Development of a membrane array-based multimarker assay for detection of circulating cancer cells in patients with non-small cell lung cancer

Is the Blood an Alternative for Programmed Cell Death Ligand 1 Assessment in Non-Small Cell Lung Cancer?

Anti-programmed cell death (PD)-1/PD-ligand 1 (L1) therapies have significantly improved the outcomes for non-small cell lung cancer (NSCLC) patients in recent years. These therapies work by reactivating the immune system and enabling it to target cancer cells once more. There is a general agreement that expression of PD-L1 on tumour cells predicts the therapeutic response to PD-1/PD-L1 inhibitors in NSCLC. Hence, immunohistochemical staining of tumour tissue biopsies from NSCLC patients with PD-L1 antibodies is the current standard used to aid selection of patients for treatment with anti-PD-1 as first line therapy. However, issues of small tissue samples, tissue heterogeneity, the emergence of new metastatic sites, and dynamic changes in the expression of PD-L1 may influence PD-L1 status during disease evolution. Re-biopsy would expose patients to the risk of complications and tardy results. Analysis of PD-L1 expression on circulating tumour cells (CTCs) may provide an accessible and non-invasive means to select patients for anti-PD-1 therapies. Additionally, CTCs could potentially provide a useful biomarker in their own right. Several published studies have assessed PD-L1 expression on CTCs from NSCLC patients. Overall, analysis of PD-L1 on CTCs is feasible and could be detected prior to and after frontline therapy. However, there is no evidence on whether PD-L1 expression on CTCs could predict the response to anti-PD-1/PD-L1 treatment. This review examines the challenges that need to be addressed to demonstrate the clinical validity of PD-L1 analysis in CTCs as a biomarker capable of predicting the response to immune checkpoint blockade.

A regulation probability model-based meta-analysis of multiple transcriptomics data sets for cancer biomarker identification

BACKGROUND

Large-scale accumulation of omics data poses a pressing challenge of integrative analysis of multiple data sets in bioinformatics. An open question of such integrative analysis is how to pinpoint consistent but subtle gene activity patterns across studies. Study heterogeneity needs to be addressed carefully for this goal.

RESULTS

This paper proposes a regulation probability model-based meta-analysis, jGRP, for identifying differentially expressed genes (DEGs). The method integrates multiple transcriptomics data sets in a gene regulatory space instead of in a gene expression space, which makes it easy to capture and manage data heterogeneity across studies from different laboratories or platforms. Specifically, we transform gene expression profiles into a united gene regulation profile across studies by mathematically defining two gene regulation events between two conditions and estimating their occurring probabilities in a sample. Finally, a novel differential expression statistic is established based on the gene regulation profiles, realizing accurate and flexible identification of DEGs in gene regulation space. We evaluated the proposed method on simulation data and real-world cancer datasets and showed the effectiveness and efficiency of jGRP in identifying DEGs identification in the context of meta-analysis.

CONCLUSIONS

Data heterogeneity largely influences the performance of meta-analysis of DEGs identification. Existing different meta-analysis methods were revealed to exhibit very different degrees of sensitivity to study heterogeneity. The proposed method, jGRP, can be a standalone tool due to its united framework and controllable way to deal with study heterogeneity.

Clinical utility of circulating tumor cells in patients with non-small-cell lung cancer

Several different studies have addressed the role of the circulating tumor cells (CTC) in non-small-cell lung cancer (NSCLC). In particular, the potential of CTC analysis in the early diagnosis of NSCLC and in the prediction of the outcome of patients with early and advanced NSCLC have been explored. A major limit of these studies is that they used different techniques for CTC isolation and enumeration, they employed different thresholds to discriminate between high- and low-risk patients, and they enrolled heterogeneous and often small cohort of patients. Nevertheless, the results of many studies are concordant in indicating a correlation between high CTC count and poor prognosis in both early and advanced NSCLC. The reduction of CTC number following treatment might also represent an important indicator of sensitivity to therapy in patients with metastatic disease. Preliminary data also suggest the potential for CTC analysis in the early diagnosis of NSCLC in high-risk individuals. However, these findings need to be confirmed in large prospective trials in order to be transferred to the clinical practice. The molecular profiling of single CTC in NSCLC might provide important information on tumor biology and on the mechanisms involved in tumor dissemination and in acquired resistance to targeted therapies. In this respect, xenografts derived from CTC might represent a valuable tool to investigate these phenomena and to develop novel therapeutic strategies.

