Rishindra M. Reddy

Survival Outcome After Stereotactic Body Radiation Therapy and Surgery for Stage I Non-Small Cell Lung Cancer: A Meta-Analysis

PURPOSE This study compared treatment outcomes of stereotactic body radiation therapy (SBRT) with those of surgery in stage I non-small cell lung cancer (NSCLC). METHODS AND MATERIALS Eligible studies of SBRT and surgery were retrieved through extensive searches of the PubMed, Medline, Embase, and Cochrane library databases from 2000 to 2012. Original English publications of stage I NSCLC with adequate sample sizes and adequate SBRT doses were included. A multivariate random effects model was used to perform a meta-analysis to compare survival between treatments while adjusting for differences in patient characteristics. RESULTS Forty SBRT studies (4850 patients) and 23 surgery studies (7071 patients) published in the same period were eligible. The median age and follow-up duration were 74 years and 28.0 months for SBRT patients and 66 years and 37 months for surgery patients, respectively. The mean unadjusted overall survival rates at 1, 3, and 5 years with SBRT were 83.4%, 56.6%, and 41.2% compared to 92.5%, 77.9%, and 66.1% with lobectomy and 93.2%, 80.7%, and 71.7% with limited lung resections. In SBRT studies, overall survival improved with increasing proportion of operable patients. After we adjusted for proportion of operable patients and age, SBRT and surgery had similar estimated overall and disease-free survival. CONCLUSIONS Patients treated with SBRT differ substantially from patients treated with surgery in age and operability. After adjustment for these differences, OS and DFS do not differ significantly between SBRT and surgery in patients with operable stage I NSCLC. A randomized prospective trial is warranted to compare the efficacy of SBRT and surgery.

Association between Functional Small Airway Disease and FEV1 Decline in Chronic Obstructive Pulmonary Disease.

RATIONALE The small conducting airways are the major site of airflow obstruction in chronic obstructive pulmonary disease and may precede emphysema development. OBJECTIVES We hypothesized a novel computed tomography (CT) biomarker of small airway disease predicts FEV1 decline. METHODS We analyzed 1,508 current and former smokers from COPDGene with linear regression to assess predictors of change in FEV1 (ml/yr) over 5 years. Separate models for subjects without and with airflow obstruction were generated using baseline clinical and physiologic predictors in addition to two novel CT metrics created by parametric response mapping (PRM), a technique pairing inspiratory and expiratory CT images to define emphysema (PRM(emph)) and functional small airways disease (PRM(fSAD)), a measure of nonemphysematous air trapping. MEASUREMENTS AND MAIN RESULTS Mean (SD) rate of FEV1 decline in ml/yr for GOLD (Global Initiative for Chronic Obstructive Lung Disease) 0-4 was as follows: 41.8 (47.7), 53.8 (57.1), 45.6 (61.1), 31.6 (43.6), and 5.1 (35.8), respectively (trend test for grades 1-4; P < 0.001). In multivariable linear regression, for participants without airflow obstruction, PRM(fSAD) but not PRM(emph) was associated with FEV1 decline (P < 0.001). In GOLD 1-4 participants, both PRM(fSAD) and PRM(emph) were associated with FEV1 decline (P < 0.001 and P = 0.001, respectively). Based on the model, the proportional contribution of the two CT metrics to FEV1 decline, relative to each other, was 87% versus 13% and 68% versus 32% for PRM(fSAD) and PRM(emph) in GOLD 1/2 and 3/4, respectively. CONCLUSIONS CT-assessed functional small airway disease and emphysema are associated with FEV1 decline, but the association with functional small airway disease has greatest importance in mild-to-moderate stage chronic obstructive pulmonary disease where the rate of FEV1 decline is the greatest. Clinical trial registered with www.clinicaltrials.gov (NCT 00608764).

A Radial Flow Microfluidic Device for Ultra‐High‐Throughput Affinity‐Based Isolation of Circulating Tumor Cells

Circulating tumor cells (CTCs) are believed to play an important role in metastasis, a process responsible for the majority of cancer-related deaths. But their rarity in the bloodstream makes microfluidic isolation complex and time-consuming. Additionally the low processing speeds can be a hindrance to obtaining higher yields of CTCs, limiting their potential use as biomarkers for early diagnosis. Here, a high throughput microfluidic technology, the OncoBean Chip, is reported. It employs radial flow that introduces a varying shear profile across the device, enabling efficient cell capture by affinity at high flow rates. The recovery from whole blood is validated with cancer cell lines H1650 and MCF7, achieving a mean efficiency >80% at a throughput of 10 mL h(-1) in contrast to a flow rate of 1 mL h(-1) standardly reported with other microfluidic devices. Cells are recovered with a viability rate of 93% at these high speeds, increasing the ability to use captured CTCs for downstream analysis. Broad clinical application is demonstrated using comparable flow rates from blood specimens obtained from breast, pancreatic, and lung cancer patients. Comparable CTC numbers are recovered in all the samples at the two flow rates, demonstrating the ability of the technology to perform at high throughputs.

