Circulating tumor cells in the diagnosis and management of pancreatic cancer

Fluorophore-Probed Curdlan Polysaccharide Chemosensor: "Turn-On" Oligosaccharide Sensing in Aqueous Media

The ability to sense saccharides in aqueous media has attracted much attention in multidisciplinary sciences because the detection of ultrahigh concentrations of sugar chains associated with serious diseases could lead to further health promotion. However, there are notable challenges. In this study, a rhodamine-modified Curdlan (Rhod-Cur) chemosensor was synthesized that exhibited distinctive fluorescence "turn-on" responses. Rhod-Cur exhibited simultaneous sensitive and selective sensing of clinically useful acarbose with a good limit of detection (5 μM) from among those of the saccharides examined. The (chir)optical properties of Rhod-Cur were elucidated using UV/vis, fluorescence, excitation, and circular dichroism spectroscopies; lifetime measurements and morphological studies using atomic force and confocal laser scanning microscopy and dynamic light scattering techniques revealed that the fluorescence "turn-on" behavior originates from globule-to-coaggregation conversion upon insertion of the oligosaccharides in the dynamic Cur backbone.

Circulating tumor cells as potential prognostic biomarkers for early-stage pancreatic cancer: A systematic review and meta-analysis

BACKGROUND

Pancreatic cancer is difficult to be diagnosed early clinically, while often leads to poor prognosis. If optimal personalized treatment plan can be provided to pancreatic cancer patient at an earlier stage, this can greatly improve overall survival (OS). Circulating tumor cells (CTCs) are a collective term for various types of tumor cells present in the peripheral blood (PB), which are formed by detachment during the development of solid tumor lesions. Most CTCs undergo apoptosis or are phagocytosed after entering the PB, whereas a few can escape and anchor at distal sites to develop metastasis, increasing the risk of death for patients with malignant tumors.

AIM

To investigate the significance of CTCs in predicting the prognosis of early pancreatic cancer patients.

METHODS

The PubMed, EMBASE, Web of Science, Cochrane Library, China National Knowledge Infrastructure, China Biology Medicine, and ChinaInfo databases were searched for articles published through December 2022. Studies were considered qualified if they included patients with early pancreatic cancer, analyzed the prognostic value of CTCs, and were full papers reported in English or Chinese. Researches were selected and assessed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol and the Newcastle-Ottawa Scale criteria. We used a funnel plot to assess publication bias.

RESULTS

From 1595 publications, we identified eight eligible studies that collectively enrolled 355 patients with pancreatic cancer. Among these original studies, two were carried out in China; three in the United States; and one each in Italy, Spain, and Norway. All eight studies analyzed the relevance between CTCs and the prognosis of patients with early-stage pancreatic cancer after surgery. A meta-analysis showed that the patients that were positive pre-treatment or post-treatment for CTCs were associated with decreased OS [hazard ratio (HR) = 1.93, 95% confidence interval (CI): 1.197-3.126, P = 0.007] and decreased relapse-free/disease-free/progression-free survival (HR = 1.27, 95%CI: 1.137-1.419, P < 0.001) in early-stage pancreatic cancer. Additionally, the results suggest no statistically noticeable publication bias for overall, disease-free, progression-free, and recurrence-free survival.

CONCLUSION

This pooled meta-analysis shows that CTCs, as biomarkers, can afford reliable prognostic information for patients with early-stage pancreatic cancer and help develop individualized treatment plans.

Dielectrophoresis-Based SERS Sensors for the Detection of Cancer Cells in Microfluidic Chips

The detection of freely circulating cancer cells (CTCs) is one of the greatest challenges of modern medical diagnostics. For several years, there has been increased attention on the use of surface-enhanced Raman spectroscopy (SERS) for the detection of CTCs. SERS is a non-destructive, accurate and precise technique, and the use of special SERS platforms even enables the amplification of weak signals from biological objects. In the current study, we demonstrate the unique arrangement of the SERS technique combined with the deposition of CTCs cells on the surface of the SERS platform via a dielectrophoretic effect. The appropriate frequencies of an alternating electric field and a selected shape of the electric field can result in the efficient deposition of CTCs on the SERS platform. The geometry of the microfluidic chip, the type of the cancer cells and the positive dielectrophoretic phenomenon resulted in the trapping of CTCs on the surface of the SERS platform. We presented results for two type of breast cancer cells, MCF-7 and MDA-MB-231, deposited from the 0.1 PBS solution. The limit of detection (LOD) is 20 cells/mL, which reflects the clinical potential and usefulness of the developed approach. We also provide a proof-of-concept for these CTCs deposited on the SERS platform from blood plasma.

