Molecular analysis of pancreatic cystic neoplasm in routine clinical practice

BACKGROUNDCystic pancreatic lesions consist of a wide variety of lesions that are becoming increasingly diagnosed with the growing use of imaging techniques. Of these, mucinous cysts are especially relevant due to their risk of malignancy. However, morphological findings are often suboptimal for their differentiation. Endoscopic ultrasound fine-needle aspiration (EUS-FNA) with molecular analysis has been suggested to improve the diagnosis of pancreatic cysts.AIMTo determine the impact of molecular analysis on the detection of mucinous cysts and malignancy.METHODSAn 18-month prospective observational study of consecutive patients with pancreatic cystic lesions and an indication for EUS-FNA following European clinical practice guidelines was conducted. These cysts included those > 15 mm with unclear diagnosis, and a change in follow-up or with concerning features in which results might change clinical management. EUS-FNA with cytological, biochemical and glucose and molecular analyses with next-generation sequencing were performed in 36 pancreatic cysts. The cysts were classified as mucinous and non-mucinous by the combination of morphological, cytological and biochemical analyses when surgery was not performed. Malignancy was defined as cytology positive for malignancy, high-grade dysplasia or invasive carcinoma on surgical specimen, clinical or morphological progression, metastasis or death related to neoplastic complications during the 6-mo follow-up period. Next-generation sequencing results were compared for cyst type and malignancy.RESULTSOf the 36 lesions included, 28 (82.4%) were classified as mucinous and 6 (17.6%) as non-mucinous. Furthermore, 5 (13.9%) lesions were classified as malignant. The amount of deoxyribonucleic acid obtained was sufficient for molecular analysis in 25 (69.4%) pancreatic cysts. The amount of intracystic deoxyribonucleic acid was not statistically related to the cyst fluid volume obtained from the lesions. Analysis of KRAS and/or GNAS showed 83.33% [95% confidence interval (CI): 63.34-100] sensitivity, 60% (95%CI: 7.06-100) specificity, 88.24% (95%CI: 69.98-100) positive predictive value and 50% (95%CI: 1.66-98.34) negative predictive value (P = 0.086) for the diagnosis of mucinous cystic lesions. Mutations in KRAS and GNAS were found in 2/5 (40%) of the lesions classified as non-mucinous, thus recategorizing those lesions as mucinous neoplasms, which would have led to a modification of the follow-up plan in 8% of the cysts in which molecular analysis was successfully performed. All 4 (100%) malignant cysts in which molecular analysis could be performed had mutations in KRAS and/or GNAS, although they were not related to malignancy (P > 0.05). None of the other mutations analyzed could detect mucinous or malignant cysts with statistical significance (P > 0.05). CONCLUSIONMolecular analysis can improve the classification of pancreatic cysts as mucinous or non-mucinous. Mutations were not able to detect malignant lesions.     

Significance of MUC2 gene methylation detection in pancreatic cancer diagnosis

PurposeThis study was conducted to explore the diagnostic value of MUC2 gene methylation in pancreatic cancer.MethodsMethylation restriction enzyme digestion (Msp I/Hap II) and polymerase chain reaction (PCR) were performed to detect methylation of the MUC2 gene in fecal and blood specimens from seven study subjects with pancreatic cancer (PC), chronic pancreatitis (CP), or normal controls (CON). Simultaneously, blood CA 19-9 levels were detected as a positive indicator of PC.ResultsMUC2 methylation was detected in 50% of PC cell lines. In fecal samples, the MUC2 methylation rate in PC (n = 30) was 43.3%, which was significantly higher than those in CP (n = 8, 0%, P < 0.05) and CON (n = 20, 5.0%, P < 0.05). In blood samples, the MUC2 methylation rate in PC (n = 40) was 52.5%, which was significantly higher than those in CP (n = 15, 0%, P < 0.01) and CON (n = 25, 4.0%, P < 0.01). For PC diagnosis, MUC2 gene methylation in blood samples showed higher specificity and positive predictive value than CA 19-9. The combined detection in the feces and blood showed a 60% MUC2 methylation rate in PC (n = 10), which was higher than those in the CP (n = 5, 0%, P < 0.01) and CON (n = 12, 0%, P < 0.01).ConclusionsThe study can clearly indicate that combined detection of MUC2 gene methylation in the peripheral blood and feces could be used as a new screening and early diagnosis method for pancreatic cancer.     

