Vascular endothelial growth factor, a novel and highly accurate pancreatic fluid biomarker for serous pancreatic cysts

Imaging of pancreatic serous cystadenoma and common imitators

Pancreatic cystic neoplasms are lesions comprised of cystic components that show different biological behaviors, epidemiology, clinical manifestations, imaging features, and malignant potential and management. Benign cystic neoplasms include serous cystic neoplasms (SCAs). Other pancreatic cystic lesions have malignant potential, such as intraductal papillary mucinous neoplasms and mucinous cystic neoplasms. SCAs can be divided into microcystic (classic appearance), honeycomb, oligocystic/macrocystic, and solid patterns based on imaging appearance. They are usually solitary but may be multiple in von Hippel-Lindau disease, which may depict disseminated involvement. The variable appearances of SCAs can mimic other types of pancreatic cystic lesions, and cross-sectional imaging plays an important role in their differential diagnosis. Endoscopic ultrasonography has helped in improving diagnostic accuracy of pancreatic cystic lesions by guiding tissue sampling (biopsy) or cyst fluid analysis. Immunohistochemistry and newer techniques such as radiomics have shown improved performance for preoperatively discriminating SCAs and their mimickers.

The role of biomarkers in the early detection of pancreatic cancer

Pancreatic surveillance can detect early-stage pancreatic cancer and achieve long-term survival, but currently involves annual endoscopic ultrasound and MRI/MRCP, and is recommended only for individuals who meet familial/genetic risk criteria. To improve upon current approaches to pancreatic cancer early detection and to expand access, more accurate, inexpensive, and safe biomarkers are needed, but finding them has remained elusive. Newer approaches to early detection, such as using gene tests to personalize biomarker interpretation, and the increasing application of artificial intelligence approaches to integrate complex biomarker data, offer promise that clinically useful biomarkers for early pancreatic cancer detection are on the horizon.

Addressing the unmet clinical need for low-volume assays in early diagnosis of pancreatic cancer

The incidental detection of pancreatic cysts, an opportunity for the early detection of pancreatic cancer, is increasing, owing to an aging population and improvements in imaging technology. The classification of pancreatic cystic precursors currently relies on imaging and cyst fluid evaluations, including cytology and protein and genomic analyses. However, there are persistent limitations that obstruct the accuracy and quality of information for clinicians, including the limited volume of the complex, often acellular, and proteinaceous milieu that comprises pancreatic cyst fluid. The constraints of currently available clinical assays lead clinicians to the subjective and inconsistent application of diagnostic tools, which can contribute to unnecessary surgery and missed pancreatic cancers. Herein, we describe the pathway toward pancreatic cyst classification and diagnosis, the volume requirements for several clinically available diagnostic tools, and some analytical and diagnostic limitations for each assay. We then discuss current and future work on novel markers and methods, and how to expand the utility of clinical pancreatic cyst fluid samples. Results of ongoing studies applying SERS as a detection mode suggest that 50 μL of pancreatic cyst fluid is more than sufficient to accurately rule out non-mucinous pancreatic cysts with no malignant potential from further evaluation. This process is expected to leave sufficient fluid to analyze a follow-up, rule-in panel of markers currently in development that can stratify grades of dysplasia in mucinous pancreatic cysts and improve clinical decision-making.

Pancreatic Cyst Fluid Analysis

Pancreatic cyst fluid analysis can help diagnose pancreatic cyst type and the risk of high-grade dysplasia and cancer. Recent evidence from molecular analysis of cyst fluid has revolutionized the field with multiple markers showing promise in accurate diagnosis and prognostication of pancreatic cysts. The availability of multi-analyte panels has great potential for more accurate prediction of cancer.

Progress on diagnostic and prognostic markers of pancreatic cancer

Pancreatic cancer is a malignant disease characterized by low survival and high recurrence rate, whose patients are mostly at the stage of locally advanced or metastatic disease when first diagnosed. Early diagnosis is particularly important because prognostic/predictive markers help guide optimal individualized treatment regimens. So far, CA19-9 is the only biomarker for pancreatic cancer approved by the FDA, but its effectiveness is limited by low sensitivity and specificity. With recent advances in genomics, proteomics, metabolomics, and other analytical and sequencing technologies, the rapid acquisition and screening of biomarkers is now possible. Liquid biopsy also occupies a significant place due to its unique advantages. In this review, we systematically describe and evaluate the available biomarkers that have the greatest potential as vital tools in diagnosing and treating pancreatic cancer.

Biochemical Intracystic Biomarkers in the Differential Diagnosis of Pancreatic Cystic Lesions

Background and Objectives: Pancreatic cystic lesions (PCLs) are frequently incidental findings. The prevalence of PCLs is increasing, mainly due to advancements in imaging techniques, but also because of the aging of the population. PCLs comprise challenging clinical problems, as their manifestations vary from benign to malignant lesions. Therefore, the recognition of PCLs is achieved through a complex diagnostic and surveillance process, which in turn is usually long-term, invasive, and expensive. Despite the progress made in the identification of novel biomarkers in the cystic fluid that also support the differentiation of PCLs, their application in clinical practice is limited. Materials and Methods: We conducted a systematic review of the literature published in two databases, Pubmed and Embase, on biochemical biomarkers in PCLs that may be applied in the diagnostic algorithms of PCLs. Results: Eleven studies on intracystic glucose, twenty studies on intracystic carcinoembryonic antigen (CEA), and eighteen studies on other biomarkers were identified. Low levels of intracystic glucose had high sensitivity and specificity in the differentiation between mucinous and non-mucinous cystic neoplasms. Conclusions: CEA and glucose are the most widely studied fluid biochemical markers in pancreatic cystic lesions. Glucose has better diagnostic accuracy than CEA. Other biochemical biomarkers require further research.

Cytopathology of solid pancreatic neoplasms: An algorithmic approach to diagnosis

The classification and management of solid pancreatic neoplasms has expanded significantly in recent years because of advances in immunohistochemical markers, molecular diagnostics, and therapeutics. Solid pancreatic masses are subdivided into 1) ill-defined, scirrhous, and stroma-rich (ductal adenocarcinoma) and 2) well circumscribed, cellular, and stroma-poor (including neuroendocrine neoplasms, acinar cell carcinoma, pancreatoblastoma, and solid-pseudopapillary neoplasm). Definitive diagnosis, particularly of stroma-poor, circumscribed tumors, requires the incorporation of radiologic and cytologic findings, along with the judicious use of (broad, but limited) immunohistochemical panels (pancytokeratin and neuroendocrine [synaptophysin], acinar [trypsin], and solid-pseudopapillary neoplasm [β-catenin] markers), along with unstained slides. Depending on the initial results, immunohistochemical panels should be expanded to include more confirmatory (acinar and neuroendocrine) markers. This ensures that adequate material is available for definitive diagnosis/subclassification and, in some cases, grading, and/or molecular studies, particularly of grade 3 neuroendocrine neoplasms and mixed-lineage tumors. The objective of this review is to expand the understanding of the cytomorphology of solid pancreatic neoplasms using an integrated, multidisciplinary approach in their diagnosis. Knowledge and understanding of recent updates in the classification of solid pancreatic neoplasms ensures that cytopathologists appropriately triage specimens, judiciously use and interpret ancillary studies, and incorporate these results in reporting.