The Value of Circulating Tumor Cells in the Prognosis and Treatment of Pancreatic Cancer

In the past few decades, tumor diagnosis and treatment theory have developed in a variety of directions. The number of people dying from pancreatic cancer increases while the mortality rate of other common tumors decreases. Traditional imaging methods show the boundaries of pancreatic tumor, but they are not sufficient to judge early micrometastasis. Although carcinoembryonic antigen (CEA) and carbohydrate antigen19-9 (CA19-9) have the obvious advantages of simplicity and minimal invasiveness, these biomarkers obviously lack sensitivity and specificity. Circulating tumor cells (CTCs) have attracted attention as a non-invasive, dynamic, and real-time liquid biopsy technique for analyzing tumor characteristics. With the continuous development of new CTCs enrichment technologies, substantial progress has been made in the basic research of CTCs clinical application prospects. In many metastatic cancers, CTCs have been studied as an independent prognostic factor. This article reviews the research progress of CTCs in the treatment and prognosis of pancreatic cancer.

Aneuploid Circulating Tumor Cells as a Predictor of Response to Neoadjuvant Chemotherapy in Non-Small Cell Lung Cancer

Purpose

This study aimed to explore the potential application of circulating tumor cells (CTCs) in predicting the therapeutic effect of neoadjuvant chemotherapy (NAC) in non-small-cell lung cancer (NSCLC).

Methods

Using integrated subtraction enrichment and immunostaining-fluorescence in situ hybridization, the serial CTCs of patients with NSCLC were detected in 7.5 mL of blood at baseline and after two cycles of cisplatin-based NAC, and all aneuploidies of chromosome 8 were examined in the enriched CTCs. Tumor responses were evaluated radiologically with serial chest computed tomography (CT) using the response evaluation criteria in solid tumors and microscopically using the tumor cell necrosis rate (TCNR) of the resected specimen after NAC.

Results

After two cycles of cisplatin-based NAC, 89% (8/9) of the patients with radiological partial response to NAC had reduced CTC numbers, while 73% (8/11) of the patients with stable disease exhibited increased CTC numbers (P = 0.0098). On pathological examination, 90% (9/10) of patients with a TCNR lower than 30% had >1 CTC post-NAC, while 80% (4/5) of patients with a TCNR higher than 30% had ≤1 CTC post-NAC (P = 0.017). In aneuploidy analysis, the positive rate (CTC > 0) of triploid CTCs was found to have increased after NAC, in contrast with the tetraploid and multiploid CTCs. Furthermore, tetraploid and multiploid CTCs were found to be significantly downregulated in the patients with partial response to NAC.

Conclusion

The correlations of aneuploid CTCs with both radiological and pathological responses in patients with NSCLC who received NAC were summarized, and the findings indicate that enumerating and karyotyping aneuploid CTCs can serve as a surrogate marker for disease monitoring in NSCLC.

Toward a New Era for the Management of Circulating Tumor Cells

Circulating tumor cells (CTCs) are malignant cells separate from primary tumors, which can migrate through the peripheral blood, colonize other tissues, and lead to the formation of metastases. The first description of CTCs dates back to 1869 when Thomas Ashworth recognized malignant cells similar to the ones of the primary tumor in the blood vessels of an autopsied patient with metastatic cancer. Currently, CTCs have been identified in various types of cancer and have been recognized for their clinical value in the prediction of prognosis, diagnosis of minimal residual diseases, assessment of tumor sensitivity to anticancer drugs, and personalization of therapies. However, research about these topics has several limitations, principally the rarity of CTCs in bloodstream and their heterogeneous characteristics, which makes detection and isolation difficult. As a result of these limitations, current studies are focused on improvement of isolation and characterization techniques to achieve better sensitivity in clinical applications. This review covers the methods of CTC isolation and detection and current research progression on CTC in different cancer types. The clinical applications, limitations, and perspectives of CTCs are also discussed.

Current updates and future perspectives on the management of renal cell carcinoma

Renal cell carcinoma (RCC) refers to renal-epithelial cancer, which represents over 90% of kidney cancer and is a cause for cancer related deaths in the world. Studies suggested somatic VHL mutations to be the cause for the occurrence of cancer, but with the time, more latest genomic and biological studies have detected variation in epigenetic regulatory genes and showed significant heterogeneity of the intratumor that may lead to strategies of diagnostic, predictive, and therapeutic importance. Immune dysfunction is responsible for almost all types of renal cancer, and angiogenesis and immunosuppression function together in the tumor microenvironment of renal cell carcinoma (RCC). Over the past few years, advancement in the management of the RCC has finally revolutionized with the arrival of the entrapped immune inhibitors which particularly concentrated on the receptor (programmed cell death-1) and focus on the new generation receptor i.e. TKRI (tyrosine-kinase receptor inhibitors). The present review deals with the comprehensive review of RCC and emphasizes on its types, pathogenesis and advancement in these diseases. This review also overviews the role of innate and adaptive immune response-related mechanism, the function of cancer stem cell in this diseases, therapeutic targeted drugs and hormonal signaling pathways as an emerging strategy in the management of the renal cancer.

