Natsuko Kawada

Hepatocellular carcinoma arising from non-cirrhotic nonalcoholic steatohepatitis

PurposeCharacteristics of hepatocellular carcinoma (HCC) complicating nonalcoholic steatohepatitis (NASH) are still controversial. Most NASH related HCCs are believed to develop from cirrhotic liver, but case reports about HCC arising from non-cirrhotic NASH have been accumulating recently. This study is designed to elucidate characteristics of NASH related HCC diagnosed with high accuracy by using surgically resected specimens that contain larger areas to validate than biopsy specimens.MethodsFor this study, 1168 patients who underwent hepatic resection at Osaka Medical Center for Cancer and Cardiovascular Diseases were enrolled. Patients who had clinically obvious causes of chronic liver dysfunction, such as viral and alcoholic hepatitis, were excluded. Histological diagnosis of NASH was confirmed according to Brunt’s criterion.ResultsEight (1%) patients were diagnosed with NASH. Six (75%) of them showed non-cirrhosis in non-cancerous areas. Stages of fibrosis in the non-cirrhotic patients were mild fibrosis (F2) in five and moderate fibrosis (F3) in one. All patients complicated with metabolic diseases. Although all these patients without cirrhosis were evaluated pathologically at tumor-node-metastasis stages I or II, three (50%) had multiple recurrences of tumor within a short time after surgery.ConclusionThis study indicates HCC might arise frequently from non-cirrhotic NASH. While further studies are needed to confirm this observation, both cirrhotic and non-cirrhotic NASH warrant regular screening for HCC.

Efficacy of an Endo-Knife With a Water-Jet Function (Flushknife) for Endoscopic Submucosal Dissection of Superficial Colorectal Neoplasms

OBJECTIVES:Endoscopic submucosal dissection (ESD) is currently not a common treatment for colorectal neoplasms because it is time consuming and technically difficult. Flushknife—an electrosurgical endo-knife with a water-jet function—is expected to reduce the difficulty of colorectal ESD. The objective of this study was to investigate the efficacy of a water-jet function for colorectal ESD.METHODS:This study was a prospective randomized controlled trial, which was conducted at a cancer referral center. A total of 49 patients, with a total of 51 superficial colorectal neoplasms (median tumor size of 30 mm), were enrolled and randomly assigned to undergo ESD using either the Flexknife (electrosurgical endo-knife without a water-jet function) or the Flushknife. Tumors were resected by ESD using each endo-knife. The procedures were conducted by two endoscopists. Operation time was defined as the main outcome measure.RESULTS:En bloc resection was achieved in 23 out of 26 (88%) lesions in the Flexknife group and in 24 out of 24 (100%) lesions in the Flushknife group. The mean operation time (95% confidence interval) was 87.3 (71.3–103.4) min in the Flexknife group and 61.0 (49.3–72.7) min in the Flushknife group (P=0.02). The Flushknife reduced the number of endoscopic device changes (P=0.001), the number of submucosal injections (P=0.001), and the mean amount of injected hyaluronate sodium (P=0.001) compared with the Flexknife. No severe adverse events were observed in either group.CONCLUSIONS:Without increasing adverse events, the endo-knife with a water-jet function efficiently reduced the operation time of colorectal ESD in patients with large superficial colorectal neoplasms. (University hospital Medical Information Network Clinical Trials Registry number UMIN000001302)

Diagnostic accuracy of endoscopic ultrasound‐guided fine needle aspiration for suspected pancreatic malignancy in relation to the size of lesions

Background and Aim:  Endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) is an accurate method for cytological confirmation of pancreatic malignancy, but it has been unknown whether its diagnostic accuracy for pancreatic lesions was affected by their size, location, or size of needles. Our aim was to investigate the accuracy of EUS‐FNA for suspected pancreatic malignancy in relation to these factors, especially to the size of lesions.

Significance of each narrow-band imaging finding in diagnosing squamous mucosal high-grade neoplasia of the esophagus

Background and Aim:  Although narrow‐band imaging (NBI) is used increasingly in clinical situations, the significance of each NBI finding has not been investigated. The primary endpoint of the present study was to identify the significant NBI findings to diagnose esophageal mucosal high‐grade neoplasia.

Factors predicting perforation during endoscopic submucosal dissection for gastric cancer.

BACKGROUND Perforation is a common complication of endoscopic submucosal dissection (ESD), but little is known about the relevant risk factors. OBJECTIVE To investigate the risk factors for perforation. DESIGN Retrospective study. SETTING A cancer referral center. PATIENTS A total of 1795 early gastric tumors in 1500 patients treated by ESD from July 2002 to December 2010 were included in the analysis. MAIN OUTCOME MEASUREMENTS The associations between the incidence of perforation and patient and lesion characteristics were investigated. RESULTS Perforation during ESD occurred in 50 lesions (2.8%). Univariate analysis identified tumor location (upper, middle, or lower stomach), tumor diameter (≤ 20 or >20 mm), and treatment period (lesions treated in the first or second period) as predictors of perforation. Multivariate analysis identified tumor location (upper stomach), tumor diameter (>20 mm), and treatment period (first half) as independent risk factors for perforation. The odds ratios were 2.4 (95% CI, 1.3-4.7; P = .006) for lesions in the upper stomach and 1.9 (95% CI, 1.0-3.5; P = .04) for lesions larger than 20 mm. Perforation risks were 5.4% for lesions in the upper stomach and 4.4% for lesions larger than 20 mm. Three patients required emergency surgery, but the rest of the patients were successfully treated with endoscopic clipping. There was no perforation-related mortality. LIMITATIONS Single-center, retrospective study design. CONCLUSIONS Lesions in the upper stomach and lesions larger than 20 mm were independent risk factors for perforation during ESD. Patients should be made aware of the estimated high risks of these lesions before undergoing ESD.