Transcriptome Meta-Analysis of Lung Cancer Reveals Recurrent Aberrations in NRG1 and Hippo Pathway Genes

Lung cancer is emerging as a paradigm for disease molecular subtyping, facilitating targeted therapy based on driving somatic alterations. Here, we perform transcriptome analysis of 153 samples representing lung adenocarcinomas, squamous cell carcinomas, large cell lung cancer, adenoid cystic carcinomas and cell lines. By integrating our data with The Cancer Genome Atlas and published sources, we analyze 753 lung cancer samples for gene fusions and other transcriptomic alterations. We show that higher numbers of gene fusions is an independent prognostic factor for poor survival in lung cancer. Our analysis confirms the recently reported CD74-NRG1 fusion and suggests that NRG1, NF1 and Hippo pathway fusions may play important roles in tumors without known driver mutations. In addition, we observe exon skipping events in c-MET, which are attributable to splice site mutations. These classes of genetic aberrations may play a significant role in the genesis of lung cancers lacking known driver mutations.

Decreased core muscle size is associated with worse patient survival following esophagectomy for cancer

Preoperative risk assessment, particularly for patient frailty, remains largely subjective. This study evaluated the relationship between core muscle size and patient outcomes following esophagectomy for malignancy. Using preoperative computed tomography scans in 230 subjects who had undergone transhiatal esophagectomy for cancer between 2001 and 2010, lean psoas area (LPA), measured at the fourth lumbar vertebra, was determined. Cox proportional hazards regression was employed to analyze overall survival (OS) and disease-free survival (DFS) adjusted for age, gender, and stage, and the Akaike information criterion was used to determine each covariate contribution to OS and DFS. Univariate analysis demonstrated that increasing LPA correlated with both OS (P = 0.017) and DFS (P = 0.038). In multivariate analysis controlling for patient and tumor characteristics, LPA correlated with OS and DFS in patients who had not received neoadjuvant treatment (n = 64), with higher LPA associated with improved OS and DFS. Moreover, LPA was of equivalent, or slightly higher importance than pathologic stage. These measures were not predictive among patients (n = 166) receiving neoadjuvant chemoradiation. Core muscle size appears to be an independent predictor of both OS and DFS, as significant as tumor stage, in patients following transhiatal esophagectomy. Changes in muscle mass related to preoperative treatment may confound this effect. Assessment of core muscle size may provide an additional objective measure for risk stratification prior to undergoing esophagectomy.

A Novel Serum 4-microRNA Signature for Lung Cancer Detection

The aim of this study was to identify differentially-expressed miRNAs in the serum of non-small cell lung cancer (NSCLC) patients that might be a clinically-useful tool for lung cancer early detection. We performed miRNA expression profile analysis using TaqMan OpenArray Human panel in a discovery set of 70 serum samples obtained at lung tumor resection and 22 non-cancer subjects (NC). Selected serum miRNAs were then validated by quantitative PCR using an independent validation set of serum samples from LC patients (n = 84) and NC (n = 23). Sixty miRNAs were significantly up-regulated and 31 were down-regulated in the serum from NSCLC patients versus NC (adjusted p < 0.001). Four miRNAs (miR-193b, miR-301, miR-141 and miR-200b) were selected for validating their diagnostic value in an independent cohort. In the discovery set, the ROC plot derived from the combination of these miRNAs yielded an area under the curve (AUC) of 0.985 (95% CI 0.961–1.000, p < 0.001). In the test set, this miRNA signature exhibited an AUC of 0.993 (95% CI 0.979–1.000, p < 0.001). In conclusion, we identified a serum 4-miRNA signature that discriminated with high accuracy lung cancer patients from NC. Further prospective validation of this miRNA signature is warranted.