Optimization of a multigene biochip for detection of relapsed and early relapsed colorectal cancer

BACKGROUND

With the recent development of molecular markers, strategies for identifying patients with colorectal cancer (CRC) having a high risk of postoperative early relapse (within 1 y) and relapse have been improved. We previously constructed a multigene biochip with 19 candidate genes. The objective of the present study was to optimize a multigene biochip for detecting the risk of postoperative early relapse and relapse in patients with CRC.

METHODS

We included 357 patients with stage I-III CRC who underwent curative resection at a single institution between June 2010 and May 2015. During each follow-up, a postoperative surveillance strategy including the National Comprehensive Cancer Network recommendations and a multigene biochip was used. A statistical algorithm was developed to select candidate biomarkers for an optimal combination.

RESULTS

After a 30.9-mo median follow-up, 67 patients (18.8%) had postoperative relapse, of whom 25 (7.0%) relapsed within 1 y after operation and accounted for 37.3% of all relapsed patients. Of the 19 circulating biomarkers, ELAVL4, PTTG1, BIRC5, PDE6D, CHRNB1, MMP13, and PSG2, which presented significant predictive validity, were selected for combination. The expression of the seven-biomarker biochip resulted in area under the receiver operating characteristic curve values of 0.854 (95% confidence interval: 0.756-0.952) for early relapse and 0.884 (95% confidence interval: 0.830-0.939) for relapse. Moreover, the sensitivity, specificity, and predictive accuracy levels were 84.0%, 83.1%, and 83.2% for early relapse and 76.1%, 91.0%, and 88.2% for relapse (P = 0.415, 0.006, and 0.054, respectively). The median lead times before the detection of postoperative early relapse and relapse were 3.8 and 10.4 mo, respectively.

CONCLUSIONS

From 19 circulating biomarkers, we optimized seven contemporary circulating biomarkers. The prediction model used for the early and accurate identification of Taiwanese patients with CRC having a high risk of postoperative early relapse and relapse seems to be feasible and comparable.

Clinicopathological and prognostic significance of circulating tumor cells in patients with lung cancer: a meta-analysis

BACKGROUND

The prognostic significance of circulating tumor cells in patients with lung cancer is controversial. Therefore, we aimed to comprehensively and quantitatively assess the prognostic role of CTCs in patients with lung cancer.

METHODS

The relevant literature was searched using PubMed, the Cochrane database and the China National Knowledge Internet database (up to June 2016). Using Review Manager 5.1.2, a meta-analysis was performed using hazard ratio (HR), odds ratio (OR) and 95% confidence interval (CI) as effect values.

RESULTS

Thirty studies comprising 2,060 patients with lung cancer were analyzed. The pooled HR values showed that circulating tumor cells were significantly correlated with overall survival (HR =2.63, 95% CI [2.04, 3.39]) and progression-free survival (HR =3.74, 95% CI [2.49, 5.61]) in these patients. Further subgroup analyses were conducted and categorized by sampling time, detection method, and histological type; these analyses showed the same trend. The pooled OR values showed that circulating tumor cells were associated with non small cell lung cancer stage(OR = 2.11, 95% CI [1.42, 3.14]), small cell lung cancer stage (OR = 10.91, 95% CI [4.10, 29.06]), distant metastasis (OR =7.06, 95%CI [2.82, 17.66]), lymph node metastasis (OR =2.31, 95% CI [1.19,4.46]), and performance status(OR =0.42, 95%CI [0.22, 0.78]).

CONCLUSION

The detection of circulating tumor cells in the peripheral blood of patients with lung cancer can be indicative of a poor prognosis.