Advances in pancreatic cancer research: Moving towards early detection

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

Pancreatic cancer early detection:Expanding higher-risk group with clinical and metabolomics parameters

Pancreatic ductal adenocarcinoma(PDAC)is the fourth and fifth leading cause of cancer death for each gender in developed countries.With lack of effective treatment and screening scheme available for the general population,the mortality rate is expected to increase over the next several decades in contrast to the other major malignancies such as lung,breast,prostate and colorectal cancers.Endoscopic ultrasound,with itshighest level of detection capacity of smaller pancreatic lesions,is the commonly employed and preferred clinical imaging-based PDAC detection method.Various molecular biomarkers have been investigated for characterization of the disease,but none are shown to be useful or validated for clinical utilization for early detection.As seen from studies of a small subset of familial or genetically high-risk PDAC groups,the higher yield and utility of imaging-based screening methods are demonstrated for these groups.Multiple recent studies on the unique cancer metabolism including PDAC,demonstrate the potential for utility of the metabolites as the discriminant markers for this disease.In order to generate an early PDAC detection screening strategy available for a wider population,we propose to expand the population of higher risk PDAC group with combination clinical and metabolomics parameters.     

Surveillance for neoplasia in the pancreas

Despite its low incidence in the general population, pancreatic cancer is one of the leading causes of cancer-related mortality. Survival greatly depends on operability, but most patients present with unresectable disease. Therefore, there is great interest in the early detection of pancreatic cancer and its precursor lesions by surveillance. Worldwide, several programs have been initiated for individuals at high risk for pancreatic cancer. Their first results suggest that surveillance in high-risk individuals is feasible, but their effectiveness in decreasing mortality remains to be proven. This review will discuss which individuals are eligible for surveillance, which lesions are aimed to be detected, and which surveillance modalities are being used in current clinical practice. Furthermore, it addresses the management of abnormalities found during surveillance and topics for future research.     

Circulating RNAs as new biomarkers for detecting pancreatic cancer

Pancreatic cancer remains difficult to treat and has a high mortality rate. It is difficult to diagnose early, mainly due to the lack of screening imaging modalities and specific biomarkers. Consequently, it is important to develop biomarkers that enable the detection of early stage tumors. Emerging evidence is accumulating that tumor cells release substantial amounts of RNA into the bloodstream that strongly resist RNases in the blood and are present at sufficient levels for quantitative analyses. These circulating RNAs are upregulated in the serum and plasma of cancer patients, including those with pancreatic cancer, compared with healthy controls. The majority of RNA biomarker studies have assessed circulating microRNAs (miRs), which are often tissue-specific. There are few reports of the tumor-specific upregulation of other types of small non-coding RNAs (ncRNAs), such as small nucleolar RNAs and Piwi-interacting RNAs. Long ncRNAs (lncRNAs), such as HOTAIR and MALAT1, in the serum/plasma of pancreatic cancer patients have also been reported as diagnostic and prognostic markers. Among tissue-derived RNAs, some miRs show increased expression even in pre-cancerous tissues, and their expression profiles may allow for the discrimination between a chronic inflammatory state and carcinoma. Additionally, some miRs and lncRNAs have been reported with significant alterations in expression according to disease progression, and they may thus represent potential candidate diagnostic or prognostic biomarkers that may be used to evaluate patients once detection methods in peripheral blood are well established. Furthermore, recent innovations in high-throughput sequencing techniques have enabled the discovery of unannotated tumor-associated ncRNAs and tumor-specific alternative splicing as novel and specific biomarkers of cancers. Although much work is required to clarify the release mechanism, origin of tumor-specific circulating RNAs, and selectivity of carrier complexes, and technical advances must also be achieved, such as creating a consensus normalization protocol for quantitative data analysis, circulating RNAs are largely unexplored and might represent novel clinical biomarkers.     

