Novel through-the-scope suture closure of colonic EMR defects (with video).

BACKGROUND AND AIMS: Large colon polyps removed by EMR can be complicated by delayed bleeding. Prophylactic defect clip closure can reduce post-EMR bleeding. Larger defects can be challenging to close using through-the-scope clips (TTSCs), and proximal defects are difficult to reach using over-the-scope techniques. A novel, through-the-scope suturing (TTSS) device allows direct closure of mucosal defects without scope withdrawal. The goal of this study was to evaluate the rate of delayed bleeding after the closure of large colon polyp EMR sites with TTSS. METHODS: A multicenter retrospective cohort study was performed involving 13 centers. All defect closure by TTSS after EMR of colon polyps ≥2 cm from January 2021 to February 2022 were included. The primary outcome was rate of delayed bleeding. RESULTS: A total of 94 patients (52% female; mean age, 65 years) underwent EMR of predominantly right-sided (n = 62 [66%]) colon polyps (median size, 35 mm; interquartile range, 30-40 mm) followed by defect closure with TTSS during the study period. All defects were successfully closed with TTSS alone (n = 62 [66%]) or with TTSS and TTSCs (n = 32 [34%]), using a median of 1 (interquartile range, 1-1) TTSS system. Delayed bleeding occurred in 3 patients (3.2%), with 2 requiring repeated endoscopic evaluation/treatment (moderate). CONCLUSION: TTSS alone or with TTSCs was effective in achieving complete closure of all post-EMR defects, despite a large lesion size. After TTSS closure with or without adjunctive devices, delayed bleeding was seen in 3.2% of cases. Further prospective studies are needed to validate these findings before wider adoption of TTSS for large polypectomy closure.

Effects of Blended (Yellow) vs Forced Coagulation (Blue) Currents on Adverse Events, Complete Resection, or Polyp Recurrence After Polypectomy in a Large Randomized Trial.

BACKGROUND & AIMS: There is debate over the type of electrosurgical setting that should be used for polyp resection. Some endoscopists use a type of blended current (yellow), whereas others prefer coagulation (blue). We performed a single-blinded, randomized trial to determine whether type of electrosurgical setting affects risk of adverse events or recurrence. METHODS: Patients undergoing endoscopic mucosal resection of nonpedunculated colorectal polyps 20 mm or larger (n = 928) were randomly assigned, in a 2 × 2 design, to groups that received clip closure or no clip closure of the resection defect (primary intervention) and then to either a blended current (Endocut Q) or coagulation current (forced coagulation) (Erbe Inc) (secondary intervention and focus of the study). The study was performed at multiple centers, from April 2013 through October 2017. Patients were evaluated 30 days after the procedure (n = 919), and 675 patients underwent a surveillance colonoscopy at a median of 6 months after the procedure. The primary outcome was any severe adverse event in a per patient analysis. Secondary outcomes were complete resection and recurrence at first surveillance colonoscopy in a per polyp analysis. RESULTS: Serious adverse events occurred in 7.2% of patients in the Endocut group and 7.9% of patients in the forced coagulation group, with no significant differences in the occurrence of types of events. There were no significant differences between groups in proportions of polyps that were completely removed (96% in the Endocut group vs 95% in the forced coagulation group) or the proportion of polyps found to have recurred at surveillance colonoscopy (17% and 17%, respectively). Procedural characteristics were comparable, except that 17% of patients in the Endocut group had immediate bleeding that required an intervention, compared with 11% in the forced coagulation group (P = .006). CONCLUSIONS: In a randomized trial to compare 2 commonly used electrosurgical settings for the resection of large colorectal polyps (Endocut vs forced coagulation), we found no difference in risk of serious adverse events, complete resection rate, or polyp recurrence. Electrosurgical settings can therefore be selected based on endoscopist expertise and preference. Clinicaltrials.gov ID NCT01936948.

Factors associated with complete clip closure after endoscopic mucosal resection of large colorectal polyps.

