KRT17High/CXCL8+ tumor cells display both classical and basal features and regulate myeloid infiltration in the pancreatic cancer microenvironment.

PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) is generally divided in two subtypes, classical and basal. Recently, single cell RNA sequencing has uncovered the co-existence of basal and classical cancer cells, as well as intermediary cancer cells, in individual tumors. The latter remains poorly understood; here, we sought to characterize them using a multimodal approach. EXPERIMENTAL DESIGN: We performed subtyping on a single cell RNA sequencing dataset containing 18 human PDAC samples to identify multiple intermediary subtypes. We generated patient-derived PDAC organoids for functional studies. We compared single cell profiling of matched blood and tumor samples to measure changes in the local and systemic immune microenvironment. We then leveraged longitudinally patient-matched blood to follow individual patients over the course of chemotherapy. RESULTS: We identified a cluster of KRT17-high intermediary cancer cells that uniquely express high levels of CXCL8 and other cytokines. The proportion of KRT17High/CXCL8+ cells in patient tumors correlated with intra-tumoral myeloid abundance, and, interestingly, high pro-tumor peripheral blood granulocytes, implicating local and systemic roles. Patient-derived organoids maintained KRT17High/CXCL8+cells and induced myeloid cell migration in an CXCL8-dependent manner. In our longitudinal studies, plasma CXCL8 decreased following chemotherapy in responsive patients, while CXCL8 persistence portended worse prognosis. CONCLUSIONS: Through single cell analysis of PDAC samples we identified KRT17High/CXCL8+ cancer cells as an intermediary subtype, marked by a unique cytokine profile and capable of influencing myeloid cells in the tumor microenvironment and systemically. The abundance of this cell population should be considered for patient stratification in precision immunotherapy.

EUS-Guided hepaticogastrostomy in a pregnant patient with Roux-en-Y hepaticojejunostomy anatomy.

Video 1EUS-Guided hepaticogastrostomy in a pregnant patient with Roux-en-Y hepaticojejunostomy anatomy.

Detection of Barrett's neoplasia with a near-infrared fluorescent heterodimeric peptide.

BACKGROUND: Esophageal adenocarcinoma (EAC) is a molecularly heterogeneous disease with poor prognosis that is rising rapidly in incidence. We aimed to demonstrate specific binding by a peptide heterodimer to Barrett's neoplasia in human subjects. METHODS: Peptide monomers specific for EGFR and ErbB2 were arranged in a heterodimer configuration and labeled with IRDye800. This near-infrared (NIR) contrast agent was topically administered to patients with Barrett's esophagus (BE) undergoing either endoscopic therapy or surveillance. Fluorescence images were collected using a flexible fiber accessory passed through the instrument channel of an upper gastrointestinal endoscope. Fluorescence images were collected from 31 BE patients. A deep learning model was used to segment the target (T) and background (B) regions. RESULTS: The mean target-to-background (T/B) ratio was significantly greater for high grade dysplasia (HGD) and EAC versus BE, low grade dysplasia (LGD), and squamous epithelium. At a T/B ratio of 1.5, sensitivity and specificity of 94.1 % and 92.6 %, respectively, were achieved for the detection of Barrett's neoplasia with an area under the curve of 0.95. No adverse events attributed to the heterodimer were found. EGFR and ErbB2 expression were validated in the resected specimens. CONCLUSIONS: This "first-in-human" clinical study demonstrates the feasibility of detection of early Barrett's neoplasia using a NIR-labeled peptide heterodimer.

Simulation Training Improves Trainee Technical Skill and Procedural Attitudes in Endoscopic Gastrostomy Tube Placement.

INTRODUCTION: Percutaneous endoscopic gastrostomy (PEG) tube placement remains a core competency of gastroenterology fellowship, although this procedure is performed infrequently. Some training programs lack sufficient procedural volume for trainees to develop confidence and competence in this procedure. We aimed to determine the impact of a simulation-based educational intervention on trainee technical skill and procedural attitudes in simulated PEG tube placement. METHODS: Gastroenterology fellows were invited to participate in the study. Baseline procedural attitudes toward PEG tube placement (self-confidence, perceived skill level, perceived level of required supervision) were assessed before simulation training using a Likert scale. Baseline technical skills were assessed by video recording-simulated PEG tube placement on a PEG tube simulator with scoring using a procedural checklist. Fellows next underwent individualized simulation training and repeated simulated PEG tube placement until greater than 90% of checklist items were achieved. Procedural attitudes were reassessed directly after the simulation. Technical skill and procedural attitudes were then reassessed 6 to 12 weeks later (delayed posttraining). RESULTS: Twelve fellows completed the study. Simulation training led to significant improvement in technical skill at delayed reassessment (52.9 ± 14.3% vs. 78.0 ± 8.9% correct, P = 0.0002). Simulation training also led to significant immediate improvements in self-confidence (2.1 ± 0.7 vs. 3.1 ± 0.3, P = 0.001), perceived skill level (2.2 ± 1.0 vs. 4 ± 1.1, P < 0.001), and perceived level of required supervision (2.2 ± 0.9 vs. 3.2 ± 0.6, P = 0.003). CONCLUSIONS: Simulation training led to sustained improvements in gastroenterology fellows' technical skill and procedural attitudes in PEG tube placement. Incorporation of simulation curricula in gastroenterology fellowships for this infrequently performed procedure should be considered.