Clinical applications of liquid biopsies for early lung cancer detection

Over the past decade, the clinical utility of liquid biopsies in lung cancer has drawn increasing attention. Having been successfully applied in targeted therapy for late stage lung cancer, liquid biopsies are being further investigated regarding their potential role for early detection of lung cancer. Novel biomarkers with high sensitivity and specificity are crucial for identifying patients at early stages as well as for monitoring high-risk populations. A variety of bodily fluids (such as plasma, serum, and sputum) and biomarkers (such as cfDNA, CTCs, gene methylation, and miRNA) have been investigated for their potential role in the diagnosis of lung cancer. In this review, we summarize recent advances in circulating biomarkers regarding the early detection of lung cancer and discuss their potential applications and challenges in clinical settings.

EVALUATING MMP-2 AND TGFß-RI EXPRESSION IN CIRCULATING TUMOR CELLS OF PANCREATIC CANCER PATIENTS AND THEIR CORRELATION WITH CLINICAL EVOLUTION

BACKGROUND

Metastasis is common in the diagnosis of pancreatic cancer, and the presence of epithelial-mesenchymal transition markers in circulating tumor cells may suggest worse prognosis.

AIM

To correlate the number of circulating tumor cells (CTCs) in the peripheral blood of patients with a locally advanced or metastatic pancreatic tumor and the protein expression involved in epithelial-mesenchymal transition (EMT) in CTCs with clinical characteristics, progression-free survival (PFS) and overall survival (OS).

METHOD

This was a prospective study conducted using peripheral blood samples collected at three different times. CTCs were quantified by the ISET test and analyzed by immunocytochemistry. Proteins involved in EMT (vimentin, TGFß-RI and MMP2) were analyzed in all CTCs.

RESULTS

Twenty-one patients were included. Median CTCs detected were 22, 20 and 8 CTCs/8 ml blood at baseline, first and second follow-up, respectively. No statistically significant correlation was found in correlating the number of CTCs and the evaluated clinical characteristics, PFS, or OS. There was no difference in PFS and OS among the EMT markers in the groups with and without markers.

CONCLUSION

CTC analysis was not relevant in this sample for comparing clinical findings, PFS and OS in patients with pancreatic cancer. However, marker analysis in CTCs could be useful for the MMP-2 and/or TGFß-RI expression, as observed by the separate PFS curve.

Identification and characterization of transforming growth factor beta-induced in circulating tumor cell subline from pancreatic cancer cell line

Distant metastasis to liver, lung, brain, or bone occurs by circulating tumor cells (CTC). We hypothesized that a subset of CTC had features that are more malignant than tumor cells at the primary site. We established a highly malignant cell line, Panc-1-CTC, derived from the human pancreatic cancer cell line Panc-1 using an in vivo selection method. Panc-1-CTC cells showed greater migratory and invasive abilities than its parent cell line in vitro. In addition, Panc-1-CTC cells had a higher tumor-forming ability than parent cells in vivo. To examine whether a difference in malignant phenotypes exists between Panc-1-CTC cells and parent cells, we carried out comprehensive gene expression array analysis. As a result, Panc-1-CTC significantly expressed transforming growth factor beta-induced (TGFBI), an extracellular matrix protein, more abundantly than did parent cells. TGFBI is considered to regulate cell adhesion, but its functions remain unclear. In the present study, knockdown of TGFBI reduced cell migration and invasion abilities, whereas overexpression of TGFBI increased both abilities. Moreover, elevated expression of TGFBI was associated with poor prognosis in patients with pancreatic cancer.

Detection of Circulating Tumor Cells Using Microfluidics

Metastasis is the main cause of death in cancer patients worldwide. During metastasis, cancer cells detach from the primary tumor and invade distant tissue. The cells that undergo this process are called circulating tumor cells (CTCs). Studies show that the number of CTCs in the peripheral blood can predict progression-free survival and overall survival and can be informative concerning the efficacy of treatment. Research is now concentrated on developing devices that can detect CTCs in the blood of cancer patients with improved sensitivity and specificity that can lead to improved clinical evaluation. This review focuses on devices that detect and capture CTCs using different cell properties (surface markers, size, deformability, electrical properties, etc.). We also discuss the process of tumor cell dissemination, the biology of CTCs, epithelial-mesenchymal transition (EMT), and several challenges and clinical applications of CTC detection.

Circulating and disseminated tumor cells in pancreatic cancer and their role in patient prognosis: a systematic review and meta-analysis

Background

Disseminated tumor cells (DTCs) and circulating tumor cells (CTCs) have been postulated to seed metastases and contribute to poorer patient outcomes in many types of solid cancer. To date, no systematic reviews have examined the role of both DTCs and CTCs in pancreatic cancer. We aimed to determine the prognostic value of DTCs/CTCs in pancreatic cancer using a systematic review and meta-analysis.

Materials and Methods

A comprehensive literature search identified studies examining DTCs and CTCs in the bone marrow and blood of pancreatic cancer patients at diagnosis with follow-up to determine disease-free/progression-free survival (DFS/PFS) and overall survival (OS). Statistical analyses were performed to determine the hazard ratio (HR) of DTCs/CTCs on DFS/PFS and OS.

