Pancreatic carcinoma

Potential of Carbohydrate Antigen 19-9 and Serum Apolipoprotein A2-Isoforms in the Diagnosis of Stage 0 and IA Pancreatic Cancer

Apolipoprotein A2-ATQ/AT (apoA2-ATQ/AT) is a new biomarker for diagnosing pancreatic cancer (PC). In this study, the value of blood carbohydrate antigen 19-9 (CA19-9) and apoA2-ATQ/AT levels in diagnosing stage 0 and IA PC was evaluated. During 2014-2021, 12 patients with stage 0 PC and 12 patients with IA PC (average age: 73.8 years) underwent resection at JA Onomichi General Hospital. In addition, the data of 200 healthy controls were collected from a community-based cohort study. Levels of two apoA2-isoforms were measured using enzyme-linked immunosorbent assay (ELISA) with specific antibodies to calculate the apoA2-i Index as a surrogate value for apoA2-ATQ/AT. The cutoff value for the apoA2-i Index was determined to be 62.9 μg/mL. CA19-9 levels were also measured through ELISA. Among all 24 patients with PC, the positivity rates for apoA2-i and CA19-9 were 33.3% and 25.0%, respectively. The positivity rates for apoA2-i and CA19-9 were 16.7% and 8.3% in patients with stage 0 PC and 50.0% and 41.7% in those with stage IA, respectively. For CA19-9-negative patients, the apoA2-i positivity rate was 9.1% in stage 0 and 42.9% in stage IA. The combined positivity rate for both markers was 16.7% in stage 0 and 66.7% in stage IA. Imaging findings in apoA2-i- and CA19-9-positive patients included pancreatic duct dilatation (87.5%/100%), duct stenosis (75.0%/50%), and atrophy (87.5%/66.7%). The imaging findings of this study suggest that apoA2-i may enhance the sensitivity for detecting CA19-9-negative stage 0 and IA PC, and complementary measurements with CA19-9 may be valuable for diagnosing early-stage PC. Therefore, minute PC with pancreatic duct dilation, duct stenosis, and atrophy may exhibit a high positivity rate, aiding differential diagnosis.

Pancreatic Juice-Derived microRNA-4516 and microRNA-4674 as Novel Biomarkers for Pancreatic Ductal Adenocarcinoma

Background and Aims

Precise diagnostic biomarkers are urgently required for pancreatic ductal adenocarcinoma (PDAC). Therefore, the aim of this study was to identify PDAC-specific exosomal microRNAs (Ex-miRs) from pancreatic juice (PJ) and evaluate their diagnostic potential.

Methods

Exosomes in PJ and serum were extracted using ultracentrifugation and confirmed morphologically and biochemically. PDAC-specific Ex-miRs were identified using our original miR arrays, in which "Ex-miRs derived from the PJ of patients with chronic pancreatitis (CP)" were subtracted from Ex-miRs commonly expressed in both "human PDAC cell lines" and "the PJ of patients with PDAC." We verified the expression of these miRs using quantitative real-time reverse transcription polymerase chain reaction. Changes in serum Ex-miR levels were assessed in 2 patients with PDAC who underwent curative resection. In situ hybridization was performed to directly visualize PDAC-specific miR expression in cancer cells.

Results

We identified novel Ex-miR-4516 and Ex-miR-4674 from the PJ of patients with PDAC, and they showed 80.0% and 81.8% sensitivity, 80.8% and 73.3% specificity, and 90.9% and 80.8% accuracy, respectively. The sensitivity, specificity, and accuracy of a triple assay of Ex-miR-4516/4674/PJ cytology increased to 93.3%, 81.8%, and 88.5%, respectively. In serum samples (n = 88), the sensitivity, specificity, and accuracy of Ex-miR-4516 were 97.5%, 34.3%, and 68%, respectively. Presurgical levels of serum-derived Ex-miR-4516 in 2 patients with relatively early disease stages declined after curative resection. In situ hybridization demonstrated that Ex-miR-4516 expression exclusively occurred in cancer cells.

Conclusion

Liquid assays using the in situ-proven Ex-miR-4516 may have a high potential for detecting relatively early-stage PDAC and monitoring its clinical course.

Impact of gut microbiome in the development and treatment of pancreatic cancer: Newer insights

The gut microbiome plays an important role in the variation of pharmacologic response. This aspect is especially important in the era of precision medicine, where understanding how and to what extent the gut microbiome interacts with drugs and their actions will be key to individualizing therapy. The impact of the composition of the gut microbiome on the efficacy of newer cancer therapies such as immune checkpoint inhibitors and chimeric antigen receptor T-cell treatment has become an active area of research. Pancreatic adenocarcinoma (PAC) has a poor prognosis even in those with potentially resectable disease, and treatment options are very limited. Newer studies have concluded that there is a synergistic effect for immunotherapy in combination with cytotoxic drugs, in the treatment of PAC. A variety of commensal microbiota can affect the efficacy of conventional chemotherapy and immunotherapy by modulating the tumor microenvironment in the treatment of PAC. This review will provide newer insights on the impact that alterations made in the gut microbial system have in the development and treatment of PAC.

Endoscopic approach in the diagnosis of high-grade pancreatic intraepithelial neoplasia

Early diagnosis of pancreatic ductal adenocarcinoma (PDAC) is essential for improving prognosis; however, diagnosing PDAC at an early stage is challenging. In patients with localized high-grade pancreatic intraepithelial neoplasia (HG-PanIN), whose tumorous lesion is undetectable on cross-sectional images such as computed tomography or magnetic resonance image, long-term survival is expected. Pancreatic cystic lesions or main pancreatic duct (MPD) dilatation are important indirect findings for the initial diagnosis of HG-PanIN. Magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound (EUS) should play important roles in detecting abnormal image findings, such as local irregular MPD stenosis, caliber MPD changes, small cystic lesions, or branch duct dilatation. Additionally, EUS could detect hypoechoic areas around the MPD stenosis in some patients with HG-PanIN. Subsequently, endoscopic retrograde cholangiopancreatography (ERCP) and its associated pancreatic juice cytology, including serial pancreatic juice aspiration cytologic examination (SPACE) after placement of an endoscopic nasopancreatic drainage (ENPD) tube, may have high diagnostic accuracy for confirming the malignancy in HG-PanIN. Although ERCP and its associated pancreatic cytology, including SPACE, may be associated with post-ERCP pancreatitis (PEP), a recent randomized trial suggested that a 4-Fr ENPD tube may reduce the incidence of PEP. In the future, further prospective multicenter studies are required to establish a standard method of SPACE. Additionally, further studies for novel biomarkers could help to establish evolutionary methods with duodenal fluid and pancreatic juice for the early and accurate diagnosis of early-stage PDAC.

Analysis of N6-methyladenosine-related lncRNAs in the tumor immune microenvironment and their prognostic role in pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is a rare solid malignancy with a poor prognosis. N6-methyladenosine (m6A) and long noncoding RNAs (lncRNAs) play essential roles in tumorigenesis and progression. However, little is known about the role of m6A-related lncRNAs in PC.

METHODS

m6A-related lncRNAs were extracted by Pearson analysis, and then prognosis-related lncRNAs were filtered from the m6A-related lncRNAs by univariate Cox regression analysis. Based on the expression patterns of the prognosis-related lncRNAs, samples were classified into distinct clusters. Least absolute shrinkage and selection operator (LASSO) Cox regression was used to construct a m6A-lncRNA-related prognostic signature for PC patients. Receiver operating characteristic (ROC) curves and the corresponding area under the curve (AUC) values were used to evaluate the prognostic ability of the model.

RESULTS

A total of 178 tumor and 4 normal samples were extracted from The Cancer Genome Atlas (TCGA) database in our study. Based on the expression of 12 filtered prognosis-related lncRNAs, two distinct clusters were eventually identified; these clusters were characterized by differences in the tumor immune microenvironment (TIME) and prognosis. A risk model comprising ten m6A-related lncRNAs was identified as an independent predictor of prognosis. ROC analysis revealed that this model had an acceptable prognostic value for PC patients. The prognostic signature was related to the TIME and the expression of critical immune checkpoint molecules.

CONCLUSION

This study comprehensively assessed the expression pattern and prognostic value of m6A-related lncRNAs in PC. The different clusters correlated with distinct TIMEs and prognoses. The study also constructed a ten-gene signature prognostic model based on m6A-related lncRNAs, which showed good accuracy in predicting overall survival.

Synchronous gastric cancer and carcinoma in situ of the pancreas

Abnormal findings in the pancreatic duct without a mass may require serial pancreatic juice aspiration cytological examination. In cases of synchronous gastric cancer and stage 0 pancreatic cancer, spleen-preserving pancreatectomy may have advantage.