Minimally invasive radical pancreatectomy for left-sided pancreatic cancer: Current status and future perspectives

Minimally invasive distal pancreatectomy with splenectomy has been regarded as a safe and effective treatment for benign and borderline malignant pancreatic lesions. However, its application for left-sided pancreatic cancer is still being debated. The clinical evidence for radical antegrade modular pancreatosplenectomy (RAMPS)-based minimally invasive approaches for left-sided pancreatic cancer was reviewed. Potential indications and surgical concepts for minimally invasive RAMPS were suggested. Despite the limited clinical evidence for minimally invasive distal pancreatectomy in left-sided pancreatic cancer, the currently available clinical evidence supports the use of laparoscopic distal pancreatectomy under oncologic principles in well-selected left sided pancreatic cancers. A pancreas-confined tumor with an intact fascia layer between the pancreas and left adrenal gland/kidney positioned more than 1 or 2 cm away from the celiac axis is thought to constitute a good condition for the use of margin-negative minimally invasive RAMPS. The use of minimally invasive (laparoscopic or robotic) anterior RAMPS is feasible and safe for margin-negative resection in well-selected left-sided pancreatic cancer. The oncologic feasibility of the procedure remains to be determined; however, the currently available interim results indicate that even oncologic outcomes will not be inferior to those of open radical distal pancreatosplenectomy.     

Systematic review and meta-analysis: Diagnostic performance of DNA alterations in pancreatic juice for the detection of pancreatic cancer

Background and aimsPancreatic cancer has a dismal prognosis. So far, imaging has been proven incapable of establishing an early enough diagnosis. Thus, biomarkers are urgently needed for early detection and improved survival. Our aim was to evaluate the pooled diagnostic performance of DNA alterations in pancreatic juice.MethodsA systematic literature search was performed in EMBASE, MEDLINE Ovid, Cochrane CENTRAL and Web of Science for studies concerning the diagnostic performance of DNA alterations in pancreatic juice to differentiate patients with high-grade dysplasia or pancreatic cancer from controls. Study quality was assessed using QUADAS-2. The pooled prevalence, sensitivity, specificity and diagnostic odds ratio were calculated.ResultsStudies mostly concerned cell-free DNA mutations (32 studies: 939 cases, 1678 controls) and methylation patterns (14 studies: 579 cases, 467 controls). KRAS, TP53, CDKN2A, GNAS and SMAD4 mutations were evaluated most. Of these, TP53 had the highest diagnostic performance with a pooled sensitivity of 42% (95% CI: 31–54%), specificity of 98% (95%-CI: 92%–100%) and diagnostic odds ratio of 36 (95% CI: 9–133).Of DNA methylation patterns, hypermethylation of CDKN2A, NPTX2 and ppENK were studied most. Hypermethylation of NPTX2 performed best with a sensitivity of 39–70% and specificity of 94–100% for distinguishing pancreatic cancer from controls.ConclusionsThis meta-analysis shows that, in pancreatic juice, the presence of distinct DNA mutations (TP53, SMAD4 or CDKN2A) and NPTX2 hypermethylation have a high specificity (close to 100%) for the presence of high-grade dysplasia or pancreatic cancer. However, the sensitivity of these DNA alterations is poor to moderate, yet may increase if they are combined in a panel.     

A decision support tool for the detection of pancreatic cancer in general practice: A modified Delphi consensus

Background/objectivesDiagnosis of pancreatic cancer is often delayed, contributing to patient and family distress and leading to worse survival. We aimed to develop a decision support tool to support primary care providers to identify patients that should undergo investigations for pancreatic cancer, and to recommend initial diagnostic pathways.MethodsA modified Delphi process, including a series of three surveys, was undertaken to ascertain clinical expert opinion on which combinations of signs, symptoms and risk factors should be included in a tool for the early identification of pancreatic cancer. A group of clinical specialists finalised the development of the tool during a focus group meeting.ResultsThe tool presents individual or combinations of signs, symptoms, and risk factors in three tiers which direct the urgency of investigation. Tier 1 includes 5 clinical presentation and risk factors clusters that indicate the need for urgent investigation of the pancreas. A further five clusters are included as Tier 2 aiming to elimate other causes and reduce the time to investigating the pancreas. Tier 3 includes a list of non-specific signs, symptoms and risk factors that indicate the need to consider pancreatic cancer as a potential diagnosis, but without specific recommendations for investigation.ConclusionsProspective validation studies are now required prior to implementation in the primary care setting. Implementation into primary care practice and as an educational resource may facilitate rapid diagnosis and improve outcomes such as distress and survival.     