Epigenetic Inactivation of microRNA-34b/c Predicts Poor Disease-Free Survival in Early-Stage Lung Adenocarcinoma

Purpose: The microRNA-34b/c (miR-34b/c) is considered a tumor suppressor in different tumor types and a transcriptional target of TP53. The main objectives of this study were to investigate the clinical implications of miR-34b/c methylation in patients with early-stage lung adenocarcinoma and to determine the functional role of miR-34b/c re-expression in lung adenocarcinoma cell lines. Experimental Design: Aberrant methylation and expression of miR-34b/c were assessed in 15 lung adenocarcinoma cell lines and a cohort of 140 early-stage lung adenocarcinoma. Lung adenocarcinoma cell lines were transfected with miR-34b/c and the effects upon cell proliferation, migration, invasion, and apoptosis were investigated. Results: Aberrant methylation of miR-34b/c was detected in 6 (40%) of 15 lung adenocarcinoma cell lines and 64 of 140 (46%) primary lung adenocarcinoma. Expression of miR-34b/c was significantly reduced in all methylated cell lines and primary tumors, especially with TP53 mutations. Patients with increased miR-34b/c methylation had significantly shorter disease-free and overall survival as compared to patients with unmethylated or low level of miR-34b/c methylation. Ectopic expression of miR-34b/c in lung adenocarcinoma cell lines decreased cell proliferation, migration, and invasion. Conclusions: Epigenetic inactivation of miR-34b/c by DNA methylation has independent prognostic value in patients with early-stage lung adenocarcinoma. Reexpression of miR-34b/c leads to a less aggressive phenotype in lung adenocarcinoma cell lines. Clin Cancer Res; 19(24); 6842–52. ©2013 AACR.

A MicroRNA Cluster at 14q32 Drives Aggressive Lung Adenocarcinoma

Purpose: To determine whether different subtypes of lung adenocarcinoma (AC) have distinct microRNA (miRNA) expression profiles, and to identify miRNAs associated with aggressive subgroups of resected lung AC. Experimental Design: miRNA expression profile analysis was performed in 91 resected lung AC and 10 matched nonmalignant lung tissues using a PCR-based array. An independent cohort of 60 lung ACs was used for validating by quantitative PCR the top 3 prognostic miRNAs. Gene-expression data from 51 miRNA profiled tumors was used for determining transcript-specific miRNA correlations and gene-enrichment pathway analysis. Results: Unsupervised hierarchical clustering of 356 miRNAs identified 3 major clusters of lung AC correlated with stage (P = 0.023), tumor differentiation (P < 0.003), and IASLC histologic subtype of lung AC (P < 0.005). Patients classified in cluster 3 had worse survival as compared with the other clusters. Eleven of 22 miRNAs associated with poor survival were encoded in a large miRNA cluster at 14q32. The top 3 prognostic 14q32 miRNAs (miR-411, miR-370, and miR-376a) were validated in an independent cohort of 60 lung AC. A significant association with cell migration and cell adhesion was found by integrating gene-expression data with miR-411, miR-370, and miR-376a expression. miR-411 knockdown significantly reduced cell migration in lung AC cell lines and this miRNA was overexpressed in tumors from patients who relapsed systemically. Conclusions: Different morphologic subtypes of lung AC have distinct miRNA expression profiles, and 3 miRNAs encoded at 14q32 (miR-411, miR-370, and miR-376a) were associated with poor survival after lung AC resection. Clin Cancer Res; 20(12); 3107–17. ©2014 AACR.

Endoscopic ultrasound is inadequate to determine which T1/T2 esophageal tumors are candidates for endoluminal therapies