Long-Term Quality of Life Following Endoscopic Therapy Compared to Esophagectomy for Neoplastic Barrett's Esophagus.

INTRODUCTION: Endoscopic therapy (ET) and esophagectomy result in similar survival for Barrett's esophagus (BE) with high-grade dysplasia (HGD) or T1a esophageal adenocarcinoma (EAC), but the long-term quality of life (QOL) has not been compared. AIMS: We aimed to compare long-term QOL between patients who had undergone ET versus esophagectomy. METHODS: Patients were included if they underwent ET or esophagectomy at the University of Michigan since 2000 for the treatment of HGD or T1a EAC. Two validated survey QOL questionnaires were mailed to the patients. We compared QOL between and within groups (ET = 91, esophagectomy = 62), adjusting for covariates. RESULTS: The median time since initial intervention was 6.8 years. Compared to esophagectomy, ET patients tended to be older, had a lower prevalence of EAC, and had a shorter duration since therapy. ET patients had worse adjusted physical and role functioning than esophagectomy patients. However, the adjusted odds ratio (OR) of having symptoms was significantly less with ET for diarrhea (0.287; 95% confidence interval [CI] = 0.114, 0.724), trouble eating (0.207; 0.0766, 0.562), choking (0.325; 0.119, 0.888), coughing (0.291; 0.114, 0.746), and speech difficulty (0.306; 0.0959, 0.978). Amongst the ET patients, we found that the number of therapy sessions and need for dilation were associated with worse outcomes. DISCUSSION: Multiple measures of symptom status were better with ET compared to esophagectomy following treatment of BE with HGD or T1a EAC. We observed worse long-term physical and role functioning in ET patients which could reflect unmeasured baseline functional status rather than a causal effect of ET.

Multimodal Mapping of the Tumor and Peripheral Blood Immune Landscape in Human Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDA) is characterized by an immune-suppressive tumor microenvironment that renders it largely refractory to immunotherapy. We implemented a multimodal analysis approach to elucidate the immune landscape in PDA. Using a combination of CyTOF, single-cell RNA sequencing, and multiplex immunohistochemistry on patient tumors, matched blood, and non-malignant samples, we uncovered a complex network of immune-suppressive cellular interactions. These experiments revealed heterogeneous expression of immune checkpoint receptors in individual patient's T cells and increased markers of CD8+ T cell dysfunction in advanced disease stage. Tumor-infiltrating CD8+ T cells had an increased proportion of cells expressing an exhausted expression profile that included upregulation of the immune checkpoint TIGIT, a finding that we validated at the protein level. Our findings point to a profound alteration of the immune landscape of tumors, and to patient-specific immune changes that should be taken into account as combination immunotherapy becomes available for pancreatic cancer.

Preoperative predictors of choledocholithiasis in patients presenting with acute calculous cholecystitis.

BACKGROUND AND AIMS: Markedly increased liver chemistries in patients presenting with acute calculous cholecystitis (AC) often prompt an evaluation for concomitant choledocholithiasis (CDL). However, current guidelines directing the workup for CDL fail to address this unique population. The aims of this study are to define the range of presenting laboratory values and imaging findings in AC, develop a model to predict the presence of concurrent CDL, and develop a management algorithm that can be easily applied on presentation. METHODS: We conducted a retrospective review of patients presenting with AC to a large tertiary hospital over a 3.5-year period. CDL was defined as common bile duct (CBD) stone(s), sludge, or debris seen on any of the following studies: US, CT, magnetic resonance imaging/MRCP, EUS, ERCP, or intraoperative cholangiogram. A multivariable model to predict CDL was developed on 70% of the patients and validated on the remaining 30%. RESULTS: A total of 366 patients were identified and 65 (17.8%) had concurrent CDL. Univariable analysis was used to predict CDL and demonstrated statistically significant odds ratios for transaminases >3 times the upper limit of normal, alkaline phosphatase (AlkPhos) above normal, lipase >3 times the upper limit of normal, total bilirubin ≥1.8 mg/dL, and CBD diameter >6 mm. In the validation cohort, an optimal model containing alanine transaminase (ALT) >3 times the upper limit of normal, abnormal AlkPhos, and CBD diameter >6 mm was found to have an area under the receiver operating curve of 0.91. When 0 or 1 risk factors were present, 98.6% of patients did not have CDL. When all 3 risk factors were present, 77.8% were found to have CDL. CONCLUSIONS: The prevalence of CDL is high among patients with AC. When a validated model is used, application of cutoffs for ALT, AlkPhos, and CBD diameter can effectively triage patients with low and high likelihood for CDL to surgery or ERCP, respectively.

