Eun Ji Shin

Comparative Genomic Analysis of Esophageal Adenocarcinoma and Squamous Cell Carcinoma

Esophageal cancer ranks sixth in cancer death. To explore its genetic origins, we conducted exomic sequencing on 11 esophageal adenocarcinomas (EAC) and 12 esophageal squamous cell carcinomas (ESCC) from the United States. Interestingly, inactivating mutations of NOTCH1 were identified in 21% of ESCCs but not in EACs. There was a substantial disparity in the spectrum of mutations, with more indels in ESCCs, A:T>C:G transversions in EACs, and C:G>G:C transversions in ESCCs (P < 0.0001). Notably, NOTCH1 mutations were more frequent in North American ESCCs (11 of 53 cases) than in ESCCs from China (1 of 48 cases). A parallel analysis found that most mutations in EACs were already present in matched Barrett esophagus. These discoveries highlight key genetic differences between EACs and ESCCs and between American and Chinese ESCCs, and suggest that NOTCH1 is a tumor suppressor gene in the esophagus. Finally, we provide a genetic basis for the evolution of EACs from Barrett esophagus.

Steroid avoidance in liver transplantation: meta-analysis and meta-regression of randomized trials.

Steroid use after liver transplantation (LT) has been associated with diabetes, hypertension, hyperlipidemia, obesity, and hepatitis C (HCV) recurrence. We performed meta‐analysis and meta‐regression of 30 publications representing 19 randomized trials that compared steroid‐free with steroid‐based immunosuppression (IS). There were no differences in death, graft loss, and infection. Steroid‐free recipients demonstrated a trend toward reduced hypertension [relative risk (RR) 0.84, P = 0.08], and statistically significant decreases in cholesterol (standard mean difference −0.41, P < 0.001) and cytomegalovirus (RR 0.52, P = 0.001). In studies where steroids were replaced by another IS agent, the risks of diabetes (RR 0.29, P < 0.001), rejection (RR 0.68, P = 0.03), and severe rejection (RR 0.37, P = 0.001) were markedly lower in steroid‐free arms. In studies in which steroids were not replaced, rejection rates were higher in steroid‐free arms (RR 1.31, P = 0.02) and reduction of diabetes was attenuated (RR 0.74, P = 0.2). HCV recurrence was lower with steroid avoidance and, although no individual trial reached statistical significance, meta‐analysis demonstrated this important effect (RR 0.90, P = 0.03). However, we emphasize the heterogeneity of trials performed to date and, as such, do not recommend basing clinical guidelines on our conclusions. We believe that a large, multicenter trial will better define the role of steroid‐free regimens in LT. Liver Transpl 14:512–525, 2008.

EUS is still superior to multidetector computerized tomography for detection of pancreatic neuroendocrine tumors

BACKGROUND The role of EUS for detection of pancreatic neuroendocrine tumors (PNETs) is not clearly defined in institutions that use multidetector CT for pancreatic imaging. OBJECTIVE The aims of this study were to (1) compare the detection rates of EUS and CT by type and size of PNET and calculate the incremental benefit of EUS over CT, (2) evaluate the CT detection rate for PNETs adjusted for improved CT technology over time, and (3) determine the factors associated with CT-negative PNETs. DESIGN Retrospective single-center cohort study. SETTING Johns Hopkins Hospital. PATIENTS Patients with pathologically proven PNETs with preoperative CT. Incidentally found PNETs (resection specimens) and those without Johns Hopkins Hospital CT imaging were excluded. MAIN OUTCOME MEASUREMENT Detection rates of CT and EUS were compared by using pathology as the reference standard. RESULTS In 217 patients (with 231 PNETs) studied, CT detected 84% of tumors (54.3% of insulinomas). The sensitivity of CT for the detection of PNETs significantly increased with improvement in CT technology (P = .02; χ(2) for trend). CT was more likely to miss lesions <2 cm (P = .005) and insulinomas (P < .0001). In 56 patients who had both CT and EUS, the sensitivity of EUS was greater than CT (91.7% vs 63.3%; P = .0002), particularly for insulinomas (84.2% vs 31.6%; P = .001). EUS detected 20 of 22 CT-negative tumors (91%). LIMITATIONS Retrospective nonrandomized design and referral bias. CONCLUSIONS The detection rate of CT has significantly improved over time. CT-negative tumors are small and more likely to be insulinomas. A sequential approach of CT followed by EUS can detect most PNETs. EUS is a more sensitive initial test for the detection of suspected insulinomas.

Biopsy with Thermally‐Responsive Untethered Microtools

Thermally activated, untethered microgrippers can reach narrow conduits in the body and be used to excise tissue for diagnostic analyses. As depicted in the figure, the feasibility of an in vivo biopsy of the porcine bile duct using untethered microgrippers is demonstrated.

A comparative evaluation of single-balloon enteroscopy and spiral enteroscopy for patients with mid-gut disorders.