Cystic Neoplasms of the Pancreas: Differential Diagnosis and Radiology Correlation

Although the probability of pancreatic cystic neoplasms (PCNs) being detected is raising year by year, their differential diagnosis and individualized treatment are still a challenge in clinical work. PCNs are tumors containing cystic components with different biological behaviors, and their clinical manifestations, epidemiology, imaging features, and malignant risks are different. Some are benign [e.g., serous cystic neoplasms (SCNs)], with a barely possible that turning into malignant, while others display a low or higher malignant risk [e.g., solid pseudopapillary neoplasms (SPNs), intraductal papillary mucinous neoplasms (IPMNs), and mucinous cystic neoplasms (MCNs)]. PCN management should concentrate on preventing the progression of malignant tumors while preventing complications caused by unnecessary surgical intervention. Clinically, various advanced imaging equipment are usually combined to obtain a more reliable preoperative diagnosis. The challenge for clinicians and radiologists is how to accurately diagnose PCNs before surgery so that corresponding surgical methods and follow-up strategies can be developed or not, as appropriate. The objective of this review is to sum up the clinical features, imaging findings and management of the most common PCNs according to the classic literature and latest guidelines.

Atypical cells in fine needle aspiration biopsies of pancreas: Causes, work-up, and recommendations for management

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is a sensitive and specific method for diagnosing cancer in solid pancreatic masses. However, some cases receive indeterminate atypical diagnoses, which creates management dilemmas. In the 2014 Papanicolaou Society of Cytopathology (PSC) standardized guidelines for pancreatobiliary cytology, specimens in the "Atypical" category show a spectrum of architectural and/or cellular changes beyond normal or reactive, but, quantitatively or qualitatively, insufficient for classification as neoplastic (benign/other), suspicious or positive for malignancy. Implementation of the PSC system decreased atypical diagnoses, particularly for cystic lesions, and redistributed many cases into benign and neoplastic categories. Because no set cytologic criteria exist for the "Atypical" category there is wide variability in its use, and its frequency ranges from 0%-16% (mean 6%). It consists of a heterogeneous mix of cases that occur because of preanalytic, lesion-specific (low cellularity, necrosis, cystic, reactive and premalignant changes), to pathologist-dependent factors (experience, expertise, training and institutional case volume). Outcomes of atypical diagnoses in solid pancreatic masses range from benign to premalignant and malignant and include reactive atypia in pancreatitis, well differentiated adenocarcinoma, and non-ductal malignancies. The associated risk of malignancy (ROM) ranges from 28%-100%, with an overall intermediate ROM in large-scale studies. Cytopathologists and institutions should monitor and keep their personal and/or laboratory's atypical rates low by judiciously using rapid onsite evaluation, ancillary studies, consensus or expert review, as well as correlation with clinical and radiologic findings. Early repeat EUS-FNA is indicated for unresolved cases.

Calponin and MUC6 complement inhibin as diagnostic immunomarkers of serous cystadenoma in endoscopic ultrasound-guided aspiration/biopsy specimens

AIMS

Because serous cystadenoma (SCA) does not usually require excision, it is critical to distinguish it from differential diagnoses which do, especially neuroendocrine tumour (NET). The gold standard for diagnosing SCA is assessment of endoscopic ultrasound-guided fine needle aspiration/biopsy (EUS-FNAB) material. Inhibin immunohistochemistry aids this assessment, but such positivity is not absolutely sensitive or specific to SCA. The following is the largest known study of SCA EUS-FNAB specimens and the first to compare four potential SCA immunomarkers between themselves and inhibin, compared against NET.

METHODS AND RESULTS

Immunohistochemistry for calponin, mucin 6 (MUC6), glucose transporter 1 (GLUT1) and vascular endothelial growth factor A (VEGFA) was performed on 30 EUS-FNAB and three resection specimens of SCA and 32 EUS-FNAB specimens of NET. GLUT1 and VEGFA were suboptimal as diagnostic immunomarkers of SCA, being expressed by 10 and 44% of NETs, respectively. Further, their expression by cellular constituents of blood which often contaminate EUS-FNAB specimens hampered identification of neoplastic cells, especially in hypocellular samples. While 19% of NETs showed nuclear MUC6 positivity, cytoplasmic expression of the protein showed 100% specificity and sensitivity as an SCA marker. However, assessing MUC6 in EUS-FNAB specimens must also consider the protein's focal expression in physiological pancreatic, gastric or duodenal tissues, which can contaminate these specimens. Calponin was less sensitive (71% versus 100%) but more specific (100% versus 91%) than inhibin, although easier to assess in EUS-FNAB specimens than MUC6.

CONCLUSIONS

Of the four potential immunomarkers of SCA suggested by the existing literature, calponin and MUC6 are useful complementary studies to inhibin for application to EUS-FNAB specimens.

Biomarker Risk Score Algorithm and Preoperative Stratification of Patients with Pancreatic Cystic Lesions

BACKGROUND

Pancreatic cysts are incidentally detected in up to 13% of patients undergoing radiographic imaging. Of the most frequently encountered types, mucin-producing (mucinous) pancreatic cystic lesions may develop into pancreatic cancer, while nonmucinous ones have little or no malignant potential. Accurate preoperative diagnosis is critical for optimal management, but has been difficult to achieve, resulting in unnecessary major surgery. Here, we aim to develop an algorithm based on biomarker risk scores to improve risk stratification.

STUDY DESIGN

Patients undergoing surgery and/or surveillance for a pancreatic cystic lesion, with diagnostic imaging and banked pancreatic cyst fluid, were enrolled in the study after informed consent (n = 163 surgical, 67 surveillance). Cyst fluid biomarkers with high specificity for distinguishing nonmucinous from mucinous pancreatic cysts (vascular endothelial growth factor [VEGF], glucose, carcinoembryonic antigen [CEA], amylase, cytology, and DNA mutation) were selected. Biomarker risk scores were used to design an algorithm to predict preoperative diagnosis. Performance was tested using surgical (retrospective) and surveillance (prospective) cohorts.

RESULTS

In the surgical cohort, the biomarker algorithm outperformed the preoperative clinical diagnosis in correctly predicting the final pathologic diagnosis (91% vs 73%; p < 0.000001). Specifically, nonmucinous serous cystic neoplasms (SCN) and mucinous cystic neoplasms (MCN) were correctly classified more frequently by the algorithm than clinical diagnosis (96% vs 30%; p < 0.000008 and 92% vs 69%; p = 0.04, respectively). In the surveillance cohort, the algorithm predicted a preoperative diagnosis with high confidence based on a high biomarker score and/or consistency with imaging from ≥1 follow-up visits.

CONCLUSIONS

A biomarker risk score-based algorithm was able to correctly classify pancreatic cysts preoperatively. Importantly, this tool may improve initial and dynamic risk stratification, reducing overdiagnosis and underdiagnosis.

Cytologic Assessment of Cystic/Intraductal Lesions of the Pancreatobiliary Tract

CONTEXT.—

Because of new and improved imaging techniques, cystic/intraductal pancreatobiliary tract lesions are increasingly being discovered, and brushings or endoscopic ultrasound/computed tomography/magnetic resonance imaging-guided fine-needle aspiration biopsies from these lesions have become an integral part of pathologists' daily practice. Because patient management has become increasingly conservative, accurate preoperative diagnosis is critical. Cytologic distinction of low-risk (pseudocysts, serous cystadenoma, lymphoepithelial cysts, and squamoid cysts of the pancreatic duct) from high-risk pancreatic cysts (intraductal papillary mucinous neoplasm and mucinous cystic neoplasm) requires incorporation of clinical, radiologic, and cytologic findings, in conjunction with chemical and molecular analysis of cyst fluid. Cytopathologists must ensure appropriate specimen triage, along with cytologic interpretation, cyst classification, and even grading of some (mucinous) cysts. Epithelial atypia in mucinous cysts (intraductal papillary mucinous neoplasm and mucinous cystic neoplasm) has transitioned from a 3-tiered to a 2-tiered classification system, and intraductal oncocytic papillary neoplasms and intraductal tubulopapillary neoplasms have been separately reclassified because of their distinctive clinicopathologic characteristics. Because these lesions may be sampled on brushing or fine-needle aspiration biopsy, knowledge of their cytomorphology is critical.