Comparison of the Diagnostic Efficiency of Radial- and Convex-Arrayed Echoendoscopes for Indirect Findings of Pancreatic Cancer: A Retrospective Comparative Study Using Propensity Score Method

Simple Summary

Pancreatic cancer (PC) has a poor prognosis; however, diagnosing PC at an earlier stage could improve long-term patient outcomes. Endoscopic ultrasonography (EUS) plays an important role in PC detection, and the indirect findings (caliber change, retention cysts, and dilatation of the branch duct) that are detected by EUS are especially important for the early detection of PC. The aim of this retrospective study was to compare the diagnostic efficacy of radial- and convex-arrayed echoendoscope for the detection rate of indirect findings. As a result, the radial-arrayed echoendoscope was found to be an independent detection factor of indirect findings by multivariate analysis. The radial-arrayed echoendoscope is useful for the detection of indirect findings.

Abstract

Endoscopic ultrasonography (EUS) is useful for detecting early-stage pancreatic cancer. Because the detection of small lesions is difficult, it is important to detect indirect findings, namely caliber change, retention cysts, and dilatation of the branch duct, during the procedure. Although two types of EUS endoscopes are frequently used, there is no comparative study on their efficacy for detecting indirect findings. Therefore, we aimed to compare the diagnostic efficacy of these two types for indirect findings. We retrospectively analyzed 316 consecutive patients who had undergone EUS for pancreaticobiliary disease at a single center between January 2017 and December 2018. The main outcome was the detection rate of indirect findings and its comparison between the two echoendoscope types. This outcome was achieved using the inverse probability of treatment weighting (IPTW) analysis. The detection rate of indirect findings was higher for the radial-arrayed endoscope than for the convex-arrayed echoendoscope (9.2% vs. 2.3% (p = 0.02)). The univariate analysis also revealed that the radial-arrayed echoendoscope was significantly superior to the convex-arrayed echoendoscope in terms of the detection of indirect findings (odds ratio, 5.94; 95% confidence interval, 1.68–21.10; p = 0.01) after IPTW. After adjustment for magnetic resonance imaging (MRI) and computed tomography (CT), radial-arrayed echoendoscope remained an independent factor for indirect finding detection (odds ratio, 6.04; 95% confidence interval, 1.74–21.00; p = 0.01). Finally, five patients who had indirect EUS findings were diagnosed with pancreatic cancer. Our results indicate that the radial-arrayed echoendoscope is useful for the detection of indirect findings.

Smad4 deficiency substitutes Cdkn2b but not Cdkn2a downregulation in pancreatic cancer following induction of genetic events in adult mice

BACKGROUND

Minor progress in pancreatic cancer treatment and prognosis implies that more reliable animal models are urgently needed to decipher its molecular mechanisms and preclinical research. We recently reported a genetically engineered adult mouse model where Cdkn2b downregulation was required together with Cdkn2a downregulation to inactivate the Rb pathway. Besides, the role of Smad4, which is mutated more frequently than Cdkn2b in human pancreatic cancer, was determined critical on the development of the pancreas tumor by some reports. However, the impact of Smad4 deficiency in combination with PDAC-relevant mutations, such as Cdkn2a when induced in adult pancreas has not been completely elucidated in mice.

METHODS

Lentiviral delivered oncogene/tumor suppressors in adult pancreas. The development of pancreatic cancer was monitored. Hematoxylin and eosin staining and immunofluorescence were performed for pathological identification of the pancreatic cancer. Real-time polymerase chain reaction, immunofluorescence and western blot were used to test gene expression.

RESULTS

Loss of Smad4 could cooperate with alterations of KRAS, Trp53, and Cdkn2a to induce pancreatic cancer in adult mice. The role of Smad4 was mainly in downregulating the expression of Cdkn2b and further inducing phosphorylation of the Rb1 protein.

CONCLUSIONS

These findings show an essential role of Smad4 deficiency in pancreatic ductal adenocarcinoma (PDAC) formation. This model better recapitulates the adult onset, clonal origin, and genetic alterations in human PDAC and can be simply generated on a large-scale.

Endoscopic Ultrasonography Diagnosis of Early Pancreatic Cancer

Early diagnosis of pancreatic cancer (PC) can improve patients’ prognosis. We aimed to investigate the utility of endoscopic ultrasonography (EUS) for the early diagnosis of PC. This study included 64 patients with PC at an early stage treated at Onomichi General Hospital between January 2007 and January 2020. Diagnostic procedures included contrast computed tomography (CT), magnetic resonance cholangiopancreatography, EUS fine-needle aspiration, and endoscopic retrograde cholangiopancreatography (ERCP) for pancreatic juice cytology. The mean age was 71.3 years. In all, 32 patients were stage 0, and 32 were stage I. As for image findings, the main pancreatic duct (MPD) stenosis was detected in several cases, although CT and MRCP seldom detected tumors. EUS had a high detection rate for stage 0 tumor lesions. The median observation period was 3.9 years. In cases with stage 0, the 1 year and 5 year survival rates were 100% and 78.9%, respectively. In cases with stage I, the 1 year and 5 year survival rates were 96.4% and 66.7%, respectively. EUS has the highest sensitivity among all imaging modalities for detecting small pancreatic tumors. Cases with MPD dilation or stenosis, especially with tumors that cannot be identified on CT and MRI, should have EUS performed. In some cases, EUS was not able to detect any tumor lesions, and ERCP-based pancreatic juice cytology should be useful for pathological diagnosis.

Roles of ERCP in the Early Diagnosis of Pancreatic Cancer

It has been reported that endoscopic retrograde cholangiopancreatography (ERCP) is of value in evaluating precise pancreatograms of the pancreatic duct (PD). Recently, institutions have tended to perform magnetic resonance cholangiopancreatography (MRCP) for the diagnosis of PD due to post-ERCP pancreatitis (PEP). In small pancreatic cancer (PC), including PC in situ (PCIS) which is undetectable on cross sectional images, endoscopic ultrasonography (EUS) and MRCP serve important roles in detecting local irregular stenosis of the PD or small cystic lesions. Subsequently, ERCP and associated serial pancreatic juice aspiration cytologic examination (SPACE) obtained by endoscopic nasopancreatic drainage (ENPD) may be useful in the diagnosis of very early-stage PC. Further prospective multicenter studies are required to establish a standard method of SPACE for the early diagnosis of PC.

Pancreatic cancer stem cells: A state or an entity?

Pancreatic ductal adenocarcinoma (PDAC), the most common type of pancreatic cancer, has a median overall survival of 6-12 months and a 5-year survival of less than 7%. While PDAC currently represents the 4th most frequent cause of death due to cancer worldwide, it is expected to become the second leading cause of cancer-related death by 2030. These alarming statistics are primarily due to both the inherent chemoresistant and metastatic nature of this tumor, and the existence of a subpopulation of highly plastic "stem"-like cells within the tumor, known as cancer stem cells (CSCs). Since their discovery in PDAC in 2007, we have come to realize that pancreatic CSCs have unique metabolic, autophagic, invasive, and chemoresistance properties that allow them to continuously self-renew and escape chemo-therapeutic elimination. More importantly, the concept of the CSC as a fixed entity within the tumor has also evolved, and current data suggest that CSCs are states rather than defined entities. Consequently, current treatments for the majority of PDAC patients are not effective, and do not significantly impact overall patient survival, as they do not adequately target the plastic CSC sub-population nor the transient/hybrid cells that can replenish the CSC pool. Thus, it is necessary that we improve our understanding of the characteristics and signals that maintain and drive the pancreatic CSC population in order to develop new therapies to target these cells. Herein, we will provide the latest updates and knowledge on the inherent characteristics of pancreatic CSCs and the CSC niche, specifically the cross-talk that exists between CSCs and niche resident cells. Lastly, we will address the question of whether a CSC is a state or an entity and discuss how the answer to this question can impact treatment approaches.

Gemcitabine in Combination with a Second Cytotoxic Agent in the First-Line Treatment of Locally Advanced or Metastatic Pancreatic Cancer: a Systematic Review and Meta-Analysis

BACKGROUND

It remains controversial whether the addition of a second cytotoxic agent can further improve the therapeutic effect of gemcitabine monotherapy in advanced or metastatic pancreatic cancer (LA/MPC).

OBJECTIVE

The objective of the present systematic review and meta-analysis was to investigate the efficacy and safety of gemcitabine-based doublet chemotherapy regimens compared to single-agent gemcitabine in the first-line treatment of unresectable LA/MPC.

METHODS

We searched for randomized controlled trials (RCTs) of gemcitabine monotherapy versus gemcitabine in combination with a second cytotoxic agent in patients with LA/MPC. The last search date was December 31, 2016.

