Lung cancer is the leading cause of cancer-related death in the United States. Here, we evaluated the potential clinical utility of soluble human epidermal growth factor receptor 2 (sHER2) for the risk assessment, screening, and diagnosis of non-small cell lung cancer (NSCLC) using an unmatched case-control study design. Serum sHER2 concentrations were measured by immunoassay in 244 primary NSCLC cases and 218 healthy controls. Wilcoxon rank-sum tests, logistic regression models, and receiver operating characteristic plots were used to assess whether sHER2 is associated with lung cancer. Median serum sHER2 concentrations are higher in patients with adenocarcinoma than squamous cell carcinoma regardless of gender, and sHER2 is a weak, independent biomarker of adenocarcinoma, but not of squamous cell carcinoma, adjusted for age and gender. The age-adjusted relative risk (odds) of adenocarcinoma is 3.95 (95% CI: 1.22, 12.81) and 7.93 (95% CI: 2.26, 27.82) greater for women and men with high sHER2 concentrations (≥6.60 ng/mL) vs. low sHER2 concentrations (≤1.85 ng/mL), respectively. When adjusted for each other, sHER2, age, and gender discern healthy controls from patients with primary adenocarcinomas of the lung with 85.9% accuracy. We conclude that even though serum sHER2 is not a strong, stand-alone discriminatory biomarker of adenocarcinoma, sHER2 may be a useful, independent covariate in multivariate risk assessment, screening, and diagnostic models of lung cancer.
Predictors of Survival in Never-Smokers with Non–Small Cell Lung Cancer: A Large-Scale, Two-Phase Genetic Study
Abstract Lung cancer in never-smokers is increasingly recognized as distinct from that in ever-smokers owing to substantial differences in etiology, clinical characteristics, and prognosis. Therefore, we aimed to identify prognostic markers specific for lung cancer in never-smokers in a two-stage study. First, 11,930 single-nucleotide polymorphisms (SNPs) in 904 inflammation-related genes were genotyped, and their associations with overall survival in 411 never-smokers with lung cancer at The University of Texas MD Anderson Cancer Center were analyzed. Next, fast-track validation of the top 37 SNPs in 311 never-smokers with lung cancer at Mayo Clinic was performed. Three SNPs (interleukin 17 receptor A:rs879576, bone morphogenetic protein 8A:rs698141, and spleen tyrosine kinase:rs290229) were validated (p<0.05), and two more SNPs (CD74:rs1056400 and CD38:rs10805347) were borderline significant (p=0.08) in the Mayo Clinic population. In combined analysis of the MD Anderson and Mayo Clinic patients, IL17RA:rs879576 resulted in a 40% reduction in the risk of death (p=4.1 × 10−5 [p=0.61, heterogeneity test]). We successfully validated a survival tree created in MD Anderson population based on gene-gene interactions in the Mayo Clinic population. This survival tree stratified patients into subsets with significantly different risks of death: patients at MD Anderson with the rs1056400_GG/rs698141_GA+AA genotype had a 2.32-fold higher risk of death (p=1.72 × 10−5) and 9-month shorter median survival time (MST) (p=4.5 × 10−4, log-rank test) than did those with the rs1056400_GG/rs698141_GG or rs1056400_GA+AA genotype in the discovery phase. Also, the patients at Mayo Clinic with the former genotype had an approximately twofold higher risk of death (p=0.02) and a strikingly shorter (by 26 months) MST (p=0.029, log-rank test) than did those with the latter genotype in the validation phase. We evaluated these five SNPs in 996 ever-smokers and found no significant associations. To our knowledge, this is the first study to systematically evaluate the associations of genetic variations in major inflammation-related genes with outcome of lung cancer in never-smokers. It provides strong evidence that inflammation-related genetic variations can affect clinical outcomes in these patients, which may lead to significant biological insight into these outcomes. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2929. doi:1538-7445.AM2012-2929
Abstract LB-346: MiRNA and gene expression signatures in lung adenocarcinoma from never-smokers
Abstract Lung cancer is the most common cause of smoking-related mortality in worldwide. However, approximately 10 to 25 % cases are not attributable to smoking. Cumulative evidence suggests that lung cancer from never smokers (<100 cigarettes lifetime) may develop via molecular mechanisms that are different from lung cancers in smokers. Recently, miRNAs have been identified as a new class of regulatory molecules that participate in a variety of biological processes. Because each miRNAs can potentially target a large set of mRNA making and therefore may play a critical role in lung tumorigenesis and patient outcome, we sought to examine the role of miRNA in lung adenocarcinoma among never smokers. A total of 298 samples were analyzed in this study including 