Jun-Chieh Tsay

Enrichment of the lung microbiome with oral taxa is associated with lung inflammation of a Th17 phenotype.

Microaspiration is a common phenomenon in healthy subjects, but its frequency is increased in chronic inflammatory airway diseases, and its role in inflammatory and immune phenotypes is unclear. We have previously demonstrated that acellular bronchoalveolar lavage samples from half of the healthy people examined are enriched with oral taxa (here called pneumotypeSPT) and this finding is associated with increased numbers of lymphocytes and neutrophils in bronchoalveolar lavage. Here, we have characterized the inflammatory phenotype using a multi-omic approach. By evaluating both upper airway and acellular bronchoalveolar lavage samples from 49 subjects from three cohorts without known pulmonary disease, we observed that pneumotypeSPT was associated with a distinct metabolic profile, enhanced expression of inflammatory cytokines, a pro-inflammatory phenotype characterized by elevated Th-17 lymphocytes and, conversely, a blunted alveolar macrophage TLR4 response. The cellular immune responses observed in the lower airways of humans with pneumotypeSPT indicate a role for the aspiration-derived microbiota in regulating the basal inflammatory status at the pulmonary mucosal surface.

CT Scan Screening for Lung Cancer: Risk Factors for Nodules and Malignancy in a High-Risk Urban Cohort

Background Low-dose computed tomography (CT) for lung cancer screening can reduce lung cancer mortality. The National Lung Screening Trial reported a 20% reduction in lung cancer mortality in high-risk smokers. However, CT scanning is extremely sensitive and detects non-calcified nodules (NCNs) in 24–50% of subjects, suggesting an unacceptably high false-positive rate. We hypothesized that by reviewing demographic, clinical and nodule characteristics, we could identify risk factors associated with the presence of nodules on screening CT, and with the probability that a NCN was malignant. Methods We performed a longitudinal lung cancer biomarker discovery trial (NYU LCBC) that included low-dose CT-screening of high-risk individuals over 50 years of age, with more than 20 pack-year smoking histories, living in an urban setting, and with a potential for asbestos exposure. We used case-control studies to identify risk factors associated with the presence of nodules (n = 625) versus no nodules (n = 557), and lung cancer patients (n = 30) versus benign nodules (n = 128). Results The NYU LCBC followed 1182 study subjects prospectively over a 10-year period. We found 52% to have NCNs >4 mm on their baseline screen. Most of the nodules were stable, and 9.7% of solid and 26.2% of sub-solid nodules resolved. We diagnosed 30 lung cancers, 26 stage I. Three patients had synchronous primary lung cancers or multifocal disease. Thus, there were 33 lung cancers: 10 incident, and 23 prevalent. A sub-group of the prevalent group were stable for a prolonged period prior to diagnosis. These were all stage I at diagnosis and 12/13 were adenocarcinomas. Conclusions NCNs are common among CT-screened high-risk subjects and can often be managed conservatively. Risk factors for malignancy included increasing age, size and number of nodules, reduced FEV1 and FVC, and increased pack-years smoking. A sub-group of screen-detected cancers are slow-growing and may contribute to over-diagnosis and lead-time biases.

Chemoprevention of lung cancer: prospects and disappointments in human clinical trials.

Decreasing the risk of lung cancer, or preventing its development in high-risk individuals, would have a huge impact on public health. The most effective means to decrease lung cancer incidence is to eliminate exposure to carcinogens. However, with recent advances in the understanding of pulmonary carcinogenesis and the identification of intermediate biomarkers, the prospects for the field of chemoprevention research have improved dramatically. Here we review the most recent research in lung cancer chemoprevention—focusing on those agents that have been investigated in human clinical trials. These agents fall into three major categories. First, oxidative stress plays an important role in pulmonary carcinogenesis; and therefore, antioxidants (including vitamins, selenium, green tea extracts, and isothiocyanates) may be particularly effective in preventing the development of lung cancer. Second, inflammation is increasingly accepted as a crucial factor in carcinogenesis, and many investigators have focused on anti-inflammatory agents, such as glucocorticoids, NSAIDs, statins, and PPARγ agonists. Finally, the PI3K/AKT/mTOR pathway is recognized to play a central role in tobacco-induced carcinogenesis, and inhibitors of this pathway, including myoinositol and metformin, are promising agents for lung cancer prevention. Successful chemoprevention will likely require targeting of multiple pathways to carcinogenesis—both to minimize toxicity and maximize efficacy.