Smoking and Lung Cancer: Future Research Directions

The aim of future research in this area is to provide the mechanistic understanding and the tools for effective prevention, early diagnosis, and therapy of lung cancer. With the established causal link between cigarette smoking and the risk of developing lung cancer, the most effective prevention is certainly not to smoke. A much better mechanistic understanding of lung cancer and its variability will support the development and evaluation of potentially reduced risk products for those who maintain smoking as well as for the development of early diagnostic tools and targeted therapies. Because of the complexity of lung cancer and the long duration for its development, nonclinical and clinical research efforts need to complement each other. Recent promising advances in this research area are the understanding of the interaction between genotoxic and epigenetic effects of smoking, the development of laboratory animal models for lung tumorigenesis by smoke inhalation, the unraveling of molecular pathways and signatures in clinical lung cancer research useful for developing diagnostic tools and therapeutic approaches, and the first successful therapy for lung cancer—although less suitable for smokers. The above—in combination with emerging data sets from explorative non-clinical and clinical studies as well as improved modeling approaches—are setting the stage for accelerated progress towards developing successful early diagnostic tools and therapies as well as for the assessment of new consumer products with potentially reduced risk.

Circulating Tumor Cell and Cell-free Circulating Tumor DNA in Lung Cancer

Circulating tumor cells (CTCs) are tumor cells that are separated from the primary site or metastatic lesion and disseminate in blood circulation. CTCs are considered to be part of the long process of cancer metastasis. As a 'liquid biopsy', CTC molecular examination and investigation of single cancer cells create an important opportunity for providing an understanding of cancer biology and the process of metastasis. In the last decade, we have seen dramatic development in defining the role of CTCs in lung cancer in terms of diagnosis, genomic alteration determination, treatment response and, finally, prognosis prediction. The aims of this review are to understand the basic biology and to review methods of detection of CTCs that apply to the various types of solid tumor. Furthermore, we explored clinical applications, including treatment monitoring to anticipate therapy resistance as well as biomarker analysis, in the context of lung cancer. We also explored the potential use of cell-free circulating tumor DNA (ctDNA) in the genomic alteration analysis of lung cancer.

Predictive and prognostic value of circulating tumor cell detection in lung cancer: a clinician's perspective

There is increasing evidence for the use of circulating tumor cells (CTCs) as a "liquid biopsy" for early detection of lung cancer recurrence, prognosticating disease and monitoring treatment response. Further, CTC molecular analysis and interrogation of single cells hold significant potential in providing insights into tumor biology and the metastatic process. Ongoing research will likely see the translation of CTCs as a prognostic and predictive biomarker in both small cell, and non-small cell, lung cancer to routine clinical practice.

Prognostic significance of circulating tumor cells in non-small-cell lung cancer patients: a meta-analysis

Background

The prognostic significance of circulating tumor cells (CTCs) detected in patients with non-small-cell lung cancer (NSCLC) is still inconsistent. We aimed to assess the prognostic relevance of CTCs using a meta-analysis.

Methods

We searched PubMed, Web of Science and EMBASE for relevant studies that assessed the prognostic relevance of CTCs in NSCLC. Statistical analyses were conducted to calculate the summary incidence, odds ratio, relative risks (RRs) and 95% confidence intervals (CIs) using fixed or random-effects models according to the heterogeneity of included studies.

Results

A total of 20 studies, comprising 1576 patients, met the inclusion criteria. In identified studies, CTCs were not correlated with histology (adenocarcinoma vs squamous cell carcinoma) (odds ratio [OR]  =  0.88; 95% confidence interval [CI]: 0.59–1.33; Z = –0.61; P = 0.545). However, pooled analyses showed that CTCs were associated with lymph node metastasis (OR = 2.06; 95% CI: 1.18–3.62; Z = 2.20; P = 0.027) and tumor stage (OR  = 1.95; 95% CI: 1.08–3.54; Z = 2.53; P = 0.011). Moreover, CTCs were significantly associated with shorter overall survival (relative risk [RR]  = 2.19; 95% CI: 1.53–3.12; Z = 4.32; P<0.0001) and progression-free/disease-free survival (RR  = 2.14; 95% CI: 1.36–3.38; Z = 3.28; P<0.0001).

