Rei Suzuki

Prospective evaluation of the optimal number of 25-gauge needle passes for endoscopic ultrasound-guided fine-needle aspiration biopsy of solid pancreatic lesions in the absence of an onsite cytopathologist

Introduction:  A prior study with 22‐gauge needles recommended more than seven needle passes for endoscopic ultrasound‐guided fine‐needle aspiration biopsy (EUS‐FNA) of solid pancreatic lesions (SPL) without onsite cytopathology for optimal acquisition of cytopathological diagnosis. The feasibility of this recommendation should be re‐evaluated considering the later development and popularity of 25‐gauge EUS‐FNA needles. We aimed to determine the optimal number of needle passes for cytopathological specimen acquisition with 25‐gauge needles for EUS‐FNA of SPL.

Efficacy of endoscopic ultrasonography-guided fine needle aspiration for pancreatic neuroendocrine tumor grading

AIM To evaluate the efficacy of endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) for grading pancreatic neuroendocrine tumors (PNETs). METHODS A total of 22 patients were diagnosed with PNET by EUS-FNA between October 2001 and December 2013 at Fukushima Medical University Hospital. Among these cases, we targeted 10 PNET patients who were evaluated according to the World Health Organization (WHO) 2010 classification. Surgery was performed in eight patients, and chemotherapy was performed in two patients due to multiple liver metastases. Specimens obtained by EUS-FNA were first stained with hematoxylin and eosin and then stained with chromogranin, synaptophysin, CD56, and Ki-67. The specimens were graded by the Ki-67 index according to the WHO 2010 classification. Specimens obtained by surgery were graded by the Ki-67 index and mitotic count (WHO 2010 classification). For the eight specimens obtained by EUS-FNA, the Ki-67 index results were compared with those obtained by surgery. In the two cases treated with chemotherapy, the effects and prognoses were evaluated. RESULTS The sampling rate for histological diagnosis by EUS-FNA was 100%. No adverse effects were observed. The concordance rate between specimens obtained by EUS-FNA and surgery was 87.5% (7/8). For the two cases treated with chemotherapy, case 1 received somatostatin analog therapy and transcatheter arterial infusion (TAI) targeting multiple liver metastases. Subsequent treatment consisted of everolimus. During chemotherapy, the primary tumor remained unconfirmed, although the multiple liver metastases diminished dramatically. Case 2 was classified as neuroendocrine carcinoma (NEC) according to the Ki-67 index of a specimen obtained by EUS-FNA; therefore, cisplatin and irinotecan therapy was started. However, severe adverse effects, including renal failure and diarrhea, were observed, and the therapy regimen was changed to cisplatin and etoposide. TAI targeting multiple liver metastases was performed. Although the liver metastases diminished, the primary tumor remained unconfirmed. These chemotherapy regimens had immediate effects for both unresectable neuroendocrine tumor (NET) and NEC cases. These two subjects are still alive. CONCLUSION EUS-FNA was effective for PNET diagnosis and Ki-67 index grading for WHO 2010 classification, enabling informed decisions on unresectable PNET treatment by identifying NET or NEC.

Feasibility and preliminary accuracy of high-resolution imaging of the liver and pancreas using FNA compatible microendoscopy (with video).

BACKGROUND EUS-guided FNA is one of the few techniques that can obtain cells and tissue from the liver and pancreas. However, the technique remains vulnerable to poor specimen quality and sampling error. OBJECTIVE To evaluate the ability of a high-resolution microendoscope (HRME) to visualize the cellular and architectural features of normal and malignant liver and pancreatic tissue ex vivo, to assess the ability of endosonographers to identify normal and neoplastic tissue by using HRME images, and to demonstrate preliminary technical feasibility of in vivo HRME imaging via EUS fine-needle puncture (FNP). DESIGN Ex vivo pilot feasibility study in human tissue; in vivo swine model. SETTING Two academic medical centers. PATIENTS Co-registered HRME images and biopsies were obtained from surgically resected hepatic and pancreatic tissues from 44 patients. INTERVENTION Images were divided into training (12 images) and test (80 images) sets containing a range of normal and pathologic conditions for each organ. After viewing the training sets, 9 endosonographers attempted to distinguish malignant tissue from normal or benign lesions in the test sets, each of which contained 40 unique images with individual diagnoses from pathology. MAIN OUTCOME MEASUREMENTS Image acquisition feasibility, ex vivo and in vivo. Ability of endosonographers to recognize features of normal/benign or malignant tissue from the liver and pancreas. RESULTS Overall, the 9 endosonographers achieved median accuracy figures of 85% in the liver and 90% in the pancreas. The endosonographers with prior experience in reading HRME images achieved accuracy rates between 90% and 95%. Technical feasibility of HRME imaging through a 19-gauge EUS-FNP needle was demonstrated in an in vivo swine model. LIMITATIONS Ex vivo study. CONCLUSION High-resolution microendoscopy allows real-time imaging of cellular-level morphology and tissue architecture in the liver and pancreas. The technique appears to have a short learning curve, after which endosonographers achieved high accuracy rates in distinguishing malignant tissue from normal and benign pathology in both organs. Translating this imaging platform to the in vivo setting appears technically feasible.