Molecular Characterization of the Peripheral Airway Field of Cancerization in Lung Adenocarcinoma

Field of cancerization in the airway epithelium has been increasingly examined to understand early pathogenesis of non-small cell lung cancer. However, the extent of field of cancerization throughout the lung airways is unclear. Here we sought to determine the differential gene and microRNA expressions associated with field of cancerization in the peripheral airway epithelial cells of patients with lung adenocarcinoma. We obtained peripheral airway brushings from smoker controls (n=13) and from the lung contralateral to the tumor in cancer patients (n=17). We performed gene and microRNA expression profiling on these peripheral airway epithelial cells using Affymetrix GeneChip and TaqMan Array. Integrated gene and microRNA analysis was performed to identify significant molecular pathways. We identified 26 mRNAs and 5 miRNAs that were significantly (FDR <0.1) up-regulated and 38 mRNAs and 12 miRNAs that were significantly down-regulated in the cancer patients when compared to smoker controls. Functional analysis identified differential transcriptomic expressions related to tumorigenesis. Integration of miRNA-mRNA data into interaction network analysis showed modulation of the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) pathway in the contralateral lung field of cancerization. In conclusion, patients with lung adenocarcinoma have tumor related molecules and pathways in histologically normal appearing peripheral airway epithelial cells, a substantial distance from the tumor itself. This finding can potentially provide new biomarkers for early detection of lung cancer and novel therapeutic targets.

Reduced lung function in smokers in a lung cancer screening cohort with asbestos exposure and pleural plaques

BACKGROUND While low dose computed tomography (LDCT) screening for lung cancer is recommended for high-risk smokers, ages 55-74 years, information about asbestos exposure may not be routinely elicited. Asbestos exposure is associated with declining respiratory function over time; however, the effect of a history of asbestos exposure in LDCT screening cohorts is limited. We report the relationship between asbestos exposure and pulmonary function in a cohort of heavy smokers with a history of occupational asbestos exposure, hypothesizing that these subjects will have additional decreased pulmonary function. We also examined relationships between spirometric measurements and the presence of isolated pleural plaques. METHODS A cross-sectional study was performed using data from the NYU Lung Cancer Biomarker Center cohort to compare study subjects with a history asbestos exposure primarily in the period since 1970 when tighter federal standards were in place (n = 359) to those without asbestos exposure (n = 1038) with respect to pulmonary function, LDCT lung imaging findings, and clinical symptoms. We further classified individuals with asbestos exposure by length of exposure time to examine the effect of duration of exposure on pulmonary function. Lastly, for asbestos-exposed participants, we examined the association of spirometric measurements with the presence of absence of isolated pleural plaques. RESULTS Individuals with asbestos exposure had decreased FVC % predicted compared to those with no asbestos exposure (76% vs. 85% predicted, P < 0.01) and FEV1 % predicted (64% vs. 67% predicted, P < 0.01). Since there was no change in FEV1 /FVC ratio, the findings are consistent with restrictive impairment. Those with ≥20 years of exposure had a lower mean FVC % predicted compared to those with less than 20 years of exposure (74% vs. 78% predicted, P = 0.017). Individuals with asbestos exposure were more likely to have pleural plaques (P < 0.001) on CT. Those with isolated pleural plaques had lower mean % predicted FEV1 (P = 0.005) and FVC (P = 0.001) compared to those without pleural plaques. CONCLUSIONS Occupational asbestos exposure in a cohort of heavy smokers was associated with a significant restrictive decline in pulmonary function, with longer duration of exposure associated with greater decline. The presence of isolated pleural plaques was also associated with reduced lung function.

Current Readings: Blood-Based Biomarkers for Lung Cancer

Lung cancer is the leading cause of cancer deaths worldwide largely owing to diagnosis of the disease at an advanced stage. Recent advances in blood-based biomarker research have the potential to reduce mortality by providing a means for detecting lung cancer at an earlier stage. Since the publication of the National Lung Cancer Screening Trial demonstrating reduction in mortality with computed tomography (CT) scan screening, the U.S. Preventive Services Task Force has released a draft statement recommending annual low-dose CT scan screening for high-risk patients. However, CT screening has a high false-positive rate leading to the need for additional imaging and invasive procedures. In this article, we review recent literature on blood-based lung cancer biomarkers that we believe will have a significant role in enhancing screening efficacy in the near future.

Inflammatory cytokines and non-small cell lung cancer in a CT-scan screening cohort: Background review of the literature.

BACKGROUND Inflammatory cytokines are at the intersection of tumor cell biology and host immune response. Peripheral cytokine expression levels may reflect the microscopic tumor milieu, and specific cytokines play an integral role in tumor initiation, growth, and metastasis. High-throughput cytokine analysis may identify panels for early-stage non-small cell lung cancer (NSCLC) diagnosis and identify individuals at high-risk for lung cancer with indeterminate lung nodules 8-20 mm in size. METHODS Thirteen serum cytokines from the NYU Lung Cancer Biomarker Center cohort with early-stage NSCLC were analyzed using bead-based immunoassay technology. RESULTS In the NYU cohort, a one unit increase in interferon-γ increased risk of lung cancer by 3% (OR = 1.03, 95% CI, 1.02-1.05) and a one unit increase in TNF-α decreased the risk of lung cancer by 53% (OR = 0.47, 95% Cl, 0.31-0.71) when both cytokines were included in a logistic regression model with adjustments for age and pack-years of smoking. The resulting AUC for the Receiver Operating Characteristic (ROC) curve was 0.88; the sensitivity and specificity at the optimal cutpoint were 78.9% and 90.3%, respectively. CONCLUSIONS Cytokines have limited value in the early diagnosis of early-stage NSCLC. Our review of the literature suggests that although inflammation is important for the development of NSCLC, that cytokines are increased in more advanced lung cancer than when the diagnosis occurs at presentation.