BACKGROUND AND STUDY AIM : Delayed bleeding is a common adverse event following endoscopic mucosal resection (EMR) of large colorectal polyps. Prophylactic clip closure of the mucosal defect after EMR of nonpedunculated polyps larger than 20 mm reduces the incidence of severe delayed bleeding, especially in proximal polyps. This study aimed to evaluate factors associated with complete prophylactic clip closure of the mucosal defect after EMR of large polyps. METHODS : This is a post hoc analysis of the CLIP study (NCT01936948). All patients randomized to the clip group were included. Main outcome was complete clip closure of the mucosal resection defect. The defect was considered completely closed when no remaining mucosal defect was visible and clips were less than 1 cm apart. Factors associated with complete closure were evaluated in multivariable analysis. RESULTS : In total, 458 patients (age 65, 58 % men) with 494 large polyps were included. Complete clip closure of the resection defect was achieved for 338 polyps (68.4 %); closure was not complete for 156 (31.6 %). Factors associated with complete closure in adjusted analysis were smaller polyp size (odds ratio 1.06 for every millimeter decrease [95 % confidence interval 1.02-1.08]), good access (OR 3.58 [1.94-9.59]), complete submucosal lifting (OR 2.28 [1.36-3.90]), en bloc resection (OR 5.75 [1.48-22.39]), and serrated histology (OR 2.74 [1.35-5.56]). CONCLUSIONS : Complete clip closure was not achieved for almost one in three resected large nonpedunculated polyps. While stable access and en bloc resection facilitate clip closure, most factors associated with clip closure are not modifiable. This highlights the need for alternative closure options and measures to prevent bleeding.

Clip Closure Prevents Bleeding After Endoscopic Resection of Large Colon Polyps in a Randomized Trial.

BACKGROUND & AIMS: Bleeding is the most common severe complication after endoscopic mucosal resection of large colon polyps and is associated with significant morbidity and cost. We examined whether prophylactic closure of the mucosal defect with hemoclips after polyp resection reduces the risk of bleeding. METHODS: We performed a multicenter, randomized trial of patients with a large nonpedunculated colon polyp (≥20 mm) at 18 medical centers in North America and Spain from April 2013 through October 2017. Patients were randomly assigned to groups that underwent endoscopic closure with a clip (clip group) or no closure (control group) and followed. The primary outcome, postprocedure bleeding, was defined as a severe bleeding event that required hospitalization, a blood transfusion, colonoscopy, surgery, or another invasive intervention within 30 days after completion of the colonoscopy. Subgroup analyses included postprocedure bleeding with polyp location, polyp size, or use of periprocedural antithrombotic medications. We also examined the risk of any serious adverse event. RESULTS: A total of 919 patients were randomly assigned to groups and completed follow-up. Postprocedure bleeding occurred in 3.5% of patients in the clip group and 7.1% in the control group (absolute risk difference [ARD] 3.6%; 95% confidence interval [CI] 0.7%-6.5%). Among 615 patients (66.9%) with a proximal large polyp, the risk of bleeding in the clip group was 3.3% and in the control group was 9.6% (ARD 6.3%; 95% CI 2.5%-10.1%); among patients with a distal large polyp, the risks were 4.0% in the clip group and 1.4% in the control group (ARD -2.6%; 95% CI -6.3% to -1.1%). The effect of clip closure was independent of antithrombotic medications or polyp size. Serious adverse events occurred in 4.8% of patients in the clip group and 9.5% of patients in the control group (ARD 4.6%; 95% CI 1.3%-8.0%). CONCLUSIONS: In a randomized trial, we found that endoscopic clip closure of the mucosal defect following resection of large colon polyps reduces risk of postprocedure bleeding. The protective effect appeared to be restricted to large polyps located in the proximal colon. ClinicalTrials.gov no: NCT01936948.

Effects of Medical Cannabis on Use of Opioids and Hospital Visits by Patients With Painful Chronic Pancreatitis.

Pain is the most common and most debilitating aspect of chronic pancreatitis and is difficult to treat.1-3 Clinical management of painful chronic pancreatitis includes abstinence from alcohol and tobacco products, analgesic medications (including opioids), antidepressant medications, and pancreatic enzyme replacement.4-8 Medical cannabis has been proposed as a therapy for chronic pain and has shown some efficacy in neuropathic and cancer pain. In this study, we investigated the efficacy of medical cannabis on pain control for chronic pancreatitis.

Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography, From Training Through Independent Practice.

