Detection of disseminated pancreatic cells by amplification of cytokeratin-19 with quantitative RT-PCR in blood, bone marrow and peritoneal lavage of pancreatic carcinoma patients

Epithelial to Mesenchymal Transition as Mechanism of Progression of Pancreatic Cancer: From Mice to Men

Owed to its aggressive yet subtle nature, pancreatic cancer remains unnoticed till an advanced stage so that in most cases the diagnosis is made when the cancer has already spread to other organs with deadly efficiency. The progression from primary tumor to metastasis involves an intricate cascade of events comprising the pleiotropic process of epithelial to mesenchymal transition (EMT) facilitating cancer spread. The elucidation of this pivotal phenotypic change in cancer cell morphology, initially heretic, moved from basic studies dissecting the progression of pancreatic cancer in animal models to move towards human disease, although no clinical translation of the concept emerged yet. Despite this transition, a full-blown mesenchymal phenotype may not be accomplished; rather, the plasticity of the program and its dependency on heterotopic signals implies a series of fluctuating modifications of cancer cells encompassing mesenchymal and epithelial features. Despite the evidence supporting the activation of EMT and MET during cancer progression, our understanding of the relationship between tumor microenvironment and EMT is not yet mature for a clinical application. In this review, we attempt to resume the knowledge on EMT and pancreatic cancer, aiming to include the EMT among the hallmarks of cancer that could potentially modify our clinical thinking with the purpose of filling the gap between the results pursued in basic research by animal models and those achieved in translational research by surrogate biomarkers, as well as their application for prognostic and predictive purposes.

Should Positive Cytology Revealed by Intraoperative Lavage Preclude Radical Resection in Resectable Pancreatic Cancer?: A Systemic Review and Meta-analysis

OBJECTIVES

The aims of this review were to determine whether positive peritoneal lavage cytology (CY+) precludes radical resection in pancreatic cancer and to propose prospections for future studies.

METHODS

MEDLINE, Embase, and Cochrane Central were searched for related articles. Dichotomous variables and survival outcomes were analyzed with the estimation of odds ratio and hazards ratio (HR), respectively.

RESULTS

A total of 4905 patients were included, of which 7.8% were CY+. Positive peritoneal lavage cytology was correlated with poor overall survival (univariate survival analysis [HR, 2.35; P < 0.00001]; multivariate analysis [HR, 1.62; P < 0.00001]), poor recurrence-free survival (univariate survival analysis [HR, 2.50; P < 0.00001]; multivariate analysis [HR, 1.84; P < 0.00001]), and higher initial peritoneal recurrence rate (odds ratio, 5.49; P < 0.00001).

CONCLUSIONS

Although CY+ predicts poor prognosis and a higher risk of peritoneal metastasis after curative resection, it is not sufficient to preclude curative resection based on the current evidence, and high-quality trials should be conducted to assess the prognostic impact of operation among resectable CY+ patients. In addition, more sensitive and accurate methods to detect peritoneal exfoliated tumor cells and more effective comprehensive treatment for resectable CY+ pancreatic cancer patients are clearly warranted.

Prognostic value of disseminated tumor cells in unresectable pancreatic ductal adenocarcinoma: a prospective observational study

BACKGROUND

Although pancreatic ductal adenocarcinoma (PDAC) rarely metastasizes to the skeleton, disseminated tumor cells have been detected in bone marrow samples from patients with this disease. The prognostic value of such findings is currently unclear. Thus, the current study aimed to clarify the prognostic information associated with disseminated tumor cell detection in samples from patients with PDAC.

METHODS

Bone marrow aspirates were obtained from 48 patients with locally advanced (n = 11) or metastatic (n = 37) PDAC, before and after 2 months of chemotherapy. Disseminated tumor cells were detected with an mRNA panel and quantitative reverse transcription PCR. We used the highest levels measured in healthy bone marrow (n = 30) as a threshold to define the positive detection of disseminated tumor cells. Progression-free and overall survival were analyzed with Kaplan-Meier and Cox proportional hazards regression analyses.

RESULTS

Disseminated tumor cells were detected in 15/48 (31%) bone marrow samples obtained before starting chemotherapy and in 8/25 (32%) samples obtained during chemotherapy. Patients with disseminated tumor cells detected before therapy had significantly shorter progression-free (p = 0.03; HR = 2.0) and overall survival (p = 0.03; HR = 2.0), compared to those without disseminated tumor cells in the bone marrow. When restricting disseminated tumor cell detection to keratins KRT7 and KRT8, the prognostic information was substantially stronger (p = 1 × 10-6; HR = 22, and p = 2 × 10-5; HR = 7.7, respectively). The multivariable Cox regression analysis demonstrated that disseminated tumor cell detection prior to treatment had independent prognostic value. In contrast, disseminated tumor cells detected during treatment did not have prognostic value.

CONCLUSIONS

Disseminated tumor cells detected before commencing chemotherapy had prognostic value in patients with inoperable PDAC.

Exploring the Clinical Utility of Pancreatic Cancer Circulating Tumor Cells

Pancreatic ductal adenocarcinoma (PDAC) is the most frequent pancreatic cancer type, characterized by a dismal prognosis due to late diagnosis, frequent metastases, and limited therapeutic response to standard chemotherapy. Circulating tumor cells (CTCs) are a rare subset of tumor cells found in the blood of cancer patients. CTCs has the potential utility for screening, early and definitive diagnosis, prognostic and predictive assessment, and offers the potential for personalized management. However, a gold-standard CTC detection and enrichment method remains elusive, hindering comprehensive comparisons between studies. In this review, we summarize data regarding the utility of CTCs at different stages of PDAC from early to metastatic disease and discuss the molecular profiling and culture of CTCs. The characterization of CTCs brings us closer to defining the specific CTC subpopulation responsible for metastasis with the potential to uncover new therapies and more effective management options for PDAC.

Cytokeratin-positive cells in the bone marrow from patients with pancreatic, periampullary malignancy and benign pancreatic disease show no prognostic information

Background

Pancreatic and periampullary carcinoma are aggressive tumours where preoperative assessment is challenging. Disseminated tumour cells (DTC) in the bone marrow (BM) are associated with impaired prognosis in a variety of epithelial cancers. In a cohort of patients with presumed resectable pancreatic and periampullary carcinoma, we evaluated the frequency and the potential prognostic impact of the preoperative presence of DTC, defined as cytokeratin-positive cells detected by immunocytochemistry (ICC).

Methods

Preoperative BM samples from 242 patients selected for surgical resection of presumed resectable pancreatic and periampullary carcinoma from 09/2009 to 12/2014, were analysed for presence of CK-positive cells by ICC. The median observation time was 21.5 months. Overall survival (OS) and disease-free survival (DFS) were calculated by Kaplan-Meier and Cox regression analysis.