Preclinical Biomarkers for the Early Detection of Lung Cancer

Noninvasive biomarkers in the blood, sputum, airway epithelium, or exhaled breath can be combined with imaging to detect early-stage lung cancer and improve mortality. Lung cancer biomarkers may reduce the problem of overdiagnosis in lung cancer screening. There has been a proliferation of research on lung cancer biomarkers, and a large number of potential diagnostic biomarkers have been identified. A novel multiomics approach to biomarker discovery has greatly advanced the field of early lung cancer detection. All of the biomarkers identified so far must be validated in larger independent clinical cohorts. Guidelines for biomarker study design and statistical evaluation suggest that validation should be conducted using a prospective specimen collection retrospective blinded evaluation design. Standardization of validation studies and the development of high-quality longitudinal cohorts for testing of promising markers should usher in a new age of biomarker validation.

Airway Microbiota Is Associated with Up-Regulation of the PI3K Pathway in Lung Cancer

Rationale: In lung cancer, upregulation of the PI3K (phosphoinositide 3‐kinase) pathway is an early event that contributes to cell proliferation, survival, and tissue invasion. Upregulation of this pathway was recently described as associated with enrichment of the lower airways with bacteria identified as oral commensals. Objectives: We hypothesize that host‐microbe interactions in the lower airways of subjects with lung cancer affect known cancer pathways. Methods: Airway brushings were collected prospectively from subjects with lung nodules at time of diagnostic bronchoscopy, including 39 subjects with final lung cancer diagnoses and 36 subjects with noncancer diagnoses. In addition, samples from 10 healthy control subjects were included. 16S ribosomal RNA gene amplicon sequencing and paired transcriptome sequencing were performed on all airway samples. In addition, an in vitro model with airway epithelial cells exposed to bacteria/bacterial products was performed. Measurements and Main Results: The composition of the lower airway transcriptome in the patients with cancer was significantly different from the control subjects, which included up‐regulation of ERK (extracellular signal‐regulated kinase) and PI3K signaling pathways. The lower airways of patients with lung cancer were enriched for oral taxa (Streptococcus and Veillonella), which was associated with up‐regulation of the ERK and PI3K signaling pathways. In vitro exposure of airway epithelial cells to Veillonella, Prevotella, and Streptococcus led to upregulation of these same signaling pathways. Conclusions: The data presented here show that several transcriptomic signatures previously identified as relevant to lung cancer pathogenesis are associated with enrichment of the lower airway microbiota with oral commensals.

Abstract 710: Identification of autoantibody to ECH1 & HNRNPA2B1 as potential biomarkers in the early detection of lung cancer

Background: Identification of biomarkers for early detection of lung cancer (LC) may lead to more effective treatment and reduction of mortality. Methods: Serological proteome analysis (SERPA) was used to identify proteins around 34 kDa, which had been previously recognized by autoantibody in sera from LC patients. We have validated autoantibody response in sera from 90 LC patients, 89 normal controls by using immunoassay. Another independent cohort of 25 LC patients with 219 serial serum samples and 56 matched normal controls were examined to evaluate whether the autoantibody can be detected in the preclinical stage. Results: The proteins with molecular weight of 34 kDa were identified as ECH1, GAPDH and HNRNPA2B1. In the validation study, autoantibody to ECH1 achieved an area under the curve (AUC) of 0.799 with sensitivity of 62.2% and specificity of 95.5% in discriminating LC from normal individuals, and showed negative correlation with tumor size (r s =0.-256, p=0.023). Autoantibody to HNRNPA2B1 performed an AUC of 0.874 with sensitivity of 72.2% and specificity of 95.5%, and showed negative correlation with lymph node metastasis (r s =0.-279, P=0.012). By using longitudinal preclinical samples, autoantibody to ECH1 showed an AUC of 0.763 with sensitivity of 60.0% and specificity of 89.3% in distinguishing LC with matched normal controls, and elevated autoantibody levels could be detected greater than two years prior to LC diagnosis. Conclusions: ECH1 and HNRNPA2B1 are autoantigens that elicit autoimmune responses in LC and can be used as potential biomarkers for the early detection of LC. Funding support: This work was supported by the National Natural Science Foundation of China (81672917, 81372371) and the National Institutes of Health (SC1CA166016 and U01CA086137). Citation Format: Liping Dai, Jitian Li, Jun-Chieh J. Tsay, Xiao Wang, John S. Munger, Harvey Pass, William N. Rom, Eng M. Tan, Jian-Ying Zhang. Identification of autoantibody to ECH1 & HNRNPA2B1 as potential biomarkers in the early detection of lung cancer [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 710. doi:10.1158/1538-7445.AM2017-710