BACKGROUND & AIMS: It is unclear whether participation in competency-based fellowship programs for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) results in high-quality care in independent practice. We measured quality indicator (QI) adherence during the first year of independent practice among physicians who completed endoscopic training with a systematic assessment of competence. METHODS: We performed a prospective multicenter cohort study of invited participants from 62 training programs. In phase 1, 24 advanced endoscopy trainees (AETs), from 20 programs, were assessed using a validated competence assessment tool. We used a comprehensive data collection and reporting system to create learning curves using cumulative sum analysis that were shared with AETs and trainers quarterly. In phase 2, participating AETs entered data into a database pertaining to every EUS and ERCP examination during their first year of independent practice, anchored by key QIs. RESULTS: By the end of training, most AETs had achieved overall technical competence (EUS 91.7%, ERCP 73.9%) and cognitive competence (EUS 91.7%, ERCP 94.1%). In phase 2 of the study, 22 AETs (91.6%) participated and completed a median of 136 EUS examinations per AET and 116 ERCP examinations per AET. Most AETs met the performance thresholds for QIs in EUS (including 94.4% diagnostic rate of adequate samples and 83.8% diagnostic yield of malignancy in pancreatic masses) and ERCP (94.9% overall cannulation rate). CONCLUSIONS: In this prospective multicenter study, we found that although competence cannot be confirmed for all AETs at the end of training, most meet QI thresholds for EUS and ERCP at the end of their first year of independent practice. This finding affirms the effectiveness of training programs. Clinicaltrials.gov ID NCT02509416.

Setting minimum standards for training in EUS and ERCP: results from a prospective multicenter study evaluating learning curves and competence among advanced endoscopy trainees.

BACKGROUND AND AIMS: Minimum EUS and ERCP volumes that should be offered per trainee in "high quality" advanced endoscopy training programs (AETPs) are not established. We aimed to define the number of procedures required by an "average" advanced endoscopy trainee (AET) to achieve competence in technical and cognitive EUS and ERCP tasks to help structure AETPs. METHODS: American Society for Gastrointestinal Endoscopy (ASGE)-recognized AETPs were invited to participate; AETs were graded on every fifth EUS and ERCP examination using a validated tool. Grading for each skill was done using a 4-point scoring system, and learning curves using cumulative sum analysis for overall, technical, and cognitive components of EUS and ERCP were shared with AETs and trainers quarterly. Generalized linear mixed-effects models with a random intercept for each AET were used to generate aggregate learning curves, allowing us to use data from all AETs to estimate the average learning experience for trainees. RESULTS: Among 62 invited AETPs, 37 AETs from 32 AETPs participated. Most AETs reported hands-on EUS (52%, median 20 cases) and ERCP (68%, median 50 cases) experience before starting an AETP. The median number of EUS and ERCPs performed per AET was 400 (range, 200-750) and 361 (range, 250-650), respectively. Overall, 2616 examinations were graded (EUS, 1277; ERCP-biliary, 1143; pancreatic, 196). Most graded EUS examinations were performed for pancreatobiliary indications (69.9%) and ERCP examinations for ASGE biliary grade of difficulty 1 (72.1%). The average AET achieved competence in core EUS and ERCP skills at approximately 225 and 250 cases, respectively. However, overall technical competence was achieved for grade 2 ERCP at about 300 cases. CONCLUSION: The thresholds provided for an average AET to achieve competence in EUS and ERCP may be used by the ASGE and AETPs in establishing the minimal standards for case volume exposure for AETs during their training. (Clinical trial registration number: NCT02509416.).

Rectal Indomethacin Does Not Prevent Post-ERCP Pancreatitis in Consecutive Patients.

BACKGROUND & AIMS: Rectal indomethacin, a nonsteroidal anti-inflammatory drug, is given to prevent pancreatitis in high-risk patients undergoing endoscopic retrograde cholangiopancreatography (ERCP), based on findings from clinical trials. The European Society for Gastrointestinal Endoscopy guidelines recently recommended prophylactic rectal indomethacin for all patients undergoing ERCP, including those at average risk for pancreatitis. We performed a randomized controlled trail to investigate the efficacy of this approach. METHODS: We performed a prospective, double-blind, placebo-controlled trial of 449 consecutive patients undergoing ERCP at Dartmouth Hitchcock Medical Center, from March 2013 through December 2014. Approximately 70% of the cohort were at average risk for PEP. Subjects were assigned randomly to groups given either a single 100-mg dose of rectal indomethacin (n = 223) or a placebo suppository (n = 226) during the procedure. The primary outcome was the development of post-ERCP pancreatitis (PEP), defined by new upper-abdominal pain, a lipase level more than 3-fold the upper limit of normal, and hospitalization after ERCP for 2 consecutive nights. RESULTS: There were no differences between the groups in baseline clinical or procedural characteristics. Sixteen patients in the indomethacin group (7.2%) and 11 in the placebo group (4.9%) developed PEP (P = .33). Complications and the severity of PEP were similar between groups. Per a priori protocol guidelines, the study was stopped owing to futility. CONCLUSIONS: In a randomized controlled study of consecutive patients undergoing ERCP, rectal indomethacin did not prevent post-ERCP pancreatitis. ClincialTrials.gov no: NCT01774604.