Safety and rate of delayed adverse events with lumen-apposing metal stents (LAMS) for pancreatic fluid collections: a multicenter study.

Background and study aims Endoscopic drainage with dedicated lumen-apposing metal stents (LAMS) is routinely performed for symptomatic pancreatic fluid collections (PFCs), walled-off necrosis (WON) and pseudocyst (PP). There has been increasing concern regarding delayed adverse events associated with the indwelling LAMS.  Patients and methods Multicenter retrospective analysis of consecutive patients who underwent endoscopic ultrasound (EUS)-guided LAMS placement for PFC from January 2010 to May 2017. Main outcomes included: (1) resolution of the PFC, (2) rate of delayed adverse events at follow-up, and (3) predictors of treatment failure and delayed adverse events on logistic regression. Results A total of 122 patients (mean age 50.9 years, 68 % male) underwent LAMS insertion for 64 WON (98.4 %) and 58 PP (98.3 %). PFC mean size was 10.6 cm. PFC resolution was significantly lower for WON (62.3 %) vs. PP (96.5 %) ( P  < 0.001) on imaging at a median of 4 weeks. Stent occlusion was identified in 18 (29.5 %) and 10 (17.5 %) patients with WON and PP, respectively ( P  = 0.13). There were no cases of delayed bleeding or buried stent on follow-up endoscopy. Use of electrocautery-enhanced LAMS was the only factor associated with treatment failure of WON (OR = 13.2; 95 % ci: 3.33 - 51.82, P  = 0.02) on logistic regression. There were no patient, operator, or procedure-related factors predictive of stent occlusion. Conclusions EUS-guided LAMS for PFC is associated with a low incidence of delayed adverse events. While nearly all PPs resolve at 4 weeks permitting LAMS removal shortly thereafter, many WON persist, with use of electrocautery-enhanced LAMS being the sole predictor of treatment failure.

Stent migration following endoscopic suture fixation of esophageal self-expandable metal stents: a systematic review and meta-analysis.

BACKGROUND: Covered self-expandable metal stents (SEMS) are utilized for the management of benign and malignant esophageal conditions; however, covered SEMS are prone to migration. Endoscopic suture fixation may mitigate the migration risk of covered esophageal SEMS. Hence, we conducted a systematic review and meta-analysis to evaluate the effectiveness and safety of endoscopic suture fixation for covered esophageal SEMS. METHODS: Following PRISMA guidelines, we performed a systematic review from 2011 to 2016 to identify studies (case control/case series) reporting the technical success and migration rate of covered esophageal SEMS following endoscopic suture fixation. We searched multiple electronic databases and conference proceedings. We calculated pooled rates (and 95% confidence intervals [CI]) of technical success and stent migration using a random effects model. RESULTS: We identified 14 studies (212 patients) describing covered esophageal SEMS placement with endoscopic suture fixation. When reported, SEMS indications included leak/fistula (n = 75), stricture (n = 65), perforation (n = 10), and achalasia (n = 4). The pooled technical success rate was 96.7% (95% CI 92.3-98.6), without heterogeneity (I 2 = 0%). We identified 29 SEMS migrations at rate of 15.9% (95% CI 11.4-21.6), without heterogeneity (I 2 = 0%). Publication bias was observed, and using the trim-and-fill method, a more conservative estimate for stent migration was 17.0%. Suture-related adverse events were estimated to occur in 3.7% (95% CI 1.6-8.2) of cases. CONCLUSIONS: Endoscopic suture fixation of covered esophageal SEMS appears to reduce stent migration when compared to published rates of non-anchored SEMS. However, SEMS migration still occurs in approximately 1 out of 6 cases despite excellent immediate technical success and low risk of suture-related adverse events.