OBJECTIVES Esophageal endoscopic ultrasound is now regarded as essential in the staging of esophageal carcinoma. There is an increasing trend toward endoluminal therapies (ie, endoscopic mucosal resection and radiofrequency ablation) for pre-cancer or early-stage cancers because of concerns of high morbidity associated with esophagectomy. This study reviews our institutional experience with preoperative endoscopic ultrasound staging of early esophageal cancers in patients who underwent an esophagectomy to evaluate the accuracy of staging by endoscopic ultrasound and how this affects treatment recommendations. METHODS A prospective esophagectomy database of all patients undergoing an esophagectomy for esophageal cancer at a single high-volume institution was retrospectively reviewed for patients with early-stage esophageal cancer. This study analyzed patients with clinical Tis to T1 disease, as predicted by preoperative endoscopic ultrasound, and correlated this with the pathologic stages after esophagectomy. The surgical outcomes were evaluated to assess the safety of esophagectomy as a treatment modality. RESULTS From 2005 to 2011, 107 patients (93 male, 14 female) with a mean age of 66 years (range, 39-91 years) were staged by preoperative endoscopic ultrasound to have esophageal high-grade dysplasia, carcinoma in situ, or T1 cancer and underwent an esophagectomy. Tumor depth was correctly staged by endoscopic ultrasound in only 39% (23/59) of pT1a tumors (invading into the lamina propria or muscularis mucosa) and 51% (18/35) of pT1b tumors (submucosal). Of the endoscopic ultrasound-staged cT1a-lpN0 lesions, there were positive lymph nodes in 15% of pathologic specimens (2/13). Patients with pT1a-mm lesions had a 9% rate of pathologic lymph node involvement (1/11), and those with pT1b tumors had a 17% rate of lymph node spread (6/35). Esophagectomy was performed in all 107 patients with a 30-day mortality rate of less than 1% (1/107). CONCLUSIONS The sensitivity and specificity of endoscopic ultrasound for determining true pathologic staging are poor for early-stage esophageal cancers. Lesions thought to be cT1a-lpN0 by endoscopic ultrasound have at least pN1 disease in 15% of cases. Endoluminal therapy of these lesions based on endoscopic ultrasound undertreats a significant number of patients. Esophagectomy is still the standard therapy for early-stage esophageal cancers in the majority of patients.

The essential role of the mitochondria-dependent death-signaling cascade in chemotherapy-induced potentiation of Apo2L/TRAIL cytotoxicity in cultured thoracic cancer cells: Amplified caspase 8 is indispensable for combination-mediated massive cell death

PURPOSEDespite adequately expressing functional receptors for tumor necrosis factor receptor apoptosis-inducing ligand (TRAIL), many cultured tumor cells are refractory to the cy-totoxic effect of this ligand. Cytotoxic chemotherapeutic drugs have been shown to synergize with Apo2L/TRAIL to mediate apoptosis in cancer cells. The main goal of this study was to evaluate the effect of either cisplatin or paclitaxel, two common used chemotherapeutic agents for solid tumors, on enhancing Apo2L/TRAIL cytotoxicity in a panel-cultured thoracic cancer cells and to examine the role of the mitochondria-dependent caspase activation cascade in mediating apoptosis of combination-treated cells. METHODSCultured thoracic cancer cells were treated with cisplatin/ Apo2L/TRAIL or paclitaxel/Apo2L/TRAIL sequential combinations in vitro. Cell viability and apoptosis were determined by 4,5-dimethylthiazo-2-yl)-2,5-diphenyl tetrazolium bromide and terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assays. Stable transfectants expressing high levels of Bcl-2 were created by retroviral gene transfer. Specific proteolytic activity of caspases 3, 6, 8, and 9 were measured by commercially available kits using fluorescent substrates. RESULTSAll cell lines preferentially expressed high levels of DR4 and/or DR5 and low levels of DcR1/DcR2; all of which were not altered by chemotherapeutic drug treatments. Pretreatment of these cancer cells with sublethal concentrations of either cisplatin or paclitaxel increased their susceptibility to Apo2L/TRAIL by twofold to > 20-fold. Profound synergistic induction of apoptosis was observed in combination-treated cells. Viability of primary normal cells was affected by neither Apo2L/TRAIL nor the combinations of chemotherapy and Apo2L/TRAIL. Overexpression of Bcl-2 or inhibition of caspase 9 activity completely abrogated combination-induced cytotoxicity and apoptosis, indicating the essential role of the mitochondria-dependent death signaling cascade in this process. Robust activation of caspase 8 in combination-treated cells was completely suppressed either by Bcl-2 overexpression or by blocking of the activity of the mitochondria-regulated caspase 9, thus identifying the amplification feedback loop as the source of elevated caspase 8 activity. Finally, mitochondria-mediated amplification of caspase 8 activity was indispensable for complete caspase activation and full execution of apoptosis, because suppression of its activity using the selective caspase 6 inhibitor (located downstream of the caspase 3 but upstream of the caspase 8 in the feedback loop) resulted in profound suppression of not only caspase 8 activity but also those of caspases 9 and 3, as well as complete protection of cancer cells from combination-induced cytotoxicity. CONCLUSIONCisplatin or paclitaxel synergistically interacts with Apo2L/ TRAIL to mediate profound induction of apoptosis. The mitochondria-dependent caspase activation cascade and the amplification feedback loop are essential for the complete execution of the cell death program. Furthermore, our data identify mitochondria as the direct target for the development of more refined strategies to enhance the therapeutic effect of Apo2L/TRAIL as an anticancer agent.