A practical molecular assay to predict survival in resected non-squamous, non-small-cell lung cancer: development and international validation studies.

BACKGROUND: The frequent recurrence of early-stage non-small-cell lung cancer (NSCLC) is generally attributable to metastatic disease undetected at complete resection. Management of such patients depends on prognostic staging to identify the individuals most likely to have occult disease. We aimed to develop and validate a practical, reliable assay that improves risk stratification compared with conventional staging. METHODS: A 14-gene expression assay that uses quantitative PCR, runs on formalin-fixed paraffin-embedded tissue samples, and differentiates patients with heterogeneous statistical prognoses was developed in a cohort of 361 patients with non-squamous NSCLC resected at the University of California, San Francisco. The assay was then independently validated by the Kaiser Permanente Division of Research in a masked cohort of 433 patients with stage I non-squamous NSCLC resected at Kaiser Permanente Northern California hospitals, and on a cohort of 1006 patients with stage I-III non-squamous NSCLC resected in several leading Chinese cancer centres that are part of the China Clinical Trials Consortium (CCTC). FINDINGS: Kaplan-Meier analysis of the Kaiser validation cohort showed 5 year overall survival of 71·4% (95% CI 60·5-80·0) in low-risk, 58·3% (48·9-66·6) in intermediate-risk, and 49·2% (42·2-55·8) in high-risk patients (p(trend)=0·0003). Similar analysis of the CCTC cohort indicated 5 year overall survivals of 74·1% (66·0-80·6) in low-risk, 57·4% (48·3-65·5) in intermediate-risk, and 44·6% (40·2-48·9) in high-risk patients (p(trend)<0·0001). Multivariate analysis in both cohorts indicated that no standard clinical risk factors could account for, or provide, the prognostic information derived from tumour gene expression. The assay improved prognostic accuracy beyond National Comprehensive Cancer Network criteria for stage I high-risk tumours (p<0·0001), and differentiated low-risk, intermediate-risk, and high-risk patients within all disease stages. INTERPRETATION: Our practical, quantitative-PCR-based assay reliably identified patients with early-stage non-squamous NSCLC at high risk for mortality after surgical resection. FUNDING: UCSF Thoracic Oncology Laboratory and Pinpoint Genomics.

Downregulation of EMX2 is associated with clinical outcomes in lung adenocarcinoma patients.

BACKGROUND: The 5-year survival rate for stage I non-small-cell lung cancer (NSCLC) of 50% to 70% indicates that our current staging methods do not adequately predict outcome. Empty spiracles homeobox 2 (EMX2) is a homeo-domain-containing transcription factor that regulates a key developmental pathway known to promote lung tumorigenesis. This study assessed the significance of EMX2 as a prognostic biomarker in lung adenocarcinoma including bronchioloalveolar carcinoma (BAC). PATIENTS AND METHODS: 144 patients with lung adenocarcinoma undergoing surgical resection were studied. Quantitative real-time reverse transcriptase polymerase chain reaction and Immunohistochemistry were used to analyze EMX2 mRNA and protein expression, respectively. Association of EMX2 mRNA expression levels with clinical outcomes was evaluated using the Kaplan-Meier method and a multivariate Cox proportional hazards regression model. RESULTS: EMX2 mRNA expression was significantly downregulated in lung adenocarcinoma compared with matched adjacent normal tissue (P < .001). EMX2 protein expression was similarly found to be downregulated in lung adenocarcinoma. The EMX2-high mRNA expressing group had statistically significant better overall survival (OS) than the EMX2-low mRNA expressing group (P = .005). Subgroup analysis also demonstrated improved survival in stage I patients (P = .01) and patients with BAC (P = .03). Lastly, the EMX2-high mRNA expressing group had statistically significant better recurrence-free survival (RFS) than the EMX2-low mRNA expression group in patients with adenocarcinoma (P < .001). CONCLUSION: EMX2 expression is downregulated in lung adenocarcinoma. Low EMX2 mRNA expression is significantly associated with decreased OS and RFS in patients with lung adenocarcinoma, particularly with stage I disease and BAC.