OBJECTIVE.—

To use an integrated, multidisciplinary approach for the evaluation of cystic/intraductal pancreatobiliary tract lesions (incorporating clinical, radiologic, and cytologic findings with [chemical/molecular] cyst fluid analysis and ancillary stains) for definitive diagnosis and classification.

DATA SOURCES.—

Review of current literature on the cytopathology of cystic/intraductal pancreatobiliary tract lesions.

CONCLUSIONS.—

Our knowledge/understanding of recent updates in cystic/intraductal pancreatobiliary lesions can ensure that cytopathologists appropriately triage specimens, judiciously use and interpret ancillary studies, and incorporate the studies into reporting.

Multi-Omic Biomarkers as Potential Tools for the Characterisation of Pancreatic Cystic Lesions and Cancer: Innovative Patient Data Integration

Pancreatic cancer (PC) is regarded as one of the most lethal malignant diseases in the world, with GLOBOCAN 2020 estimates indicating that PC was responsible for almost half a million deaths worldwide in 2020. Pancreatic cystic lesions (PCLs) are fluid-filled structures found within or on the surface of the pancreas, which can either be pre-malignant or have no malignant potential. While some PCLs are found in symptomatic patients, nowadays many PCLs are found incidentally in patients undergoing cross-sectional imaging for other reasons-so called 'incidentalomas'. Current methods of characterising PCLs are imperfect and vary hugely between institutions and countries. As such, there is a profound need for improved diagnostic algorithms. This could facilitate more accurate risk stratification of those PCLs that have malignant potential and reduce unnecessary surveillance. As PC continues to have such a poor prognosis, earlier recognition and risk stratification of PCLs may lead to better treatment protocols. This review will focus on the importance of biomarkers in the context of PCLs and PCand outline how current 'omics'-related work could contribute to the identification of a novel integrated biomarker profile for the risk stratification of patients with PCLs and PC.

Application of EUS-based techniques in the evaluation of pancreatic cystic neoplasms

Pancreatic cystic neoplasms (PCNs) are being detected increasingly frequently due to the widespread use of high-resolution abdominal imaging modalities. Some subtypes of PCNs have the potential for malignant transformation. Therefore, accurate diagnosis of PCNs is crucial to determine whether surgical resection or surveillance is the best management strategy. However, the current cross-section imaging modalities are not accurate enough to enable definite diagnoses. In the last decade, EUS-based techniques have emerged, aiming to overcome the limitations of standard cross-section imaging modalities. These novel EUS-based techniques were primarily designed to acquire distinct images to make radiological diagnoses, collect cyst fluid to undergo biochemical or molecular analyses, and obtain tissue to conclude the pathological diagnoses. In this article, we present a comprehensive and critical review of these emerging EUS techniques for the diagnosis of PCNs, with emphasis being placed on the advantages, feasibilities, diagnostic performances, and limitations of these novel techniques.

Novel expression of vascular endothelial growth factor isoforms in the pancreas and pancreatic cystic lesions

Vascular endothelial growth factor (VEGF)-A is known to play key biological roles in angiogenesis and vascular permeability. We previously identified VEGF-A as an accurate biomarker of benign pancreatic cystic lesions known as serous cystic neoplasms (SCN). In the present study, we seek to further characterize the expression of VEGF-A and its splice isoforms in different pancreatic cysts including SCN. Patients undergoing surgery were consented for the collection of pancreatic cystic lesion tissue (SCN, pseudocysts, mucinous cysts) and normal adjacent pancreas as well as pancreatic cyst fluid. Following RNA isolation from the tissues, relative VEGF-A gene expression was quantitatively analyzed using real-time PCR (qPCR), and VEGF-A isoform expression was evaluated by reverse transcriptase (RT)-PCR. Relative VEGF-A gene expression was significantly increased in SCN, demonstrating transcriptional upregulation in SCN compared to other pancreatic cyst tissues (P < 0.0001). VEGF-189, -165, -145, and -121 splice variants were detected in both normal adjacent pancreas and pancreatic cystic lesions; the novel VEGF-111 isoform was variably expressed in normal and cyst tissues. Finally, VEGF isoform levels in pancreatic cyst fluid were measured by isoform-specific ELISAs. VEGF-165, -145, and -121 proteins were present in pancreatic cyst fluids; VEGF-165 levels were significantly higher in SCN cyst fluid. Thus, multiple VEGF isoforms were expressed in normal pancreas and pancreatic cysts. Of particular interest are VEGF-145 and -111, which have not previously been described in human pancreas where they may exhibit unique biological activities in health and/or disease.

The genetics of ductal adenocarcinoma of the pancreas in the year 2020: dramatic progress, but far to go

The publication of the "Pan-Cancer Atlas" by the Pan-Cancer Analysis of Whole Genomes Consortium, a partnership formed by The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC), provides a wonderful opportunity to reflect on where we stand in our understanding of the genetics of pancreatic cancer, as well as on the opportunities to translate this understanding to patient care. From germline variants that predispose to the development of pancreatic cancer, to somatic mutations that are therapeutically targetable, genetics is now providing hope, where there once was no hope, for those diagnosed with pancreatic cancer.

A multimodality test to guide the management of patients with a pancreatic cyst

Pancreatic cysts are common and often pose a management dilemma, because some cysts are precancerous, whereas others have little risk of developing into invasive cancers. We used supervised machine learning techniques to develop a comprehensive test, CompCyst, to guide the management of patients with pancreatic cysts. The test is based on selected clinical features, imaging characteristics, and cyst fluid genetic and biochemical markers. Using data from 436 patients with pancreatic cysts, we trained CompCyst to classify patients as those who required surgery, those who should be routinely monitored, and those who did not require further surveillance. We then tested CompCyst in an independent cohort of 426 patients, with histopathology used as the gold standard. We found that clinical management informed by the CompCyst test was more accurate than the management dictated by conventional clinical and imaging criteria alone. Application of the CompCyst test would have spared surgery in more than half of the patients who underwent unnecessary resection of their cysts. CompCyst therefore has the potential to reduce the patient morbidity and economic costs associated with current standard-of-care pancreatic cyst management practices.

Molecular Diagnosis of Cystic Neoplasms of the Pancreas: a Review

BACKGROUND

The prevalence of incidental pancreatic cystic neoplasms (PCNs) has increased dramatically with advancements in cross-sectional imaging. Diagnostic imaging is limited in differentiating between benign and malignant PCNs. The aim of this review is to provide an overview of biomarkers that can be used to distinguish PCNs.

METHODS

A review of the literature on molecular diagnosis of cystic neoplasms of the pancreas was performed.

RESULTS

Pancreatic cysts can be categorized into inflammatory and non-inflammatory lesions. Inflammatory cysts include pancreatic pseudocysts. Noninflammatory lesions include both mucinous and non-mucinous lesions. Mucinous lesions include intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm. Non-mucinous lesions include serous cystadenoma and solid-pseudopapillary tumor of the pancreas. Imaging, cyst aspiration, and histologic findings, as well as carcinoembryonic antigen and amylase are commonly used to distinguish between cyst types. However, molecular techniques to detect differences in genetic mutations, protein expression, glycoproteomics, and metabolomic profiling are important developments in distinguishing between cyst types.

DISCUSSION

Nomograms incorporating common clinical, laboratory, and imaging findings have been developed in a better effort to predict malignant IPMN. The incorporation of top molecular biomarker candidates to nomograms may improve the predictive ability of current models to more accurately diagnose malignant PCNs.