Results

Successful resections of malignant tumours were performed in 179 of the cases, 30 patients resected had benign pancreatic disease based on postoperative histology, and 33 were deemed inoperable intraoperatively due to advanced disease. Overall survival for patients with resected carcinoma was 21.1 months (95% CI: 18.0–24.1), for those with benign disease OS was 101 months (95% CI: 69.4–132) and for those with advanced disease OS was 8.8 months (95% CI: 4.3–13.3). The proportion of patients with detected CK-positive cells was 6/168 (3.6%) in resected malignant cases, 2/31 (6.5%) in advanced disease and 4/29 (13.8%) in benign disease. The presence of CK-positive cells was not correlated to OS or DFS, neither in the entire cohort nor in the subgroup negative for circulating tumour cells (CTC).

Conclusions

The results indicate that CK-positive cells may be present in both patients with malignant and benign diseases of the pancreas. Detection of CK-positive cells was not associated with differences in prognosis for the entire cohort or any of the subgroups analysed.

Trial registration

clinicaltrials.gov (NCT01919151).

Circulating Tumor Cells in Pancreatic Cancer: Current Perspectives

Pancreatic cancer is the fourth leading cause of cancer-related death in the USA and Europe; early symptoms and screenings are lacking, and it is usually diagnosed late with a poor prognosis. Circulating tumor cells (CTCs) have been promising new biomarkers in solid tumors. In the last twenty years (1999-2019), 140 articles have contained the key words "Circulating tumor cells, pancreatic cancer, prognosis and diagnosis." Articles were evaluated for the use of CTCs as prognostic markers and their correlation to survival in pancreatic ductal adenocarcinoma (PDAC). In the final selected 17 articles, the CTC detection rate varied greatly between different enrichment methodologies and ranged from 11% to 92%; the majority of studies used the antigen-dependent CellSearch^© system for CTC detection. Fifteen of the reviewed studies showed a correlation between CTC presence and a worse overall survival. The heterogeneity of CTC-detection methods and the lack of uniform results hinder a comparison of the evaluated studies. However, CTCs can be detected in pancreatic cancer and harbor a hope to serve as an early detection tool. Larger studies are needed to corroborate CTCs as valid biomarkers in pancreatic cancer.

Liquid biopsies for management of pancreatic cancer

Pancreatic cancer is one of the main causes of cancer-related deaths worldwide. It is asymptomatic at an early stage, and most diagnosis occurs when the disease is already at a late stage, by which time the tumor is nonresectable. In order to increase the overall survival of patients with pancreatic cancer, as well as to decrease the cancer burden, it is necessary to perform early diagnosis, prognosis stratifications and cancer monitoring using accurate, minimally invasive, and cost-effective methods. Liquid biopsies seek to detect tumor-associated biomarkers in a variety of extractable body fluids and can help to monitor treatment response and disease progression, and even predict patient outcome. In patients with pancreatic cancer, tumor-derived materials, primarily circulating tumor DNA, circulating tumor cells and exosomes, are being studied for inclusion in the management of the disease. This review focuses on describing the biology of these biomarkers, methods for their enrichment and detection, as well as their potential for clinical application. Moreover, we discuss the future direction of liquid biopsies and introduce how they can be exploited toward point of care personalized medicine for the management of pancreatic cancer.

Pancreatic cancer circulating tumor cells: applications for personalized oncology

INTRODUCTION

Pancreatic cancer (PC) is a highly lethal disease, in part because of early metastasis, late diagnosis, and limited treatment options. Circulating tumor cells (CTCs) are cancer cells that have achieved the metastatic step of intravasation, and are thus a unique source of biomarkers with potential applications in the staging, prognostication, and treatment of PC. Areas covered: This review describes the use of CTCs in PC, including isolation methods, the significance of CTC enumeration, and studies examining phenotypic and molecular characteristics of CTCs. We also speculate on future directions for PC CTC research such as single-cell analysis and CTC culture. Expert commentary: CTCs represent a potential unique serial source of cancer tissue via a convenient and minimally invasive blood draw. Recent development of isolation methods that allow for the release of viable CTCs with unaltered molecular characteristics has set the stage for single-cell analysis and ex vivo culture. Although there is significant potential for CTCs as a biomarker to impact PC from diagnosis to therapy, there still remain a number of challenges to the routine implementation of CTCs in the clinical management of PC.

Circulating Tumor Cells: Diagnostic and Therapeutic Applications

Metastasis contributes to poor prognosis in many types of cancer and is the leading cause of cancer-related deaths. Tumor cells metastasize to distant sites via the circulatory and lymphatic systems. In this review, we discuss the potential of circulating tumor cells for diagnosis and describe the experimental therapeutics that aim to target these disseminating cancer cells. We discuss the advantages and limitations of such strategies and how they may lead to the development of the next generation of antimetastasis treatments.

Improved Risk Stratification by Circulating Tumor Cell Counts in Pancreatic Cancer

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RT-PCR of peritoneal washings predicts peritoneal pancreatic cancer recurrence

BACKGROUND

Peritoneal recurrence of pancreatic cancer is a frequent and lethal outcome after R0 resection. A method to predict peritoneal recurrence could be helpful in its prevention.

MATERIALS AND METHODS

Peritoneal washings were prospectively obtained from 29 patients in whom R0 resection was performed. Cytological examination (CY) and real-time reverse transcription polymerase chain reaction (RT-PCR) of the peritoneal washing for the detection of cancer-related genes, CEACAM5, KRT7, KRAS, and MUC1, were performed. Clinicopathological characteristics and real-time RT-PCR results of the peritoneal washing were compared between patients whose pancreatic cancer recurred peritoneally (n = 7) and those patients who it did not recur (n = 22).

RESULTS

Only one CY-positive (CY⁺) case was detected, and that patient recurred. MUC1 mRNA expression was significantly higher in the recurrence group (P = 0.015). Cumulative incidence-function analysis demonstrated that peritoneal recurrence rate was significantly higher in MUC1-positive (MUC1⁺) patients (P = 0.044). MUC1⁺ patients had significantly decreased disease-free survival (P = 0.009) and disease-specific survival (P = 0.031). MUC1 protein was detected in the primary tumor in 18 of 29 patients. However, no significant difference was observed in the expression of MUC1 protein in peritoneal washings from the primary tumor (P = 0.579).

CONCLUSIONS

High expression of MUC1 mRNA in peritoneal washings is a significant risk factor for peritoneal recurrence of pancreatic cancer after R0 resection along with poor disease-specific survival. RT-PCR of MUC1 mRNA in peritoneal washing may be useful for individualization of adjuvant chemotherapy.