RESULTS

Twenty-seven RCTs were identified and included in the present systematic review and meta-analysis, involving a total of 7343 patients. The meta-analysis showed that gemcitabine-based combination therapy significantly improved overall survival (OS) (HR: 0.89; 95% confidence interval (CI): 0.85-0.94; P < 0.0001), progression-free survival (PFS) (HR: 0.80; 95% CI: 0.73-0.88; P < 0.0001), and overall response rate (ORR) (RR: 1.83; 95% CI: 1.62-2.07; P < 0.0001) in comparison to single-agent gemcitabine. Subgroup analysis suggested that the antitumor activity differed between gemcitabine-based combination regimens: doublet regimens of gemcitabine plus a taxoid, and gemcitabine plus a fluoropyrimidine, in particular an oral fluoropyrimidine, resulted in a significant OS benefit for the patients. However, the combination of gemcitabine with other cytotoxic agents, such as platinum compounds or topoisomerase inhibitors failed to reduce the mortality risk. Combination therapy caused more grade 3/4 toxicities, including neutropenia, thrombocytopenia, vomiting, diarrhea, and fatigue.

CONCLUSIONS

Gemcitabine-based doublet regimens demonstrated superiority over gemcitabine monotherapy in overall efficacy, but were associated with increased toxicity. Different gemcitabine-based combinations showed different antitumor activity, and doublet regimens of gemcitabine in combination with a taxoid or a fluoropyrimidine, in particular an oral fluoropyrimidine provided significant survival benefits in the first-line treatment of unresectable LA/MPC.

Biliary Obstruction: Endoscopic Approaches

Painless jaundice is a harbinger of malignant biliary obstruction, with the majority of cases due to pancreatic adenocarcinoma. Despite advances in treatment, including improved surgical techniques and neoadjuvant (preoperative) chemotherapy, long-term survival from pancreatic cancer is rare. This lack of significant improvement in outcomes is believed to be due to multiple reasons, including the advanced stage at diagnosis and lack of an adequate biomarker for screening and early detection, prior to the onset of jaundice or epigastric pain. Close attention is required to select appropriate patients for preoperative biliary decompression, and to prevent morbid complications from biliary drainage procedures, such as pancreatitis and cholangitis. Use of small caliber plastic biliary stents during endoscopic retrograde cholangiopancreatography should be minimized, as metal stents have increased area for improved bile flow and a reduced risk of adverse events during neoadjuvant therapy. Efforts are underway by translational scientists, radiologists, oncologists, surgeons, and gastroenterologists to augment lifespan for our patients and to more readily treat this deadly disease. In this review, the authors discuss the rationale and techniques of endoscopic biliary intervention, mainly focusing on malignant biliary obstruction by pancreatic cancer.

Early diagnosis of pancreatic cancer: Current trends and concerns

Early detection of pancreatic cancer (PC) is essential for a better prognosis. Some recent studies have demonstrated that a slight dilatation of the main pancreatic duct (MPD) and small cystic lesions were detected initially in most cases diagnosed at an early stage. Detecting these abnormal findings in cases with high risk factors through an effective screening system including image diagnosis, some biological markers, or familial cancer registrations should contribute to early diagnosis of PC. It has been reported that endoscopic ultrasonography (EUS) is essential for detecting tumors <10 mm with a favorable prognosis. Additionally, EUS‐guided fine‐needle aspiration biopsy is useful for confirming final histological diagnosis. For the diagnosis of stage 0 PC, local irregular stenosis of MPD should be an important initial abnormal sign detected by EUS or magnetic resonance cholangiopancreatography. Cytodiagnosis multiple times using pancreatic juice obtained by endoscopic nasopancreatic drainage should be essential for the final diagnosis. Recently, activities of regional networks between specialist doctors in medical centers and general practitioners for early diagnosis of PC have been reported in Japan. In the future, these activities may play an important role in the early diagnosis of PC.

Synthesis and functionalization of protease-activated nanoparticles with tissue plasminogen activator peptides as targeting moiety and diagnostic tool for pancreatic cancer

Background

Functionalized nanoparticles (NPs) are one promising tool for detecting specific molecular targets and combine molecular biology and nanotechnology aiming at modern imaging. We aimed at ligand-directed delivery with a suitable target-biomarker to detect early pancreatic ductal adenocarcinoma (PDAC). Promising targets are galectins (Gal), due to their strong expression in and on PDAC-cells and occurrence at early stages in cancer precursor lesions, but not in adjacent normal tissues.

Results

Molecular probes (10-29 AA long peptides) derived from human tissue plasminogen activator (t-PA) were selected as binding partners to galectins. Affinity constants between the synthesized t-PA peptides and Gal were determined by microscale thermophoresis. The 29 AA-long t-PA-peptide-1 with a lactose-functionalized serine revealed the strongest binding properties to Gal-1 which was 25-fold higher in comparison with the native t-PA protein and showed additional strong binding to Gal-3 and Gal-4, both also over-expressed in PDAC. t-PA-peptide-1 was selected as vector moiety and linked covalently onto the surface of biodegradable iron oxide nanoparticles (NPs). In particular, CAN-doped maghemite NPs (CAN-Mag), promising as contrast agent for magnetic resonance imaging (MRI), were selected as magnetic core and coated with different biocompatible polymers, such as chitosan (CAN-Mag-Chitosan NPs) or polylactic co glycolic acid (PLGA) obtaining polymeric nanoparticles (CAN-Mag@PNPs), already approved for drug delivery applications. The binding efficacy of t-PA-vectorized NPs determined by exposure to different pancreatic cell lines was up to 90%, as assessed by flow cytometry. The in vivo targeting and imaging efficacy of the vectorized NPs were evaluated by applying murine pancreatic tumor models and assessed by 1.5 T magnetic resonance imaging (MRI). The t-PA-vectorized NPs as well as the protease-activated NPs with outer shell decoration (CAN-Mag@PNPs-PEG-REGAcp-PEG/tPA-pep1_Lac) showed clearly detectable drop of subcutaneous and orthotopic tumor staining-intensity indicating a considerable uptake of the injected NPs. Post mortem NP deposition in tumors and organs was confirmed by Fe staining of histopathology tissue sections.

Conclusions

The targeted NPs indicate a fast and enhanced deposition of NPs in the murine tumor models. The CAN-Mag@PNPs-PEG-REGAcp-PEG/tPA-pep1_Lac interlocking steps strategy of NPs delivery and deposition in pancreatic tumor is promising.

The endoscopist's role in the diagnosis and management of pancreatic cancer

Pancreatic cancer remains one of the most lethal malignancies with little improvement in survival over the past several decades in spite of advances in imaging, risk factor identification, surgical technique and chemotherapy. This disappointing outcome is mainly due to failures to make an early diagnosis. In fact, the majority of the patients present with inoperable advanced stages of the disease. Though some of the new tumor markers are promising, we are still in search of the one that has a high sensitivity and accuracy, yet is inexpensive and easy to obtain. The paradigm of management has shifted from up-front surgery followed by adjuvant chemotherapy to neoadjuvant chemoradiation followed by surgery, especially for borderline resectable cancers and even for some resectable cancers. In this article, we will critically assess the limitations of tumor markers and review the advancements in endoscopic techniques in the management of pancreatic cancer.

Comparative evaluation of respiratory-gated and ungated FDG-PET for target volume definition in radiotherapy treatment planning for pancreatic cancer

OBJECTIVE

The purpose of this study was to evaluate the usefulness of respiratory-gated positron emission tomography (4D-PET) in pancreatic cancer radiotherapy treatment planning (RTTP).

MATERIALS AND METHODS

Fourteen patients with 18F-fluorodeoxyglucose (FDG)-avid pancreatic tumours were evaluated between December 2013 and March 2015. Two sets of volumes were contoured for the pancreatic tumour of each patient. The biological target volume in three-dimensional RTTP (BTV3D) was contoured using conventional respiratory un-gated PET. The BTV3D was then expanded using population-based margins to generate a series of internal target volume 3D (ITV3D) values. The ITV 4D (ITV4D) was contoured using 4D-PET. Each of the five phases of 4D-PET was used for 4D contouring, and the ITV4D was constructed by summing the volumes defined on the five individual 4D-PET images. The relative volumes and normalized volumetric overlap were computed between ITV3D and ITV4D.

RESULTS

On average, the FDG-avid tumour volumes were 1.6 (range: 0.8-2.3) fold greater in the ITV4D than in the BTV3D. On average, the ITV3D values were 2.0 (range: 1.1-3.4) fold larger than the corresponding ITV4D values.

CONCLUSION

The ITV generated from 4D-PET can be used to improve the accuracy or reduce normal tissue irradiation compared with conventional un-gated PET-based ITV.