Corrigendum: 2016 ACG Abstracts- Clinical Vignettes/Case Reports - Esophagus.

This corrects the article DOI: 10.1038/ajg.2016.368.

Cost-effectiveness and clinical efficacy of biliary stents in patients undergoing neoadjuvant therapy for pancreatic adenocarcinoma in a randomized controlled trial.

BACKGROUND AND AIMS: The optimal type of stent for the palliation of malignant biliary obstruction in patients with pancreatic adenocarcinoma undergoing neoadjuvant chemoradiotherapy with curative intent is unknown. We performed a prospective trial comparing 3 types of biliary stents-fully covered self-expandable metal (fcSEMS), uncovered self-expandable metal (uSEMS), and plastic-to determine which best optimized cost-effectiveness and important clinical outcomes. METHODS: In this prospective randomized trial, consecutive patients with malignant biliary obstruction from newly diagnosed pancreatic adenocarcinoma who were to start neoadjuvant chemoradiotherapy were randomized to receive fcSEMSs, uSEMSs, or plastic stents during the index ERCP. The primary outcomes were time to stent occlusion, attempted surgical resection, or death after the initiation of neoadjuvant therapy, and the secondary outcomes were total patient costs associated with the stent, including the index ERCP cost, downstream hospitalization cost due to stent occlusion, and the cost associated with procedural adverse event. RESULTS: Fifty-four patients were randomized and reached the primary end point: 16 in the fcSEMS group, 17 in the uSEMS group, and 21 in the plastic stent group. No baseline demographic or tumor characteristic differences were noted among the groups. The fcSEMSs had a longer time to stent occlusion compared with uSEMSs and plastic stents (220 vs 74 and 76 days, P < .01), although the groups had equivalent rates of stent occlusion, attempted surgical resection, and death. Although SEMS placement cost more during the index ERCP (uSEMS = $24,874 and fcSEMS = $22,729 vs plastic = $18,701; P < .01), they resulted in higher procedural AE costs per patient (uSEMS = $5522 and fcSEMS = $12,701 vs plastic = $0; P < .01). Conversely, plastic stents resulted in an $11,458 hospitalization cost per patient due to stent occlusion compared with $2301 for uSEMSs and $0 for fcSEMSs (P < .01). CONCLUSIONS: In a prospective trial comparing fcSEMSs, uSEMSs, and plastic stents for malignant biliary obstruction in patients undergoing neoadjuvant therapy with curative intent for pancreatic adenocarcinoma, no stent type was superior in optimizing cost-effectiveness, although fcSEMSs resulted in fewer days of neoadjuvant treatment delay and a longer time to stent occlusion. (Clincial trial registration number: NCT01038713.).

Quality of optical diagnosis of diminutive polyps and associated factors.

BACKGROUND AND AIMS: The aim of the study was to identify endoscopist-related and procedural factors that may be associated with the quality of optical diagnosis of diminutive polyps using narrow-band imaging (NBI). METHODS: All subjects who participated in a randomized trial on cap-assisted colonoscopy were eligible for the current study. Optical polyp diagnosis was an a priori outcome of the initial trial. Ten participating endoscopists used NBI to assess all of the diagnosed polyps as adenomatous or non-adenomatous in real-time and provided a degree of diagnostic certainty. The main outcome measures were quality benchmarks of optical diagnosis (negative predictive value [NPV] for diminutive rectosigmoid adenomas, agreement with pathology-based surveillance interval) and assessment of endoscopist-related and procedural factors potentially associated with the quality of optical diagnosis. RESULTS: A total of 1650 polyps were found in 607 patients, with 1311 polyps (79 %) being diminutive, of which 672 (53 %) were adenomatous. The NPV of optical diagnosis for rectosigmoid adenomas was 95 %. The optical diagnosis-based surveillance interval agreed with the pathology-based recommendation in 93 % of patients. Prior experience with image-enhanced endoscopy had no effect on optical diagnosis. Low and high adenoma detectors were not different in achieving the quality benchmarks. Cap-assisted colonoscopy was not associated with quality of optical diagnosis. Quality metrics of optical diagnosis remained similar during the first and second half of the study period. CONCLUSION: High quality optical diagnosis of diminutive polyps can be achieved and sustained by endoscopists previously inexperienced in this practice with minimal training. None of the examined factors appear to affect the quality of optical diagnosis; particularly, endoscopists' adenoma detection was not associated with optical diagnosis.