Conclusion

The presence of CTCs indicates a poor prognosis in patients with NSCLC. Further well-designed prospective studies are required to explore the clinical applications of CTCs in lung cancer.

Meta-analysis of circulating tumor cells as a prognostic marker in lung cancer

INTRODUCTION

Recent studies have shown that circulating tumor cells (CTCs) play potential roles as diagnostic and prognostic biomarkers with various cancer types. The aim of this study was to comprehensively and quantitatively summarize the evidence for the use of CTCs to predict the survival outcome of lung cancer patients.

MATERIALS AND METHODS

Relevant literature was identified using Medline and EMBASE. Patients' clinical characteristics, overall survival (OS) and progression-free survival (PFS) together with CTC positive rates at different time points (before, during and after treatment) were extracted. A meta-analysis was performed to clarify the prognostic role of CTCs and the correlation between the CTC appearance and clinical characteristics.

RESULTS

A total of 12 articles containing survival outcomes and clinical characteristics and 15 articles containing only clinical characteristics were included for the global meta-analysis. The hazard ratio (HR) for OS predicted by pro-treatment CTCs was 2.61 [1.82, 3.74], while the HR for PFS was 2.37 [1.41, 3.99]. The HR for OS predicted by post-treatment CTCs was 4.19 [2.92, 6.00], while the HR for PFS was 4.97 [3.05, 8.11]. Subgroup analyses were conducted according to histological classification and detection method. Odds ratio (OR) showed the appearance of pro-treatment CTCs correlated with the lymph node status, distant metastasis, and TNM staging, while post-treatment CTCs correlated with TNM staging only.

CONCLUSION

Detection of CTCs in the peripheral blood indicates a poor prognosis in patients with lung cancer.

The clinical and therapeutic implications of cancer stem cell biology

Cancer stem cells (CSCs) have provided new insights into the tumorigenesis and metastatic potential of cancer. The discovery of CSCs has provided many new insights into the complexities of cancer therapy: tumor initiation, treatment resistance, metastasis, recurrence, assessment of prognosis and prediction of clinical course. Recent rapid advances in molecular analysis have contributed to the better understanding of the molecular attributes and pathways that give CSCs their unique attributes. Use of these molecular techniques has facilitated elucidation of specific surface markers and pathways that favor propagation of CSCs - allowing for targeted therapy. Furthermore, it has been discovered that a specific microenvironment, or niche, is essential for the genesis of tumors from CSCs. Therapeutic strategies that alter these microenvironments compromise CSC proliferation and constitute another method of targeted cancer therapy. We review the clinical and therapeutic implications of CSCs, with a focus on treatment resistance and metastasis, and the emerging approaches to target CSCs and their microenvironments in order to attain improved outcomes in cancer. It is noteworthy that CSCs are the only cells capable of sustaining tumorigenesis; however, the cell of origin of cancer, in which tumorigenesis is initiated, may be distinct from CSCs that propagate the tumor.

Detection of circulating tumor cells as a prognostic factor in patients undergoing radical surgery for non-small-cell lung carcinoma: comparison of the efficacy of the CellSearch Assay™ and the isolation by size of epithelial tumor cell method

Comparison of the efficacy of different enrichment methods for detection of circulating tumor cells (CTCs) before radical surgery is lacking in non-small-cell lung carcinoma (NSCLC) patients. Detection and enumeration of CTCs in 210 consecutive patients undergoing radical surgery for NSCLC were evaluated with the CellSearch Assay™ (CS), using the CellSearch Epithelial Cell Kit, and by the isolation by size of epithelial tumor (ISET) method, using double immunolabeling with anti-cytokeratin and anti-vimentin antibodies. CTCs were detected in 144 of 210 (69%) patients using CS and/or ISET and in 104 of 210 (50%) and 82 of 210 (39%) patients using ISET and CS, respectively. Using ISET, 23 of 210 (11%) patients had vimentin-positive cells with cytological criteria of malignancy. Disease-free survival (DFS) was worse for patients with CTCs compared to patients without CTCs detected by CS alone (p < 0.0001; log rank = 30.59) or by ISET alone (p < 0.0001; log rank = 33.07). The presence of CTCs detected by both CS and ISET correlated even better with shorter DFS at a univariate (p < 0.0001; log rank = 42.15) and multivariate level (HR, 1.235; 95% CI, 1.056-1.482; p < 0.001). CS and ISET are complementary methods for detection of CTCs in preoperative radical surgery for NSCLC. CTC detection in resectable NSCLC patients using CS and/or ISET could be a prognostic biomarker of great interest and may open up new avenues into improved therapeutic strategies for lung carcinoma patients.