[Ductal adenocarcinoma and unusual differential diagnosis]

Ductal pancreatic adenocarcinoma is by far the most common solid tumor of the pancreas. It has a very poor prognosis, especially in the more advanced stages which are no longer locally confined. Due to mostly unspecific symptoms, imaging is key in the diagnostic process. Because of the widespread use of imaging techniques, incidental findings are to a greater extent discovered in the pancreas, which subsequently entail further work-up. Ductal pancreatic adenocarcinoma can be mimicked by a large number of different lesions, such as anatomical variants, peripancreatic structures and tumors, rarer primary solid pancreatic tumors, cystic tumors, metastases or different variants of pancreatitis. Additionally, a number of precursor lesions can be differentiated. The correct classification is thus important as an early diagnosis of ductal pancreatic adenocarcinoma is relevant for the prognosis and because the possibly avoidable treatment is very invasive. All major imaging techniques are principally suitable for pancreatic imaging. In addition to sonography of the abdomen, usually the baseline diagnostic tool, computed tomography (CT) with its superior spatial resolution, magnetic resonance imaging (MRI) with its good soft tissue differentiation capabilities, possibly in combination with MR cholangiopancreatography (MRCP), endosonography with its extraordinary spatial resolution, conceivably with additional endoscopic retrograde CP or the option of direct biopsy and finally positron emission tomography CT (PET-CT) as a molecular imaging tool are all particularly useful modalities. The various techniques all have its advantages and disadvantages; depending on the individual situation they may need to be combined.

Effective screening for early diagnosis of pancreatic cancer

Diagnosis of pancreatic cancer (PC) at an early stage with curative surgery should improve long-term patient outcome. At present, improving survival should lie in identifying those cases with high-risk factors or precursor lesions through an effective screening including ultrasonography, some biological markers, or national familial pancreatic cancer registration. Recently, cases with PC < 10 mm with a favorable prognosis have been reported. For the diagnoses of cases with PC < 10 mm, the rate of tumor detection was higher on endoscopic ultrasonography (EUS) than on CT or other modalities, and EUS-guided fine needle aspiration was helpful in confirming the histologic diagnosis. Additionally, for the diagnosis of cases with PC in situ, EUS and magnetic resonance cholangiopancreatography (MRCP) may play important roles in detecting the local irregular stenosis of the pancreatic duct. Cytodiagnosis of pancreatic juice using endoscopic nasopancreatic drainage multiple times may be useful in the final diagnosis.

Pretreatment C-reactive protein level predicts outcome and patterns of failure after chemoradiotherapy for locally advanced pancreatic cancer

OBJECTIVES

In this study we evaluated the predictive value of pretreatment C-reactive protein (CRP) levels on patterns of failure and survival outcomes in patients with locally advanced pancreatic cancer (LAPC) who received chemoradiotherapy (CRT).

METHODS

Data from 65 patients who underwent CRT for LAPC from July 2001 to May 2013 were retrospectively collected. Factors, including age, gender, Eastern Cooperative Oncology Group performance status (PS), histological confirmation, tumor size, tumor location, biliary drainage, stage, induction chemotherapy, CRP levels, neutrophil-to-lymphocyte ratio, platelet-lymphocyte ratio, albumin and carbohydrate antigen 19-9, were evaluated with regard to overall survival (OS) and patterns of failure using a Cox proportional hazards model.

RESULTS

The 1-year OS and median follow-up for all of the patients were 63.9% and 15.2 months, respectively. The median survival time and 1-year OS were 18.0 months and 72.5%, respectively, in the patients with lower CRP levels (≤3.0 mg/L), whereas 11.0 months and 30.8%, respectively, in the patients with higher CRP levels (>3.0 mg/L). Thirty-seven patients had tumor recurrence after CRT. All of the patients with higher CRP levels developed distant metastases as a primary sign of treatment failure. In a multivariate analysis, higher CRP levels were significantly correlated with distant disease-free survival (p = 0.004, HR = 4.50) and OS (p = 0.004, HR = 3.001). By contrast, local progression-free survival was not significantly different between the CRP subgroups.

CONCLUSION

The CRP levels were a significant predictor of survival and distant disease control for the LAPC patients who received CRT.

Gemcitabine sensitizes pancreatic cancer cells to the CTLs antitumor response induced by BCG-stimulated dendritic cells via a Fas-dependent pathway

BACKGROUND/OBJECTIVES

There are increasing evidences suggesting that chemotherapeutic agents can enhance the cytotoxic T lymphocytes (CTLs) antitumor effect, but the precise mechanism is not fully explained. This study aims to investigate whether gemcitabine (GEM) can sensitize pancreatic cancer cells to the CTLs antitumor response, and explore the potential mechanism.

METHODS

Cell counting kit-8 assays (CCK-8) were performed to determine the tumor cell proliferation. Flow cytometric analysis was conducted to analyze maturation of DCs and the expression of Fas. An Annexin V FITC Apoptosis Detection Kit was performed to detect tumor cell apoptosis. CytoTox 96 Nonradioactive Cytotoxicity assays were used to determine T cell-mediated tumor cell lysis.

RESULTS

First, it was demonstrated that Bacillus Calmette Guérin (BCG) could be used to induce effective CTLs antitumor response. Then, GEM inhibited the growth of SW1990 cells, induced apoptosis and upregulated the Fas expression even at a low concentration. When antagonistic anti-Fas mAb ZB4 was preincubated with GEM-treated SW1990 cells, the lysis induced by CTLs was reduced. Moreover, agonistic anti-Fas mAb CH11 induced more apoptosis of GEM-treated SW1990 cells.

CONCLUSION

Our results show that GEM sensitizes pancreatic cancer cells to the CTLs antitumor response, and the sensitization is associated with upregulation of Fas on pancreatic cancer cells.

Diagnostic strategies for early pancreatic cancer

Diagnosis of pancreatic cancer (PC) at an early stage with curative surgery is the approach with the potential to significantly improve long-term patient outcome. Recently, some reports showed that patients with pancreatic tumors smaller than 10 mm showed a favorable prognosis. However, the rate of tumor detection on computed tomography in patients with small pancreatic tumors is low. For the diagnoses of PC with tumors smaller than 10 mm, the rate of tumor detection was higher on endoscopic ultrasonography (EUS) than on computed tomography or other modalities, and histologic diagnosis using EUS-guided fine-needle aspiration was helpful in confirming the diagnosis. For the diagnosis of PC in situ, EUS and magnetic resonance cholangiopancreatography may play important roles in detecting the local irregular stenosis of the pancreatic duct. Endoscopic retrograde pancreatography and sequential cytodiagnosis using pancreatic juice obtained by endoscopic nasopancreatic drainage multiple times was useful in the final diagnosis of PC in situ. At present, improving survival lies in identifying those individuals with high-risk factors or precursor lesions through an effective screening method. For example, these should include ultrasonography, various biological markers, or national familial pancreatic cancer registration. Additionally, the relationship between specialists in PC from medical centers and practicing physicians plays an important role in the early diagnosis of PC.

(125)I particle implantation combined with chemoradiotherapy to treat advanced pancreatic cancer

OBJECTIVE

To evaluate the therapy effects of (125)I implantation combined with chemoradiotherapy on pancreatic cancer patients.

METHODS

30 patients with Stage III or IV pancreatic cancer were equally divided into two groups (control and treatment group). The patients in the treatment group (nine males, six females) received chemotherapy in the first week and (125)I implantation in the third week, followed by combined chemoradiotherapy in the fifth week. The patients in the control group (10 males, 5 females) received the same treatment except (125)I implantation. The therapy in the control group and treatment group was repeated every 4 weeks.

RESULTS

The median conformal radiotherapy dose in the treatment group (30.62 Gy) was significantly lower than that in the control group (47.86 Gy). The total radiation dose was 88.71 ± 27.39 Gy, and the surface activity was 0.6 mCi in the treatment group. After treatment, the average tumour size decreased both in the treatment group [9.17 cm(2), 95% confidence interval (CI): 5.60-12.74, p < 0.001] and in the control group (4.54 cm(2), 95% CI: 2.74-6.35, p < 0.001). The median survival time in the treatment group was 14 months (95% CI: 12.215-14.785) and in the control group was 12 months (95% CI: 10.884-13.116). There was no statistical significance in survival rates between the two groups (χ(2) = 0.908, p = 0.341).

CONCLUSION

(125)I implanted into tumour combined with chemoradiotherapy has higher local control rate of advanced pancreatic cancer than chemoradiotherapy.

ADVANCES IN KNOWLEDGE

We combined chemoradiotherapy with (125)I implantation to treat advanced pancreatic cancer and obtained a higher local control rate and better quality of life than when using chemoradiatherapy alone.

Development and characterization of nanoparticles for the delivery of gemcitabine hydrochloride

Gemcitabine (2,2-difluorodeoxycytidine) is a deoxycytidine analog, currently being used as a first-choice drug in pancreatic metastatic cancer. Gemcitabine is administered weekly as 30-minute infusion with starting dose ranging from 800 to 1250 mg/m(2). The aim of the present work was to develop starch nanoparticles (NPs) for the delivery of gemcitabine hydrochloride that could reduce its dose related side effects and may prolong its retention time (24 hrs) for the treatment of pancreatic cancer. Nanoparticles were prepared by emulsification diffusion method with slight modifications. Size and morphology of nanoparticles were investigated. Particles were spherical in shape with slightly rough surfaces. Particle size and polydispersity index were 231.4 nm and 1.0, respectively while zeta potential of blank NPs and drug loaded NPs were found to be -11.8 mV and -9.55 mV, respectively. Percent entrapment efficiency of different formulations was around ∼ 54% to 65%. In vitro release profile studies showed that around 70%-83% of drug was released from different formulations. Anticancerous cell line studies were also performed in human pancreatic cell lines (MIA-PA-CA-2).