Results

The literature search identified 16 articles meeting the inclusion criteria. The meta-analysis demonstrated statistically significant HR differences in DFS/PFS (HR = 1.93, 95% CI 1.19–3.11, P = 0.007) and OS (HR = 1.84, 95% CI 1.37–2.45, P =< 0.0001), indicating patients with detectable DTCs/CTCs at diagnosis have worse prognoses. Subgroup analyses suggested CTCs in the peripheral blood (HR =2.03) were more indicative of poor OS prognosis than DTCs in the bone marrow (HR = 1.91), although the difference between these was not statistically significant. Positivity of the CellSearch detection method for DTC/CTC had the highest correlation with decreased OS (HR = 2.79) while immunodetection (HR = 1.91) and RT-PCR (HR = 1.25) were less effective in determining prognosis.

Conclusion

The detection of DTCs/CTCs at diagnosis is associated with poorer DFS/PFS and OS in pancreatic cancer.

The Yonsei criteria as a clinically detectable parameter for excellent prognosis in resected left-sided pancreatic cancer: outcomes of a propensity score-matched analysis

BACKGROUND

This study aimed to identify that Yonsei criteria (YC) can be regarded as a preoperative clinical parameter to predict biological behavior of the left-sided pancreatic cancer.

METHODS

Between June 2007 and December 2014, 135 patients who underwent minimally invasive (MIS) or open distal pancreatectomy for left-sided pancreatic cancer were enrolled in this study consecutively. Perioperative short-term and long-term oncologic outcomes were analyzed according to the YC retrospectively.

RESULTS

Fifty-four and 81 patients did and did not meet the YC, respectively. Short-term oncologic outcomes were favorable among those meeting the YC even after propensity score matching. Patients within the YC also had better disease-free and disease-specific overall survival (p < 0.05). In analysis for receiver operating characteristic curve, area under curve of CA19-9 was satisfactory only within YC group. Multivariate analysis for disease-free survival identified the YC as a strong independent prognostic factor (p < 0.05). In preoperative clinical setting, patients' survival was clearly different based on following clinical groups, such as within YC, beyond YC, and unresectable.

CONCLUSIONS

Preoperative CT-based determined YC can predict excellent short-term and long-term oncologic outcomes. YC might have a potential role as a preoperative clinical staging for left-sided pancreatic cancer. External validations of YC based on multicenter cohorts are mandatory to confirm this oncologic significance of YC.

Circulating tumor cell status monitors the treatment responses in breast cancer patients: a meta-analysis

Whether circulating tumor cells (CTCs) can be used as an indicator of treatment response in breast cancer (BC) needs to be clarified. We addressed this issue by a meta-analysis. PubMed, EMBase and Cochrane library databases were searched in June 2016. Effect measures were estimated as pooled risk ratio (RR), odds ratio (OR) or mean difference by fixed- or random-effect models, according to heterogeneity of included studies. In total, 50 studies with 6712 patients were recruited. Overall analysis showed that there was a significant reduction of CTC-positive rate (RR = 0.68, 95% CI: 0.61–0.76, P < 0.00001) after treatment. Subgroup analyses revealed that neoadjuvant treatment, adjuvant treatment, metastatic treatment or combination therapy could reduce the CTC-positive rate, but surgery could not; moreover, the reduction was only found in HER2+ or HER2- patients but not in the triple-negative ones. Reduction of CTC-positive rate was associated with lower probability of disease progression (OR = 0.54, 95% CI: 0.33–0.89, P = 0.01) and longer overall survival period (mean difference = 11.61 months, 95% CI: 8.63–14.59, P < 0.00001) as well as longer progression-free survival period (mean difference = 5.07 months, 95% CI: 2.70–7.44, P < 0.0001). These results demonstrate that CTC status can serve as an indicator to monitor the effectiveness of treatments and guide subsequent therapies in BC.

Microfluidics cell sample preparation for analysis: Advances in efficient cell enrichment and precise single cell capture

Single cell analysis has received increasing attention recently in both academia and clinics, and there is an urgent need for effective upstream cell sample preparation. Two extremely challenging tasks in cell sample preparation-high-efficiency cell enrichment and precise single cell capture-have now entered into an era full of exciting technological advances, which are mostly enabled by microfluidics. In this review, we summarize the category of technologies that provide new solutions and creative insights into the two tasks of cell manipulation, with a focus on the latest development in the recent five years by highlighting the representative works. By doing so, we aim both to outline the framework and to showcase example applications of each task. In most cases for cell enrichment, we take circulating tumor cells (CTCs) as the target cells because of their research and clinical importance in cancer. For single cell capture, we review related technologies for many kinds of target cells because the technologies are supposed to be more universal to all cells rather than CTCs. Most of the mentioned technologies can be used for both cell enrichment and precise single cell capture. Each technology has its own advantages and specific challenges, which provide opportunities for researchers in their own area. Overall, these technologies have shown great promise and now evolve into real clinical applications.