Elevating pancreatic cystic lesion stratification: Current and future pancreatic cancer biomarker(s)

Pancreatic ductal adenocarcinoma (PDAC) is an incredibly deadly disease with a 5-year survival rate of 9%. The presence of pancreatic cystic lesions (PCLs) confers an increased likelihood of future pancreatic cancer in patients placing them in a high-risk category. Discerning concurrent malignancy and risk of future PCL progression to cancer must be carefully and accurately determined to improve survival outcomes and avoid unnecessary morbidity of pancreatic resection. Unfortunately, current image-based guidelines are inadequate to distinguish benign from malignant lesions. There continues to be a need for accurate molecular and imaging biomarker(s) capable of identifying malignant PCLs and predicting the malignant potential of PCLs to enable risk stratification and effective intervention management. This review provides an update on the current status of biomarkers from pancreatic cystic fluid, pancreatic juice, and seromic molecular analyses and discusses the potential of radiomics for differentiating PCLs harboring cancer from those that do not.

Cytohistological diagnosis of pancreatic serous cystadenoma: a multimodal approach

Aims

Serous cystadenomata (SCAs) are benign pancreatic cystic neoplasms that present a diagnostic challenge despite many investigational approaches. Notwithstanding the promise of molecular diagnostics, these tests have limited accessibility in day-to-day surgical pathology practices. We aim to corroborate and build on recent evidence which suggests that positive α-inhibin immunohistochemistry (IHC) is a helpful adjunct in the biopsy confirmation of pancreatic SCA.

Methods

We retrospectively reviewed 22 fine-needle aspirates/biopsies from 14 patients (mean age 65 years, 47–83 years) with pancreatic multicystic lesions radiologically suspicious for SCA (location: 6 body, 2 head, 4 tail, 1 neck, 1 uncinate; cyst size: mean 3.7 cm, 2.0–7.6 cm), as well as an additional 10 pancreatic resection specimens with confirmed SCA; α-inhibin IHC was performed on all cell blocks, biopsy slides and representative resection specimen sections. Where available, associated cyst fluid was analysed for correlative vascular endothelial growth factor A (VEGF-A) and carcinoembryonic antigen levels.

Results

An α-inhibin IHC sensitivity of 80% was observed in the cases with resection confirmed SCA. Of the fine-needle aspirate/biopsy specimens, 59% (13/22) contained epithelial cells strongly positive for α-inhibin. When selecting for specimens that exhibited distinct strips of epithelium, the α-inhibin strong positivity rate increased to 73% (8/11). VEGF-A values were supportive of false-negative α-inhibin IHC in three cases and true-negative α-inhibin IHC in one case.

Conclusion

This study postulates a diagnostic algorithm to confirm pancreatic SCA which may help to decrease unnecessary follow-up endoscopy/surgical resection and would decrease the associated morbidity, mortality and financial costs in patients with this otherwise benign condition.

Current indications and yield of endoscopic ultrasound and ancillary techniques in pancreatic cystic neoplasms

An increase in the diagnosis of pancreatic cystic neoplasm has been described lately. Surgical treatment or surveillance is advised depending on the type of lesion diagnosed. The most accurate diagnostic approach is needed to make the best therapeutic decision. Endoscopic ultrasound is a very valuable tool in the evaluation of pancreatic cystic neoplasm. It generates high-quality images and allows the possibility of sampling the cystic fluid for cytology, microbiological and molecular evaluation. Even with this evaluation, the sensitivity of this approach is not always adequate. New technological resources have been developed to try to improve the diagnostic accuracy of pancreatic cystic neoplasms. The two most promising techniques are needle-based confocal laser endomicroscopy and contrast-enhanced harmonic endoscopic ultrasound. Needle-based confocal laser endomicroscopy allows a microscopic evaluation of mucosal glands and vascular pattern, to differentiate mucinous from non-mucinous lesions. Contrast-enhanced harmonic endoscopic ultrasound is used for the vascular evaluation of the microcirculation of the cyst wall and mural nodule, mainly to make the difference between malignant nodules and mucus plugs. A combination of these different diagnostic techniques can improve the diagnostic accuracy of pancreatic cystic neoplasms to offer the adequate therapeutic decision.

A case of duodenal hemorrhage due to arteriovenous malformation around a serous cystic neoplasm

Background

No reports have so far described arteriovenous malformation (AVM) in the pancreas caused by a tumor. We herein report a case of pancreatoduodenectomy for a patient who developed duodenal hemorrhage due to AVM developed around serous cystic neoplasm (SCN) of the pancreas.

Case presentation

A 79-year-old man was referred to our hospital because of anemia (Hb 7.4 g/dl) and pancreatic head tumor. Computed tomography showed microcystic-type SCN, 87 mm in size, in the pancreatic head. Vascular hyperplasia had developed around the cystic lesion. Upper gastrointestinal endoscopy and colonoscopy did not reveal the cause of anemia, so the patient was followed closely without hemostatic therapy. Iron preparations had improved the anemia. Three months later, the patient developed anemia (Hb 5.8 g/dl) again. Gastrointestinal endoscopy showed oozing from the mucosa in the duodenum via the swollen vascular hyperplasia. He was diagnosed as duodenal hemorrhage from the blood vessels around SCN. Pancreatoduodenectomy was performed to control repeated duodenal bleeding. A histopathological examination revealed that the cystic lesion in the pancreatic head was SCN, and the AVM developed around SCN and duodenum, causing repeated duodenal hemorrhage. The patient was discharged on postoperative day 22. Nine months after surgery, the patient had no recurrence of anemia.

Conclusions

There have been no reports of duodenal hemorrhage due to acquired pancreatic AVM around pancreatic tumor, including SCN. We successfully treated a case of duodenal hemorrhage due to pancreatic AVM around SCN by pancreatoduodenectomy.

Cyst Fluid Biomarkers - Diagnosis and Prediction of Malignancy for Cystic Lesions of the Pancreas

Pancreatic cysts are common, and are identified in 2-13% of individuals undergoing cross-sectional imaging. Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) are pancreatic cysts which are precursors to pancreatic adenocarcinoma. Currently available tools are imperfect at differentiating IPMNs and MCNs from other, benign types of pancreatic cysts. The role of molecular markers in the evaluation of pancreatic cysts and the identification of cysts with high-grade dysplasia or invasive adenocarcinoma is reviewed.

Quantitative proteomic analysis of pancreatic cyst fluid proteins associated with malignancy in intraductal papillary mucinous neoplasms

Background

The application of advanced imaging technologies for identifying pancreatic cysts has become widespread. However, accurately differentiating between low-grade dysplasia (LGD), high-grade dysplasia (HGD), and invasive intraductal papillary mucinous neoplasms (IPMNs) remains a diagnostic challenge with current biomarkers, necessitating the development of novel biomarkers that can distinguish IPMN malignancy.

Methods

Cyst fluid samples were collected from nine IPMN patients (3 LGD, 3 HGD, and 3 invasive IPMN) during their pancreatectomies. An integrated proteomics approach that combines filter-aided sample preparation, stage tip-based high-pH fractionation, and high-resolution MS was applied to acquire in-depth proteomic data of pancreatic cyst fluid and discover marker candidates for IPMN malignancy. Biological processes of differentially expressed proteins that are related to pancreatic cysts and aggressive malignancy were analyzed using bioinformatics tools such as gene ontology analysis and Ingenuity pathway analysis. In order to confirm the validity of the marker candidates, 19 cyst fluid samples were analyzed by western blot.

Results

A dataset of 2992 proteins was constructed from pancreatic cyst fluid samples. A subsequent analysis found 2963 identified proteins in individual samples, 2837 of which were quantifiable. Differentially expressed proteins between histological grades of IPMN were associated with pancreatic diseases and malignancy according to ingenuity pathway analysis. Eighteen biomarker candidates that were differentially expressed across IPMN histological grades were discovered—7 DEPs that were upregulated and 11 that were downregulated in more malignant grades. HOOK1 and PTPN6 were validated by western blot in an independent cohort, the results of which were consistent with our proteomic data.

Conclusions

This study demonstrates that novel biomarker candidates for IPMN malignancy can be discovered through proteomic analysis of pancreatic cyst fluid.

