Prospective, Multi-Institutional, Real-Time Next-Generation Sequencing of Pancreatic Cyst Fluid Reveals Diverse Genomic Alterations That Improve the Clinical Management of Pancreatic Cysts.

BACKGROUND & AIMS: Next-generation sequencing (NGS) of pancreatic cyst fluid is a useful adjunct in the assessment of patients with pancreatic cyst. However, previous studies have been retrospective or single institutional experiences. The aim of this study was to prospectively evaluate NGS on a multi-institutional cohort of patients with pancreatic cyst in real time. METHODS: The performance of a 22-gene NGS panel (PancreaSeq) was first retrospectively confirmed and then within a 2-year timeframe, PancreaSeq testing was prospectively used to evaluate endoscopic ultrasound-guided fine-needle aspiration pancreatic cyst fluid from 31 institutions. PancreaSeq results were correlated with endoscopic ultrasound findings, ancillary studies, current pancreatic cyst guidelines, follow-up, and expanded testing (Oncomine) of postoperative specimens. RESULTS: Among 1933 PCs prospectively tested, 1887 (98%) specimens from 1832 patients were satisfactory for PancreaSeq testing. Follow-up was available for 1216 (66%) patients (median, 23 months). Based on 251 (21%) patients with surgical pathology, mitogen-activated protein kinase/GNAS mutations had 90% sensitivity and 100% specificity for a mucinous cyst (positive predictive value [PPV], 100%; negative predictive value [NPV], 77%). On exclusion of low-level variants, the combination of mitogen-activated protein kinase/GNAS and TP53/SMAD4/CTNNB1/mammalian target of rapamycin alterations had 88% sensitivity and 98% specificity for advanced neoplasia (PPV, 97%; NPV, 93%). Inclusion of cytopathologic evaluation to PancreaSeq testing improved the sensitivity to 93% and maintained a high specificity of 95% (PPV, 92%; NPV, 95%). In comparison, other modalities and current pancreatic cyst guidelines, such as the American Gastroenterology Association and International Association of Pancreatology/Fukuoka guidelines, show inferior diagnostic performance. The sensitivities and specificities of VHL and MEN1/loss of heterozygosity alterations were 71% and 100% for serous cystadenomas (PPV, 100%; NPV, 98%), and 68% and 98% for pancreatic neuroendocrine tumors (PPV, 85%; NPV, 95%), respectively. On follow-up, serous cystadenomas with TP53/TERT mutations exhibited interval growth, whereas pancreatic neuroendocrine tumors with loss of heterozygosity of ≥3 genes tended to have distant metastasis. None of the 965 patients who did not undergo surgery developed malignancy. Postoperative Oncomine testing identified mucinous cysts with BRAF fusions and ERBB2 amplification, and advanced neoplasia with CDKN2A alterations. CONCLUSIONS: PancreaSeq was not only sensitive and specific for various pancreatic cyst types and advanced neoplasia arising from mucinous cysts, but also reveals the diversity of genomic alterations seen in pancreatic cysts and their clinical significance.

Cost-utility advantage of interventional endoscopy.

BACKGROUND: Gastroenterologists frequently face the dilemma of how to choose among different management options. AIM: To develop a tool of medical decision analysis that helps choosing between competing management options of interventional endoscopy and surgery. METHODS: Carcinoma-in-situ of the esophagus, large colonic polyps, and ampullary adenoma serve as three examples for disorders being managed by both techniques. A threshold analysis using a decision tree was modeled to compare the costs and utility values associated with managing the three examples. If the expected healing or success rate of interventional endoscopy exceeds a threshold calculated as the ratio of endoscopy costs over surgery costs, endoscopy becomes the preferred management option. A low threshold speaks in favor of endoscopic intervention as initial management strategy. RESULTS: If the decision in favor of surgery is focused exclusively on preventing death from a given disease, surgical intervention may seem to provide the best treatment option. However, interventional endoscopy becomes a viable alternative, if the comparison is based on a broader perspective that includes adverse events and long-term disability, as well as the healthcare costs of both procedures. For carcinoma-in-situ of the esophagus, the threshold for the expected success rate is 24% (range in the sensitivity analysis: 7-29%); for large colonic polyps it is 10% (5-12%), and for duodenal papillary adenoma it is 17% (5-21%). CONCLUSIONS: Even if a management strategy surpasses its alternative with respect to one important outcome parameter, there is often still room for the lesser alternative to be considered as viable option.