Circulating Tumor Cells and Circulating Tumor DNA Provide New Insights into Pancreatic Cancer

Pancreatic cancer has a rather dismal prognosis mainly due to high malignance of tumor biology. Up to now, the relevant researches on pancreatic cancer lag behind seriously partly due to the obstacles for tissue biopsy, which handicaps the understanding of molecular and genetic features of pancreatic cancer. In the last two decades, liquid biopsy, including circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), is promising to provide new insights into the biological and clinical characteristics of malignant tumors. Both CTCs and ctDNA provide an opportunity for studying tumor heterogeneity, drug resistance, and metastatic mechanism for pancreatic cancer. Furthermore, they can also play important roles in detecting early-stage tumors, providing prognostic information, monitoring tumor progression and guiding treatment regimens. In this review, we will introduce the latest findings on biological features and clinical applications of both CTCs and ctDNA in pancreatic cancer. In a word, CTCs and ctDNA are promising to promote precision medicine in pancreatic cancer.

Role of detection of circulating tumor cells in early diagnosis of pancreatic cancer

Pancreatic cancer is a kind of highly malignant digestive system tumor. The early clinical symptoms of pancreatic cancer are insidious and atypical, so it is difficult to early diagnose pancreatic cancer, and most patients are diagnosed at an advanced stage. Therefore, the early diagnosis of pancreatic cancer is of great clinical significance for improving prognosis. Circulating tumor cells are a group of tumor cells that are present in patient's peripheral blood, which mainly reflects tumor metastasis. However, studies have found that circulating tumor cells may have entered the blood before primary cancer is diagnosed. If circulating tumor cells could be early detected in patient's peripheral blood, this would increase the rate of early diagnosis of the tumor. This paper mainly introduces the detection of circulating tumor cells and its role in the early diagnosis of pancreatic cancer.

Cellular and molecular aspects of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a deadly malignancy that affects nearly 50,000 patients each year. The overall 5-year survival rate for this malignancy remains the lowest of any cancer at around 7% due to limited diagnostic methods, disease aggressiveness and a lack of targeted therapeutic interventions. This review highlights the successes achieved over the past several decades as well as the significant cellular and molecular hurdles that remain in combatting this deadly disease at a translational level.

Current Status of CTCs as Liquid Biopsy in Lung Cancer and Future Directions

Circulating tumor cells (CTCs) have garnered a lot of attention in the past few decades. Isolation of these rare cells from the billions of blood cells has been a challenge until recent times. With the advent of new sensitive technologies that permit live cell isolation and downstream genomic analysis, the existing paradigm of CTC research has evolved to explore clinical utility of these cells. CTCs have been identified as prognostic and pharmacodynamic biomarkers in many solid tumors, including lung cancer. As a means of liquid biopsy, CTCs could play a major role in the development of personalized medicine and targeted therapies. This review discusses the state of various isolation strategies, cell separation techniques and key studies that illustrate the application of liquid biopsy to lung cancer.

Phase II clinical trials on investigational drugs for the treatment of pancreatic cancers

INTRODUCTION

Despite some recent advances in treatment options, pancreatic cancer remains a devastating disease with poor outcomes. In a trend contrary to most malignancies, both incidence and mortality continue to rise due to pancreatic cancer. The majority of patients present with advanced disease and there are no treatment options for this stage that have demonstrated a median survival > 1 year. As the penultimate step prior to Phase III studies involving hundreds of patients, Phase II clinical trials provide an early opportunity to evaluate the efficacy of new treatments that are desperately needed for this disease.

AREAS COVERED

This review covers the results of published Phase II clinical trials in advanced pancreatic adenocarcinoma published within the past 5 years. The treatment results are framed in the context of the current standards of care and the historic challenge of predicting Phase III success from Phase II trial results.

EXPERT OPINION

Promising therapies remain elusive in pancreatic cancer based on recent Phase II clinical trial results. Optimization and standardization of clinical trial design in the Phase II setting, with consistent incorporation of biomarkers, is needed to more accurately identify promising therapies that warrant Phase III evaluation.

Circulating Epithelial Cells in Patients with Pancreatic Lesions: Clinical and Pathologic Findings

BACKGROUND

Circulating epithelial cell (CEC) isolation has provided diagnostic and prognostic information for a variety of cancers, previously supporting their identity as circulating tumor cells in the literature. However, we report CEC findings in patients with benign, premalignant, and malignant pancreatic lesions using a size-selective filtration device.

STUDY DESIGN

Peripheral blood samples were drawn from patients found to have pancreatic lesions on preoperative imaging at a surgical clinic. Blood was filtered using ScreenCell devices, which were evaluated microscopically by a pancreatic cytopathologist. Pathologic data and clinical outcomes of these patients were obtained from medical records during a 1-year follow-up period.