168 fresh frozen (FF) tissues from 88 lung adenocarcinomas and 80 adjacent non-involved lung tissues; and 132 formalin-fixed paraffin embedded (FFPE) tissues from 68 tumors and 64 normal lung samples. Gene expression profiling was performed for miRNA and mRNA using Illumina Whole Genome DASL platform. We identified 20 miRNAs with the most significant expression changes between the tumor and normal in both FF and FFPE samples (Fold change > 1.5, p <0.01, FDR <0.05). We also examined mRNA expression signature using 56 matched FF tumors and normal lung tissues. Cox proportional hazard analysis was performed independently for both FF and FFPE cohorts and showed that increased expression of mir-708 was strongly associated with an increased risk of patient death after adjusting for age, sex and tumor stage (FF cohort, HR =1.92; 95% CI =1.02–3.63; p < 0.05 and FFPE cohort, HR=1.90; 95% CI=1.08–3.34; P < 0.05). Candidate biological targets of mir-708 were identified using TargetScan and MicroCosm Targets databases. A total of 13 candidate genes were found and one of these genes, CMT11 (Candidate Mir-708 Target), was down-regulated 1.6 fold on average in tumors that were high in mir-708 expression. Based on the sequence, CMT11 is a novel transmembrane protein. In Cox analysis, reduced CMT11 expression was strongly correlated with an increased risk of death in patients (HR = 2.43, 95% CI = 1.17 − 5.26; P <0.01). Functionally, overexpression of mir-708 in A549 and HEK293T cells significantly increased the rate of cellular proliferation and migration. Over expression of mir-708 in HEK293T cells also repressed ∼70% of the luciferase activity when the reporter RNA contained the 3′ UTR of CMT11. Recently, several studies have showed mir-708 is a potential squamous cell lung cancer marker and one of miRNAs that may predict the recurrence of Stage I lung cancer after surgical resection. Additional evidence also suggests that CMT11 is a negative regulator of Wnt-signaling pathway. Our data provides clinical and functional evidence supporting an important role of mir-708 in lung cancer progression and identifies CMT11 as a down stream target gene mediating this process. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-346. doi:10.1158/1538-7445.AM2011-LB-346
Abstract 5060: Gene network predicts overall survival in patients with primary lung adenocarcinoma
Abstract Lung adenocarcinoma is the most common type of primary lung cancer. Previous studies have shown that gene expression signatures may predict clinical outcome. In this study, we used a systems biology approach, weighted gene co-expression network analysis (WGCNA), to identify survival related networks and gene signatures. We first analyzed whole genome gene expression profiles in 82 lung adenocarcinoma tumor tissues from never smokers (smoked <100 cigarettes lifetime) and found a significant correlation of an expression module with tumor grade of differentiation (r=0.38, p=4×10−4) and overall survival (OS, p =0.027, HR, 1.71; 95% CI, 1.06-2.74) after adjusting for potential confounders (age and tumor grade). When this module signature was incorporated and compared to the conventional model consisting of clinical variables only, the survival prediction accuracy was increased from 0.70 to 0.75. Gene Ontology (GO) enrichment analysis indicated this module was significantly enriched in biological process GO term “cell cycle” (p = 2.1×10−53). To explore the effect of this network module at germline level, we performed the WGCNA on normal lung tissues derived from 78 of the 82 patients and observed significant association of an expression module with OS (adjusted p=3×10−4, HR=1.98; 95% CI, 1.36-2.87). Interestingly, this module was also significantly enriched in cell cycle-related genes (p=4.1×10−41). To further validate this result, we analyzed an independent microarray gene expression dataset including 442 lung adenocarcinoma patients from NCI Director's Challenge Consortium. We found the same association: the cell cycle-enriched module was correlated with tumor grade of cell differentiation (r=0.55, p-value=5×10−37) and OS (adjusted p=7.4×10−3; HR, 1.20; 95% CI, 1.05-1.37). We further identified 30 genes in the OS-related module that overlapped between the discovery and validation data sets. Furthermore, all these 30 genes were found to be up-regulated in adenocarcinoma compared to adjacent normal lung tissues in the discovery data set. Of the 30 genes, three key genes, UBE2C, TPX2 and MELK, were identified with highest connectivity in cell cycle-enriched module; their expression levels were significantly associated with OS in both discovery and validation sets. UBE2C and TPX2 have been reported as gene signatures for human lung cancer prognosis in vitro lung carcinogenesis system; MELK was identified as a key regulator of the proliferation of malignant brain tumors and malignant grade in human astrocytomas, and was also associated with breast cancer prognosis. Our results suggest that genes involved in cell-cycle are likely related with tumor aggressiveness and therefore can predict survival in lung adenocarcinoma. Further studies are needed to validate the key genes that could improve survival prediction and provide potential new targets to intervene progression of lung adenocarcinoma. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5060. doi:10.1158/1538-7445.AM2011-5060