Circulating Tumor Cells Predict Occult Metastatic Disease and Prognosis in Pancreatic Cancer

BACKGROUND

Occult metastatic tumors, below imaging thresholds, are a limitation of staging systems that rely on cross-sectional imaging alone and are a cause of the routine understaging of pancreatic ductal adenocarcinomas (PDACs). We investigated circulating tumor cells (CTCs) as a preoperative predictor of occult metastatic disease and as a prognostic biomarker for PDAC patients.

EXPERIMENTAL DESIGN

A total of 126 patients (100 with cancer, 26 with benign disease) were enrolled in our study and CTCs were identified and enumerated from 4 mL of venous blood using the microfluidic NanoVelcro assay. CTC enumeration was correlated with clinicopathologic variables and outcomes following both surgical and systemic therapies.

RESULTS

CTCs were identified in 78% of PDAC patients and CTC counts correlated with increasing stage (ρ = 0.42, p < 0.001). Of the 53 patients taken for potentially curative surgery, 13 (24.5%) had occult metastatic disease intraoperatively. Patients with occult disease had significantly more CTCs than patients with local disease only (median 7 vs. 1 CTC, p < 0.0001). At a cut-off of three or more CTCs/4 mL, CTCs correctly identified patients with occult metastatic disease preoperatively (area under the receiver operating characteristic curve 0.82, 95% confidence interval (CI) 0.76-0.98, p < 0.0001). CTCs were a univariate predictor of recurrence-free survival following surgery [hazard ratio (HR) 2.36, 95% CI 1.17-4.78, p = 0.017], as well as an independent predictor of overall survival on multivariate analysis (HR 1.38, 95% CI 1.01-1.88, p = 0.040).

CONCLUSIONS

CTCs show promise as a prognostic biomarker for PDAC patients at all stages of disease being treated both medically and surgically. Furthermore, CTCs demonstrate potential as a preoperative biomarker for identifying patients at high risk of occult metastatic disease.

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.

Autophagy Is Required for Activation of Pancreatic Stellate Cells, Associated With Pancreatic Cancer Progression and Promotes Growth of Pancreatic Tumors in Mice

BACKGROUND & AIMS

Pancreatic stellate cells (PSCs) change from a quiescent to activated state in the tumor environment and secrete extracellular matrix (ECM) molecules and cytokines to increase the aggressiveness of tumors. However, it is not clear how PSCs are activated to produce these factors, or whether this process can be inhibited. PSCs have morphologic and functional similarities to hepatic stellate cells, which undergo autophagy to promote fibrosis and tumor growth. We investigated whether autophagy activates PSCs, which promotes development of the tumor stroma and growth of pancreatic tumors in mice.

METHODS

We used immunofluorescence microscopy and immunohistochemistry to analyze pancreatic tumor specimens from 133 patients who underwent pancreatectomy in Japan from 2000 to 2009. PSCs were cultured from pancreatic tumor tissues or tissues of patients with chronic pancreatitis; these were analyzed by immunofluorescence microscopy, immunoblots, quantitative reverse transcription polymerase chain reaction, and in assays for invasiveness, proliferation, and lipid droplets. Autophagy was inhibited in PSCs by administration of chloroquine or transfection with small interfering RNAs. Proteins were knocked down in immortalized PSCs by expression of small hairpin RNAs. Cells were transplanted into pancreatic tails of nude mice, and tumor growth and metastasis were quantified.

RESULTS

Based on immunohistochemical analyses, autophagy was significantly associated with tumor T category (P = .018), histologic grade (P = .001), lymph node metastases (P < .001), stage (P = .009), perilymphatic invasion (P = .001), and perivascular invasion (P = .003). Autophagy of PSCs was associated with shorter survival times of patients with pancreatic cancer. PSC expression of microtubule-associated protein 1 light chain 3, a marker of autophagosomes, was associated with poor outcomes (shorter survival time, disease recurrence) for patients with pancreatic cancer (relative risk of shorter survival time, 1.56). Immunoblots showed that PSCs from pancreatic tumor samples expressed higher levels of markers of autophagy than PSCs from chronic pancreatitis samples. Inhibitors of autophagy increased the number of lipid droplets of PSCs, indicating a quiescent state of PSCs, and reduced their production of ECM molecules and interleukin 6, as well as their proliferation and invasiveness in culture. PSCs exposed to autophagy inhibitors formed smaller tumors in nude mice (P = .001) and fewer liver metastases (P = .018) with less peritoneal dissemination (P = .018) compared to PSCs not exposed to autophagy inhibitors.

CONCLUSIONS

Autophagic PSCs produce ECM molecules and interleukin 6 and are associated with shorter survival times and disease recurrence in patients with pancreatic cancer. Inhibitors of PSC autophagy might reduce pancreatic tumor invasiveness by altering the tumor stroma.

Clinical impact of circulating tumor cells and therapy response in pancreatic cancer

BACKGROUND

Among gastrointestinal cancers, the prognosis of pancreatic cancer is one of the poorest, with a large number of patients being diagnosed with unresectable tumors at the first visit to a doctor. The aims of the present study were to investigate the circulating tumor cells (CTC) in peripheral blood in order to assess their clinical significance in patients with pancreatic cancer.

METHODS

Sixty-five patients with advanced pancreatic cancer were enrolled. Borderline resectable pancreatic tumor patients were 9, and Unresectable patients were 56. The CellSearch system was used to isolate and enumerate CTCs.

RESULTS

CTCs were identified in 21 out of 65 patients (32.3%) with only unresectable tumors. The overall survival rate was significantly lower in unresectable patients with than in those without CTCs (P = 0.0051). CTC positivity was significantly higher in patients with than in those without liver metastasis. A multivariate analysis identified the presence or absence of CTCs as an independent prognostic factor. Follow-up blood specimens were obtained from 40 patients treated with chemotherapy or chemoradiotherapy. The incidences of CTC positivity at three months after beginning of treatments in patients with progressive disease and stable disease or a partial response were 45.4% and 24.1%, respectively. The overall survival rate was significantly lower in patients with than in those without CTCs even after treatments (P = 0.045).

CONCLUSION

CTC numbers represents a useful tool for predicting prognoses and therapeutic responses to chemotherapy among patients with advanced pancreatic cancer.

Opportunities and Challenges for Pancreatic Circulating Tumor Cells

Sensitive and reproducible platforms have been developed for detection, isolation, and enrichment of circulating tumor cells (CTCs)-rare cells that enter the blood from solid tumors, including those of the breast, prostate gland, lung, pancreas, and colon. These might be used as biomarkers in diagnosis or determination of prognosis. CTCs are no longer simply detected and quantified; they are now used in ex vivo studies of anticancer agents and early detection. We review what we have recently learned about CTCs from pancreatic tumors, describing advances in their isolation and analysis and challenges to their clinical utility. We summarize technologies used to isolate CTCs from blood samples of patients with pancreatic cancer, including immunoaffinity and label-free physical attribute-based capture. We explain methods of CTC analysis and how findings from these studies might be used to detect cancer at earlier stages, monitor disease progression, and determine prognosis. We review studies that have expanded CTCs for testing of anticancer agents and how these approaches might be used to personalize treatment. Advances in the detection, isolation, and analysis of CTCs have increased our understanding of the dissemination and progression of pancreatic cancer. However, standardization of methodologies and prospective studies are needed for this emerging technology to have a significant effect on clinical care.