Dynamic computed tomography of locally advanced pancreatic cancer: effect of low tube voltage and a hybrid iterative reconstruction algorithm on image quality

OBJECTIVE

The objective of this study was to evaluate the effect of a low-tube-voltage technique and hybrid iterative reconstruction (HIR) on image quality at dynamic computed tomography (CT) of the pancreas.

METHODS

The study included 18 consecutive patients (10 women, 8 men; mean age, 68.5 ± 9.5 years) with locally advanced pancreatic cancer who received chemotherapy and had stable disease during the 100- and 120-kV CT studies. The 120-kV images were reconstructed using filtered back projection, and the 100-kV images were postprocessed using filtered back projection and HIR. Scans obtained during 3 pancreatic phases were subjected to quantitative and qualitative analysis.

RESULTS

The mean effective dose was significantly lower under the 100- than the 120-kV protocols (29.2 ± 3.6 vs 52.1 ± 5.1 mSv; P < 0.01). The mean contrast-to-noise ratio of the pancreatic cancer and the visual scores were significantly higher under 100 kV with HIR than those under the other 2 protocols (P < 0.01).

CONCLUSIONS

Use of low tube voltage and HIR can provide significantly improved image quality at pancreatic dynamic CT.

Efficacy of nimotuzumab plus gemcitabine usage as first-line treatment in patients with advanced pancreatic cancer

Advanced pancreatic cancer patients have poor prognosis and scarcely respond to conventional therapies. Clinical trials support the use of molecular-targeted therapy against epidermal growth factor receptor (EGFR) signaling. The objective of the current study was to evaluate the contribution of a monoclonal antibody against EGFR, nimotuzumab, to standard gemcitabine therapy. Patients with unresectable locally advanced or metastatic pancreatic adenocarcinoma were assigned to receive gemcitabine plus nimotuzumab. The primary end point was overall survival, whereas the secondary end points included progression-free survival, objective response, and adverse side effects. A total of 18 eligible patients were accrued between December 2007 and July 2010. The disease control rate, calculated as the sum of complete response, partial response, and stable disease, was 55.6%. The median overall survival time was 9.29 months (95% CI, 5.499 to 13.072). The median progression-free survival was 3.71 months (95% CI, 2.526 to 4.902), and the 1-year survival rate was 38.9%. Of all the patients, 88.8% had at least one adverse side effect; however, no grade 4 adverse side effect was reported. Nimotuzumab as a high-purity humanized monoclonal antibody with favorable safety profile, its value in the treatment of pancreatic cancer along with gemcitabine, particularly in the comprehensive treatment of advanced pancreatic cancer, is appealing for further prospective randomized large-scale clinical trials.

Isolated pancreatic heamorrhage in association with anticoagulation

Haemorrhage is the primary complication of anticoagulation therapy with the gastrointestinal, urinary and nasal tracts the most common sites of bleeding. Haematoma within solid organs is uncommon especially in the absence of blunt trauma. We describe two patients on long term Warfarin therapy who developed focal haematomas within the pancreas. To the best of our knowledge these are the first isolated unprovoked focal pancreatic hematoma cases reported in the literature. The non-specific clinical symptoms and confusing radiological features mimicked pancreatic malignancy and this led to misdiagnosis in the one patient who underwent unnecessary surgical exploration. The haematoma was correctly identified in the second patient who was managed conservatively and had an uneventful recovery.

Cisplatin-induced non-apoptotic death of pancreatic cancer cells requires mitochondrial cyclophilin-D-p53 signaling

The pancreatic cancer remains a fatal disease for the majority of patients. Cisplatin has displayed significant cytotoxic effects against the pancreatic cancer cells, however the underlying mechanisms remain inconclusive. Here, we found that cisplatin mainly induced non-apoptotic death of the pancreatic cancer cells (AsPC-1 and Capan-2), which was associated with a significant p53 activation (phosphorylation and accumulation). Further, activated p53 was found to translocate to mitochondria where it formed a complex with cyclophilin D (Cyp-D). We provided evidences to support that mitochondrial Cyp-D/p53 complexation might be critical for cisplatin-induced non-apoptotic death of pancreatic cancer cells. Inhibition of Cyp-D by its inhibitor cyclosporine A (CsA), or by shRNA-mediated knockdown suppressed cisplatin-induced pancreatic cancer cell death. Both CsA and Cyp-D knockdown also disrupted the Cyp-D/p53 complex formation in mitochondria. Meanwhile, the pancreatic cancer cells with p53 knockdown were resistant to cisplatin. On the other hand, HEK-293 over-expressing Cyp-D were hyper-sensitive to cisplatin. Interestingly, camptothecin (CMT)-induced pancreatic cancer cell apoptotic death was not affected CsA or Cyp-D knockdown. Together, these data suggested that cisplatin-induced non-apoptotic death requires mitochondria Cyp-D-p53 signaling in pancreatic cancer cells.

Comparison of the utility of covered metal stents versus uncovered metal stents in the management of malignant biliary strictures in 749 patients

BACKGROUND

Self-expandable metal stents (SEMSs) are used to relieve malignant biliary obstruction.

OBJECTIVE

To compare outcomes between covered self-expandable metal stents (CSEMSs) and uncovered self-expandable metal stents (USEMSs) in malignant biliary obstruction.

DESIGN

Retrospective cohort study.

SETTING

Tertiary cancer center.

PATIENTS

Patients with malignant biliary obstruction.

INTERVENTIONS

Placement of CSEMS or USEMS.

MAIN OUTCOME MEASUREMENTS

Time to recurrent biliary obstruction (TRO), overall survival (OS), and adverse events.

RESULTS

From January 2000 to June 2011, 749 patients received SEMSs: 171 CSEMSs and 578 USEMSs. At 1 year, there was no significant difference in the percentage of patients with recurrent obstruction (CSEMSs, 35% vs USEMSs, 38%) and survival (CSEMSs, 45% vs USEMSs, 49%). There was no significant difference in the median OS (CSEMSs, 10.4 months vs USEMSs, 11.8 months; P = .84) and the median TRO (CSEMSs, 15.4 months vs USEMSs, 26.3 months; P = .61). The adverse event rate was 27.5% for the CSEMS group and 27.7% for the USEMS group. Although tumor ingrowth with recurrent obstruction was more common in the USEMS group (76% vs 9%, P < .001), stent migration (36% vs 2%, P < .001) and acute pancreatitis (6% vs 1%, P < .001) were more common in the CSEMS group.

LIMITATIONS

Retrospective study.

CONCLUSIONS

There was no significant difference in the patency rate or overall survival between CSEMSs and USEMSs for malignant distal biliary strictures. The CSEMS group had a significantly higher rate of migration and pancreatitis than the USEMS group. No significant SEMS-related adverse events were observed in patients undergoing neoadjuvant chemoradiation or surgical resection.

Endoscopic ultrasound elastography for differentiation of benign and malignant pancreatic masses: a systemic review and meta-analysis

BACKGROUND

Endoscopic ultrasound (EUS) elastography is a novel method for visualization of tissue elasticity modulus during a conventional EUS examination. The reported yield of EUS elastography for the differentiation of benign and malignant pancreatic masses has shown variable results. The objective of this study was to assess the accuracy of EUS elastography by pooling data of available trials.

METHODS

The Medline, PubMed, Embase, and Cochrane Central Trials databases were used to retrieve all the studies that assessed the diagnostic accuracy of EUS elastography for the differentiation of benign and malignant pancreatic masses. Pooling was carried out using a fixed-effect model when significant heterogeneity was not present; otherwise, the random-effect model was used. If there were less than four studies using the same diagnostic standard, forest plots were constructed without pooling.

RESULTS

In six studies using the qualitative color pattern as the diagnostic standard, the sensitivity was 99% (95% confidence interval 98-100%) and the specificity was 74% (95% confidence interval 65-82%). The area under the curve under the summary receiver-operating characteristic was 0.9624. In three studies using the quantitative hue histogram value as the diagnostic standard, the sensitivity was 85-93% and the specificity was 64-76%.

CONCLUSION

EUS elastography is a promising noninvasive technique for the differentiation of pancreatic masses with a high sensitivity, and may prove to be a valuable complementary method to EUS-FNA.

Endoscopic ultrasound fine-needle aspiration characteristics of primary adenocarcinoma versus other malignant neoplasms of the pancreas

BACKGROUND

Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) is often used to assist in the evaluation of pancreatic lesions and may help to diagnose benign versus malignant neoplasms. However, there is a paucity of literature regarding comparative EUS characteristics of various malignant pancreatic neoplasms (primary and metastatic).