BACKGROUND Single-balloon enteroscopy (SBE) and spiral enteroscopy (SE) are recently described device-assisted techniques in endoluminal evaluation of the small bowel. No studies comparing SBE and SE in patients with suspected small-bowel disorders have previously been reported. OBJECTIVE The aims of this study were to compare SBE and SE in terms of diagnostic yield, procedure time, depth of maximal insertion, and complications. DESIGN Retrospective cohort study. SETTING Tertiary-care referral center. PATIENTS A retrospective analysis was performed on all patients at our institution undergoing anterograde SBE or SE between 2007 and 2009. Patients with altered anatomy or prior small-bowel surgery were excluded. INTERVENTION Deep enteroscopy. MAIN OUTCOME MEASUREMENT Diagnostic yield. RESULTS During the study period, 92 patients underwent 105 procedures (52 SBE, 53 SE). The most common indication for small-bowel endoscopy was obscure GI bleeding (n = 42). The diagnostic yield was not statistically different between SBE and SE (59.6% and 43.4%, respectively, P = .12). The overall diagnostic yield in patients with obscure GI bleeding was 67%. There was no significant difference between mean SBE and SE procedure times (53 minutes [range 15-99 minutes] vs 47 minutes [range 20-125 minutes], respectively; P = .2). The mean depth of maximal insertion beyond the ligament of Treitz for SE was significantly higher than that for SBE (301 cm [range 175-400 cm] vs 222 cm [range 110-400 cm], respectively; P < .001). Perforation occurred in one SBE procedure. LIMITATIONS Retrospective design and nonstandardized gas insufflation. CONCLUSION This is the first report comparing SE and SBE. Although SE yielded greater depth of maximal insertion than SBE, both techniques had similar diagnostic yields and procedure times. In addition, both techniques were safe and were particularly useful in patients with obscure GI bleeding.

Long non-coding RNA HNF1A-AS1 regulates proliferation and migration in oesophageal adenocarcinoma cells

Objectives Long non-coding RNAs (lncRNA) have been shown to play important roles in the development and progression of cancer. However, functional lncRNAs and their downstream mechanisms are largely unknown in the molecular pathogenesis of oesophageal adenocarcinoma (EAC) and its progression. Design lncRNAs that are abnormally upregulated in EACs were identified by RNA-sequencing analysis, followed by quantitative RT-PCR (qRTPCR) validation using tissues from 25 EAC patients. Cell biological assays in combination with small interfering RNA-mediated knockdown were performed in order to probe the functional relevance of these lncRNAs. Results We discovered that a lncRNA, HNF1A-AS1, is markedly upregulated in human primary EACs relative to their corresponding normal oesophageal tissues (mean fold change 10.6, p<0.01). We further discovered that HNF1A-AS1 knockdown significantly inhibited cell proliferation and anchorage-independent growth, suppressed S-phase entry, and inhibited cell migration and invasion in multiple in vitro EAC models (p<0.05). A gene ontological analysis revealed that HNF1A-AS1 knockdown preferentially affected genes that are linked to assembly of chromatin and the nucleosome, a mechanism essential to cell cycle progression. The well known cancer-related lncRNA, H19, was the gene most markedly inhibited by HNF1A-AS1 knockdown. Consistent to this finding, there was a significant positive correlation between HNF1A-AS1 and H19 expression in primary EACs (p<0.01). Conclusions We have discovered abnormal upregulation of a lncRNA, HNF1A-AS1, in human EAC. Our findings suggest that dysregulation of HNF1A-AS1 participates in oesophageal tumorigenesis, and that this participation may be mediated, at least in part, by modulation of chromatin and nucleosome assembly as well as by H19 induction.

Should we do EUS/FNA on patients with pancreatic cysts? The incremental diagnostic yield of EUS over CT/MRI for prediction of cystic neoplasms.

Objectives To evaluate the performance characteristics of endoscopic ultrasonography (EUS) compared with computed tomography (CT) and magnetic resonance imaging (MRI) and determine the incremental diagnostic yield and accuracy of EUS with or without fine needle aspiration (FNA) over CT and MRI for prediction of neoplastic pancreatic cysts. Methods The EUS database was queried for procedures performed for pancreatic cysts between March 2006 and January 2010. Cystic pancreatic ductal adenocarcinoma, cystic pancreatic neuroendocrine tumor, mucinous cystic neoplasm, intraductal papillary neoplasm, and solid pseudopapillary neoplasm were categorized as neoplastic; pseudocysts and serous cysts were designated as nonneoplastic/low risk. Results Final diagnoses were established by surgery in 154 patients (mucinous cystic neoplasm/intraductal papillary neoplasm [69.4%], pancreatic neuroendocrine tumor [10%], pancreatic ductal adenocarcinoma [6.4%], solid pseudopapillary neoplasm [0.6%], nonneoplastic/low risk [13.6%]). Endoscopic ultrasonography with or without FNA was superior to CT and MRI in accurately classifying a cyst as neoplastic (P < 0.0001). After CT and MRI, EUS increased the rate of correctly predicting neoplastic cysts in 43 (36%) and 27 (54%) additional cases, respectively. Conclusions The incremental increase in diagnostic yield of EUS and fluid analysis over CT and MRI for prediction of a neoplastic cyst is 36% and 54%, respectively. The addition of EUS-FNA to abdominal imaging significantly increases overall accuracy for diagnosis of neoplastic pancreatic cysts.