Pancreatobiliary drainage using the EUS-FNA technique: EUS-BD and EUS-PD

The recent progression of endoscopic ultrasonography (EUS) enables EUS-guided transmural drainage based on the EUS-guided fine-needle aspiration biopsy technique. Prior to the development of EUS-guided drainage procedures, the options for treating obstruction of the pancreatobiliary system included surgical drainage, percutaneous drainage using ultrasound and radiological guidance, and endoscopic (non EUS-guidance) transmural drainage. Today, using EUS guidance and dedicated accessories, it is possible to create bilio- or pancreato-digestive anastomosis, EUS-guided biliary drainage (EUS-BD), and EUS-guided pancreatic drainage (EUS-PD). The recent literature describes that EUS-BD and EUS-PD have acceptable success and complication rates. These procedures are anticipated for use as alternatives to surgery or percutaneous drainage when endoscopic transpapillary procedures fail.

Diagnostic yield of EUS-FNA-based cytology distinguishing malignant and benign IPMNs: A systematic review and meta-analysis

OBJECTIVES Differential diagnosis of malignant and benign intraductal papillary mucinous neoplasms (IPMNs) is essential to determine the optimal treatment. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is currently used to diagnose pancreatic cystic lesions worldwide, but few studies have focused on the diagnostic yield to distinguish malignant and benign IPMNs. Therefore, we aim to systematically review the diagnostic yield of EUS-FNA-based cytology to distinguish malignant and benign IPMNs. METHODS Relevant studies with a reference standard of definitive surgical histology which published between 2002 and 2012 were identified via MEDLINE and SCOPUS. Malignant IPMNs included invasive adenocarcinoma, carcinoma in situ, and high-grade dysplasia. RESULTS Four studies with 96 patients were included in this meta-analysis. For diagnostic yield of EUS-FNA-based cytology distinguishing malignant and benign IPMNs, the pooled sensitivity and specificity were 64.8% (95% CI, 0.44-0.82) and 90.6% (95% CI, 0.81-0.96), respectively. Similarly, the positive likelihood ratio and negative likelihood ratio were 6.35 (95% CI, 2.95-13.68) and 0.43 (95% CI, 0.14-1.34), respectively. Malignant IPMNs were observed in 20.8% (20/96) of patients in EUS-FNA studies. CONCLUSIONS EUS-FNA-based cytology has good specificity but poor sensitivity in differentiating benign from malignant IPMNs. Newer techniques or markers are needed to improve diagnostic yield.

Diagnostic yield of endoscopic retrograde cholangiopancreatography‐based cytology for distinguishing malignant and benign intraductal papillary mucinous neoplasm: Systematic review and meta‐analysis

Published studies have revealed the diagnostic yield of cytology obtained from endoscopic retrograde cholangiopancreatography (ERCP) in distinguishing malignant and benign intraductal papillary mucinous neoplasm (IPMN). However as a result of small sample sizes, the overall magnitude of benefit is unknown. Additionally, the optimal endoscopic procedure for cytology acquisition is also unclear. The aim of the present study was to evaluate the diagnostic yield of ERCP‐based cytology in patients with IPMN and clarify the optimal sampling technique.

Two-dimensional culture of human pancreatic adenocarcinoma cells results in an irreversible transition from epithelial to mesenchymal phenotype.