RESULTS

Nine healthy volunteers formed the control group and were found to be negative for CECs. There were 179 patients with pancreatic lesions that formed the study cohort. Circulating epithelial cells were morphologically similar in patients with a variety of pancreatic lesions. Specifically, CECs were identified in 51 of 105 pancreatic ductal adenocarcinomas (49%), 7 of 11 neuroendocrine tumors (64%), 13 of 21 intraductal papillary mucinous neoplasms (62%), and 6 of 13 patients with chronic pancreatitis. Rates of CEC identification were similar in patients with benign, premalignant, and malignant lesions (p = 0.41). In addition, CEC findings in pancreatic ductal adenocarcinoma patients were not associated with poor prognosis.

CONCLUSIONS

Although CECs were not identified in healthy volunteers, they were identified in patients with benign, premalignant, and malignant pancreatic lesions. The presence of CECs in patients presenting with pancreatic lesions is neither diagnostic of malignancy nor prognostic for patients with pancreatic ductal adenocarcinoma.

Genomic profiling guides the choice of molecular targeted therapy of pancreatic cancer

Pancreatic cancer has the worst five-year survival rate of all malignancies due to its aggressive progression and resistance to therapy. Current therapies are limited to gemcitabine-based chemotherapeutics, surgery, and radiation. The current trend toward "personalized genomic medicine" has the potential to improve the treatment options for pancreatic cancer. Gene identification and genetic alterations like single nucleotide polymorphisms and mutations will allow physicians to predict the efficacy and toxicity of drugs, which could help diagnose pancreatic cancer, guide neoadjuvant or adjuvant treatment, and evaluate patients' prognosis. This article reviews the multifaceted roles of genomics and pharmacogenomics in pancreatic cancer.

Extracellular vesicles: potential applications in cancer diagnosis, prognosis, and epidemiology

Both normal and diseased cells continuously shed extracellular vesicles (EVs) into extracellular space, and the EVs carry molecular signatures and effectors of both health and disease. EVs reflect dynamic changes that are occurring in cells and tissue microenvironment in health and at a different stage of a disease. EVs are capable of altering the function of the recipient cells. Trafficking and reciprocal exchange of molecular information by EVs among different organs and cell types have been shown to contribute to horizontal cellular transformation, cellular reprogramming, functional alterations, and metastasis. EV contents may include tumor suppressors, phosphoproteins, proteases, growth factors, bioactive lipids, mutant oncoproteins, oncogenic transcripts, microRNAs, and DNA sequences. Therefore, the EVs present in biofluids offer unprecedented, remote, and non-invasive access to crucial molecular information about the health status of cells, including their driver mutations, classifiers, molecular subtypes, therapeutic targets, and biomarkers of drug resistance. In addition, EVs may offer a non-invasive means to assess cancer initiation, progression, risk, survival, and treatment outcomes. The goal of this review is to highlight the current status of information on the role of EVs in cancer, and to explore the utility of EVs for cancer diagnosis, prognosis, and epidemiology.

Circulating tumor cells in pancreatic cancer patients: Enrichment and cultivation

AIM: To investigate the feasibility of separation and cultivation of circulating tumor cells (CTCs) in pancreatic cancer (PaC) using a filtration device.

METHODS: In total, 24 PaC patients who were candidates for surgical treatment were enrolled into the study. Peripheral blood samples were collected before an indicated surgery. For each patient, approximately 8 mL of venous blood was drawn from the antecubital veins. A new size-based separation MetaCell^® technology was used for enrichment and cultivation of CTCs in vitro. (Separated CTCs were cultured on a membrane in FBS enriched RPMI media and observed by inverted microscope. The cultured cells were analyzed by means of histochemistry and immunohistochemistry using the specific antibodies to identify the cell origin.

RESULTS: CTCs were detected in 16 patients (66.7%) of the 24 evaluable patients. The CTC positivity did not reflect the disease stage, tumor size, or lymph node involvement. The same percentage of CTC positivity was observed in the metastatic and non-metastatic patients (66.7% vs 66.7%). We report a successful isolation of CTCs in PaC patients capturing proliferating cells. The cells were captured by a capillary action driven size-based filtration approach that enabled cells cultures from the viable CTCs to be unaffected by any antibodies or lysing solutions. The captured cancer cells displayed plasticity which enabled some cells to invade the separating membrane. Further, the cancer cells in the “bottom fraction”, may represent a more invasive CTC-fraction. The CTCs were cultured in vitro for further downstream applications.

CONCLUSION: The presented size-based filtration method enables culture of CTCs in vitro for possible downstream applications.