Morphological analysis of circulating tumour cells in patients undergoing surgery for non-small cell lung carcinoma using the isolation by size of epithelial tumour cell (ISET) method

BACKGROUND AND OBJECTIVE

Recurrence rates after surgery for non-small cell lung cancer (NSCLC) range from 25 to 50% and 5-year survival is only 60-70%. Because no biomarkers are predictive of recurrence or the onset of metastasis, pathological TNM (pTNM) staging is currently the best prognostic factor. Consequently, the preoperative detection of circulating tumour cells (CTCs) might be useful in tailoring therapy. The aim of this study was to characterize morphologically any circulating non-haematological cells (CNHCs) in patients undergoing surgery for NSCLC using the isolation by size of epithelial tumour cell (ISET) method.

METHODS

Of 299 blood samples tested, 250 were from patients with resectable NSCLC and 59 from healthy controls. The presence of CNHCs was assessed blindly and independently by 10 cytopathologists on May-Grünwald-Giemsa stained filters and the cells classified into three groups: (i) malignant cells, (ii) uncertain malignant cells, and (iii) benign cells. We assessed interobserver agreement using Kappa (κ) analysis as the measure of agreement.

RESULTS

A total of 123 out of 250 (49%) patients showed CNHCs corresponding to malignant, uncertain malignant and benign cells, in 102/250 (41%), 15/250 (6%) and 6/250 (2%) cases, respectively. No CNHCs were detected in the blood of healthy subjects. Interobserver diagnostic variability was absent for CNHCs, low for malignant cells and limited for uncertain malignant and benign cells.

CONCLUSION

Identification of CTCs in resectable NSCLC patients, using ISET technology and according to cytopathological criteria of malignancy, appears to be a new and promising field of cytopathology with potential relevance to lung oncology.

Cytopathologic detection of circulating tumor cells using the isolation by size of epithelial tumor cell method: promises and pitfalls

Detection of circulating tumor cells (CTCs) morphologically may be a promising new approach in clinical oncology. We tested the reliability of a cytomorphologic approach to identify CTCs: 808 blood samples from patients with benign and malignant diseases and healthy volunteers were examined using the isolation by size of epithelial tumor cell (ISET) method. Cells having nonhematologic features (so-called circulating nonhematologic cells [CNHCs]) were classified into 3 categories: CNHCs with malignant features, CNHCs with uncertain malignant features, and CNHCs with benign features. CNHCs were found in 11.1% and 48.9% of patients with nonmalignant and malignant pathologies, respectively (P < .001). CNHCs with malignant features were observed in 5.3% and in 43.1% of patients with nonmalignant and malignant pathologies, respectively. Cytopathologic identification of CTCs using the ISET method represents a promising field for cytopathologists. The possibility of false-positive diagnosis stresses the need for using ancillary methods to improve this approach.

Preoperative circulating tumor cell detection using the isolation by size of epithelial tumor cell method for patients with lung cancer is a new prognostic biomarker

PURPOSE

Pathologic TNM staging is currently the best prognostic factor for non-small cell lung carcinoma (NSCLC). However, even in early-stage NSCLC, the recurrence rates after surgery range from 25% to 50%. The preoperative detection of circulating tumor cells (CTC) could be useful to tailor new therapeutic strategies in NSCLC. We assessed the presence of CTC in NSCLC patients undergoing surgery, using cytologic analyses, after their isolation by size of epithelial tumor cells (ISET method). The presence and the number of CTCs were considered and correlated with clinicopathologic parameters including patient follow-up.