Many commercially available cell lines have been in culture for ages, acquiring phenotypes that differ from the original cancers from which these cell lines were derived. Therefore, research on new cell lines could improve the success rates of translational research in cancer. We have developed methods for the isolation and culture of human pancreatic ductal adenocarcinoma (PDAC) cells from murine xenografts of human PDAC. We hypothesize that phenotypes of PDAC cells are modified by in vitro culture conditions over time and by in vivo implantation. Patient-derived xenografts were created in immunodeficient mice using surgically resected tumor specimens. These murine xenografts were then used to establish human PDAC cell lines in culture. Earlier (<5) passage and later (>20) passage cell lines were evaluated separately regarding proliferation, cell cycle, genetic mutations, invasiveness, chemosensitivity, tumorigenesis, epithelial–mesenchymal transition (EMT) status, and proteomics. Later passage cells accelerated their doubling time and colony formation, and were more concentrated in the G0/G1 phase and less in the G2/M checkpoint phase. Later passage cells were more sensitive to gemcitabine and 5-fluorouracil than earlier passage cells, but all four new cell lines were more chemo-resistant compared with commercial ATCC cell lines. EMT induction was observed when establishing and passaging cell lines in vitro and furthermore by growing them as subcutaneous tumors in vivo. This study demonstrates a novel approach to the establishment of PDAC cell lines and observes a process by which newly established cell lines undergo phenotypic changes during in vitro culture and in vivo tumorigenesis. This may help explain differences of treatment effects often observed between experiments conducted in vitro, in vivo, and in human clinical trials.

Preparation and evaluation of polyethyleneimine-single walled carbon nanotube conjugates as vectors for pancreatic cancer treatment

High quality single-walled carbon nanotubes (SWNTs) were obtained following a new purification procedure, based on using Cl2 gas at high temperature. Cl2-treated SWNTs were fluorinated and modified with branched polyethyleneimine (PEI) to afford covalently functionalised PEI-SWNTs, which were then tested for cytotoxicity both in vitro (HPNE and BxPC3 pancreatic cell lines) and in vivo (BxPC3 xenografts from nude mice) to establish that functionalization with lower molecular weight PEI (600 and 1800 Da) achieved higher cell viability in MTT assay. A shortened version of the nanotubes, PEI(1800)-cut-SWNT (1800 Da branched PEI), was also prepared and tested for cellular internalization in the BxPC3 adenocarcinoma cell line. Laser confocal imaging of the cells after incubation in the presence of RhoB-PEI(1800)-cut-SWNT (covalently labelled with rhodamine B) indicates that the PEI(1800)-cut-SWNTs can reach both the cytoplasm and nucleus of pancreatic cancer cells.

An automated spring-loaded needle for endoscopic ultrasound-guided abdominal paracentesis in cancer patients.

AIM To evaluate the feasibility of using an automated spring-loaded needle device for endoscopic ultrasound (EUS)-guided abdominal paracentesis (EUS-P) to see if this would make it easier to puncture the mobile and lax gastric wall for EUS-P. METHODS The EUS database and electronic medical records at Fukushima Medical University Hospital were searched from January 2001 to April 2011. Patients with a history of cancer and who underwent EUS-P using an automated spring-loaded needle device with a 22-gauge puncture needle were included. The needle was passed through the instrument channel and advanced through the gastrointestinal wall under EUS guidance into the echo-free space in the abdominal cavity and ascitic fluid was collected. The confirmed diagnosis of malignant ascites included positive cytology and results from careful clinical observation for at least 6 mo in patients with negative cytology. The technical success rate, cytology results and complications were evaluated. RESULTS We found 11 patients who underwent EUS-P with an automated spring-loaded needle device. In 4 cases, ascites was revealed only with EUS but not in other imaging modalities. EUS-P was done in 7 other cases because there was minimal ascitic fluid and no safe window for percutaneous abdominal aspiration. Ascitic fluid was obtained in all cases by EUS-P. The average amount aspirated was 14.1 mL (range 0.5-38 mL) and that was sent for cytological exam. The etiology of ascitic fluid was benign in 5 patients and malignant in 6. In all cases, ascitic fluid was obtained with the first needle pass. No procedure-related adverse effects occurred. CONCLUSION EUS-P with an automated spring-loaded needle device is a feasible and safe method for ascites evaluation.

The role of endoscopic ultrasound in pancreatic cancer screening.

Pancreatic cancer (PC) is a highly lethal cancer. Despite a significant advancement in cancer treatment, the mortality rate of PC is nearly identical to the incidence rates. Early detection of tumor or its precursor lesions with dysplasia may be the most effective approach to improve survival. Screening strategies should include identification of the population at high risk of developing PC, and an intense application of screening tools with adequate sensitivity to detect PC at an early curable stage. Endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) seem to be the most promising modalities for PC screening based on the data so far. EUS had an additional advantage over MRI by being able to obtain tissue sample during the same examination. Several questions remain unanswered at this time regarding the age to begin screening, frequency of screening, management of asymptomatic pancreatic lesions detected on screening, timing of resection, and extent of surgery and impact of screening on survival. Novel techniques such as needle-based confocal laser endomicroscopy (nCLE), along with biomarkers, may be helpful to identify pancreatic lesions with more aggressive malignant potential. Further studies will hopefully lead to the development of strategies combining EUS with other technological/biological advancements that will be cost-effective and have an impact on survival.