Human Trial of a Genetically Modified Herpes Simplex Virus for Rapid Detection of Positive Peritoneal Cytology in the Staging of Pancreatic Cancer

Introduction

Patients with peritoneal dissemination of pancreatic adenocarcinoma do not benefit from surgical resection, but radiologic and cytologic detection of peritoneal cancer lack sensitivity. This trial sought to determine if an oncolytic virus may be used as a diagnostic agent to detect peritoneal cancer.

Methods

Peritoneal washings from patients with pancreatic adenocarcinoma were incubated with the enhanced green fluorescent protein (eGFP)-expressing oncolytic herpes simplex virus (HSV) NV1066. eGFP-positive or negative status was recorded for each specimen and compared to results obtained by conventional cytologic evaluation. These results were correlated with recurrence and survival for patients who underwent R0 resection.

Results

Of 82 patients entered in this trial, 12 (15%) had positive cytology and 50 (61%) had virally-mediated eGFP positive cells in peritoneal washings. All cytology-positive patients were also eGFP positive. HSV-mediated fluorescence detection had sensitivities of 94% and 100% for detection of any and peritoneal metastatic disease; respectively. Median recurrence free and disease specific survival were 6.5 and 18.3 months for eGFP positive patients, versus 12.2 and 36.2 months for eGFP negative patients (P = 0.01 and 0.19); respectively.

Conclusions

A genetically modified HSV can be used as a highly sensitive diagnostic agent for detection of micro-metastatic disease in patients with pancreatic adenocarcinoma and may improve patient selection for surgery.

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Oncolytic virus-mediated fluorescence is a sensitive assay for detection of cancer cells in peritoneal fluid.

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Pancreatic cancer patients with eGFP-positive cells in peritoneal washings had a poor prognosis following surgery.

Pancreatic cancer is an aggressive disease. Even with complete surgical removal of a pancreatic tumor, recurrence is common. Patients with microscopic spread of cancer cells into the abdomen, or peritoneum, do not benefit from surgery. Current methods of detection of this kind of spread are not very sensitive. This study utilized a virus that specifically infects cancer cells and expresses a green fluorescent protein within them to detect peritoneal disease. Viral fluorescence was more sensitive than standard methods for detecting peritoneal disease and may help to identify which patients with pancreas cancer will benefit from surgery.

Clinical Significance of Circulating Tumor Microemboli as a Prognostic Marker in Patients with Pancreatic Ductal Adenocarcinoma

BACKGROUND

Characterization of circulating tumor cells (CTCs) has been used to provide prognostic, predictive, and pharmacodynamic information in many different cancers. However, the clinical significance of CTCs and circulating tumor microemboli (CTM) in patients with pancreatic ductal adenocarcinoma (PDAC) has yet to be determined.

METHODS

In this prospective study, CTCs and CTM were enumerated in the peripheral blood of 63 patients with PDAC before treatment using anti-EpCAM (epithelial cell adhesion molecule)–conjugated supported lipid bilayer–coated microfluidic chips. Associations of CTCs and CTM with patients' clinical factors and prognosis were determined.

RESULTS

CTCs were abundant [mean (SD), 70.2 (107.6)] and present in 81% (51 of 63) of patients with PDAC. CTM were present in 81% (51 of 63) of patients with mean (SD) 29.7 (1101.4). CTM was an independent prognostic factor of overall survival (OS) and progression free survival (PFS). Patients were stratified into unfavorable and favorable CTM groups on the basis of CTM more or less than 30 per 2 mL blood, respectively. Patients with baseline unfavorable CTM, compared with patients with favorable CTM, had shorter PFS (2.7 vs 12.1 months; P &lt; 0.0001) and OS (6.4 vs 19.8 months; P &lt; 0.0001). Differences persisted if we stratified patients into early and advanced diseases. The number of CTM before treatment was an independent predictor of PFS and OS after adjustment for clinically significant factors.

CONCLUSIONS

The number of CTM, instead of CTCs, before treatment is an independent predictor of PFS and OS in patients with PDAC.

No-touch isolation techniques for pancreatic cancer

The rate of recurrence, including liver metastasis is high in pancreatic cancer, even when complete surgical resection is performed as a curative treatment. In patients with pancreatic cancer, the handling and grasping of the pancreas during surgery may increase the risk of liver metastasis, as squeezing may spread cancer cells via the portal vein. A no-touch isolation technique might prevent the spread of cancer cells via the hematogenous metastatic route in patients with pancreatic cancer. However, while no-touch isolation techniques are simple, feasible and, in theory, ideal procedures for the surgical treatment of pancreatic cancer, there have been no randomized controlled prospective studies to validate their advantages and their efficacy remains controversial. It is, therefore, worth investigating the use of no-touch isolation techniques in pancreatic cancer.

Clinical applications of circulating tumor DNA and circulating tumor cells in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is the most frequent pancreatic cancer type and is characterized by a dismal prognosis due to late diagnosis, local tumor invasion, frequent distant metastases and poor sensitivity to current therapy. In this context, circulating tumor cells and circulating tumor DNA constitute easily accessible blood-borne tumor biomarkers that may prove their clinical interest for screening, early diagnosis and metastatic risk assessment of PDAC. Moreover these markers represent a tool to assess PDAC mutational landscape. In this review, together with key biological findings, we summarize the clinical results obtained using "liquid biopsies" at the different stages of the disease, for early and metastatic diagnosis as well as monitoring during therapy.

Snail transcript levels in diagnosis of pancreatic carcinoma with fine-needle aspirate

Expression of the transcription factor Snail that mediates epithelial-mesenchymal transition is correlated with poor prognosis in many tumour types. The aim of this study is to determine, as a proof of principle, whether Snail messenger RNA (mRNA) could be detected in fine-needle aspirate (FNA) biopsies of pancreatic ductal adenocarcinoma (PDAC) and could accurately differentiate malignant from benign pancreatic tissues. We also investigate the expression of Snail mRNA and its clinical significance in PDAC. FNA (22- or 25-gauge needle) samples were obtained from patients from June 1999 to June 2010. FNA samples that were either benign or chronic pancreatitis or confirmed as PDAC were included in this study. Snail mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The associations of Snail mRNA expression with various clinicopathological parameters was analysed in addition to the relation between its expression and patient survival. Levels of Snail mRNA were increased in tumour samples in comparison to benign and chronic pancreatitis. Transcript copy numbers for Snail were 0.7 ± 0.21 for tumour, 0.16 ± 0.09 for benign (P = 0.002) and 0.23 ± 0.12 for chronic pancreatitis (P = 0.024). Snail expression was found to be associated significantly with lymph node metastasis (P = 0.001), perineural invasion (P = 0.038) and elevated preoperative serum carcinoembryonic antigen (CEA) level (P = 0.043). Snail mRNA was increased in patients with poor outcome compared with those who remained alive and well. Snail mRNA levels can aid in the pathological evaluation of suspicious cases and may become a valuable asset in obtaining a definitive diagnosis of PDAC. The strong association between Snail expression and lymph node metastasis suggests that Snail mRNA can be used as an adjunct to lymph node positivity to predict survival in pancreatic cancer.