Strategies for early detection of resectable pancreatic cancer

Pancreatic cancer is difficult to diagnose at an early stage and generally has a poor prognosis. Surgical resection is the only potentially curative treatment for pancreatic carcinoma. To improve the prognosis of this disease, it is essential to detect tumors at early stages, when they are resectable. The optimal approach to screening for early pancreatic neoplasia has not been established. The International Cancer of the Pancreas Screening Consortium has recently finalized several recommendations regarding the management of patients who are at an increased risk of familial pancreatic cancer. In addition, there have been notable advances in research on serum markers, tissue markers, gene signatures, and genomic targets of pancreatic cancer. To date, however, no biomarkers have been established in the clinical setting. Advancements in imaging modalities touch all aspects of the clinical management of pancreatic diseases, including the early detection of pancreatic masses, their characterization, and evaluations of tumor resectability. This article reviews strategies for screening high-risk groups, biomarkers, and current advances in imaging modalities for the early detection of resectable pancreatic cancer.     

胰腺癌早期诊断的现状与展望

本文综述胰腺痛早期诊断中应用影像学、血清肿瘤标示物、基因、端粒酶、蛋白质组学、流式细胞术和对高危人群筛查的现状，并展望建立真正意义上早期诊断胰腺癌的进一步研究方向。     

Current status and progress of pancreatic cancer in China

Cancer is currently one of the most important public health problems in the world. Pancreatic cancer is a fatal disease with poor prognosis. As in most other countries, the health burden of pancreatic cancer in China is increasing, with annual mortality rates almost equal to incidence rates. The increasing trend of pancreatic cancer incidence is more significant in the rural areas than in the urban areas. Annual diagnoses and deaths of pancreatic cancer in China are now beyond the number of cases in the United States. GLOBOCAN 2012 estimates that cases in China account for 19.45% (65727/337872) of all newly diagnosed pancreatic cancer and 19.27% (63662/330391) of all deaths from pancreatic cancer worldwide. The population’s growing socioeconomic status contributes to the rapid increase of China’s proportional contribution to global rates. Here, we present an overview of control programs for pancreatic cancer in China focusing on prevention, early diagnosis and treatment. In addition, we describe key epidemiological, demographic, and socioeconomic differences between China and developed countries. Facts including no nationwide screening program for pancreatic cancer, delay in early detection resulting in a late stage at presentation, lack of awareness of pancreatic cancer in the Chinese population, and low investment compared with other cancer types by government have led to backwardness in China’s pancreatic cancer diagnosis and treatment. Finally, we suggest measures to improve health outcomes of pancreatic cancer patients in China.     

Longitudinal changes of serum protein N-Glycan levels for earlier detection of pancreatic cancer in high-risk individuals

BackgroundSurveillance of individuals at risk of developing pancreatic ductal adenocarcinoma (PDAC) has the potential to improve survival, yet early detection based on solely imaging modalities is challenging. We aimed to identify changes in serum glycosylation levels over time to earlier detect PDAC in high-risk individuals.MethodsIndividuals with a hereditary predisposition to develop PDAC were followed in two surveillance programs. Those, of which at least two consecutive serum samples were available, were included. Mass spectrometry analysis was performed to determine the total N-glycome for each consecutive sample. Potentially discriminating N-glycans were selected based on our previous cross-sectional analysis and relative abundances were calculated for each glycosylation feature.Results165 individuals (“FPC-cohort” N = 119; Leiden cohort N = 46) were included. In total, 97 (59%) individuals had a genetic predisposition (77 CDKN2A, 15 BRCA1/2, 5 STK11) and 68 (41%) a family history of PDAC without a known genetic predisposition (>10-fold increased risk of developing PDAC). From each individual, a median number of 3 serum samples (IQR 3) was collected.Ten individuals (6%) developed PDAC during 35 months of follow-up; nine (90%) of these patients carried a CDKN2A germline mutation. In PDAC cases, compared to all controls, glycosylation characteristics were increased (fucosylation, tri- and tetra-antennary structures, specific sialic linkage types), others decreased (complex-type diantennary and bisected glycans). The largest change over time was observed for tri-antennary fucosylated glycans, which were able to differentiate cases from controls with a specificity of 92%, sensitivity of 49% and accuracy of 90%.ConclusionSerum N-glycan monitoring may support early detection in a pancreas surveillance program.     

Therapeutic resistance in pancreatic ductal adenocarcinoma: Current challenges and future opportunities

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related deaths in the United States. Although chemotherapeutic regimens such as gemcitabine+ nab-paclitaxel and FOLFIRINOX (FOLinic acid, 5-Fluroruracil, IRINotecan, and Oxaliplatin) significantly improve patient survival, the prevalence of therapy resistance remains a major roadblock in the success of these agents. This review discusses the molecular mechanisms that play a crucial role in PDAC therapy resistance and how a better understanding of these mechanisms has shaped clinical trials for pancreatic cancer chemotherapy. Specifically, we have discussed the metabolic alterations and DNA repair mechanisms observed in PDAC and current approaches in targeting these mechanisms. Our discussion also includes the lessons learned following the failure of immunotherapy in PDAC and current approaches underway to improve tumor’s immunological response.     