OBJECTIVE

To compare and characterize primary pancreatic adenocarcinoma versus other malignant neoplasms, hereafter referred to as nonprimary pancreatic adenocarcinoma (NPPA), diagnosed by EUS-guided FNA.

METHODS

The present study was a retrospective analysis of a prospectively maintained database. The setting was a tertiary care, academic medical centre. Patients referred for suspected pancreatic neoplasms were evaluated. Based on EUS-FNA characteristics, primary pancreatic adenocarcinoma was differentiated from other malignant neoplasms. The subset of other neoplasms was defined as malignant lesions that were 'NPPAs' (ie, predominantly solid or solid⁄cystic based on EUS appearance and primary malignant lesions or metastatic lesions to the pancreas). Pancreatic masses that were benign cystic lesions (pseudocyst, simple cyst, serous cystadenoma) and focal inflammatory lesions (acute, chronic and autoimmune pancreatitis) were excluded.

RESULTS

A total of 230 patients were evaluated using EUS-FNA for suspected pancreatic mass lesions. Thirty-eight patients were excluded because they were diagnosed with inflammatory lesions or had purely benign cysts. One hundred ninety-two patients had confirmed malignant pancreatic neoplasms (ie, pancreatic adenocarcinoma [n=144], NPPA [n=48]). When comparing adenocarcinoma with NPPA lesions, there was no significant difference in mean age (P=0.0675), sex (P=0.3595) or average lesion size (P=0.3801). On average, four FNA passes were necessary to establish a cytological diagnosis in both lesion subtypes (P=0.396). Adenocarcinomas were more likely to be located in the pancreatic head (P=0.0198), whereas masses in the tail were more likely to be NPPAs (P=0.0006). Adenocarcinomas were also more likely to exhibit vascular invasion (OR 4.37; P=0.0011), malignant lymphadenopathy (P=0.0006), pancreatic duct dilation (OR 2.4; P=0.022) and common bile duct dilation (OR 2.87; P=0.039).

CONCLUSIONS

Adenocarcinoma was more likely to be present in the head of the pancreas, have lymph node and vascular involvement, as well as evidence of pancreatic duct and common bile duct obstruction. Of all malignant pancreatic lesions analyzed by EUS-FNA, 25% were NPPA, suggesting that FNA is crucial in establishing a diagnosis and may be helpful in preoperative planning.

Sulforaphane regulates self-renewal of pancreatic cancer stem cells through the modulation of Sonic hedgehog-GLI pathway

Sulforaphane (SFN), a component of dietary cruciferous vegetables has been characterized for its anti-proliferative properties. We have recently demonstrated that pancreatic CSCs display activation of sonic hedgehog pathway which are fundamental drivers of stem cell renewal, and SFN inhibits the self-renewal of pancreatic CSCs in vitro. Consistent with these observations, we sought to determine the chemopreventive potential of SFN in an in vivo setting. We show here for the first time that sulforaphane treatment resulted in a significant reduction in the tumor growth of orthotopically implanted primary pancreatic CSCs isolated from human pancreatic tumors into the pancreas of NOD/SCID/IL2Rgamma mice, which is mediated through the modulation of Sonic hedgehog-GLI signaling. Hedgehog pathway blockade by SFN at a dose of 20 mg/kg resulted in a 45 % reduction in growth of pancreatic cancer tumors and reduced expression of Shh pathway components, Smo, Gli 1, and Gli 2 in mouse tissues. Further, SFN inhibited the expression of pluripotency maintaining transcription factors Nanog and Oct-4 and angiogenic markers VEGF and PDGFRα which are downstream targets of Gli transcription. Furthermore, SFN treatment resulted in a significant reduction in EMT markers Zeb-1, which correlated with increase in E-Cadherin expression suggesting the blockade of signaling involved in early metastasis. Interestingly, SFN downregulated the expression of Bcl-2 and XIAP to induce apoptosis. These data demonstrate that, at a tolerable dose, inhibition of Shh pathway by SFN results in marked reduction in EMT, metastatic, angiogenic markers with significant inhibition in tumor growth in mice. Since aberrant Shh signaling occurs in pancreatic tumorigenesis, therapeutics that target Shh pathway may improve the outcomes of patients with pancreatic cancer by targeting CSCs, thus suggesting the use of sulforaphane to further improve preventive and therapeutic approaches in patients with this devastating disease.

Ursolic acid inhibits growth and induces apoptosis in gemcitabine-resistant human pancreatic cancer via the JNK and PI3K/Akt/NF-κB pathways

Pancreatic cancer is one of the most deadly carcinomas worldwide. Although gemcitabine as the standard chemotherapy agent has been proven to be effective, the response rate remains at 5.4% and the 5-year survival rate is extremely poor. Ursolic acid (UA) is a small molecule compound extracted from Chinese herbs as well as edible vegetables and a well-known anti-inflammatory and immunosuppressive agent. Here, we show that UA has potential to be developed into an anti-neoplastic agent against gemcitabine-resistant pancreatic cancer and to explore its molecular mechanism of action. In vitro, we used three different malignancy grades of pancreatic resistant cancer cell lines including MIA PaCa-2, PANC-1 and Capan-1 to assess the antitumor effect of UA. We found that UA inhibited growth and induced apoptosis in a dose-dependent manner in all of the three pancreatic cancer cell lines. Both extrinsic and intrinsic pathways were found to be involved in apoptotic cascade. The potential signaling pathways are concerned with inactivation of the PI3K/Akt/NF-κB pathway and activation of the c-Jun-terminal kinase (JNK) pathway. The JNK inhibitor SP600125 partly abrogated the caspase-9 activation caused by UA. The Akt inhibitor LY294002 did not mimic the effect of UA on caspase-8 and -9, but inhibited the viability of MIA PaCa-2 cells to some extent. Equally, UA also overcame the chemoresistance in the chemoresistant endometrial and ovarian carcinoma cell lines (HEC-1A and OVCAR-3). Moreover, UA caused cytotoxicity to a nude mouse xenograft model in vivo. Therefore, our present data suggest that UA can act as a novel and potent therapeutic agent in gemcitabine-resistant pancreatic cancer and even as a promising candidate in other chemoresistant cancers.

The efficacy of a novel, dual PI3K/mTOR inhibitor NVP-BEZ235 to enhance chemotherapy and antiangiogenic response in pancreatic cancer

Gemcitabine has limited clinical benefits for pancreatic ductal adenocarcinoma (PDAC). The phosphatidylinositol-3-kinase (PI3K)/AKT and mammalian target of rapamycin (mTOR) signaling pathways are frequently dysregulated in PDAC. We investigated the effects of NVP-BEZ235, a novel dual PI3K/mTOR inhibitor, in combination with gemcitabine and endothelial monocyte activating polypeptide II (EMAP) in experimental PDAC. Cell proliferation and protein expression were analyzed by WST-1 assay and Western blotting. Animal survival experiments were performed in murine xenografts. BEZ235 caused a decrease in phospho-AKT and phospho-mTOR expression in PDAC (AsPC-1), endothelial (HUVECs), and fibroblast (WI-38) cells. BEZ235 inhibited in vitro proliferation of all four PDAC cell lines tested. Additive effects on proliferation inhibition were observed in the BEZ235-gemcitabine combination in PDAC cells and in combination of BEZ235 or EMAP with gemcitabine in HUVECs and WI-38 cells. BEZ235, alone or in combination with gemcitabine and EMAP, induced apoptosis in AsPC-1, HUVECs, and WI-38 cells as observed by increased expression of cleaved poly (ADP-ribose) polymerase-1 (PARP-1) and caspase-3 proteins. Compared to controls (median survival: 16 days), animal survival increased after BEZ235 and EMAP therapy alone (both 21 days) and gemcitabine monotherapy (28 days). Further increases in survival occurred in combination therapy groups BEZ235 + gemcitabine (30 days, P = 0.007), BEZ235 + EMAP (27 days, P = 0.02), gemcitabine + EMAP (31 days, P = 0.001), and BEZ235 + gemcitabine + EMAP (33 days, P = 0.004). BEZ235 has experimental PDAC antitumor activity in vitro and in vivo that is further enhanced by combination of gemcitabine and EMAP. These findings demonstrate advantages of combination therapy strategies targeting multiple pathways in pancreatic cancer treatment.