Electronic supplementary material

The online version of this article (10.1186/s12014-018-9193-1) contains supplementary material, which is available to authorized users.

Differences in MUC4 Expression in Pancreatic Cancers and Pancreatic Cysts in Egypt

Pancreatic cancer is the fourth cause of cancer deaths in the U.S. with most patients diagnosed at advanced stages followed by short survival. Therefore, biomarkers for early detection are urgently needed. Mucin 4 (MUC4) is a mucin protein encoded by the MUC4 gene and identified in the majority of pancreatic cancers. With increasing clinical identification and diagnosis of pancreatic cysts globally and transformation of some cysts into pancreatic cancer, it is important to evaluate if MUC4 is expressed in pancreatic cysts.

Immunohistochemistry assays utilizing heat-induced epitope retrieval (HIER) were performed to examine MUC4 protein expression in 44 paraffin-embedded tissues of pancreatic cancers and 20 pancreatic cysts. All patients were diagnosed and operated upon at the Mansoura University Gastrointestinal Surgery Center in Egypt. Clinical, demographic, and survival information were abstracted from the patients’ medical records. Logistic regression was performed to predict expression of MUC4 protein in cancer and cysts, by type of cysts.

Pancreatic cyst patients were significantly younger than pancreatic cancer patients (Mean age of 28.7 ± 5.25 vs. 54.84 ± 10.60 years) (p=0.0001). Expression of MUC4 was not different between cancers and pancreatic cysts (p=0.16). However, type of pancreatic cysts was predictive of MUC4 expression. Mucinous cystic neoplasms and serous cystadenoma cysts showed significantly higher MUC4 expression than non-specified and pseudocysts (80%, 75%, 25%, and 0% expression for the 4 types of cysts, respectively) (p=0.022).

MUC4 expression may be associated with certain types of cysts. Follow-up of pancreatic cyst patients who show MUC4 expression might reveal clues to early detection of pancreatic cancer.

Benign Tumors and Tumorlike Lesions of the Pancreas

The pancreas is a complex organ that may give rise to large number of neoplasms and non-neoplastic lesions. This article focuses on benign neoplasms, such as serous neoplasms, and tumorlike (pseudotumoral) lesions that may be mistaken for neoplasm not only by clinicians and radiologists, but also by pathologists. The family of pancreatic pseudotumors, by a loosely defined conception of that term, includes a variety of lesions including heterotopia, hamartoma, and lipomatous pseudohypertrophy. Autoimmune pancreatitis and paraduodenal ("groove") pancreatitis may also lead to pseudotumor formation. Knowledge of these entities will help in making an accurate diagnosis.

Analysis of Pancreatic Cyst Fluid

Pancreatic cysts are extremely common, and are identified in between 2% to 13% on abdominal imaging studies. Most pancreatic cysts are pseudocysts, serous cystic neoplasms, mucinous cystic neoplasms, or intraductal papillary mucinous neoplasms. The management of pancreatic cysts depends on whether a cyst is benign, has malignant potential, or harbors high-grade dysplasia or invasive carcinoma. The diagnosis of pancreatic cysts, and assessment of risk of malignant transformation, incorporates clinical history, computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasound, and fine-needle aspiration of cyst fluid. This article reviews the cyst fluid markers that are currently used, as well as promising markers under development.

Global Protease Activity Profiling Provides Differential Diagnosis of Pancreatic Cysts

Purpose: Pancreatic cysts are estimated to be present in 2%-3% of the adult population. Unfortunately, current diagnostics do not accurately distinguish benign cysts from those that can progress into invasive cancer. Misregulated pericellular proteolysis is a hallmark of malignancy, and therefore, we used a global approach to discover protease activities that differentiate benign nonmucinous cysts from premalignant mucinous cysts.Experimental Design: We employed an unbiased and global protease profiling approach to discover protease activities in 23 cyst fluid samples. The distinguishing activities of select proteases was confirmed in 110 samples using specific fluorogenic substrates and required less than 5 μL of cyst fluid.Results: We determined that the activities of the aspartyl proteases gastricsin and cathepsin E are highly increased in fluid from mucinous cysts. IHC analysis revealed that gastricsin expression was associated with regions of low-grade dysplasia, whereas cathepsin E expression was independent of dysplasia grade. Gastricsin activity differentiated mucinous from nonmucinous cysts with a specificity of 100% and a sensitivity of 93%, whereas cathepsin E activity was 92% specific and 70% sensitive. Gastricsin significantly outperformed the most widely used molecular biomarker, carcinoembryonic antigen (CEA), which demonstrated 94% specificity and 65% sensitivity. Combined analysis of gastricsin and CEA resulted in a near perfect classifier with 100% specificity and 98% sensitivity.Conclusions: Quantitation of gastricsin and cathepsin E activities accurately distinguished mucinous from nonmucinous pancreatic cysts and has the potential to replace current diagnostics for analysis of these highly prevalent lesions. Clin Cancer Res; 23(16); 4865-74. ©2017 AACR.

Serous pancreatic neoplasia, data and review

AIM

To describe the imaging features of serous neoplasms of the pancreas using ultrasound, endoscopic ultrasound, computed tomography and magnetic resonance imaging.

METHODS

This multicenter international collaboration enhances a literature review to date, reporting features of 287 histologically confirmed cases of serous pancreatic cystic neoplasms (SPNs).

RESULTS

Female predominance is seen with most SPNs presenting asymptomatically in the 5^th through 7^th decade. Mean lesion size was 38.7 mm, 98% were single, 44.2% cystic, 46% mixed cystic and solid, and 94% hypoechoic on B-mode ultrasound. Vascular patterns and contrast-enhancement profiles are described as hypervascular and hyperenhancing.

CONCLUSION

The described ultrasound features can aid differentiation of SPN from other neoplastic lesions under most circumstances.

Genomic Variations in Pancreatic Cancer and Potential Opportunities for Development of New Approaches for Diagnosis and Treatment

Human pancreatic cancer has a very poor prognosis with an overall five-year survival rate of less than 5% and an average median survival time of six months. This is largely due to metastatic disease, which is already present in the majority of patients when diagnosed. Although our understanding of the molecular events underlying multi-step carcinogenesis in pancreatic cancer has steadily increased, translation into more effective therapeutic approaches has been inefficient in recent decades. Therefore, it is imperative that novel and targeted approaches are designed to facilitate the early detection and treatment of pancreatic cancer. Presently, there are numerous ongoing studies investigating the types of genomic variations in pancreatic cancer and their impact on tumor initiation and growth, as well as prognosis. This has led to the development of therapeutics to target these genetic variations for clinical benefit. Thus far, there have been minimal clinical successes directly targeting these genomic alterations; however research is ongoing to ultimately discover an innovative approach to tackle this devastating disease. This review will discuss the genomic variations in pancreatic cancer, and the resulting potential diagnostic and therapeutic implications.

Pancreatic Cyst Fluid Vascular Endothelial Growth Factor A and Carcinoembryonic Antigen: A Highly Accurate Test for the Diagnosis of Serous Cystic Neoplasm

BACKGROUND

Accurate differentiation of pancreatic cystic lesions is important for pancreatic cancer early detection and prevention as well as avoidance of unnecessary surgical intervention. Serous cystic neoplasms (SCN) have no malignant potential, but may mimic premalignant mucinous cystic lesions: mucinous cystic neoplasm (MCN) and intraductal papillary mucinous neoplasm (IPMN). We recently identified vascular endothelial growth factor (VEGF)-A as a novel pancreatic fluid biomarker for SCN. We hypothesize that combining cyst fluid carcinoembryonic antigen (CEA) with VEGF-A will improve the diagnostic accuracy of VEGF-A.

METHODS

Pancreatic cyst/duct fluid was collected from consenting patients undergoing surgical cyst resection with corresponding pathologic diagnoses. Pancreatic fluid VEGF-A and CEA levels were detected by ELISA.