Human bile contains MicroRNA‐laden extracellular vesicles that can be used for cholangiocarcinoma diagnosis

Cholangiocarcinoma (CCA) presents significant diagnostic challenges, resulting in late patient diagnosis and poor survival rates. Primary sclerosing cholangitis (PSC) patients pose a particularly difficult clinical dilemma because they harbor chronic biliary strictures that are difficult to distinguish from CCA. MicroRNAs (miRs) have recently emerged as a valuable class of diagnostic markers; however, thus far, neither extracellular vesicles (EVs) nor miRs within EVs have been investigated in human bile. We aimed to comprehensively characterize human biliary EVs, including their miR content. We have established the presence of extracellular vesicles in human bile. In addition, we have demonstrated that human biliary EVs contain abundant miR species, which are stable and therefore amenable to the development of disease marker panels. Furthermore, we have characterized the protein content, size, numbers, and size distribution of human biliary EVs. Utilizing multivariate organization of combinatorial alterations (MOCA), we defined a novel biliary vesicle miR‐based panel for CCA diagnosis that demonstrated a sensitivity of 67% and specificity of 96%. Importantly, our control group contained 13 PSC patients, 16 with biliary obstruction of varying etiologies (including benign biliary stricture, papillary stenosis, choledocholithiasis, extrinsic compression from pancreatic cysts, and cholangitis), and 3 with bile leak syndromes. Clinically, these types of patients present with a biliary obstructive clinical picture that could be confused with CCA. Conclusion: These findings establish the importance of using extracellular vesicles, rather than whole bile, for developing miR‐based disease markers in bile. Finally, we report on the development of a novel bile‐based CCA diagnostic panel that is stable, reproducible, and has potential clinical utility. (Hepatology 2014;60:896–907)

Tumor size and location correlate with behavior of pancreatic serous cystic neoplasms.

OBJECTIVES:The majority of pancreatic serous cystic neoplasms (SCNs) are benign. However, these neoplasms can cause symptoms and rarely can be aggressive. Identification of factors associated with symptomatic or aggressive SCNs may aid management decisions. The aim of this study was to identify variables that predict aggressive SCNs.METHODS:Prospective pathology database was queried for SCNs that were surgically resected at Johns Hopkins Hospital. Tumors were considered aggressive if they invaded surrounding structures and/or vessels or if they metastasized to lymph nodes or distant organs. The associations of gender, tumor size, and tumor location, with the presence or absence of symptoms and tumor behavior were examined using Fishers exact test, logistic regression, and multivariate analyses.RESULTS:A total of 257 patients with SCNs underwent surgical resection. Mean tumor diameter was 4.9 cm. Tumor location in the head of pancreas (HOP) was associated with symptoms (odds ratio (OR) 1.87, 95% confidence interval (CI) 1.1–3.3). Computed tomography (CT) predicted the diagnosis of SCN in approximately a quarter of patients. Thirteen tumors (mean 10.5 cm) were considered aggressive. Multivariate analysis showed that tumor diameter (OR 1.53, 95% CI 1.24–1.89) and location of tumor in pancreatic head (OR 10.44, 95% CI 1.73–63.04) were independently associated with aggressive behavior.CONCLUSIONS:We describe the largest case series of patients with pathologically proven SCNs. CT performed poorly in preoperative diagnosis of SCNs. Large tumor size and head location predicted aggressive behavior. These factors should be considered in the management of patients with SCN.

EUS-guided portal vein catheterization: a promising novel approach for portal angiography and portal vein pressure measurements

BACKGROUND Portal vein (PV) pressure measurements can provide valuable information for the management of patients with liver disease and portal hypertension. OBJECTIVE To evaluate the feasibility and the safety of EUS-guided PV catheterization and pressure measurements in a porcine model. SETTING Acute and survival experiments on five 50-kg pigs. DESIGN AND INTERVENTIONS Intrahepatic PV was punctured under EUS guidance by using a 19-gauge FNA needle. A 0.035-inch guidewire was advanced through the needle into the PV. The needle was withdrawn. A 5.5F ERCP catheter was advanced over the guidewire into the PV and then connected to a pressure monitor. Continuous PV measurements were obtained for an hour. Afterward, the catheter was removed, and the animals were observed for 30 minutes. Three animals were then immediately euthanized for a necropsy. The other two animals were observed for two weeks and then were euthanized. MAIN OUTCOME MEASUREMENTS The ability to perform EUS-guided PV catheterization and pressure measurement without complications. RESULTS PV catheterization, angiography, and pressure measurements were performed without any problems or complications. There were no changes in vital signs and hemodynamic parameters during PV catheterizations, angiography, pressure measurements, and catheter removal. Survival experiments did not demonstrate any change in animal condition, behavior, or eating habits after the procedure. A necropsy in all animals revealed no active bleeding, and no damage to the liver, other intra-abdominal organs, or blood vessels. LIMITATIONS No validation of measured PV pressure was made. CONCLUSIONS EUS-guided PV catheterization is feasible, safe, and can be used for portal angiography and pressure measurements.