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.

Improving pancreatic cancer diagnosis using circulating tumor cells: prospects for staging and single-cell analysis

Pancreatic cancer (PC) is the fourth most common cause of cancer-related death in the USA, primarily due to late presentation coupled with an aggressive biology. The lack of adequate biomarkers for diagnosis and staging confound clinical decision-making and delay potentially effective therapies. Circulating tumor cells (CTCs) are a promising new biomarker in PC. Preliminary studies have demonstrated their potential clinical utility, and newer CTC isolation platforms have the potential to provide clinicians access to tumor tissue in a reliable, real-time manner. Such a 'liquid biopsy' has been demonstrated in several cancers, and small studies have demonstrated its potential applications in PC. This article reviews the available literature on CTCs as a biomarker in PC and presents the latest innovations in CTC research as well as their potential applications in PC.

Diagnostic utility of clinical and biochemical parameters in pancreatic head malignancy patients with normal carbohydrate antigen 19-9 levels

BACKGROUND

Carbohydrate antigen (CA)19-9 that is the most widely used biomarker for pancreatic cancer has certain limitations in diagnosis, which results in a tough job to distinguish pancreatic cancer from benign tumors with normal CA19-9. The aim of this study was to investigate the diagnostic utility of clinical parameters and serum markers in patients with pancreatic head masses but without elevated CA19-9.

METHODS

Retrospectively, 106 (69 malignant, 37 benign) of 487 patients admitted for pancreatic head masses were enrolled with CA19-9 level of <37u/ml. Clinical parameters and serum biomarkers were assessed. Among the patients with pancreatic head mass, male individuals (p=0.025) and elder individuals (p<0.001) were more likely to have cancer; and cancer patients were more likely to present with abdominal-pain (p=0.023), weight-loss (p=0.013) and jaundice (p<0.001). Serum bilirubin levels among malignancies, including total bilirubin (p<0.001), direct bilirubin (p<0.001) and indirect bilirubin (p<0.001), were considerably higher than those of benign ones. Logistic regression further concluded that age-distribution, abdominal-pain and direct-bilirubin were three independent factors correlating with final diagnosis. However, CEA (p=0.156) was not sufficient enough to exclude pancreatic cancer.

CONCLUSIONS

In patients with pancreatic head masses and CA19-9 of <37u/ml, age-distribution, abdominal-pain and direct bilirubin might be helpful in differential diagnosis. CEA was insufficient for exclusion of malignancy.

Circulating tumor cells in the diagnosis and management of pancreatic cancer

Pancreatic cancers are typically resistant to chemo and radiation therapy and are predisposed to distant metastases. Circulating tumor cells (CTCs) are tumor cells disseminated from primary and metastatic sites and can be isolated from peripheral blood. CTC may overcome the limitation of the current available tumor markers, CA19-9. As a surrogate for 'real-time biopsy', CTCs allow recurrent assessment of a tumor's biological activity. We review the current methodologies for CTC extraction and characterization including antibody-based immunological assays, PCR-based assays, and novel technologies based on the physical or biological characteristics of CTCs. CTCs also provide an accessible link to the existence of epithelial to mesenchymal transition, tumor stem cell markers, and ongoing clonal mutations and epigenetic changes in the tumor. We also explore the potential of using CTC profiling in diagnosis, selection of neoadjuvant and adjuvant therapy, detection of recurrent disease, examination of pharmacodynamic biomarkers, as well as in gene therapy and immunotherapy for pancreatic cancer. Ongoing CTC characterization not only has the potential to represent all cells shed from primary pancreatic tumor and each metastatic site, but also allows dynamic sampling at multiple time points during the clinical course to identify the subpopulations of CTCs and the specific molecules driving metastasis and chemo resistance. We predict that CTC genotyping and phenotyping will play an increasing role in personalized therapy and in identification of novel therapeutic targets as well as monitoring the course and status of the disease.

Preoperative evaluation and management of the pancreatic head mass

The differential diagnosis of a pancreatic head mass encompasses a wide range of clinical entities that include both solid and cystic lesions. This chapter focuses on our approach to the patient presenting with a newly found pancreatic head mass with the main goals of determining the risk of the lesion being malignant or premalignant, resectability if the patient is appropriate for surgical intervention, assessment of need for multimodality treatment and determination the patient's surgical risk.

Multimarker gene analysis of circulating tumor cells in pancreatic cancer patients: a feasibility study

OBJECTIVE

The aim of this study was to develop an immunomagnetic/real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay and assess its clinical value for the molecular detection of circulating tumor cells (CTCs) in peripheral blood of pancreatic cancer patients.

METHODS

The presence of CTCs was evaluated in 34 pancreatic cancer patients before systemic therapy and in 40 healthy controls, through immunomagnetic enrichment, using the antibodies BM7 and VU1D9 [targeting mucin 1 and epithelial cell adhesion molecule (EpCAM), respectively], followed by real-time RT-PCR analysis of the genes KRT19, MUC1, EPCAM, CEACAM5 and BIRC5.

RESULTS

The developed assay showed high specificity, as none of the healthy controls were found to be positive for the multimarker gene panel. CTCs were detected in 47.1% of the pancreatic cancer patients before the beginning of systemic treatment. Shorter median progression-free survival (PFS) was observed for patients who had at least one detectable tumor-associated transcript, compared with patients who were CTC negative. Median PFS time was 66.0 days [95% confidence interval (CI) 44.8-87.2] for patients with baseline CTC positivity and 138.0 days (95% CI 124.1-151.9) for CTC-negative patients (p = 0.01, log-rank test).

CONCLUSION

Our results suggest that in addition to the current prognostic methods, CTC analysis represents a potential complementary tool for prediction of outcome in pancreatic cancer patients.