Evaluation of poly-mechanistic antiangiogenic combinations to enhance cytotoxic therapy response in pancreatic cancer

Gemcitabine (Gem) has limited clinical benefits in pancreatic ductal adenocarcinoma (PDAC). The present study investigated combinations of gemcitabine with antiangiogenic agents of various mechanisms for PDAC, including bevacizumab (Bev), sunitinib (Su) and EMAP II. Cell proliferation and protein expression were analyzed by WST-1 assay and Western blotting. In vivo experiments were performed via murine xenografts. Inhibition of in vitro proliferation of AsPC-1 PDAC cells by gemcitabine (10 µM), bevacizumab (1 mg/ml), sunitinib (10 µM) and EMAP (10 µM) was 35, 22, 81 and 6 percent; combination of gemcitabine with bevacizumab, sunitinib or EMAP had no additive effects. In endothelial HUVECs, gemcitabine, bevacizumab, sunitinib and EMAP caused 70, 41, 86 and 67 percent inhibition, while combination of gemcitabine with bevacizumab, sunitinib or EMAP had additive effects. In WI-38 fibroblasts, gemcitabine, bevacizumab, sunitinib and EMAP caused 79, 58, 80 and 29 percent inhibition, with additive effects in combination as well. Net in vivo tumor growth inhibition in gemcitabine, bevacizumab, sunitinib and EMAP monotherapy was 43, 38, 94 and 46 percent; dual combinations of Gem+Bev, Gem+Su and Gem+EMAP led to 69, 99 and 64 percent inhibition. Combinations of more than one antiangiogenic agent with gemcitabine were generally more effective but not superior to Gem+Su. Intratumoral proliferation, apoptosis and microvessel density findings correlated with tumor growth inhibition data. Median animal survival was increased by gemcitabine (26 days) but not by bevacizumab, sunitinib or EMAP monotherapy compared to controls (19 days). Gemcitabine combinations with bevacizumab, sunitinib or EMAP improved survival to similar extent (36 or 37 days). Combinations of gemcitabine with Bev+EMAP (43 days) or with Bev+Su+EMAP (46 days) led to the maximum survival benefit observed. Combination of antiangiogenic agents improves gemcitabine response, with sunitinib inducing the strongest effect. These findings demonstrate advantages of combining multi-targeting agents with standard gemcitabine therapy for PDAC.

H19-promoter-targeted therapy combined with gemcitabine in the treatment of pancreatic cancer

Pancreatic cancer is the eighth cancer leading cause of cancer-related death in the world and has a 5-year survival rate of 1–4% only. Gemcitabine is a first line agent for advanced pancreatic therapy; however, its efficacy is limited by its poor intracellular metabolism and chemoresistance. Studies have been conducted in an effort to improve gemcitabine treatment results by adding other chemotherapeutic agents, but none of them showed any significant advantage over gemcitabine monotherapy. We found that 85% of human pancreatic tumors analyzed by in situ hybridization analyses showed moderated to strong expression of the H19 gene. We designed a preclinical study combining gemcitabine treatment and a DNA-based therapy for pancreatic cancer using a non viral vector BC-819 (also known as DTA-H19), expressing the diphtheria toxin A chain under the control of the H19 gene regulatory sequences. The experiments conducted either in an orthotopic and heterotopic pancreatic carcinoma animal model showed better antitumor activity following the sequential administration of the vector BC-819 and gemcitabine as compared to the effect of each of them alone. The results presented in the current study indicate that treatment with BC-819 in combination with gemcitabine might be a viable new therapeutic option for patients with advanced pancreatic cancer.

Different subtypes of intraductal papillary mucinous neoplasm in the pancreas have distinct pathways to pancreatic cancer progression

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) is recognized as a precursor lesion to pancreatic cancer, a unique pathological entity. IPMN has subtypes with different clinical characteristics. However, the molecular mechanisms of cancer progression from IPMN remain largely unknown. In this study we examined the differences in genetic alteration(s) among the IPMN subtypes.

METHODS

Surgically resected IPMNs (n = 25) were classified into four subtypes by hematoxylin and eosin (H&E) and mucin immunostaining. Mutations in KRAS, BRAF, and PIK3CA genes and expression of CDKN2A, TP53, SMAD4, phospho-ERK, and phospho-SMAD1/5/8 proteins were examined.

RESULTS

There were 11 gastric, 11 intestinal, one pancreatobiliary, and two oncocytic types in this study. We then compared the two major subtypes, gastric-type and intestinal-type IPMN. Gastric-type IPMN showed a significantly higher incidence of KRAS mutations (9/11, 81.8%) compared with intestinal type (3/11, 27.3%; p < 0.05), although the intestinal type showed a higher grade of dysplasia than gastric type (p < 0.01). All cases with KRAS mutations showed phospho-ERK immunostaining. In contrast, intestinal type (9/11, 81.8%) showed more frequent SMAD1/5/8 phosphorylation compared with gastric-type IPMN (3/11, 27.3%; p < 0.05%).

CONCLUSIONS

There may be distinct mechanisms of pancreatic cancer progression in the different subtypes of IPMN. In particular, KRAS mutation and bone morphogenetic protein-SMAD signaling status may be crucial diverging steps for the two representative pathways to pancreatic cancer in IPMN patients.

Self-expandable metal stents in malignant biliary obstruction

Malignant biliary obstruction can be due to direct tumor infiltration, extrinsic compression, adjacent inflammation, desmoplastic reaction from tumors or, more commonly, a combination of the above factors. Pancreatic cancer is the most common cause of malignant biliary obstruction, and jaundice occurs in 70-90% of the patients during the course of the disease. Compared with the uncovered metal stents, covered metal stents have longer patency and a lower rate of tumor ingrowth, but have a higher rate of stent migration. To combat the occlusion and provide an antitumor effect, drug-eluting stents were developed. A duodenal stricture complicates biliary stent placement in 10-20% of patients with distal biliary obstruction due to pancreatic cancer. When both strictures are considered, a biliary stent can be placed either preceding or following duodenal stent placement. Complications of self-expandable metal stents include stent occlusion, stent migration, cholecystitis and pancreatitis.

Safety evaluation of self-expanding metallic biliary stents eluting gemcitabine in a porcine model

BACKGROUND AND AIM

Palliative biliary decompression by metal stent is the treatment of choice for unresectable malignant biliary obstruction; however, conventional stents provide only mechanical palliation and exert no anti-tumor effects. Gemcitabine (GEM) has been reported to be more effective in unresectable pancreatic cancer and biliary cancer compared with other chemotherapeutic drugs. We evaluated the safety of a GEM-eluting stent by analyzing histologic responses of the porcine bile duct.

METHODS

Stents containing GEM (0%, 10%, 15%, and 20% [w/v]) were surgically inserted into bile ducts of pigs (each group, n = 2). The animals were euthanized after 4 weeks, and the stented bile duct segment underwent gross and microscopic examination. Laboratory assay was performed for aspartate transaminase (AST), alanine transaminase (ALT), total bilirubin, and gamma-glutamyl transferase (γ-GTP).

RESULTS

Moderate to severe inflammation was observed in the bile ducts in contact with stents containing 15 and 20% GEM, compared with no inflammation with 0% GEM and mild inflammation with 10% GEM. Fibrous reactions observed in the submucosal layer did not differ among groups. Transmural necrosis and perforations were not observed in any animal. No abnormal laboratory test findings were directly caused by GEM.

CONCLUSION

Our newly developed GEM eluting stents can be used safely in normal bile ducts. Our results indicated that 10% GEM produced mild histologic changes in the stented segment and adjacent tissue; this concentration may be appropriate for clinical application.

Drugs in preclinical and early-stage clinical development for pancreatic cancer

INTRODUCTION

Pancreatic cancer (PC) is the fourth leading cause of cancer-related deaths in the US and Europe, and the lethality of this cancer is demonstrated by the fact that the annual incidences are approximately equal to the annual deaths. Current therapy for PC is multimodal, involving surgery and chemotherapy. Clinical symptoms are unspecific, and consequently about 85% of patients with PC are diagnosed at advanced tumor stages without any surgical therapy options. Since the therapeutic rates for PC are so dismal, it is essential to review the clinical targets for diagnosis and treatment of this lethal cancer.

AREAS COVERED

In this review, we discuss potential treatment options for PC by identifying molecular targets including those involved in cell proliferation, survival, migration, invasion and angiogenesis. Targeting these molecules in combination with surgery could improve the clinical outcome for PC patients.

EXPERT OPINION

For a decade, gemcitabine has remained the single first-line chemotherapeutic agent for advanced adenocarcinoma of the pancreas; however, less than 25% of patients benefit from gemcitabine. The reason for frequent reoccurrence of PC after conventional methods such as surgery, radiation and/or chemotherapy is due to the lack of understanding of the basic underlying metabolic cause of the cancer and thus consequently remains uncorrected. Our understanding of drug resistance in PC is still not clear and may be answered by focusing on new useful biomarkers and their role in chemo- and radioresistance.