RESULTS

One hundred forty-nine patients with pancreatic cystic lesions met inclusion criteria. Pathologic diagnoses included pseudocyst (n=14), SCN (n=26), MCN (n=40), low/moderate grade IPMN (n=34), high grade IPMN (n=20), invasive IPMN (n=10) and solid pseudopapillary neoplasm (n=5). VEGF-A was significantly elevated in SCN cyst fluid compared to all other diagnoses (p<0.001). With a threshold of >5,000 pg/ml, VEGF-A alone has 100% sensitivity and 83.7% specificity to distinguish SCN from other cystic lesions. With a threshold of ≤10ng/ml, CEA alone identifies SCN with 95.5% sensitivity and 81.5% specificity. Sensitivity and specificity of the VEGF-A/CEA combination are 95.5% and 100% respectively. The c-statistic increased from 0.98 to 0.99 when CEA was added to VEGF-A alone in the ROC analysis.

CONCLUSIONS

Although VEGF-A alone is a highly accurate test for SCN, the combination of VEGF-A with CEA approaches the gold-standard of pathologic diagnosis, thus importantly avoiding false positives. Patients with a positive test indicating benign SCN can be spared a high risk surgical pancreatic resection.

Precursors of pancreatic cancer

Pancreatic cancer (PC) behaves very differently in comparison with other malignancies. Its incidence has been increasing continuously; mortality has not decreased, the diagnosis is frequently late, radical surgery is performed only in 15-20% of patients, and chemotherapy is only palliative. PC occurs in three different forms. Sporadic PC accounts for 90% of all PCs. Its most frequent form is the pancreatic ductal adenocarcinoma. The remaining 10% constitute two minority groups: familial PC (7%) and PC as a manifestation of a genetic cancer syndrome (3%). PCs are preceded by a precancerous lesion (precursor). At present, six different precursors are known. They have different histomorphological characteristics and malignant potential. The recognition and correct interpretation of individual precursors influences adequate clinical decision-making. The publication surveys the present knowledge of individual precursors and their role in the early pancreatic carcinogenesis.

The Evolving Role of Pathology in New Developments, Classification, Terminology, and Diagnosis of Pancreatobiliary Neoplasms

Pancreatobiliary tract lesions are increasingly being discovered because of more sensitive imaging modalities. Magnetic resonance imaging has identified incidental pancreatic cysts in 13.5% of patients of progressively increasing age. Pancreatobiliary tissue is more accessible through endoscopic ultrasound and magnetic resonance imaging-guided biopsy procedures, and is now an integral part of pathologists' routine practice. Accordingly, several new tumor categories have been recently recognized, including intraductal tubulopapillary neoplasm, a new addition to tumoral intraepithelial neoplasms. Other entities have been reclassified, including the recent transition to 2-tiered grading of preinvasive neoplasms, as well as new perspectives on the distinctive biologic behavior of oncocytic intraductal papillary mucinous neoplasms (IPMNs) compared with other IPMN subtypes. This has led to proposals for revised staging of virtually every segment of the pancreatobiliary tree, with theranostic markers becoming an integral part of workup. Ki-67 is now an integral part of the classification of neuroendocrine tumors, with new definitions of "high-grade neuroendocrine carcinoma." Although bile duct brushings have opened new avenues for diagnosis, their sensitivity remains low and often requires concomitant fluorescent in situ hybridization to better define ambiguous cases. Various molecular pathways have been elucidated for pancreatic cysts, including KRAS for ductal neoplasia, GNAS for intestinal IPMNs, RNF3 for mucinous cysts, and VHL for serous cystic neoplasms, all key players in diagnostic workup. Integration of these updates into our understanding of pancreatobiliary disease requires active engagement of pathologists for appropriate specimen triage, judicious interpretation of results, and incorporation into reporting and staging. They also provide exciting opportunities for targeted therapy.

A Gastric Glycoform of MUC5AC Is a Biomarker of Mucinous Cysts of the Pancreas

Molecular indicators to specify the risk posed by a pancreatic cyst would benefit patients. Previously we showed that most cancer-precursor cysts, termed mucinous cysts, produce abnormal glycoforms of the proteins MUC5AC and endorepellin. Here we sought to validate the glycoforms as a biomarker of mucinous cysts and to specify the oligosaccharide linkages that characterize MUC5AC. We hypothesized that mucinous cysts secrete MUC5AC displaying terminal N-acetylglucosamine (GlcNAc) in either alpha or beta linkage. We used antibody-lectin sandwich assays to detect glycoforms of MUC5AC and endorepellin in cyst fluid samples from three independent cohorts of 49, 32, and 66 patients, and we used monoclonal antibodies to test for terminal, alpha-linked GlcNAc and the enzyme that produces it. A biomarker panel comprising the previously-identified glycoforms of MUC5AC and endorepellin gave 96%, 96%, and 87% accuracy for identifying mucinous cysts in the three cohorts with an average sensitivity of 92% and an average specificity of 94%. Glycan analysis showed that MUC5AC produced by a subset of mucinous cysts displays terminal alpha-GlcNAc, a motif expressed in stomach glands. The alpha-linked glycoform of MUC5AC was unique to intraductal papillary mucinous neoplasms (IPMN), whereas terminal beta-linked GlcNAc was increased in both IPMNs and mucinous cystic neoplasms (MCN). The enzyme that synthesizes alpha-GlcNAc, A4GNT, was expressed in the epithelia of mucinous cysts that expressed alpha-GlcNAc, especially in regions with high-grade dysplasia. Thus IPMNs secrete a gastric glycoform of MUC5AC that displays terminal alpha-GlcNAc, and the combined alpha-GlcNAc and beta-GlcNAc glycoforms form an accurate biomarker of mucinous cysts.

Routine Cyst Fluid Cytology Is Not Indicated in the Evaluation of Pancreatic Cystic Lesions

BACKGROUND

The work-up of cystic lesions of the pancreas often involves endoscopic ultrasound (EUS) with fine needle aspiration (FNA). In addition to CEA and amylase measurement, fluid is routinely sent for cytologic examination. We evaluated the utility of cytologic findings in clinical decision-making.

MATERIALS AND METHODS

Records of patients who underwent EUS-guided pancreatic cyst aspiration were reviewed. Findings from axial imaging and EUS were compared to cyst fluid cytology as well as fluid amylase and CEA. All results were then compared to final diagnosis, determined by clinical analysis for those patients not resected, and surgical pathology report for those who underwent resection.

RESULTS

A total of 167 patients were reviewed. Of 48 patients with suspicious findings on imaging, cytology yielded diagnostic information in 89.6 % of cases (43 patients). However, in the 119 patients where no suspicious components were revealed on imaging, fluid cytology yielded no significant diagnostic results in any case. In all cases where mucin was noted on cytologic review, thick fluid was also seen at the time of aspiration.

DISCUSSION

In our cohort of patients with cystic pancreatic lesions, cytologic analysis of pancreatic cyst fluid yielded no diagnostic benefit over radiologic findings alone. In such cases where fluid is to be aspirated, specimens that would otherwise be sent for cytologic evaluation would be better served for other purposes, such as molecular analysis or banking for future research.

Cyst Fluid Telomerase Activity Predicts the Histologic Grade of Cystic Neoplasms of the Pancreas

PURPOSE

Pancreatic cysts frequently pose clinical dilemmas. On one hand, cysts with high-grade dysplasia offer opportunities for cure, on the other hand, those with low-grade dysplasia are easily over treated. Cyst fluid markers have the potential to improve the evaluation of these cysts. Because telomerase activity is commonly activated in malignant cells, we evaluated the diagnostic performance of cyst fluid telomerase activity measurements for predicting histologic grade.