RNA sequencing distinguishes benign from malignant pancreatic lesions sampled by EUS-guided FNA.

BACKGROUND AND AIMS: EUS-guided FNA (EUS-FNA) is the primary method used to obtain pancreatic tissue for preoperative diagnosis. Accumulating evidence suggests diagnostic and prognostic information may be obtained by gene-expression profiling of these biopsy specimens. RNA sequencing (RNAseq) is a newer method of gene-expression profiling, but published data are scant on the use of this method on pancreas tissue obtained via EUS-FNA. The aim of this study was to determine whether RNAseq of EUS-FNA biopsy samples of undiagnosed pancreatic masses can reliably discriminate between benign and malignant tissue. METHODS: In this prospective study, consenting adults presented to 2 tertiary care hospitals for EUS of suspected pancreatic mass. Tissue was submitted for RNAseq. The results were compared with cytologic diagnosis, surgical pathology diagnosis, or benign clinical follow-up of at least 1 year. RESULTS: Forty-eight patients with solid pancreatic mass lesions were enrolled. Nine samples were excluded because of inadequate RNA and 3 because of final pathologic diagnosis of neuroendocrine tumor. Data from the first 13 patients were used to construct a linear classifier, and this was tested on the final 23 patients (15 malignant and 8 benign lesions). RNAseq of EUS-FNA biopsy samples distinguishes ductal adenocarcinoma from benign pancreatic solid masses with a sensitivity of .87 (range, .58-.98) and specificity of .75 (range, .35-.96). CONCLUSIONS: This proof-of-principle study suggests RNAseq of EUS-FNA samples can reliably detect adenocarcinoma and may provide a new method to evaluate more diagnostically challenging pancreatic lesions.

Management of Suspected Choledocholithiasis: A Decision Analysis for Choosing the Optimal Imaging Modality.

BACKGROUND AND AIMS: Magnetic resonance cholangiography (MRC), endoscopic ultrasound (EUS), and endoscopic retrograde cholangio-pancreatography (ERCP) all represent viable options to establish the diagnosis of choledocholithiasis. The aim of the study was to assess how the three imaging modalities perform in head-to-head comparisons and in what order to apply them when using these procedures sequentially. METHODS: A threshold analysis using a decision tree was modeled to compare the costs associated with different imaging techniques of the biliary system in a patient with suspected cholestasis secondary to choledocholithiasis. The main outcome parameter was the pre-test probability of common bile duct (CBD) stones that would guide the physician towards starting the work-up with MRC or EUS versus going straight to ERCP as the primary procedure. RESULTS: For low pre-test probabilities of CBD stones in the common bile duct, MRC represents the procedure of choice. For pre-test probabilities ranging between 40 and 91 %, EUS should be the preferred imaging modality. If CBD stones are suspected with an even higher pre-test probability, patients could go straight to ERCP as their first procedure. Low costs associated with any of the three procedures increase its range of applicability at the expense of the other competing imaging modalities. CONCLUSIONS: MRC, EUS, and ERCP should be used in sequence and dependent on the pre-test probability of choledocholithiasis.

Small-bowel endoscopy core curriculum.

This is one of a series of documents prepared by the ASGE Training Committee. This curriculum document contains recommendations for training, intended for use by endoscopy training directors, endoscopists involved in teaching endoscopy, and trainees in endoscopy. It was developed as an overview of techniques currently favored for the performance and training of small-bowel endoscopy and to serve as a guide to published references, videotapes, and other resources available to the trainer. By providing information to endoscopy trainers about the common practices used by experts in performing the technical aspects of the procedure, the ASGE hopes to improve the teaching and performance of small-bowel endoscopy.

A multicenter, U.S. experience of single-balloon, double-balloon, and rotational overtube-assisted enteroscopy ERCP in patients with surgically altered pancreaticobiliary anatomy (with video).