EXPERIMENTAL DESIGN

Of the 247 blood samples tested, 208 samples were from patients with resectable NSCLC and 39 from healthy subjects. The mean follow-up was 24 months. An image of detected cells with presumably nonhematologic features [initially defined as "circulating nonhematologic cells" (CNHC)] was recorded. The presence of CNHC was assessed blindly and independently by 10 cytopathologists, using cytologic criteria of malignancy on stained filters. The count of detected CNHCs was made for each filter.

RESULTS

One hundred two of 208 (49%) patients showed CNHCs corresponding to CNHC with malignant cytopathologic features in 76 of 208 (36%) cases. CNHCs were not detected in the control group. A level of 50 or more CNHCs corresponding to the third quartile was associated with shorter overall and disease-free-survival, independently of disease staging, and with a high risk of recurrence and death in early-stage I + II-resectable NSCLC.

CONCLUSION

A high percentage of NSCLC patients show preoperative detection of CNHC by the ISET method. The presence and level of 50 or more CNHCs are associated with worse survival of patients with resectable NSCLC.

Triosephosphate isomerase and peroxiredoxin 6, two novel serum markers for human lung squamous cell carcinoma

There is currently substantial interest in the identification of human tumor antigens for the diagnosis and immunotherapy of cancer. In our previous study, secretion character and up-regulation of triosephosphate isomerase were observed in lung squamous cell carcinoma, and autoantibodies against triosephosphate isomerase and peroxiredoxin 6 were detected in the sera from over 25% of patients, but in none of the healthy controls. In this study, peroxiredoxin 6 was also found at higher levels in the sera of the patients. Up-regulated triosephosphate isomerase and peroxiredoxin 6 were further validated by enzyme-linked immunosorbent assay in an additional 61 lung squamous cell carcinoma patients, 23 lung adenocarcinoma patients, 56 other types of carcinoma patients, 12 benign lung disease patients, and 59 healthy controls. We found that both triosephosphate isomerase and peroxiredoxin 6 were specifically elevated in lung squamous cell carcinoma sera compared with other groups, with the exception of peroxiredoxin 6 in lung adenocarcinoma patients. Positive correlation between triosephosphate isomerase and distant metastasis was found. At the cut-off point 0.221 (optical density value) on the receiver operating characteristic curve, triosephosphate isomerase could comparatively discriminate lung squamous cell carcinoma from healthy controls with a sensitivity of 65.6%, specificity 84.7%, and total accuracy 75%. For peroxiredoxin 6, at the cut-off point 0.151, it could discriminate the two groups with a sensitivity of 70.5%, specificity 62.7%, and total accuracy 65.8%. With both triosephosphate isomerase and peroxiredoxin 6, discriminant analysis results showed that 68.9% of the lung squamous cell carcinoma and 83.1% of healthy controls were correctly classified. We concluded that triosephosphate isomerase and peroxiredoxin 6 could be markers for lung squamous cell carcinoma.

A fast and convenient new technique to detect the therapeutic target, K-ras mutant, from peripheral blood in non-small cell lung cancer patients

Activating mutation of the K-ras gene was one of the earliest discoveries of genetic alterations in lung cancer. Moreover, K-ras somatic mutations might be suggested for predicting resistance to molecular antibodies targeting the epidermal growth factor receptor (EGFR). However, activated K-ras mutant detection methods are limited to traditional techniques. The techniques are complicated and are used only in tissue samples, which are limited for clinical applications. In a previous study, we established a low-cost, convenient, and easy technique for detecting activated K-ras in a small number of circulating tumor cells by the colorimetric membrane array method (CLMA). However, the sensitivity still needs further improvement. The aim of this study is to develop a new platform with chemiluminescence as reporter and weighted values of target genes on the chip in order to achieve a more sensitive, easier to read, and more accurate platform-weighted chemiluminecent membrane array (WCHMA). In advance, we collected 209 peripheral blood samples of non-small cell lung cancer (NSCLC) from patients to evaluate clinical K-ras activation detection using Activating KRAS Detection Chip both conducted by CLMA and WCHMA. Results show 71 specimens with K-ras mutation, of which 59 were identified as positive through CLMA and 66 were positive through WCHMA. After statistical analysis, the sensitivity of CLMA was found to be 83% and the specificity was 96%. On the other hand, the sensitivity of WCHMA increased to 93% and the specificity remained at 94%. Results of the detection limitation of peripheral blood on two platforms are: 3cancer cells/cm(3) blood using WCHMA, which is better than 5cancer cells/cm(3) blood using CLMA. Further analysis on the correlation between the test results and clinical pathological features shows that the mean score obtained using WCHMA is significantly correlated to TNM stage, tumor size, and metastasis.