Cap-assisted colonoscopy and detection of Adenomatous Polyps (CAP) study: a randomized trial.

BACKGROUND AND STUDY AIM: Cap-assisted colonoscopy has improved adenoma detection in some but not other studies. Most previous studies have been limited by small sample sizes and few participating endoscopists. The aim of the current study was to evaluate whether cap-assisted colonoscopy improves adenoma detection in a two-center, multi-endoscopist, randomized trial. PATIENTS AND METHODS: Consecutive patients who presented for an elective colonoscopy were randomized to cap-assisted colonoscopy (4-mm cap) or standard colonoscopy performed by one of 10 experienced endoscopists. Primary outcome measures were mean number of adenomas per patient and adenoma detection rate (ADR). Secondary outcomes included procedural measures and endoscopist variation; a logistic regression model was employed to examine predictors of increased detection with cap use. RESULTS: A total of 1113 patients (64 % male, mean age 62 years) were randomized to cap-assisted (n = 561) or standard (n = 552) colonoscopy. The mean number of adenomas detected per patient in the cap-assisted and standard groups was similar (0.89 vs. 0.82; P = 0.432), as was the ADR (42 % vs. 40 %; P = 0.452). Cap-assisted colonoscopy achieved a faster cecal intubation time (4.9 vs. 5.8 minutes; P < 0.001), a similar cecal intubation rate (99 % vs. 98 %; P = 0.326), and a higher terminal ileum intubation rate (93 % vs. 89 %; P < 0.028). Cap-assisted colonoscopy resulted in a 20 % increase in ADR for some endoscopists and in a 15 % decrease for others. Individual preference for the cap was an independent predictor of increased adenoma detection in adjusted analysis (P < 0.001), whereas baseline low adenoma detection was not. CONCLUSION: Although the efficiency of cecal and terminal ileum intubation was slightly improved by cap-assisted colonoscopy, adenoma detection was not. Cap-assisted colonoscopy may be beneficial for selected endoscopists. TRIAL REGISTRATION: clinicalTrials.gov (NCT01935180).

Incomplete polyp resection during colonoscopy-results of the complete adenoma resection (CARE) study.

BACKGROUND & AIMS: Although the adenoma detection rate is used as a measure of colonoscopy quality, there are limited data on the quality of endoscopic resection of detected adenomas. We determined the rate of incompletely resected neoplastic polyps in clinical practice. METHODS: We performed a prospective study on 1427 patients who underwent colonoscopy at 2 medical centers and had at least 1 nonpedunculated polyp (5-20 mm). After polyp removal was considered complete macroscopically, biopsies were obtained from the resection margin. The main outcome was the percentage of incompletely resected neoplastic polyps (incomplete resection rate [IRR]) determined by the presence of neoplastic tissue in post-polypectomy biopsies. Associations between IRR and polyp size, morphology, histology, and endoscopist were assessed by regression analysis. RESULTS: Of 346 neoplastic polyps (269 patients; 84.0% men; mean age, 63.4 years) removed by 11 gastroenterologists, 10.1% were incompletely resected. IRR increased with polyp size and was significantly higher for large (10-20 mm) than small (5-9 mm) neoplastic polyps (17.3% vs 6.8%; relative risk = 2.1), and for sessile serrated adenomas/polyps than for conventional adenomas (31.0% vs 7.2%; relative risk = 3.7). The IRR for endoscopists with at least 20 polypectomies ranged from 6.5% to 22.7%; there was a 3.4-fold difference between the highest and lowest IRR after adjusting for size and sessile serrated histology. CONCLUSIONS: Neoplastic polyps are often incompletely resected, and the rate of incomplete resection varies broadly among endoscopists. Incomplete resection might contribute to the development of colon cancers after colonoscopy (interval cancers). Efforts are needed to ensure complete resection, especially of larger lesions. ClinicalTrials.gov Number: NCT01224444.