EXPERIMENTAL DESIGN

Telomerase activity was measured using telomerase repeat amplification with digital-droplet PCR in surgically aspirated cyst fluid samples from 219 patients who underwent pancreatic resection for a cystic lesion (184 discovery, 35 validation) and 36 patients who underwent endoscopic ultrasound fine-needle aspiration. Methodologic and clinical factors associated with telomerase activity were examined.

RESULTS

Telomerase activity was reduced in samples that had undergone prior thawing. Among 119 samples not previously thawed, surgical cyst fluids from cystic neoplasms with high-grade dysplasia ± associated invasive cancer had higher telomerase activity [median (interquartile range), 1,158 (295.9-13,033)] copies/μL of cyst fluid than those without [19.74 (2.58-233.6) copies/μL; P < 0.001)]. Elevated cyst fluid telomerase activity had a diagnostic accuracy for invasive cancer/high-grade dysplasia of 88.1% (discovery), 88.6% (validation), and 88.2% (merged). Among cysts classified preoperatively as having "worrisome features," cyst fluid telomerase activity had high diagnostic performance (sensitivity 73.7%, specificity 90.6%, accuracy, 86.1%). In multivariate analysis, telomerase activity independently predicted the presence of invasive cancer/high-grade dysplasia.

CONCLUSIONS

Cyst fluid telomerase activity can be a useful predictor of the neoplastic grade of pancreatic cysts. Clin Cancer Res; 22(20); 5141-51. ©2016 AACRSee related commentary by Allen et al., p. 4966.

Serous Neoplasms of the Pancreas: A Clinicopathologic Analysis of 193 Cases and Literature Review With New Insights on Macrocystic and Solid Variants and Critical Reappraisal of So-called "Serous Cystadenocarcinoma"

The literature on "variants" and "malignant" counterparts of pancreatic serous cystic neoplasms (SCNs) is highly conflicted. Clinicopathologic characteristics of 193 SCNs were investigated, along with a critical literature review. For the macrocystic (oligocystic) variant, in this largest series, a demographic profile in contrast to current literature was elucidated, with 21% frequency, predominance in female individuals (4:1), body/tail location (1.7×), younger age of patients (mean age, 50 y), and frequent radiologic misdiagnosis as other megacystic neoplasms. Solid SCNs were rare (n=4, 2%) and often misinterpreted radiologically as neuroendocrine tumors. Available fine-needle aspiration in 11 cases was diagnostic in only 1. Radiologic impression was "malignancy" in 5%. Associated secondary tumors were detected in 13% of resections, mostly neuroendocrine. Secondary "infiltration" (direct adhesion/penetration) of spleen, stomach, colon, and/or adjacent nodes was seen in 6 (3%) fairly large SCNs (mean, 11 cm) with no distant metastasis. Three SCNs recurred locally, but completeness of original resection could not be verified. Our only hepatic SCN lacked a concurrent pancreatic tumor. Literature appraisal revealed that there are virtually no deaths that are directly attributable to dissemination/malignant behavior of SCNs, and most cases reported as "malignant" in fact would no longer fulfill the more recent World Health Organization criteria but instead would represent either (1) local adhesion/persistence of tumor, (2) cases with no histologic verification of malignancy, or (3) liver SCNs with benevolent behavior (likely representing multifocality, rather than true metastasis, especially considering there was no fatality related to this and no reported metastases to other remote sites). In conclusion, in contrast to the literature, the clinicopathologic characteristics of solid and macrocystic SCN variants are similar to their microcystic counterpart, although their radiologic diagnosis is challenging. Recurrence/secondary invasion of neighboring organs occurs rarely in larger SCNs but seems innocuous. An SCN should not be classified as "malignant" unless there is clear-cut evidence of histologic malignancy or documented distant metastasis.

Serous cystic neoplasm of the pancreas: a multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)

OBJECTIVES

Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality.

DESIGN

Retrospective multinational study including SCN diagnosed between 1990 and 2014.

RESULTS

2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58 years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40 mm (2-200)), 9% had resection beyond 1 year of follow-up (3 years (1-20), size at diagnosis: 25 mm (4-140)) and 39% had no surgery (3.6 years (1-23), 25.5 mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1 year (n=1271), size increased in 37% (growth rate: 4 mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1).

CONCLUSIONS

After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN.

TRIAL REGISTRATION NUMBER

IRB 00006477.

Differential Diagnosis of Cystic Pancreatic Lesions Including the Usefulness of Biomarkers

Background

Cystic pancreatic lesions are more and more often found. Malignant risk ranges from nil to more than 60%. A precise diagnosis is required to adapt surveillance or therapeutic strategy.

Methods

We tried to identify the most difficult differential diagnoses encountered in a tertiary center of pancreatology and to guide the reader as how to reach the correct strategy and diagnosis in these situations.

Results

We identified eight clinically difficult situations: i) chronic pancreatitis versus intraductal papillary mucinous neoplasms, ii) serous versus mucinous cystic neoplasms, iii) serous cystic neoplasms versus branch-duct intraductal papillary mucinous neoplasms, iv) intraductal papillary mucinous neoplasms versus acinar cell cystadenoma, v) (pseudo-) solid serous cystic neoplasm versus neuroendocrine tumor, vi) pancreatic neuroendocrine tumors versus solid pseudopapillary tumors, vii) cystic forms of a solid tumor, and viii) rare pancreatic or peripancreatic cystic lesions. The work-up should rely on computed tomography scan, pancreatic magnetic resonance imaging, and, only if necessary, endoscopic ultrasound with or without fine needle aspiration.

Conclusion

An expert analysis of imaging data allows a precise diagnosis in most of the cases. Pancreatic resection should no longer be performed in case of diagnostic doubt.

A high sensitive electrochemical aptasensor for the determination of VEGF(165) in serum of lung cancer patient

Herein, a label free electrochemical aptasensor based on ordered mesoporous carbon-gold nanocomposite modified screen printed electrode has been fabricated for the detection of vascular endothelial growth factor (VEGF165) as a tumor marker. The electrochemical behavior of prepared biosensor was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The principle of operation of the proposed aptasensor is based on the changes in the interfacial properties of the electrode due to interaction of the immobilized antiVEGF165 aptamer at the electrode surface with VEGF165 tumor marker in the sample solution, which results in a change in the interfacial charge transfer resistance as detected by electrochemical impedance spectroscopy. The calibration curve for VEGF165 determination was linear over 10.0-300.0 pg mL(-1) with a limit of detection (3σ/S) of 1.0 pg mL(-1). The prepared aptasensor exhibited high sensitivity and good selectivity and reproducibility. The aptasensor was successfully applied to the determination of VEGF165 in serum sample of a lung cancer patient.

Highly sensitive label free electrochemical detection of VGEF165 tumor marker based on "signal off" and "signal on" strategies using an anti-VEGF165 aptamer immobilized BSA-gold nanoclusters/ionic liquid/glassy carbon electrode

In this work, a label free electrochemical aptasensor for the detection of ultra-traces of vascular endothelial growth factor (VEGF165) based on "signal off" and "signal on" mechanisms of response was developed. The BSA-gold nanoclusters/ionic liquid (BSA-AuNCs/IL) was used as a suitable nanocomposite platform for immobilization of the aptamer on a glassy carbon electrode. In "signal off" mechanism, the interaction of VEGF165 with its anti-VEGF165 aptamers, resulted in desorption of methylene blue (MB) probe from aptamer and its release into solution. Consequently, the decrease in current intensity of the differential pulse voltammogram of adsorbed MB was monitored and found to be linearly proportional with increasing concentration of VEGF165 in sample solution in the range of 1-120 pM with a limit of detection of 0.32p M. While, in "signal on" mechanism, the interaction of immobilized anti-VEGF165 aptamers on the electrode surface with VEGF165, led to more mass-transfer limiting of the [Fe(CN)6](3-/4-) probe to the electrode surface. Therefore, the charge transfer resistance (Rct) of the probe was increased linearly with increasing concentration of VEGF165 in the range of 2.5-250 pM with a limit of detection of 0.48 pM. The experimental results demonstrated that both of these mechanisms are suitable for determination of low levels of the VEGF165 tumor marker in serum samples.