CA 19-9 in pancreatic cancer: retrospective evaluation of patients with suspicion of pancreatic cancer

CA 19.9 serum levels were prospectively determined in 573 patients admitted to hospital for suspicion of pancreatic cancer. The final diagnosis was 77 patients with no malignancy, 389 patients with pancreatic cancer, 37 neuroendocrine pancreatic cancer, 28 cholangiocarcinomas, 4 gallbladder cancer, 27 ampullary carcinomas, and 11 periampullary carcinomas. CA 19.9 was determined using a commercial assay from Roche Diagnostics, and 37 U/ml was considered as the upper limit of normality. Abnormal CA 19.9 serum levels were found in 27%, 81.5%, 85.7%, 59.3%, 63.6%, and 18.9% of patients with benign diseases, pancreatic cancer, cholangiocarcinomas, and ampullary, periampullary, or neuroendocrine tumors. Significantly higher concentrations of CA 19.9 were found in patients with than in those without malignancy or with neuroendocrine tumors. CA 19.9 serum levels were higher in pancreatic cancer or cholangiocarcinoma than in other malignancies (p < 0.0001). CA 19.9 serum levels were also correlated with tumor stage, treatment (significantly lower concentrations in resectable tumors), and tumor location (the highest in those located in the body, the lowest in those in the tail or uncinate) and site of metastases (highest in liver metastases). A trend to higher CA 19.9 serum concentrations was found in patients with jaundice, but only with statistical significance in the early stages. Using 50 or 100 U/ml in patients with jaundice, CA 19.9 was useful as an aid in the diagnosis of pancreatic cancer (sensitivity 77.9%, specificity 95.9%) as well as tumor resectability in pancreatic cancer with different cutoffs according to tumor location and bilirubin serum levels with specificities ranging from 90% to 100%. CA 19.9 is the tumor marker of choice in pancreatic adenocarcinomas, with a clear relationship with tumor location, stage, and resectability.

The proline TP53 variant stimulates likely lymphangiogenesis in an orthotopic mouse model of pancreatic cancer

Background:

Pancreatic cancer is a deadly disease characterised by high incidence of TP53 mutations. Restoration of TP53 function is perceived as a highly attractive therapeutic strategy, whose effects are not well characterised.

Methods:

The current work adapted an inducible strategy of stage-specific reexpression of wild-type (wt) TP53 in an in vivo orthotopic mouse model of pancreatic cancer.

Results:

The reconstitution of wt TP53 function in TP53-mutant DanG and MiaPaCa-2 cells caused G1 cell cycle arrest but no evidence of apoptosis induction. Consistent with subcutaneous xenograft models, we found that wt TP53 reduced primary tumour growth. Wt TP53 reexpression during early tumour growth led to significant increase in vascularisation. This correlated with an unexpectedly high rate of micro-metastases in lymph nodes of animals with wt TP53 induction, despite the 90% decrease in median primary tumour weight. Reexpression of wt TP53 later in tumour development did not significantly affect the number of CD31-reactive vessels, but increased lymphatic vessel density.

Conclusion:

The increased number of lymphatic vessels and micro-metastases suggests that wt TP53 induction complexly affected the biology of different tumour constituents of pancreatic cancer. Our observation suggests that combination of the inducible system with an orthotopic model can yield important insights into in vivo pancreatic cancer biology.

Cyclooxygenase-2 polymorphisms and pancreatic cancer susceptibility

OBJECTIVES

DNA sequence variants in the cyclooxygenase-2 (COX-2) gene may lead to altered COX-2 production and/or activity, resulting in interindividual differences in susceptibility to pancreatic cancer. To test this hypothesis, we investigated the relationship between polymorphisms in the COX-2 gene and the risk of pancreatic cancer in a European population.

METHODS

The COX-2 genotypes for 7 single-nucleotide polymorphisms (rs2745557, rs5277, rs2066826, rs4648261, rs4648262, rs2206593, and rs5275) were determined in 162 pancreatic cancer patients and 170 control subjects without cancer who were matched for age and sex. Data analysis was by conditional logistic regression analysis, adjusting for age, sex, and smoking.

RESULTS

Two haplotypes (GGAGGGT and GCGGGGT for rs2745557, rs5277, rs2066826, rs4648261, rs4648262, rs2206593, rs5275, respectively) were more frequent among the patients compared with control subjects (P < 0.024), although no individually statistically significant associations for the 7 single-nucleotide polymorphisms studied were detected.

CONCLUSIONS

Our findings suggest the individual polymorphisms we studied in the COX-2 gene are not associated with risk of pancreatic cancer. However, the finding of a modest association with 2 haplotypes might be consistent with a small effect, which could be also seen at the genotype level had more samples been available.

Endosonography in solid and cystic pancreatic tumors

Pancreatic tumors being either benign or malignant can be solid or cystic. Although diverse in presentation, their imaging features share commonalities and it is often difficult to distinguish these tumors. Endoscopic ultrasonography (EUS) is the most sensitive of the imaging procedures currently available for characterizing pancreatic tumors, and is especially good in identifying the smaller sized tumors. Additional applications inclusive of EUS-guided fine needle aspiration (EUS-FNA) are useful in tissue sampling and preoperative staging of pancreatic tumors.Although diagnostic capabilities have greatly evolved with advances in EUS and tissue processing technology (cytology, tumor markers, DNA analysis), differentiation of benign and malignant neoplasms, neoplastic and non-neoplastic (chronic pancreatitis) conditions, continues to be challenging.Recent innovative applications include contrast-enhanced EUS with Doppler mode, contrast-enhanced harmonic EUS, 3-dimensinal EUS, and EUS elastography. Incorporation of these methods has improved the differential diagnosis of pancreatic tumors. Finally, a multi-disciplinary approach involving radiology, gastroenterology and surgical specialties is often necessary for accurate diagnosis and management of solid and cystic pancreatic tumors.

Enjoy the Silence: The Story of let-7 MicroRNA and Cancer

Cancer is a multi-step disease involving dynamic changes in the genome. However, studies on cancer genome so far have focused most heavily on protein-coding genes, and our knowledge on alterations of the functional noncoding sequences in cancer is largely absent. MicroRNAs (miRNAs) are endogenous small noncoding RNAs weighing 20 to 23 nucleotides that negatively regulate gene expression at the posttranscriptional level by base pairing to the 3' untranslated region of target messenger RNAs. Hundreds of miRNAs have been identified in humans and are evolutionarily conserved from plants to animals. These tiny but potent molecules regulate various physiological and pathological pathways such as cell differentiation and cell proliferation. Recently, miRNA alterations have been linked to the initiation and the progression of human cancer. As a consequence, MiRNA-expression profiling of human tumors has identified signatures associated with diagnosis, staging, progression, prognosis and response to treatment. In addition, profiling has been exploited to identify miRNA genes that might represent downstream targets of activated oncogenic pathways, or that target proteincoding genes involved in cancer. Of importance, pioneering studies described let-7 miRNA as a negative regulator of the oncogenic family of Ras guanosine triphosphatases in both Caenorhabditis elegans and human tumor cell lines. Later, let-7 expression deregulation was reported in several cancers, suggesting that let-7 may act as a tumor suppressor. This review will discuss the late insights in let-7 function, the elationship between let-7 and tumorigenesis, and the potential for modulating let-7 expression for the treatment of cancer.

Self-expandable metal stents for malignant distal biliary strictures

Obstructive jaundice can result from benign or malignant etiologies. The common benign conditions include primary sclerosing cholangitis, chronic pancreatitis, and gallstones. Malignant biliary obstruction can be caused by direct tumor infiltration, extrinsic compression by enlarged lymph nodes or malignant lesions, adjacent inflammation, desmoplastic reaction from a tumor, or a combination of these factors. Malignant diseases causing biliary obstruction include pancreatic cancer, ampullary cancer, cholangiocarcinoma, and metastatic diseases. This article focuses on malignant distal biliary obstruction and its management.

Gemcitabine in the chemoradiotherapy for locally advanced pancreatic cancer: a meta-analysis

AIMS

Whether gemcitabine based chemoradiotherapy (GEM-based CRT) is superior to 5-fluorouracil based chemoradiotherapy (5-FU-based CRT) for locally advanced pancreatic cancer (LAPC) remains uncertain. The aim of the present study was to evaluate the effect of GEM-based CRT compared with 5-FU-based CRT.

METHODS

Electronic database including Medline, Embase, Cochrane controlled trials register, PubMed (update to December 2010) and manual bibliography searches were carried out. A meta-analysis of all randomized clinical trials (RCTs) or other comparative studies comparing GEM-based CRT and 5-FU-based CRT were performed.

RESULTS

Three RCTs and one retrospective comparative study including 229 patients were assessed. Meta-analysis showed survival advantage of GEM-based CRT compared with 5-FU-based CRT for 12-month (12-mo) survival rates (SRs) (RR=1.54, 95% CI 1.05-2.26, p=0.03). Moreover, there were also trends of benefit for SR after 6-months (RR 1.13, 95% CI 0.98-1.30, p=0.09) and 24-months (24-mo: RR 2.41, 95% CI 0.90-6.48, p=0.08), though the trends did not reach statistical significance. More frequent severe acute hematologic toxicities were found in the GEM-based CRT group.

CONCLUSIONS

The meta-analysis found that GEM-based CRT was better than 5-FU-based CRT in the treatment of LAPC, especially for 12-mo SRs. However, the acute toxicity should be carefully regarded.