BACKGROUND: Data on overtube-assisted enteroscopy to facilitate ERCP in patients with surgically altered pancreaticobiliary anatomy, or long-limb surgical bypass, is limited. OBJECTIVE: To evaluate and compare ERCP success by using single-balloon (SBE), double-balloon (DBE), or rotational overtube enteroscopy. DESIGN: Consecutive patients identified retrospectively. SETTING: Eight U.S. referral centers. PATIENTS: Long-limb surgical bypass patients with suspected pancreaticobiliary diseases. INTERVENTION: Overtube-assisted enteroscopy ERCP. MAIN OUTCOME MEASUREMENTS: Enteroscopy success: visualizing the pancreaticobiliary-enteric anastomosis or papilla. ERCP success: completing the intended pancreaticobiliary intervention. Clinical success: greater than 50% reduction in abdominal pain or level of hepatic enzyme elevations or resolution of jaundice. RESULTS: From January 2008 through October 2009, 129 patients had 180 enteroscopy-ERCPs. Anatomy was Roux-en-Y: gastric bypass (n = 63), hepaticojejunostomy (n = 45), postgastrectomy (n = 6), Whipple procedure (n = 10), and other (n = 5). ERCP success was 81 of 129 (63%). Enteroscopy success: 92 of 129 (71%), of whom 81 of 92 (88%) achieved ERCP success. Reasons for ERCP failure (n = 48): afferent limb entered but pancreaticobiliary anastomosis and/or papilla not reached (n = 23), cannulation failure (n = 11), afferent limb angulation (n = 8), and jejunojejunostomy not identified (n = 6). Select interventions: anastomotic stricturoplasty (cautery ± dilation, n = 16), stone removal (n = 21), stent (n = 25), and direct cholangioscopy (n = 11). ERCP success rates were similar between Roux-en-Y gastric bypass and other long-limb surgical bypass and among SBE, DBE, and rotational overtube enteroscopy. Complications were 16 of 129, 12.4%. LIMITATIONS: Retrospective study. CONCLUSION: (1) ERCP is successful in nearly two-thirds of long-limb surgical bypass patients and in 88% when the papilla or pancreaticobiliary-enteric anastomosis is reached. (2) Enteroscopy success in long-limb surgical bypass is similar among SBE, DBE, and rotational overtube enteroscopy methods. (3) Referral of long-limb surgical bypass patients who require ERCP to high-volume institutions may be considered before more invasive percutaneous or surgical alternatives.

Understanding Post-Esophagectomy Complications and Their Management: The Early Complications.

Esophagectomy is a technically complex operation performed for both benign and malignant esophageal disease. Medical and surgical advancements have led to improved outcomes in esophagectomy patients over the past several decades; however, surgeons must remain vigilant as complications happen often and can be severe. Post-esophagectomy complications can be grouped into early and late categories. The aim of this review is to discuss the early complications of esophagectomy along with their risk factors, work-up, and management strategies with special attention given to anastomotic leaks.

Intraprocedural tissue diagnosis during ERCP employing a new cytology preparation of forceps biopsy (Smash protocol).

OBJECTIVES: Techniques of tissue sampling at endoscopic retrograde cholangiopancreatography (ERCP) have been underutilized due to technical demands, low yield, and lack of immediate intraprocedural diagnosis. The objective of this study was to describe a new inexpensive, highly efficient ERCP tissue processing, and interpretation technique to address these issues. METHODS: A retrospective, institutional review board approved, single-center study was done at a tertiary-care medical center. Between June 2004 and February 2009, 133 patients (age 38-95 years; men 53%) with suspicious biliary strictures underwent ERCP with tissue sampling using a new technique. Small forceps biopsy specimens were forcefully smashed between two dry glass slides, immediately fixed, stained with rapid Papanicolaou, and interpreted by an on-site pathologist during the procedure (Smash protocol). RESULTS: Of the 117 proven to have cancer, true-positive Smash preps included pancreatic cancer 49/66 (74%), cholangiocarcinoma 23/29 (79%), metastatic cancer 8/15 (53%), and other 4/7 (57%). The median number of Smash biopsies to diagnosis was 3 (range 1-17). Suspicious or atypical results were considered to be negative in this study. There were no false positives and no complications. Smash had an overall sensitivity of 89/117 (76%) for all cases. The true-positive yield of immediate Smash prep cytology, combined with ERCP fine needle aspirate (FNA) and forceps biopsy histology was 77/95 (81%) for primary pancreaticobiliary cancers. CONCLUSIONS: Immediate cytopathologic diagnosis at ERCP was established in 72% of patients presenting with suspected malignant biliary obstruction using a new cytological preparation of forceps biopsies. This approach to ERCP tissue sampling permits immediate diagnosis and avoids the need for subsequent procedures, adds little cost and time, and is safe to perform.

Failure of cost-benefit analysis in gastrointestinal endoscopy.