Systematic Review of Pancreatic Cyst Fluid Biomarkers: The Path Forward

There is significant research interest in developing and validating novel pancreatic cyst-fluid biomarkers given the increasing recognition of the prevalence of pancreatic cysts and their associated malignant potential. Although current international consensus guidelines are helpful, they fail to diagnose with certainty the cyst type and the level of epithelial dysplasia. They also fall short in predicting the future likelihood of malignant transformation. A systematic review was performed with the objective of summarizing cyst-fluid-based biomarkers that have been published in the medical literature over the past 10 years and characterizing the current quality of evidence. Our review demonstrates that there is an increasing interest in this topic with several different and innovative approaches including DNA, RNA, proteomic, and metabolomics profiling. Further techniques to improve upon cytological yield have also been studied. Besides identifying potentially useful clinical biomarkers, these empiric approaches have provided further insight into their pathogenesis. The level of evidence for the vast majority of these studies, however, is limited to retrospective early validation studies. The path forward will be to select out the most promising biomarkers and develop multicenter consortiums capable of capturing adequate sample sizes with appropriate study designs.

Diagnosis and Management of Pancreatic Cystic Neoplasms

Incidentally discovered pancreatic cystic lesions are increasingly common, affecting up to 10% to 15% of patients undergoing cross-sectional imaging. Although some pancreatic cystic neoplasms harbor invasive malignancy or the potential to progress over time, a majority are benign and can be observed safely. Accurate diagnosis is key to appropriate management. Diagnosis requires a multidisciplinary and multimodal approach. This review discusses each type of pancreatic cystic neoplasm and the current data on diagnosis and treatment.

The changing spectrum of surgically treated cystic neoplasms of the pancreas

Introduction. While the incidence of pancreatic cystic lesions has steadily increased, we sought to evaluate the changes in their surgical management. Methods. Patients with pancreatic cystic lesions who underwent surgical resection from 2003 to 2013 were identified. Clinicopathologic factors were analyzed and compared to a similar cohort from 1992 to 2002. Results. There were 134 patients with pancreatic cystic lesions who underwent surgical resection from 2003 to 2013, compared to 73 from 1992 to 2002. The most common preoperative imaging was a CT scan, although 66% underwent EUS and 63% underwent biopsy. Pathology included 18 serous, 47 mucinous, 11 pseudopapillary, and 58 intraductal papillary mucinous neoplasms (IPMN). In comparing cohorts, there were significantly fewer serous lesions and more IPMN. Postoperative complication rates were similar, and perioperative mortality rates were comparable. Conclusion. There has been a dramatic change in surgically treated pancreatic cystic tumors over the past two decades. Our data suggests that the incorporation of new imaging and diagnostic tests has led to greater detection of cystic tumors and a decreased rate of potentially unnecessary resections. Therefore, all patients with cystic pancreatic lesions should undergo a focused CT-pancreas, and an EUS biopsy should be considered, in order to best select those that would benefit from surgical resection.

Genomic landscapes of pancreatic neoplasia

Pancreatic cancer is a deadly disease with a dismal prognosis. However, recent advances in sequencing and bioinformatic technology have led to the systematic characterization of the genomes of all major tumor types in the pancreas. This characterization has revealed the unique genomic landscape of each tumor type. This knowledge will pave the way for improved diagnostic and therapeutic approaches to pancreatic tumors that take advantage of the genetic alterations in these neoplasms.

Analysis of VEGF/PlGF heterodimer level in pancreatic cyst fluid as a biomarker for serous cystadenoma

INTRODUCTION

Pancreatic cyst fluid (PCF) analysis provides valuable information in the preoperative evaluation of pancreatic cysts. Vascular endothelial growth factors (VEGF) and other proangiogenesis factors such a placental growth factor (PlGF) are promising biomarkers for identifying serous cystadenoma (SCA). VEGF-A has recently been reported as a SCA marker. We sought to assess the value of the VEGF-A/PlGF heterodimer as a potential biomarker of SCA in PCF.

MATERIALS AND METHODS

PCF was analyzed for VEGF/PlGF and 7 additional proangiogenic markers including VEGF-A, VEGF-C, VEGF-D, TEK tyrosine kinase, endothelial (TIE-2), soluble fms-like tyrosine kinase-1 (sFlt-1), PlGF, and basic fibroblast growth factor (bFGF). True-positive or false-negative results were determined by histological confirmation of SCA and false-positive or true-negative results with confirmation of a non-SCA cyst by either cytology or histology, elevated carcinoembryonic antigen ≥192 ng/mL, elevated amylase ≥5000 U/L, or detected KRAS/GNAS mutations.

RESULTS

Forty-eight PCFs were analyzed; 1 was technically inadequate. Of the remaining 47, 3 (6%) contained measurable (>60 pg/mL) concentrations of VEGF/PlGF heterodimer: 1 pseudocyst, 1 cystic adenocarcinoma, and 1 SCA. Of 6 histologically confirmed SCAs, there was only 1 (17%) true positive. Six PCFs were not classifiable due to insufficient data, leaving 41 PCFs for performance calculations (33 true negative, 5 false negative, 1 true positive, and 2 false positive) yielding a sensitivity of 17% and specificity of 94%.

CONCLUSIONS

VEGF/PlGF heterodimer is present in low concentrations in PCF and is an insensitive biomarker for SCA. Additional study is required to determine clinical utility of heterodimeric VEGF/PlGF in combination with other proangiogenic markers.

Serous cystic neoplasms of the pancreas: clinicopathologic and molecular characteristics

We herein summarize the pathology and most recent advances in the molecular genetics of serous cystic neoplasms of the pancreas. They typically present as relatively large, well-demarcated tumors (mean size, 6cm), predominantly occurring in females. Pre-operative diagnosis remains challenging; imaging findings and cyst fluid analysis often prove non-specific and fine-needle aspiration often does not yield diagnostic cells. Pathologically, they are characterized by a distinctive cytology referred to as "serous." Although they have ductal differentiation, they distinctly lack the mucin production that characterizes most other pancreatic ductal tumors, including ductal adenocarcinoma and its variants, intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm (MCN). They instead produce abundant glycogen (glycogen-rich adenoma). Serous cystadenomas also lack the molecular alterations that characterize ductal neoplasms, such as mutation of KRAS (high prevalence in most mucinous ductal neoplasms), inactivation of SMAD4 (seen in ductal adenocarcinomas), and mutations in GNAS (seen in some IPMNs) and RNF43 (detected in MCNs and IPMNs). Instead, new molecular and immunohistochemical observations place serous pancreatic tumors closer to "clear cell neoplasms" seen in various other organs that are associated with the von Hippel-Lindau (VHL) pathway, such as clear cell renal cell carcinomas and capillary hemangioblastomas. Patients with VHL syndrome have an increased risk of developing serous pancreatic tumors and somatic mutations of the VHL gene are common in these tumors along with modification of its downstream effectors including hypoxia-inducible factor (HIF1), glucose uptake and transporter-1 (GLUT-1), a common factor in clear cell (glycogen-rich) tumors, as well as expression of vascular endothelial growth factor (VEGF), thought to be a factor in the striking capillarization of serous cystadenomas and other non-pancreatic clear cell tumors. VEGF may prove to be of significant diagnostic value since its elevation in cyst fluid has recently been found highly sensitive and specific for serous neoplasms. These molecular alterations establish serous tumors as prototypes of clear cell tumorigenesis and angiogenesis and may prove helpful both as diagnostic and non-surgical therapeutic targets.