Artificial intelligence for early detection of pancreatic adenocarcinoma: The future is promising

Pancreatic ductal adenocarcinoma (PDAC) is a worldwide public health concern. Despite extensive research efforts toward improving diagnosis and treatment, the 5-year survival rate at best is approximately 15%. This dismal figure can be attributed to a variety of factors including lack of adequate screening methods, late symptom onset, and treatment resistance. Pancreatic ductal adenocarcinoma remains a grim diagnosis with a high mortality rate and a significant psy-chological burden for patients and their families. In recent years artificial intelligence (AI) has permeated the medical field at an accelerated pace, bringing potential new tools that carry the promise of improving diagnosis and treatment of a variety of diseases. In this review we will summarize the landscape of AI in diagnosis and treatment of PDAC.     

联合检测vimentin和SFRP2甲基化在大肠癌筛查中的应用评价

目的评价在粪便样本中联合检测vimentin和SFRP2甲基化来筛查大肠癌的性能。方法搜集合格的新鲜粪便标本95例,其中40例大肠癌患者、25例进展期腺瘤患者和30例结肠镜阴性的正常人,应用甲基化特异性PCR(MSP)法检测vimentin和SFRP2甲基化状态,并与单个基因甲基化检测和粪隐血试验(FOBT)的诊断性能相比较是否有统计学差异。结果大肠癌组中vimentin和SFRP2甲基化阳性检出率分别为55.0%(22/40)和70.0%(28/40);进展期腺瘤组中为48.0%(12/25)和64.0%(16/25);正常对照组中为6.7%(2/30)和0(0/30)。在病例组中两基因联合检测的敏感性为83.1%(54/65),明显高于vimentin的52.3%(34/65)和SFRP2的67.7%(44/65),更要高于FOBT的27.7%(18/65)(均P0.05)。而在正常对照组中两基因联合检测的特异性为93.3%(28/30),与vimentin的93.3%(28/30)和SFRP2的100%(30/30)以及FOBT的96.7%(29/30)相比均无明显差异(均P0.05)。结论在大肠癌筛查中,联合检测粪便中vimentin和SFRP2基因甲基化状态明显优于单个基因和粪便潜血试验,具有潜在的应用价值。     

Irreversible electroporation for the management of pancreatic cancer: Current data and future directions

Pancreatic cancer is currently the seventh leading cause of cancer death(4.5% of all cancer deaths) while 80%-90% of the patients suffer from unresectable disease at the time of diagnosis.Prognosis remains poor,with a mean survival up to 15 mo following systemic chemotherapy.Loco-regional thermal ablative techniques are rarely implemented due to the increased risk of thermal injury to the adjacent structures,which can lead to severe adverse events.Irreversible electroporation,a promising novel n...     

Neoadjuvant therapy for pancreas cancer: Past lessons and future therapies

Pancreatic adenocarcinoma remains a most deadly malignancy, with an overall 5-year survival of 5%. A subset of patients will be diagnosed with potentially resectable disease, and while complete surgical resection provides the only chance at cure, data from trials of postoperative chemoradiation and/or chemotherapy demonstrate a modest survival advantage over those patients who undergo resection alone. As such, most practitioners believe that completion of multimodality therapy is the optimal treatment. However, the sequence of surgery, chemotherapy and radiation therapy is frequently debated, as patients may benefit from a neoadjuvant approach by initiating chemotherapy and/or chemoradiation prior to resection. Here we review the rationale for neoadjuvant therapy, which includes a higher rate of completion of multimodality therapy, minimizing the risk of unnecessary surgical resection for patients who develop early metastatic disease, improved surgical outcomes and the potential for longer overall survival. However, there are no prospective, randomized studies of the neoadjuvant approach compared to a surgery-first strategy; the established and ongoing investigations of neoadjuvant therapy for pancreatic cancer are discussed in detail. Lastly, as the future of therapeutic regimens is likely to entail patient-specific genetic and molecular analyses, and the treatment that is best applied based on those data, a review of clinically relevant biomarkers in pancreatic cancer is also presented.