A microRNA-based test improves endoscopic ultrasound-guided cytologic diagnosis of pancreatic cancer.

BACKGROUND & AIMS: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in combination with cytopathology is the optimal method for diagnosis and staging of pancreatic ductal adenocarcinoma (PDAC) and other pancreatic lesions. Its clinical utility, however, can be limited by high rates of indeterminate or false-negative results. We aimed to develop and validate a microRNA (miRNA)-based test to improve preoperative detection of PDAC. METHODS: Levels of miRNAs were analyzed in a centralized clinical laboratory by relative quantitative polymerase chain reaction in 95 formalin-fixed paraffin-embedded specimens and 228 samples collected by EUS-FNA during routine evaluations of patients with solid pancreatic masses at 4 institutions in the United States, 1 in Canada, and 1 in Poland. RESULTS: We developed a 5-miRNA expression classifier, consisting of MIR24, MIR130B, MIR135B, MIR148A, and MIR196, that could identify PDAC in well-characterized, formalin-fixed, paraffin-embedded specimens. Detection of PDAC in EUS-FNA samples increased from 78.8% by cytology analysis alone (95% confidence interval, 72.2%-84.5%) to 90.8% when combined with miRNA analysis (95% confidence interval, 85.6%-94.5%). The miRNA classifier correctly identified 22 additional true PDAC cases among 39 samples initially classified as benign, indeterminate, or nondiagnostic by cytology. Cytology and miRNA test results each were associated significantly with PDAC (P < .001), with positive predictive values greater than 99% (95% confidence interval, 96%-100%). CONCLUSIONS: We developed and validated a 5-miRNA classifier that can accurately predict which preoperative pancreatic EUS-FNA specimens contain PDAC. This test might aid in the diagnosis of pancreatic cancer by reducing the number of FNAs without a definitive adenocarcinoma diagnosis, thereby reducing the number of repeat EUS-FNA procedures.

Molecular profiling of appendiceal epithelial tumors using massively parallel sequencing to identify somatic mutations.

BACKGROUND: Some epithelial neoplasms of the appendix, including low-grade appendiceal mucinous neoplasm and adenocarcinoma, can result in pseudomyxoma peritonei (PMP). Little is known about the mutational spectra of these tumor types and whether mutations may be of clinical significance with respect to therapeutic selection. In this study, we identified somatic mutations using the Ion Torrent AmpliSeq Cancer Hotspot Panel v2. METHODS: Specimens consisted of 3 nonneoplastic retention cysts/mucocele, 15 low-grade mucinous neoplasms (LAMNs), 8 low-grade/well-differentiated mucinous adenocarcinomas with pseudomyxoma peritonei, and 12 adenocarcinomas with/without goblet cell/signet ring cell features. Barcoded libraries were prepared from up to 10 ng of extracted DNA and multiplexed on single 318 chips for sequencing. Data analysis was performed using Golden Helix SVS. Variants that remained after the analysis pipeline were individually interrogated using the Integrative Genomics Viewer. RESULTS: A single Janus kinase 3 (JAK3) mutation was detected in the mucocele group. Eight mutations were identified in the V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and GNAS complex locus (GNAS) genes among LAMN samples. Additional gene mutations were identified in the AKT1 (v-akt murine thymoma viral oncogene homolog 1), APC (adenomatous polyposis coli), JAK3, MET (met proto-oncogene), phosphatidylinositol-4,5-bisphosphate 3-kinase (PIK3CA), RB1 (retinoblastoma 1), STK11 (serine/threonine kinase 11), and tumor protein p53 (TP53) genes. Among the PMPs, 6 mutations were detected in the KRAS gene and also in the GNAS, TP53, and RB1 genes. Appendiceal cancers showed mutations in the APC, ATM (ataxia telangiectasia mutated), KRAS, IDH1 [isocitrate dehydrogenase 1 (NADP+)], NRAS [neuroblastoma RAS viral (v-ras) oncogene homolog], PIK3CA, SMAD4 (SMAD family member 4), and TP53 genes. CONCLUSIONS: Our results suggest molecular heterogeneity among epithelial tumors of the appendix. Next generation sequencing efforts have identified mutational spectra in several subtypes of these tumors that may suggest a phenotypic heterogeneity showing mutations that are relevant for targeted therapies.

Metastatic Neuroendocrine Neoplasms to the Pancreas: Two Unusual Cases and a Review of the Literature.