Specialist Endoscopists Are Associated with a Decreased Risk of Incomplete Polyp Resection During Endoscopic Mucosal Resection in the Colon.

BACKGROUND: Endoscopic experience is known to correlate with outcomes of endoscopic mucosal resection (EMR), particularly complete resection of the polyp tissue. Whether specialist endoscopists can protect against incomplete polypectomy in the setting of known risk factors for incomplete resection (IR) is unknown. AIMS: We aimed to characterize how specialist endoscopists may help to mitigate the risk of IR of large sessile polyps. METHODS: This is a retrospective cohort study of patients who underwent EMR at the University of Michigan from January 1, 2006, to November 15, 2015. The primary outcome was endoscopist-reported polyp tissue remaining at the end of the initial EMR attempt. Specialist endoscopists were defined as endoscopists who receive tertiary referrals for difficult colonoscopy cases and completed at least 20 EMR colonic polyp resections over the study period. RESULTS: A total of 257 patients with 269 polyps were included in the study. IR occurred in 40 (16%) cases. IR was associated with polyp size ≥ 40 mm [adjusted odds ratio (aOR) 3.31, 95% confidence interval (CI) 1.38-7.93], flat/laterally spreading polyps (aOR 2.61, 95% CI 1.24-5.48), and difficulty lifting the polyp (aOR 11.0, 95% CI 2.66-45.3). A specialist endoscopist performing the initial EMR was protective against IR, even in the setting of risk factors for IR (aOR 0.13, 95% CI 0.04-0.41). CONCLUSIONS: IR is associated with polyp size ≥ 40 mm, flat and/or laterally spreading polyps, and difficulty lifting the polyp. A specialist endoscopist initiating the EMR was protective of IR.

Autoimmune Pancreatitis Diagnosed with Core Biopsy Obtained from a Novel Fork-Tip EUS Needle.

The endoscopic diagnosis of autoimmune pancreatitis from histologic criteria remains challenging as it requires adequate architectural details rather than cytology alone. A 67-year-old man presented with progressive abdominal pain and weight loss. Cross-sectional imaging showed inflammatory changes of the pancreatic body and tail and periaortitis on abdominal computed tomography, but normal serum immunoglobulin G4. A mass-like lesion of the pancreatic body and tail was identified on endoscopic ultrasonography. A histologic diagnosis of autoimmune pancreatitis was accomplished through needle biopsy using a novel fork-tip needle.

Clinical outcomes of EUS-guided drainage of debris-containing pancreatic pseudocysts: a large multicenter study.

Background and study aims Data on clinical outcomes of endoscopic drainage of debris-free pseudocysts (PDF) versus pseudocysts containing solid debris (PSD) are very limited. The aims of this study were to compare treatment outcomes between patients with PDF vs. PSD undergoing endoscopic ultrasound (EUS)-guided drainage via transmural stents. Patients and methods Retrospective review of 142 consecutive patients with pseudocysts who underwent EUS-guided transmural drainage (TM) from 2008 to 2014 at 15 academic centers in the United States. Main outcome measures included TM technical success, treatment outcomes (symptomatic and radiologic resolution), need for endoscopic re-intervention at follow-up, and adverse events (AEs). Results TM was performed in 90 patients with PDF and 52 with PSD. Technical success: PDF 87 (96.7 %) vs. PSD 51 (98.1 %). There was no difference in the rates for endoscopic re-intervention (5.5 % in PDF vs. 11.5 % in PSD; P = 0.33) or AEs (12.2 % in PDF vs. 19.2 % in PSD; P = 0.33). Median long-term follow-up after stent removal was 297 days (interquartile range [IQR]: 59 - 424 days) for PDF and 326 days (IQR: 180 - 448 days) for PSD (P = 0.88). There was a higher rate of short-term radiologic resolution of PDF (45; 66.2 %) vs. PSD (21; 51.2 %) (OR = 0.30; 95 % CI: 0.13 - 0.72; P = 0.009). There was no difference in long-term symptomatic resolution (PDF: 70.4 % vs. PSD: 66.7 %; P = 0.72) or radiologic resolution (PDF: 68.9 % vs. PSD: 78.6 %; P = 0.72) Conclusions There was no difference in need for endoscopic re-intervention, AEs or long-term treatment outcomes in patients with PDF vs. PSD undergoing EUS-guided drainage with transmural stents. Based on these results, the presence of solid debris in pancreatic fluid collections does not appear to be associated with a poorer outcome.

Detection of Sessile Serrated Adenomas in the Proximal Colon Using Wide-Field Fluorescence Endoscopy.