Advances in pancreatic cancer research: Moving towards early detection

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal forms of cancer. Substantial progress has been made in the understanding of the biology of pancreatic cancer, and advances in patient management have been significant. However, most patients (nearly 80%) who present with locally advanced or metastatic disease have an extremely poor prognosis. Survival is better for those with malignant disease localized to the pancreas, because surgical resection at present offers the only chance of cure. Therefore, the early detection of pancreatic cancer may benefit patients with PDAC. However, its low rate of incidence and the limitations of current screening strategies make early detection difficult. Recent advances in the understanding of the pathogenesis of PDAC suggest that it is possible to detect PDAC in early stages and even identify precursor lesions. The presence of new-onset diabetes mellitus in the early phase of pancreatic cancer may provide clues for its early diagnosis. Advances in the identification of novel circulating biomarkers including serological signatures, autoantibodies, epigenetic markers, circulating tumor cells and microRNAs suggest that they can be used as potential tools for the screening of precursors and early stage PDAC in the future. However, proper screening strategies based on effective screening methodologies need to be tested for clinical application.

Application of circulating tumor cells scope technique on circulating tumor cell research

Circulating tumor cells (CTCs) are becoming promising biomarkers in several cancers, such as colon, prostate, and breast carcinomas. Independent research groups have reported a correlation between CTC numbers and patient prognosis. Even more, the development of personalized medicine gives physicians impetus to utilize the advancement of molecular characterization of CTCs. This review introduces a new technique, CTCscope, and compares it with the current methods of CTCs detection, with particular emphasis on cancer research, and discusses the future application of this new method from bench to bed-side.

Application of circulating tumor cells scope technique on circulating tumor cell research

Circulating tumor cells (CTCs) are becoming promising biomarkers in several cancers, such as colon, prostate, and breast carcinomas. Independent research groups have reported a correlation between CTC numbers and patient prognosis. Even more, the development of personalized medicine gives physicians impetus to utilize the advancement of molecular characterization of CTCs. This review introduces a new technique, CTCscope, and compares it with the current methods of CTCs detection, with particular emphasis on cancer research, and discusses the future application of this new method from bench to bed-side.

Bridging population and tissue scale tumor dynamics: a new paradigm for understanding differences in tumor growth and metastatic disease

To provide a better understanding of the relationship between primary tumor growth rates and metastatic burden, we present a method that bridges tumor growth dynamics at the population level, extracted from the SEER database, to those at the tissue level. Specifically, with this method, we are able to relate estimates of tumor growth rates and metastatic burden derived from a population-level model to estimates of the primary tumor vascular response and the circulating tumor cell (CTC) fraction derived from a tissue-level model. Variation in the population-level model parameters produces differences in cancer-specific survival and cure fraction. Variation in the tissue-level model parameters produces different primary tumor dynamics that subsequently lead to different growth dynamics of the CTCs. Our method to bridge the population and tissue scales was applied to lung and breast cancer separately, and the results were compared. The population model suggests that lung tumors grow faster and shed a significant number of lethal metastatic cells at small sizes, whereas breast tumors grow slower and do not significantly shed lethal metastatic cells until becoming larger. Although the tissue-level model does not explicitly model the metastatic population, we are able to disengage the direct dependency of the metastatic burden on primary tumor growth by introducing the CTC population as an intermediary and assuming dependency. We calibrate the tissue-level model to produce results consistent with the population model while also revealing a more dynamic relationship between the primary tumor and the CTCs. This leads to exponential tumor growth in lung and power law tumor growth in breast. We conclude that the vascular response of the primary tumor is a major player in the dynamics of both the primary tumor and the CTCs, and is significantly different in breast and lung cancer.

Capture, release and culture of circulating tumor cells from pancreatic cancer patients using an enhanced mixing chip

Circulating tumor cells (CTCs) from peripheral blood hold important information for cancer diagnosis and disease monitoring. Analysis of this "liquid biopsy" holds the promise to usher in a new era of personalized therapeutic treatments and real-time monitoring for cancer patients. But the extreme rarity of CTCs in blood makes their isolation and characterization technologically challenging. This paper reports the development of a geometrically enhanced mixing (GEM) chip for high-efficiency and high-purity tumor cell capture. We also successfully demonstrated the release and culture of the captured tumor cells, as well as the isolation of CTCs from cancer patients. The high-performance microchip is based on geometrically optimized micromixer structures, which enhance the transverse flow and flow folding, maximizing the interaction between CTCs and antibody-coated surfaces. With the optimized channel geometry and flow rate, the capture efficiency reached >90% with a purity of >84% when capturing spiked tumor cells in buffer. The system was further validated by isolating a wide range of spiked tumor cells (50-50,000) in 1 mL of lysed blood and whole blood. With the combination of trypsinization and high flow rate washing, captured tumor cells were efficiently released. The released cells were viable and able to proliferate, and showed no difference compared with intact cells that were not subjected to the capture and release process. Furthermore, we applied the device for detecting CTCs from metastatic pancreatic cancer patients' blood; and CTCs were found from 17 out of 18 samples (>94%). We also tested the potential utility of the device in monitoring the response to anti-cancer drug treatment in pancreatic cancer patients, and the CTC numbers correlated with the clinical computed tomograms (CT scans) of tumors. The presented technology shows great promise for accurate CTC enumeration, biological studies of CTCs and cancer metastasis, as well as for cancer diagnosis and treatment monitoring.