Abstract 1285: Genetic variations predicting cisplatin cytotoxicity associated with the overall survival in lung cancer patients receiving platinum-based chemotherapy
Abstract Background: Candidate gene and candidate pathway-based pharmacogenomic studies have been used to investigate the inherited variability of prognosis of lung cancer treated with platinum-based chemoptherapy. In order to make it possible to conduct an ‘unbiased’ query across the entire genome, a genome-wide association study (GWAS) in 283 lymphoblastoid cell lines (LCLs) was carried out to help identify candidate SNPs associated with variation in cisplatin cytotoxicity. Furthermore, we set out to test the hypothesis that genetic variation resulting in differences in cisplatin cytotoxicity might influence the overall survival of patients with lung cancer treated with platinum-based antineoplastic agents. Material and Methods: We applied ethnically diverse Coriell “Human Variation Panel” LCLs for GWAS. Then, we picked 168 top significant SNPs selected from GWAS in 283 LCLs and genotyped these SNPs in 1183 lung cancer patients (222 SCLC and 961 NSCLC) who received platinum-based chemotherapy. Genotyping was performed using the Illumina Golden Gate platform. The association of SNPs with lung cancer overall survival was analyzed by Cox regression model after adjusting for disease stage. Functional validation of candidate genes was performed by siRNA screening in NSCLC cell lines CRL5872, H1299 and SCLC cell line CRL5823. Results: A total of 157 SNPs were successfully genotyped for 1183 lung cancer patient samples. The Cox regression analysis indicated that 9 and 10 different SNPs were associated with overall survival for NSCLC and SCLC patients, respectively (p value <0.05). Fifteen genes including 7 genes located in the region of 200kb up or downstream of 4 SNPs (rs11169748, rs2440915, rs5952066 and rs7620841) and 8 genes for which the expression was correlated with three SNPs (rs11169748, rs2440915 and rs5952066) were selected for siRNA screening. Knockdown of DAPK3 and METTL6, for which the expression levels were correlated with the SNPs rs11169748 and rs2440915, significantly decreased cisplatin sensitivity in lung cancer cell lines CRL5872, H1299 and CRL5823. Conclusions: This series of clinical and complementary laboratory-based functional studies identified several candidate genes and SNPs that might help predict treatment outcomes of platinum-based therapy in lung cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1285. doi:10.1158/1538-7445.AM2011-1285
EGFR Somatic Mutations in Lung Tumors: Radon Exposure and Passive Smoking in Former- and Never-Smoking U.S. Women
Purpose Recent evidence has suggested a relationship between the baseline quality of life (QOL) self-reported by patients with cancer and genetic disposition. We report an analysis exploring relationships among baseline QOL assessments and candidate genetic variations in a large cohort of patients with lung cancer. Patients and Methods QOL data were provided by 1,299 patients with non–small-cell lung cancer observed at the Mayo Clinic between 1997 and 2007. Overall QOL and subdomains were assessed by either Lung Cancer Symptom Scale or Linear Analog Self Assessment measures; scores were transformed to a scale of 0 to 10, with higher scores representing better status. Baseline QOL scores assessed within 1 year of diagnosis were dichotomized as clinically deficient (CD) or not. A total of 470 single nucleotide polymorphisms (SNPs) in 56 genes of three biologic pathways were assessed for association with QOL measures. Logistic regression with training/validation samples was used to test the association of SNPs with CD QOL. Results Six SNPs on four genes were replicated using our split schemes. Three SNPs in the MGMT gene (adjusted analysis, rs3858300; unadjusted analysis, rs10741191 and rs3852507) from DNA repair pathway were associated with overall QOL. Two SNPs (rs2287396 [GSTZ1] and rs9524885 [ABCC4]) from glutathione metabolic pathway were associated with fatigue in unadjusted analysis. In adjusted analysis, two SNPs (rs2756109 [ABCC2] and rs9524885 [ABCC4]) from glutathione metabolic pathway were associated with pain. Conclusion We identified three SNPs in three glutathione metabolic pathway genes and three SNPs in two DNA repair pathway genes associated with QOL measures in patients with non–small-cell lung cancer.