Background and study aims We discuss the occurrence of two cases, where the endoscopic pursuit of diagnostic certainty resulted in adverse events that exceeded the clinical relevance of the endoscopic diagnosis itself. In both instances, physicians were hesitant to subject their patients to a necessary surgical intervention before gastrointestinal endoscopy had provided them with absolute assurance that no other mitigating factors could possibly jeopardize the success of a planned intervention. In trying to avoid a single and potentially bad outcome of a necessary medical intervention, the physicians exposed their patients to many more additional and unnecessary risks. As key players in clinical decision-making, physicians sometimes may find it difficult to disentangle their own risk-benefit considerations from those of their patients.

Viral and host factors induce macrophage activation and loss of toll-like receptor tolerance in chronic HCV infection.

BACKGROUND & AIMS: Persistent inflammation contributes to progression of liver damage in chronic HCV (cHCV) infection. Repeated exposure to toll-like receptor (TLR) ligands results in tolerance, a protective mechanism aimed at limiting inflammation. METHODS: Monocytes/macrophages were repeatedly stimulated via proinflammatory cytokine-inducing TLRs and evaluated for activation markers. RESULTS: Unlike monocytes of controls or patients with nonalcoholic steatohepatitis, the monocytes of cHCV patients were hyperresponsive and failed to show homo- or heterotolerance to TLR ligands, manifested by elevated tumor necrosis factor (TNF)-alpha production. Serum levels of interferon (IFN)-gamma, endotoxin (TLR4 ligand), and HCV core protein (TLR2 ligand) were elevated in cHCV patients suggesting potential mechanisms for in vivo monocyte preactivation. Treatment of normal monocytes with IFN-gamma resulted in loss of tolerance to lipopolysaccharide (LPS) or HCV core protein. Furthermore, we found increased levels of MyD88-IRAK1 complexes and nuclear factor (NF)-kappaB activity both in monocytes of cHCV patients and in normal monocytes that lost TLR tolerance after IFN-gamma + LPS pretreatment. In vitro differentiation of TLR non-tolerant cHCV monocytes into macrophages restored their capacity to exhibit TLR tolerance to LPS and HCV core protein, and this could be reversed by administration of IFN-gamma. cHCV patients exhibited increased TNF-alpha in the circulation and in the liver. In cHCV livers, we found Kupffer cell/macrophage activation indicated by increased CD163 and CD33 expression. CONCLUSIONS: We identified that host-derived factors (IFN-gamma and endotoxin) and viral factors (HCV core protein) act in tandem to induce and maintain monocyte/macrophage activation, thus favoring persistent inflammation in patients with cHCV infection.

Hepatitis C virus (HCV) core protein-induced, monocyte-mediated mechanisms of reduced IFN-alpha and plasmacytoid dendritic cell loss in chronic HCV infection.

IFN-alpha production by plasmacytoid dendritic cells (PDCs) is critical in antiviral immunity. In the present study, we evaluated the IFN-alpha-producing capacity of PDCs of patients with chronic hepatitis C virus (HCV) infection in treatment-naive, sustained responder, and nonresponder patients. IFN-alpha production was tested in PBMCs or isolated PDCs after TLR9 stimulation. Treatment-naive patients with chronic HCV infection had reduced frequency of circulating PDCs due to increased apoptosis and showed diminished IFN-alpha production after stimulation with TLR9 ligands. These PDC defects correlated with the presence of HCV and were in contrast with normal PDC functions of sustained responders. HCV core protein, which was detectable in the plasma of infected patients, reduced TLR9-triggered IFN-alpha and increased TNF-alpha and IL-10 production in PBMCs but not in isolated PDCs, suggesting HCV core induced PDC defects. Indeed, addition of rTNF-alpha and IL-10 induced apoptosis and inhibited IFN-alpha production in PDCs. Neutralization of TNF-alpha and/or IL-10 prevented HCV core-induced inhibition of IFN-alpha production. We identified CD14+ monocytes as the source of TNF-alpha and IL-10 in the HCV core-induced inhibition of PDC IFN-alpha production. Anti-TLR2-, not anti-TLR4-, blocking Ab prevented the HCV core-induced inhibition of IFN-alpha production. In conclusion, our results suggest that HCV interferes with antiviral immunity through TLR2-mediated monocyte activation triggered by the HCV core protein to induce cytokines that in turn lead to PDC apoptosis and inhibit IFN-alpha production. These mechanisms are likely to contribute to HCV viral escape from immune responses.