Clinical significance of detecting survivin-expressing circulating cancer cells in patients with non-small cell lung cancer

We previously demonstrated that the detection of circulating cancer cells (CCC) expressing survivin mRNA could provide valuable information for predicting metastasis and recurrence in breast cancer. The objective of this study was to investigate the significance of detecting survivin-expressing CCC on the clinical outcomes of patients with non-small cell lung cancer (NSCLC). Peripheral blood samples collected from 143 NSCLC patients and 177 healthy volunteers were quantitatively evaluated using a technique developed in our laboratory that detected reverse transcription-polymerase chain reaction (RT-PCR) products based on a hybridisation-enzyme linked immunosorbant essay (ELISA), which we called RT-PCR ELISA. The presence of survivin-expressing CCC was detected in 63 cancer patients (44.1%) and was significantly associated with pathological T classification, nodal status, and disease stages (all P<0.001). During a follow-up period of 36 months, patients who had positive survivin expressions at the time of the initial assay test had a higher relapse rate and shorter survival time when compared to those who had negative survivin expressions (all P<0.001). Through multivariate analysis, the detection of survivin-expressing CCC was found to be an independent predictor for cancer recurrence (HR=43.5; 95% CI=2.67-70.9; P=0.008) and survival (HR=1.35; 95% CI=1.02-4.31; P=0.049). Thus, detection of survivin-expressing CCC could be used in the prediction of disease recurrence as well as in the prognosis of NSCLC.

Decreased adhesiveness, resistance to anoikis and suppression of GRP94 are integral to the survival of circulating tumor cells in prostate cancer

The presence of circulating tumor cells (CTC) is common in prostate cancer patients, however until recently their clinical significance was unknown. The CTC stage is essential for the formation of distant metastases, and their continuing presence after radical prostatectomy has been shown to predict recurrent or latent disease. Despite their mechanistic and prognostic importance, due both to their scarcity and difficulties in their isolation, little is known about the characteristics that enable their production and survival. The aim of this study was to investigate the molecular mechanisms underlying the survival of CTC cells. A novel CTC cell line from the bloodstream of an orthotopic mouse model of castration-resistant prostate cancer was established and compared with the primary tumor using attachment assays, detachment culture, Western blot, flow cytometry and 2D gel electrophoresis. Decreased adhesiveness and expression of adhesion molecules E-cadherin, beta4-integrin and gamma-catenin, together with resistance to detachment and drug-induced apoptosis and upregulation of Bcl-2 were integral to the development of CTC and their survival. Using proteomic studies, we observed that the GRP94 glycoprotein was suppressed in CTC. GRP94 was also shown to be suppressed in a tissue microarray study of 79 prostate cancer patients, indicating its possible role in prostate cancer progression. Overall, this study suggests molecular alterations accounting for the release and survival of CTC, which may be used as drug targets for either anti-metastatic therapy or the suppression of latent disease. We also indicate the novel involvement of GRP94 suppression in prostate cancer metastasis.

Multiple molecular markers as predictors of colorectal cancer in patients with normal perioperative serum carcinoembryonic antigen levels

PURPOSE

In this study, a high-sensitivity colorimetric membrane array method was used to detect circulating tumor cells (CTC) in the peripheral blood of colorectal cancer (CRC) patients with normal perioperative serum carcinoembryonic antigen (CEA) levels. This membrane array method was evaluated as a potential diagnostic and postoperative surveillance tool.