BACKGROUND & AIMS: Many cancers in the proximal colon develop via from sessile serrated adenomas (SSAs), which have flat, subtle features that are difficult to detect with conventional white-light colonoscopy. Many SSA cells have the V600E mutation in BRAF. We investigated whether this feature could be used with imaging methods to detect SSAs in patients. METHODS: We used phage display to identify a peptide that binds specifically to SSAs, using subtractive hybridization with HT29 colorectal cancer cells containing the V600E mutation in BRAF and Hs738.St/Int cells as a control. Binding of fluorescently labeled peptide to colorectal cancer cells was evaluated with confocal fluorescence microscopy. Rats received intra-colonic 0.0086 mg/kg, 0.026 mg/kg, or 0.86 mg/kg peptide or vehicle and morbidity, mortality, and injury were monitored twice daily to assess toxicity. In the clinical safety study, fluorescently labeled peptide was topically administered, using a spray catheter, to the proximal colon of 25 subjects undergoing routine outpatient colonoscopies (3 subjects were given 2.25 µmol/L and 22 patients were given 76.4 µmol/L). We performed blood cell count, chemistry, liver function, and urine analyses approximately 24 hours after peptide administration. In the clinical imaging study, 38 subjects undergoing routine outpatient colonoscopies, at high risk for colorectal cancer, or with a suspected unresected proximal colonic polyp, were first evaluated by white-light endoscopy to identify suspicious regions. The fluorescently labeled peptide (76.4 µmol/L) was administered topically to proximal colon, unbound peptide was washed away, and white-light, reflectance, and fluorescence videos were recorded digitally. Fluorescence intensities of SSAs were compared with those of normal colonic mucosa. Endoscopists resected identified lesions, which were analyzed histologically by gastrointestinal pathologists (reference standard). We also analyzed the ability of the peptide to identify SSAs vs adenomas, hyperplastic polyps, and normal colonic mucosa in specimens obtained from the tissue bank at the University of Michigan. RESULTS: We identified the peptide sequence KCCFPAQ and measured an apparent dissociation constant of Kd = 72 nM and an apparent association time constant of K = 0.174 min-1 (5.76 minutes). During fluorescence imaging of patients during endoscopy, regions of SSA had 2.43-fold higher mean fluorescence intensity than that for normal colonic mucosa. Fluorescence labeling distinguished SSAs from normal colonic mucosa with 89% sensitivity and 92% specificity. The peptide had no observed toxic effects in animals or patients. In the analysis of ex vivo specimens, peptide bound to SSAs had significantly higher mean fluorescence intensity than to hyperplastic polyps. CONCLUSIONS: We have identified a fluorescently labeled peptide that has no observed toxic effects in animals or humans and can be used for wide-field imaging of lesions in the proximal colon. It distinguishes SSAs from normal colonic mucosa with 89% sensitivity and 92% specificity. This targeted imaging method might be used in early detection of premalignant serrated lesions during routine colonoscopies. ClinicalTrials.gov ID: NCT02156557.

The Race-Specific Incidence of Esophageal Squamous Cell Carcinoma in Individuals With Exposure to Tobacco and Alcohol.

OBJECTIVES: The relative impact of esophageal squamous cell carcinoma (ESCC) in minority populations is incompletely understood. We aimed to estimate the race-specific incidences of ESCC and place these in the context of the incidence of esophageal adenocarcinoma (EAC) in white men with gastroesophageal reflux disease (GERD). METHODS: The race- and sex-specific exposures to tobacco and alcohol in the United States were obtained from the National Health Interview Survey. The standardized incidence ratios of exposure to tobacco smoke and/or alcohol for ESCC were estimated from meta-analyses. Existing incidences of ESCC in the United States were obtained from the Surveillance, Epidemiology, and End Results (SEER) program. We then used this data to inform a Markov computer model estimating the incidence of ESCC. RESULTS: The incidence of ESCC reported in SEER was the greatest among African-Americans compared with white non-Hispanics, Hispanics, or Asians. In our model, the estimated incidence of ESCC in African-American men exposed to tobacco and alcohol approached the risk of EAC in white non-Hispanic men with weekly GERD. For instance, at age 60 years, the incidence of ESCC in African-American men who have used both tobacco and alcohol was 30/100,000 compared with an incidence of EAC in white men with GERD of 40/100,000. In comparison, the risk of EAC in white non-Hispanic women with weekly GERD at this age was 6.2/100,000. CONCLUSIONS: The incidence of ESCC in African-American men who use alcohol and tobacco is the highest and comparable to other screened diseases. Development of screening and prevention programs for ESCC in high-risk populations should be considered.