weeden, Mohit Dalwadi, Charles Swanton, Philip Pearce, Karen M. Page. Modelling the role of EGFR mutation in the initiation of never-smoker lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 861.