Lung cancer therapeutics that target signaling pathways: an update.

Claiming more than 150,000 lives each year, lung cancer is the deadliest cancer in the USA. First-line treatments in lung cancer include surgical resection and chemotherapy, the latter of which offers only modest survival benefits at the expense of often severe and debilitating side effects. Recent advances in elucidating the molecular biology of lung carcinogenesis have elucidated novel drug targets, and treatments are rapidly evolving into specialized agents that hone in on specific aspects of the disease. Of particular interest is blocking tumor growth by targeting the physiological processes surrounding angiogenesis, pro-tumorigenic growth factor activation, anti-apoptotic cascades and other cancer-promoting signal transduction events. This article looks at several areas of interest to lung cancer therapeutics and considers the current state of affairs surrounding the development of these therapies.

Inhibition of Hsp90 leads to cell cycle arrest and apoptosis in human malignant pleural mesothelioma.

INTRODUCTION: Heat shock protein 90 (Hsp90) is an abundant molecular chaperone that mediates the maturation and stability of a variety of proteins associated with the promotion of cell growth and survival. Inhibition of Hsp90 function leads to proteasomal degradation of its mis-folded client proteins. Recently, Hsp90 has emerged as being of prime importance to the growth and survival of cancer cells and its inhibitors have already been used in phase I and II clinical trials. METHODS: We investigated how 17-allylamino-17-demethoxygeldanamycin (17-AAG), a small molecule inhibitor of Hsp90, is implicated in human malignant pleural mesothelioma (MM). RESULTS: We found that 17-AAG led to significant G1 or G2/M cell cycle arrest, inhibition of cell proliferation, and decrease of AKT, AKT1, and survivin expression in all human malignant pleural mesothelioma cell lines examined. We also observed significant apoptosis induction in all MM cell lines treated with 17-AAG. Furthermore, 17-AAG induced apoptosis in freshly cultured primary MM cells and caused signaling changes identical to those in 17-AAG treated MM cell lines. CONCLUSION: These results suggest that Hsp90 is strongly associated with the growth and survival of MM and that inhibition of Hsp90 may have therapeutic potential in the treatment of MM.

A multigene assay is prognostic of survival in patients with early-stage lung adenocarcinoma.

PURPOSE: Clinical staging does not adequately risk stratify patients with early stage non-small cell lung cancer. We sought to generate a real-time PCR (RT-PCR)-based prognostic model in patients with early stage lung adenocarcinoma, the dominant histology of lung cancer in the United States. EXPERIMENTAL DESIGN: We studied gene expression of 61 candidate genes in 107 patients with completely surgically resected lung adenocarcinoma using RT-PCR. We used crossvalidation methods to select and validate a prognostic model based on the expression of a limited number of genes. A risk score was generated based on model coefficients, and survival of patients with high- and low-risk scores were analyzed. RESULTS: We generated a four-gene model based on expression of WNT3a, ERBB3, LCK, and RND3. Risk score predicted mortality better than clinical stage or tumor size (adjusted hazard ratio, 6.7; 95% confidence interval, 1.6-28.9; P=0.001). Among 70 patients with stage I disease, 5-year overall survival was 87% among patients with low-risk scores, and 38% among patients with high-risk scores (P=0.0002). Among all patients, 5-year overall survival was 62% and 41%, respectively (P=0.0054). Disease-free survival was also significantly different among low- and high-risk score patients. CONCLUSIONS: This multigene assay predicts overall and disease-free survival significantly better than clinical stage and tumor size in patients with early stage lung adenocarcinoma and performs especially well in patients with stage I disease. Prospective clinical trials are needed to determine whether high-risk patients with stage I disease benefit from adjuvant chemotherapy.