STUDY DESIGN

Membrane arrays consisting of a panel of mRNA markers that include human telomerase reverse transcriptase, cytokeratin-19, cytokeratin-20, and CEA mRNA were used to detect CTCs in the peripheral blood of 157 postoperative CRC patients with normal perioperative serum CEA levels and in 80 healthy individuals. Digoxigenin-labeled cDNA were amplified by reverse transcription-PCR from the peripheral blood samples, which were then hybridized to the membrane array. The sensitivity, specificity, and accuracy of membrane arrays for the detection of CTCs were then calculated.

RESULTS

Using the four markers in combination, expression of any three markers or all the four markers in this panel was significantly correlated with the clinicopathologic characteristics, including depth of tumor invasion, lymph node metastasis, tumor-node-metastasis stage, and postoperative relapse (all P < 0.05). The interval between the detection of all four positive molecular markers and subsequent elevated CEA ranged from 3 to 8 months (median 6 months). The expression of all four mRNA markers was an independent predictor for postoperative relapse. CRC patients with all four mRNA markers expression showed a significantly poorer survival rate than those with less than four positive markers.

CONCLUSIONS

The constructed membrane array method was helpful in the early prediction of postoperative relapse in CRC patients with normal perioperative serum CEA levels.

Implications of cancer stem cells in the treatment of cancer

Identification of cancer stem cells (CSCs) in both hematological and solid malignancies suggests that CSCs may be a common phenomenon for most malignancies. Similarly to normal stem cells, CSCs can self-renew and differentiate into progeny cancer cells. Almost all current therapy against cancer targets differentiated cancer cells. CSCs are more resistant to therapy secondary to quiescence, increased expression of antiapoptotic proteins and drug efflux transporters. In this article, we review the current status of CSC research and propose the targeting of CSC cell-surface molecules, signal transduction pathways, the stem cell niche, stem cell differentiation and drug resistance.

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Background

Convenient approaches for accurate biopsy are extremely important to the diagnosis of lung cancer. We aimed to systematically review the clinical updates and development trends of approaches for biopsy, i.e., CT-guided PTNB (Percutaneous Transthoracic Needle Biopsy), ENB (Electromagnetic Navigation Bronchoscopy), EBUS-TBNA (Endobroncheal Ultrasonography-Transbronchial Needle Aspiration), mediastinoscopy and CTC (Circulating Tumor Cell).

Methods

Medline and manual searches were performed. We identified the relevant studies, assessed study eligibility, evaluated methodological quality, and summarized diagnostic yields and complications regarding CT-guided PTNB (22 citations), ENB(31 citations), EBUS-TBNA(66 citations), Mediastinoscopy(15 citations) and CTC (19 citations), respectively.

Results

The overall sensitivity and specificity of CT-guided PTNB were reported to be 92.52% ± 3.14% and 97.98% ± 3.28%, respectively. The top two complications of CT-guided PTNB was pneumothorax (946/4170:22.69%) and hemorrhage (138/1949:7.08%). The detection rate of lung cancer by ENB increased gradually to 79.79% ± 15.34% with pneumothorax as the top one complication (86/1648:5.2%). Detection rate of EBUS-TBNA was 86.06% ± 9.70% with the top three complications, i.e., hemorrhage (53/8662:0.61%), pneumothorax (46/12432:0.37%) and infection (34/11250:0.30%). The detection rate of mediastinoscopy gradually increased to 92.77% ± 3.99% with .hoarseness as the refractory complication (4/2137:0.19%). Sensitivity and specificity of CTCs detection by using PCR (Polymerase Chain Reaction) were reported to be 78.81% ± 14.72% and 90.88% ± 0.53%, respectively.

Conclusion

The biopsy approaches should be chosen considering a variety of location and situation of lesions. CT-guided PTNB is effective to reach lung parenchyma, however, diagnostic accuracy and incidence of complications may be impacted by lesion size or needle path length. ENB has an advantage for biopsy of smaller and deeper lesions in lung parenchyma. ENB plus EBUS imaging can further improve the detection rate of lesion in lung parenchyma. EBUS-TBNA is relatively safer and mediastinoscopy provides more tissue acquisition and better diagnostic yield of 4R and 7th lymph node. CTC detection can be considered for adjuvant diagnosis.