A natural course of main duct intraductal papillary mucinous neoplasm of the pancreas with lower likelihood of malignancy.

Objectives: Main duct intraductal papillary mucinous neoplasms (IPMNs) of the pancreas include neoplasms with varying likelihood of progression to malignancy. The aim of this study was to investigate a natural course of main duct IPMNs with a lower likelihood of malignancy. Methods: Twenty main duct IPMNs with a lower likelihood of malignancy, which was defined as mural nodule of less than 10 mm or no visualized mural nodule, and negative result of cytological examination of pancreatic juice, underwent regular ultrasound every 3 months. Special imaging examinations and additional pancreatic juice cytological examination were performed when necessary. Surgery was considered when a mural nodule enlarged to 10 mm or the cytological examination result indicated malignancy. Results: During a mean of 70 months, 12 IPMNs (60%) did not progress and 6 (30%) progressed within a lower likelihood of malignancy. The remaining 2 IPMNs (10%) progressed to meet the criteria for resection, underwent surgery, and were demonstrated to be carcinomas. Conclusions: Main duct IPMN with a lower likelihood of malignancy was divided into 2 subgroups: neoplasm that progressed and that which did not progress during its natural course. The former should be resected considering its malignant potential, whereas the latter may be managed nonsurgically as long as it stays unchanged.Abbreviations: IPMN - intraductal papillary mucinous neoplasm, WHO - World Health Organization, US - ultrasound, CT - computed tomography, ERCP - endoscopic retrograde cholangiopancreatography, EUS - endoscopic ultrasound, MRCP - magnetic resonance cholangiopancreatography

JSUM ultrasound elastography practice guidelines: pancreas

Ultrasound elastography is a relatively new diagnostic technique for measuring the elasticity (hardness) of tissue. Eleven years have passed since the debut of elastography. Various elastography devices are currently being marketed by manufacturers under different names. Pancreatic elastography can be used not only with transabdominal ultrasonography but also with endoscopic ultrasonography, but some types of elastography are difficult to perform for the pancreas. These guidelines aim to classify the various types of elastography into two major categories depending on the differences in the physical quantity (strain, shear wave), and to present the evidence for pancreatic elastography and how to use pancreatic elastography in the present day. But the number of reports on ultrasound elastography for the pancreas is still small, and there are no reports on some elastography devices for the pancreas. Therefore, these guidelines do not recommend methods of imaging and analysis by elastography device.

Improved diagnosis of well‐differentiated hepatocellular carcinoma with gadolinium ethoxybenzyl diethylene triamine pentaacetic acid‐enhanced magnetic resonance imaging and Sonazoid contrast‐enhanced ultrasonography

Aim:  Two new imaging modalities have been developed recently that are directed at the focal liver lesions: gadolinium ethoxybenzyl diethylene triamine pentaacetic acid (Gd‐EOB‐DTPA)‐enhanced magnetic resonance imaging (MRI) and Sonazoid contrast‐enhanced ultrasonography (CEUS). We investigated the usefulness of these modalities for the diagnosis of small (<2 cm), well‐differentiated hepatocellular carcinoma (HCC).

Human equilibrative nucleoside transporter 1 level does not predict prognosis in pancreatic cancer patients treated with neoadjuvant chemoradiation including gemcitabine

BackgroundGemcitabine is a key drug for the treatment of pancreatic cancer. Human equilibrative nucleoside transporter 1 (hENT1) is a major transporter responsible for gemcitabine uptake into cells. This study was conducted to elucidate the association between expression level of hENT1 and outcome for pancreatic cancer patients treated with neoadjuvant therapy including gemcitabine.MethodsSixty-three patients who underwent neoadjuvant chemoradiation followed by curative surgery for pancreatic ductal adenocarcinomas were included. Immunohistochemistry was performed using resected specimens and the staining intensity of hENT1 was scored as having no staining, low staining, or high staining; the former two were defined as negative expression of hENT1. The association between expression level of hENT1 and overall survival was evaluated by Cox proportional regression model.ResultsExpression level of hENT1 was evaluated as positive in 22 (35%) patients, and as negative in 41 (65%) patients. Univariate analysis showed that regional lymph node metastasis, vascular permeation, and perineural invasion are prognostic factors; however, expression level of hENT1 did not reach statistical significance. Multivariate analysis showed only vascular permeation as a prognostic factor.ConclusionsExpression level of hENT1 was not associated with prognosis for pancreatic cancer patients who were treated with neoadjuvant chemoradiation including gemcitabine.

Elastography for the pancreas: Current status and future perspective

Elastography for the pancreas can be performed by either ultrasound or endoscopic ultrasound (EUS). There are two types of pancreatic elastographies based on different principles, which are strain elastography and shear wave elastography. The stiffness of tissue is estimated by measuring the grade of strain generated by external pressure in the former, whereas it is estimated by measuring propagation speed of shear wave, the transverse wave, generated by acoustic radiation impulse (ARFI) in the latter. Strain elastography is difficult to perform when the probe, the pancreas and the aorta are not located in line. Accordingly, a fine elastogram can be easily obtained in the pancreatic body but not in the pancreatic head and tail. In contrast, shear wave elastography can be easily performed in the entire pancreas because ARFI can be emitted to wherever desired. However, shear wave elastography cannot be performed by EUS to date. Recently, clinical guidelines for elastography specialized in the pancreas were published from Japanese Society of Medical Ultrasonics. The guidelines show us technical knacks of performing elastography for the pancreas.