Neuroendocrine tumor metastases to the pancreas are rare, and they share substantial overlap with the significantly more common primary pancreatic neuroendocrine neoplasms, representing a potential diagnostic pitfall. Elucidating whether a neuroendocrine tumor within the pancreas is a primary neoplasm versus a metastasis has significant prognostic and treatment implications. Correlation with clinical history and imaging as well as incorporating an appropriate immunohistochemical panel are essential to establish the correct diagnosis. Herein, we present 2 rare neuroendocrine tumors that metastasized to the pancreas: a medullary thyroid carcinoma and an atypical carcinoid tumor of lung origin. We also provide a brief review of the literature.

Pancreatic cyst prevalence and the risk of mucin-producing adenocarcinoma in US adults.

OBJECTIVES: The presence of a pancreatic cyst often prompts concern, although the rate of malignant transformation to mucin-producing adenocarcinoma is not known. We aimed to determine the prevalence rate of mucin-producing adenocarcinoma in US adults with pancreatic cysts. METHODS: This retrospective, population-based cross-sectional study calculated the annual number of mucin-producing adenocarcinomas using the Surveillance Epidemiology and End Results (SEER 18) database and the 2010 US census. The overall prevalence rate of cysts in the population was found using data from large cross-sectional imaging studies of incidental cyst prevalence. Prevalence rates were then calculated by dividing the annual number of mucin-producing adenocarcinomas by the cyst prevalence rate. RESULTS: Between 2005 and 2009, 1,137 mucin-producing adenocarcinomas were estimated to be found annually in a US adult population of 137,154,960. The total number of pancreas cysts, given a cyst prevalence rate of 2.5%, was 3,428,874. Therefore, the prevalence rate of mucin-producing adenocarcinoma arising in patients with pancreatic cysts was 33.2 per 100,000 (95% confidence interval (CI): 21.9-44.5). The prevalence rate was 32.8 per 100,000 (95% CI: 21.6-44.0) in women and 33.5 per 100,000 (95% CI: 22.2-44.8) in men. As expected, the rate of malignant transformation increased linearly with advancing age (highest 38.6 per 100,000 in 80- to 84-year-old men). CONCLUSIONS: Malignant transformation of pancreatic cysts into mucin-producing adenocarcinoma in US adults is a very rare event. Current clinical guidelines and resource allocation for pancreatic cyst disease should be reconsidered given these findings.

Radiofrequency ablation for long- and ultralong-segment Barrett's esophagus: a comparative long-term follow-up study.

BACKGROUND: The safety, efficacy, and durability of radiofrequency ablation (RFA), with or without EMR, have been established for long-segment Barrett's esophagus (LSBE). Ablating ultralong-segment Barrett's esophagus (ULSBE) may be associated with increased stricture formation, eradication failure, and treatment session requirements. OBJECTIVES: Our primary objective was to compare eradication and stricture rates between LSBE (≥3 to <8 cm) and ULSBE (≥8 cm). Our secondary objective was to evaluate treatment durability and session requirements. DESIGN: Retrospective review of prospectively collected data. SETTING: Tertiary care facility. PATIENTS: A total of 72 patients (34 ULSBE, 38 LSBE; mean Barrett's segment length of 10.8 and 4.7 cm) underwent RFA between August 2005 and September 2010. Mean follow-up was 45 and 34 months, respectively. MAIN OUTCOME MEASUREMENTS: Eradication and complication rates for ULSBE and LSBE. RESULTS: Eradication rates for dysplasia (90% vs 88%, P = 1.0) and intestinal metaplasia (IM) (77% vs 82%, P = .77) were similar. ULSBE patients required more overall (P < .01) and circumferential (P < .01) RFA; however, stricture rates were identical (14%). There was no dysplasia recurrence, and IM recurrence was similar (ULSBE, 23%; LSBE, 16%; P = .52). At 3 years, IM remained eradicated in 65% of ULSBE and 82% of LSBE, without maintenance RFA. On multivariate regression analysis, increasing Barrett's length was associated with a reduced likelihood for eradicating IM (odds ratio 0.87; 95% CI, 0.75-1.00), but not dysplasia (odds ratio 1.13; 95% CI, 0.95-1.35). LIMITATIONS: Single center. CONCLUSION: ULSBE can be treated in its entirety at each session with efficacy and safety comparable to LSBE. ULSBE requires more effort to achieve IM eradication, and RFA is less durable in maintaining this eradication at 3-year follow-up.