Advances in biomarker research for pancreatic cancer

Pancreatic cancer (PC) is a leading cause of cancer related deaths in United States. The lack of early symptoms results in latestage detection and a high mortality rate. Currently, the only potentially curative approach for PC is surgical resection, which is often unsuccessful because the invasive and metastatic nature of the tumor masses makes their complete removal difficult. Consequently, patients suffer relapses from remaining cancer stem cells or drug resistance that eventually lead to death. To improve the survival rate, the early detection of PC is critical. Current biomarker research in PC indicates that a serum carbohydrate antigen, CA 19-9, is the only available biomarker with approximately 90% specificity to PC. However, the efficacy of CA 19-9 for assessing prognosis and monitoring patients with PC remains contentious. Thus, advances in technology and the detection of new biomarkers with high specificity to PC are needed to reduce the mortality rate of pancreatic cancer.

Disseminated tumor cells in pancreatic cancer-an independent prognosticator of disease progression and survival

Pancreatic cancer is one of the most devastating cancers with a 6-month median survival and a 5-year survival rate of 3-5%. Still important aspects of its aggressive biology remain elusive and advanced therapeutic regimens have not been substantially successful. We investigated the prognostic role of disseminated tumor cells (DTC) in bone marrow, a reservoir for early DTC potentially contributing to metastatic progression, of pancreatic cancer patients. After exclusion of patients with different postsurgery diagnosis or missing DTC status (n = 40) a total of 175 patients remained for final analyses. One-hundred and nineteen patients were male and 96 female with a median age of 67 years, 96 patients underwent complete resection. Bone marrow aspirates taken at primary surgery were analyzed for DTC by an immunocytochemical cytokeratin assay and correlated to survival data. Overall 13.7% of patient samples (24/175) harbored DTC in their bone marrow. Histopathological parameters did not correlate significantly. Univariate survival analysis revealed a borderline significant correlation between DTC and decreased progression-free survival (p = 0.069), and was significant for overall survival (p = 0.036). Regarding patients with resected tumors, the respective p-values were 0.058 for progression-free and 0.016 for overall survival. Importantly, the prognostic influence was independent from other risk factors as shown by multivariate analyses for progression-free (p = 0.030, HR: 2.057; CI (95%): 1.073-3.943) and overall survival (p = 0.006, HR: 2.283; CI (95%): 1.260-4.135). The presence of DTC in bone marrow is a strong and independent prognostic factor of survival in patients with pancreatic cancer. Thus, bone-targeting may be a new future therapeutic option for DTC-positive patients.

Disseminated and circulating tumor cells in gastrointestinal oncology

Circulating (CTCs) and disseminated tumor cells (DTCs) are two different steps in the metastatic process. Several recent techniques have allowed detection of these cells in patients, and have generated many results using different isolation techniques in small cohorts. Herein, we review the detection results and their clinical consequence in esophageal, gastric, pancreatic, colorectal, and liver carcinomas, and discuss their possible applications as new biomarkers.

Circulating tumor cells in prostate cancer: a potential surrogate marker of survival

Prostate-specific antigen (PSA) levels in blood are widely used in prostate cancer (PCa) for the management of this disease at every stage of progression. Currently, PSA levels combined with clinical stage and Gleason score provide the best predictor of survival and the main element to monitor treatment efficiency. However, these areas could be improved by utilizing emerging biomarkers. Recently, circulating tumor cells (CTCs) and disseminating tumor cells (DTCs) have been detected in PCa and may be a new surrogate candidate. Here we provide a systematic review of the literature in order to describe the current evidence of CTC/DTC surrogacy regarding outcome of prostate cancer patients. We also discuss several markers that could be used to increase the sensitivity and specificity of CTC/DTC detection. CTC/DTC detection is performed using a wide variety of techniques. Initially, reverse transcriptase polymerase chain reaction (RT-PCR) based methods were utilized with weak correlation between their positive detection and patients' outcome. More recent immunological techniques have indicated a reproducible correlation with outcome. Such surrogate markers may enable clinicians to provide early detection for inefficient treatments and patients with poor prognosis that are candidates for treatment intensification. Dissecting the micrometastasis phenomenon in CTCs/DTCs is a key point to increase surrogacy of this biomarker.

Effect of chymotrypsin C and related proteins on pancreatic cancer cell migration

Pancreatic cancer is a malignant cancer with a high mortality rate. The amount of chymotrypsin C in pancreatic cancer cells is only 20% of that found in normal cells. Chymotrypsin C has been reported to be involved in cancer cell apoptosis, but its effect on pancreatic cancer cell migration is unclear. We performed cell migration scratch assays and Transwell experiments, and found that cell migration ability was downregulated in pancreatic cancer Aspc-1 cells that overexpressed chymotrypsin C, whereas the cell migration ability was upregulated in Aspc-1 cells in which chymotrypsin C was suppressed. Two-dimensional fluorescence differential in gel electrophoresis/mass spectrometry method was used to identify the proteins that were differentially expressed in Aspc-1 cells that were transfected with plasmids to induce either overexpression or suppressed expression of chymotrypsin C. Among 26 identified differential proteins, cytokeratin 18 was most obviously correlated with chymotrypsin C expression. Cytokeratin 18 is expressed in developmental tissues in early stages of cancer, and is highly expressed in most carcinomas. We speculated that chymotrypsin C might regulate pancreatic cancer cell migration in relation to cytokeratin 18 expression.

Perioperative cancer cell dissemination detected with a real-time RT-PCR assay for EpCAM is not associated with worse prognosis in pancreatic ductal adenocarcinoma

Background

Epithelial cell adhesion molecule (EpCAM) has been used as surrogate marker for the quantification of circulating tumour cells (CTC). Our aim was to prospectively study the value of a real-time RT-PCR assay for EpCAM detection in the peripheral blood and peritoneal cavity of patients undergoing pancreatectomy for pancreatic ductal adenocarcinoma (PDAC).

Methods

From 48 patients with PDAC (40 resectable, 8 unresectable) and 10 patients with chronic pancreatitis undergoing pancreatectomy 10 ml of venous blood was drawn preoperatively (PB) and postoperatively (POB, day 1 (D1B), day 7 (D7B) and after 6 weeks (6WB). Of all patients undergoing pancreatectomy, 40 ml peritoneal lavage fluid was taken preoperatively and postoperatively. A real-time RT-PCR assay (TaqMan, ABI Prism 7700) was developed for the detection of EpCAM mRNA. To discriminate between EpCAM-positive and negative samples a cut-off was applied. Median postoperative follow-up was 24.0 months (range: 0.7 - 41.3).

Results

PB was EpCAM-positive (+) in 25% of patients versus 65% of patients in POB (p < 0.0001). EpCAM(+) was noted at D1B, D7B and 6WB was found in 28.6%, 23.1% and 23.5% of patients respectively. Preoperative peritoneal lavage fluid was EpCAM(+) in 10.3% versus 53.8% of patients postoperatively (p < 0.0001).

At none of the time-points, an association was found between EpCAM positivity in blood and/or peritoneal cavity and cancer-specific or disease-free survival. Also, no significant associations were found between clinicopathological variables and perioperative EpCAM positivity.