Transcatheter arterial embolization promotes liver tumor metastasis by increasing the population of circulating tumor cells

Transcatheter arterial embolization (TAE) is widely used as an effective palliative treatment for hepatocellular carcinoma (HCC), and can prolong survival time. However, the high incidence of tumor recurrence and metastasis after TAE is still a major problem. Recent studies demonstrated that circulating tumor cells (CTCs) contribute to tumor metastasis. In this study, we tried to clarify whether the residual HCC after TAE can increase metastasis by increasing the number of CTCs. An orthotopic liver tumor model in the Buffalo rat was established using green fluorescent protein (GFP)-transfected HCC cell line, McA-RH7777. Two weeks after orthotopic liver tumor implantation, the rats underwent TAE treatment from the gastroduodenal artery. Iodized oil or saline was injected intra-arterially. Blood samples were taken on day 0, 1, 3, 7, 14, and 21 for detection of CTCs after TAE treatment. We analyzed the number of CTCs and assessed the metastatic potential of surviving tumor cells in rats between TAE and control groups. Our results demonstrated that the metastatic colonies in the lung were significantly increased by TAE treatment. The number of CTCs was also significantly increased by TAE treatment from day 7 to day 21. The expression of hypoxia-inducible factor (HIF)-1α and epithelial–mesenchymal transition (EMT) marker proteins (N-cadherin and vimentin) was upregulated, but E-cadherin was downregulated after TAE treatment. In conclusion, the metastatic potential of residual HCC can be induced by TAE treatment in a rat liver tumor model, which involves the acquisition of EMT features and an increased number of CTCs.

Is the detection of circulating tumor cells in locally advanced pancreatic cancer a useful prognostic marker?

Evaluation of: Bidard FC, Huguet F, Louvet C et al. Circulating tumor cells in locally advanced pancreatic adenocarcinoma: the ancillary CirCe 07 study to the LAP 07 trial. Ann. Oncol. 24(8), 2057-2061 (2013). Circulating tumor cells (CTCs) may be shed from the primary tumor and lead to metastatic disease. This evaluated article reports on CTCs in locally advanced pancreatic cancer (LAPC). By assessing CTCs from peripheral blood prior to any treatment and after 2 months of chemotherapy, 11% of patients had detectable CTCs. These patients had a poorer overall survival. With such low numbers of CTCs detected in LAPC patients, it is unclear whether CTCs can actually contribute toward tumor invasiveness and spread in such an aggressive cancer. Although this is a well-designed study, the small number of patients with detectable CTCs means that the statistical power is not great enough to make firm conclusions. Therefore, this expensive assay needs further investigation before being used a prognostic marker in patients with LAPC.

Detection of Circulating Tumour Cells from Blood of Breast Cancer Patients via RT-qPCR

Breast cancer is still the most frequent cause of cancer-related death in women worldwide. Often death is not caused only by the primary tumour itself, but also by metastatic lesions. Today it is largely accepted, that these remote metastases arise out of cells, which detach from the primary tumour, enter circulation, settle down at secondary sites in the body and are called Circulating Tumour Cells (CTCs). The occurrence of such minimal residual diseases in the blood of breast cancer patients is mostly linked to a worse prognosis for therapy outcome and overall survival. Due to their very low frequency, the detection of CTCs is, still a technical challenge. RT-qPCR as a highly sensitive method could be an approach for CTC-detection from peripheral blood of breast cancer patients. This assumption is based on the fact that CTCs are of epithelial origin and therefore express a different gene panel than surrounding blood cells. For the technical approach it is necessary to identify appropriate marker genes and to correlate their gene expression levels to the number of tumour cells within a sample in an in vitro approach. After that, samples from adjuvant and metastatic patients can be analysed. This approach may lead to new concepts in diagnosis and treatment.

A Speculative Role for Stromal Gastrin Signaling in Development and Dissemination of Pancreatic Ductal Adenocarcinoma

The peptide growth factor gastrin and its receptor, the G-protein coupled cholecystokinin receptor type B (CCK_BR), play an integral role in the growth and progression of pancreatic ductal adenocarcinoma (PDAC). Gastrin immunoreactivity is found in the fetal pancreas but its expression is not detected in normal pancreas after birth, except when it is re-expressed in malignant lesions.

Using aptamers for cancer biomarker discovery

Aptamers are single-stranded synthetic DNA- or RNA-based oligonucleotides that fold into various shapes to bind to a specific target, which includes proteins, metals, and molecules. Aptamers have high affinity and high specificity that are comparable to that of antibodies. They are obtained using iterative method, called (Systematic Evolution of Ligands by Exponential Enrichment) SELEX and cell-based SELEX (cell-SELEX). Aptamers can be paired with recent advances in nanotechnology, microarray, microfluidics, and other technologies for applications in clinical medicine. One particular area that aptamers can shed a light on is biomarker discovery. Biomarkers are important in diagnosis and treatment of cancer. In this paper, we will describe ways in which aptamers can be used to discover biomarkers for cancer diagnosis and therapeutics.