Conclusions

Despite a significant increase in EpCAM counts in postoperative blood and peritoneal lavage fluid this was not associated with worse prognosis after pancreatectomy for PDAC.

Trial registration

Clinicaltrials.gov NCT00495924

Effects of perioperative red blood cell transfusion on disease recurrence and survival after pancreaticoduodenectomy for ductal adenocarcinoma

BACKGROUND

The premise that allogeneic red blood cell transfusion (RBCT) contributes to adverse oncologic outcomes after surgery remains controversial. We examined the effects of RBCT during and after pancreaticoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC) on disease recurrence and survival.

METHODS

A prospective database of 220 patients undergoing PD for PDAC from 2000 to 2008 was reviewed and transfusion data collected. Univariate and multivariate analyses were performed for factors influencing RBCT, recurrence-free survival (RFS), and overall survival (OS). The effect of amount and timing (intraoperative vs. postoperative) of RBCT was analyzed.

RESULTS

One hundred forty-seven patients (67%) received RBCT: 70 (32%) received 1 to 2 units, and 77 (35%) received >2 units. Median RFS and OS for the entire cohort was 12 and 16 months, respectively. RBCT of >2 units was associated with reduced RFS (9 vs. 15 months; P = 0.033) and OS (14 vs. 20 months; P = 0.003). Stratified by timing of transfusion, postoperative RBCT was associated with shortened RFS and OS. Controlling for age, body mass index, comorbidities, tumor factors, and major complications, each incremental unit of postoperative RBCT was associated with reduced RFS (hazard ratio 1.10, 95% confidence interval 1.02-1.18) and OS (hazard ratio 1.08, 95% confidence interval 1.03-1.12). Low hemoglobin and presence of comorbidities were the only preoperative factors independently associated with RBCT.

CONCLUSIONS

Allogeneic red blood cell transfusion after PD for PDAC is independently associated with earlier cancer recurrence and reduced survival, in particular when administered postoperatively and in larger quantities. Blood-conservation methods are especially indicated for patients with preoperative anemia and medical comorbidities.

Marker expression in circulating cancer cells of pancreatic cancer patients

BACKGROUND

By the time patients are diagnosed with pancreatic cancer, circulating cancer cells probably exist. Therefore, the detection of pancreatic cancer cells in the peripheral circulation could be used to diagnose early pancreatic cancer, which would otherwise not be detected by current imaging methods.

METHODS

The expression levels of h-TERT, CK20, CEA, and C-MET were detected in a model of circulating micrometastasis in pancreatic cancer that were enriched using immune-magnetic separation of the circulating cancer cells. The sensitivity and specificity of the measurements were evaluated. The expression of the above genes was measured in the circulating cancer cells of pancreatic cancer patients. We compared their expression rate in pancreatic cancer patients at different stages to screen for the indicator with highest sensitivity and specificity for the detection of circulating pancreatic cancer cells.

RESULTS

Immuno-magnetic nanoparticles combined with RT-PCR enabled the detection of one tumor cell per 1×10(7) peripheral blood mononuclear cells. The positive expression rates of C-MET, h-TERT, CK20, and CEA in the pancreatic cancer group were 80% (20/25), 100% (25/25), 84% (21/25), and 80% (20/25), respectively, while in the benign disease control group the rates were 0% (0/15), 0% (0/15), 6.77% (1/15), and 0% (0/15), respectively. There was a significant difference in the positive expression rate between the two groups (P<0.05). The specificity of h-TERT, CEA, and C-MET was higher than that of CK20. The positive expression rate of the four genes was not related to gender, age, tumor size, CA 19-9, or CEA serum levels (P>0.05). However, the positive expression of C-MET, CK20, and CEA closely correlated with tumor stage (P<0.05). Immuno-magnetic nanoparticles combined with RT-PCR were specific and sensitive for the detection of circulating cancer cells.

CONCLUSIONS

The positive expression of C-MET, h-TERT, CK20, and CEA in the circulation of pancreatic patients could be used as an indicator for circulating cancer cells. The combined detection of the four genes improved the specificity and sensitivity to 100%, which may be attributable to the use of immuno-magnetic separation and enrichment of the circulating pancreatic cancer cells. Our results suggest the clinical utility of this approach.

Circulating tumor cells in gastrointestinal cancer

Since the first report in the nineteenth century, there have been numerous reports on the isolation and characterization of circulating tumor cells (CTCs) in peripheral blood in patients with various carcinomas. In general, CTCs have been observed in the peripheral blood of cancer patients at very low concentrations of 10(-7)-10(-8) of normal peripheral blood cells. The characterization is of considerable biomedical interest in order to understand how these cells can travel via the blood stream to anatomically distant sites and form metastatic disease. Recent progress in molecular oncology enables us to detect the CTCs in blood with highly sensitivity and specificity, and several studies have indicated the prognostic value of CTC detection in patients with gastrointestinal cancers. Detection and measurement of CTCs in patients with gastrointestinal cancers such as colorectal, gastric, and pancreatic cancers can be useful as a promising tool for judging tumor stage, predicting the distant metastasis and patient survival, and monitoring the response to cancer therapy. Standard procedures for CTC detection have to be established, and the clinical relevance should be verified in large-scale clinical trials. However, CTC detection is suggested to provide useful information for the tumor staging and anticancer treatments in clinical practices in the near future.

Detection of circulating tumor cells in prostate cancer patients: methodological pitfalls and clinical relevance

Disseminated malignancy is the major cause of prostate cancer-related mortality. Circulating tumor cells (CTCs) are essential for the establishment of metastasis. Various contemporary and molecular methods using prostate-specific biomarkers have been applied to detect extraprostatic disease that is undetectable by conventional imaging techniques, assessing the risk for disease recurrence after therapy of curative intent. However, the clinical relevance of CTC detection is still controversial. We review current literature regarding molecular methods used for the detection of CTCs in the peripheral blood and bone marrow biopsies of patients with prostate cancer, and we discuss the methodological pitfalls that influence the clinical significance of molecular staging.

Cancer micrometastasis and tumour dormancy

Many epithelial cancers carry a poor prognosis even after curative resection of early stage tumours. Tumour progression in these cancer patients has been attributed to the existence and persistence of disseminated tumour cells (DTC) in various body compartments as a sign of minimal residual disease. Bone marrow (BM) has been shown to be a common homing organ and reservoir for DTC. A significant correlation between the presence of DTC in BM and metastatic relapse has been reported in various tumour types. However, only a portion of patients with DTC in BM at primary surgery relapse. Thus far, little is known about the conditions required for the persistence of dormancy or the escape from the dormant phase into the active phase of metastasis formation. Thereby, this peculiar stage of conceivably balanced tumour cell division and death may last for decades in cancer patients. Most likely, the ability of a dormant DTC to "be activated" is a complex process involving (i) somatic aberrations in the tumour cells, (ii) the interaction of the DTC with the new microenvironment at the secondary site, and (iii) hereditary components of the host (i.e., cancer patient). In this review, we will summarize the key findings of research on micrometastatic cancer cells and discuss these findings in the context of the concept of tumour dormancy.

Analysis of microRNAs in pancreatic fine-needle aspirates can classify benign and malignant tissues

BACKGROUND

MicroRNAs (miRNAs) are RNA molecules that are involved in the regulation of many cellular processes, including those related to human cancers. The aim of this study was to determine, as a proof of principle, whether specific candidate miRNAs could be detected in fine-needle aspirate (FNA) biopsies of pancreatic ductal adenocarcinoma (PDAC) and could accurately differentiate malignant from benign pancreatic tissues.

METHODS

We used TaqMan(R) assays to quantify miRNA levels in FNA samples collected in RNARetain (n = 16) and compared the results with a training set consisting of frozen macrodissected pancreatic samples (n = 20).

RESULTS

Quantitative reverse-transcription PCR analysis confirmed that miRNA levels are affected in PDAC FNAs and correlate well with the changes observed in the training set of frozen pancreatic samples. Analysis of the amounts produced for a few specific miRNAs enabled identification of PDAC samples. The combination of miR-196a and miR-217 biomarkers further improved the ability to distinguish between healthy tissue, PDAC, and chronic pancreatitis in the training set (P = 8.2 x 10(-10)), as well as segregate PDAC FNA samples from other FNA samples (P = 1.1 x 10(-5)). Furthermore, we showed that miR-196a production is likely specific to PDAC cells and that its incidence paralleled the progression of PDAC.

CONCLUSIONS

To the best of our knowledge, this study is the first to evaluate the diagnostic potential of miRNAs in a clinical setting and has shown that miRNA analysis of pancreatic FNA biopsy samples can aid in the pathologic evaluation of suspicious cases and may provide a new strategy for improving the diagnosis of pancreatic diseases.

Gemcitabine in the treatment of metastatic pancreatic cancer

Gemcitabine (2 ,2 -difluorodeoxycytidine) is a deoxycytidine-analog antimetabolite with broad activity against a variety of solid tumors and lymphoid malignancies. It was approved as standard of care in patients with pancreatic cancer one decade ago, based primarily on improvement in clinical benefit response such as pain reduction, improvement in Karnofsky performance status and increase in body weight. This article gives an overview of the pharmacodynamics and pharmacokinetics of gemcitabine, highlights the clinical activity of gemcitabine and summarizes the treatment options in metastatic pancreatic cancer with focus on gemcitabine-based chemotherapy. The emerging role of combinations of gemcitabine with novel targeted agents, including small-molecule inhibitors and other investigational drugs, is also discussed.

Diagnostic and prognostic biomarkers in pancreatic carcinoma

Pancreatic ductal carcinoma, one of the leading causes of cancer mortality, is typically diagnosed at an advanced stage, which significantly contributes to its high mortality rates. Studies have demonstrated that resection of small pancreatic tumors and tumors at lower stages correlates with improved survival. Detection of pancreatic carcinoma at an early, surgically resectable stage is the key to decreasing mortality and improving survival. Identification of sensitive diagnostic biomarkers as screening tools is crucial in detecting preinvasive pancreatic neoplasms. Numerous new DNA-, RNA- and protein-based biomarkers have been extensively investigated. This review aims to provide an update on these molecular markers, including biomarkers from blood, tissue as well as pancreatic juice and cystic fluid. These biomarkers hold potential utility in early diagnosis and prognostification of pancreatic ductal carcinoma, though many of which need to be validated in large-scale prospective studies before they can be used in clinical settings.

Progress on molecular markers of pancreatic cancer

PURPOSE OF REVIEW

To describe advances in the development of biomarkers for pancreatic cancer over the past year.

RECENT FINDINGS

Several new approaches were taken in the search for biomarkers for pancreatic cancer. Studies of CA19-9 revealed new prognostic abilities of the already well known biomarker. New blood biomarkers were investigated and CEACAM1 and MIC-1 were found to be superior to CA19-9 at distinguishing cancer from normal but, unfortunately, not from chronic pancreatitis. MUC1 was reported to be superior to CA19-9 based on the use of a novel immunoassay. The superiority of the concept of a panel of biomarkers as opposed to single biomarkers was supported by several studies, but no such panel was identified. RNA levels in blood and DNA methylation in pancreatic juice yielded some promising findings. Advancements were also made in the area of tissue biomarkers, which can improve the diagnostic accuracy of fine-needle aspirations and provide prognostic information. A new source of potential biomarkers, microRNAs, also made its debut in the past year.

SUMMARY

The tools to identify pancreatic-cancer biomarkers and sources of samples needed in this search are expanding. The field has not yet achieved its aims, but several encouraging breakthroughs have been made.

Haemoglobin, serum albumin and transferrin variants of Bali (Banteng) cattle, Bos (Bibos) javanicus

1. Individual blood samples from 144 Bali (Banteng) cattle [Bos (Bibos) javanicus] in the Northern Territory of Australia and from 61 Bali cross cattle, were examined by zone electrophoresis to determine the variants of haemoglobin, serum albumin and transferrin that are present. 2. Of the common cattle haemoglobin variants (A and B) only variant B occurs in the Bali cattle samples. A second variant, designated CBali, occurs in Bali cattle either as the heterozygote (B CBali) or as the homozygote, the frequencies of occurrence indicating a two-allele system of inheritance without dominance. The CBali cross samples may exhibit the homozygous or heterozygous A variant. 3. The CBali variant has an electrophoretic mobility intermediate between those of the A and B variants at pH 8.6 and 9.1 but closer to B than to A (B greater than C greater than A). It appears to be similar in mobility to the C variants found in Indian Khillan (CKhillan) by Naik, Sukumaran and Sanghvi (Anim. Prodn, 1965 I, 275-277), and in Asian cattle by Oishi, Abe and Namikama (Immunogenet. Lett., 1968 5, 170-173) and Abe, Mogi, Oishi, Tanaka and Suzuki (Proc. XIIth Europ. Conf. Anim. Blood Groups Biochem. Polymorphisms 1972, pp. 225-228), but appreciably different from those in Kenyan and Rhodesian cattle (CRhodesia) found by Braend (Anim. Blood Grps Biochem. Genet., 1971 2, 15-21) and Carr (Rhod. J. agric. Res., 1964 3, 62-62A), respectively. It is also different in mobility from the C variant found by Winter, Mayr, Schleger, Dworak, Krutzler and Burger (Res. vet. Sci., 1984 36, 276-283) in the mithun.(ABSTRACT TRUNCATED AT 250 WORDS)