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Although the number of minimally invasive liver resections (MILRs) has been steadily increasing in many institutions, minimally invasive anatomic liver resection (MIALR) remains a complicated procedure that has not been standardized. We present the results of a survey among expert liver surgeons as a benchmark for standardizing MIALR.We administered this survey to 34 expert liver surgeons who routinely perform MIALR. The survey contained questions on personal experience with liver resection, inflow/outflow control methods, and identification techniques of intersegmental/sectional planes (IPs).All 34 participants completed the survey; 24 experts (70%) had more than 11 years of experience with MILR, and over 80% of experts had performed over 100 open resections and MILRs each. Regarding the methods used for laparoscopic or robotic anatomic resection, the Glissonean approach (GA) was a more frequent procedure than the hilar approach (HA). Although hepatic veins were considered essential landmarks, the exposure methods varied. The top three techniques that the experts recommended for identifying IPs were creating a demarcation line, indocyanine green negative staining method, and intraoperative ultrasound.Minimally invasive anatomic liver resection remains a challenging procedure; however, a certain degree of consensus exists among expert liver surgeons.

Background Although postoperative pancreatic fistula (POPF) is a common and critical complication of pancreatoduodenectomy (PD), effective strategies to prevent POPF have not yet been completely developed. Because appropriate management of POPF is important to reduce the mortality rate after PD, in this study we aimed to evaluate our approach for the management of POPF after PD, including the postoperative course. Methods This retrospective study included 605 consecutive patients who underwent PD at our hospital between 2010 and 2020. All patients who developed POPF were first managed conservatively, with drainage tubes placed during surgery retained to manage POPF. In cases wherein conservative treatment was unsuccessful, open drainage, followed by continuous negative pressure and continuous irrigation, was used. For open drainage, the surgical wound was opened bluntly (approximate length, 5 cm) under local anesthesia, and the fluid was directly and completely drained. Results The prevalence of POPF of grades B and C was 15.4% (n = 93) and 0.33% (n = 2), respectively. Of these patients, 1 required reoperation, 43 recovered with conservative management only, 47 required open drainage, and 4 required image-guided percutaneous drainage. Postoperative hemorrhage with a pseudoaneurysm was identified in 3 (0.66%) patients. The postoperative in-hospital mortality rate was low (n = 1, 0.16%). The rate of successful POPF management was 98.9%. Conclusion Based on our high success rate in POPF management, we consider open drainage to be a safe primary management method for POPF.

Isolating the root of the splenic artery (SPA) is a challenging procedure in laparoscopic distal pancreatectomy (LDP). We investigated the usefulness of evaluation of the relationship between the SPA and pancreatic parenchyma using three-dimensional computed tomography (3D-CT). In total, 104 patients were evaluated. The relationship between the SPA and pancreatic parenchyma was classified into two types: buried and non-buried. Video clips of 50 patients who underwent LDP requiring isolation of the SPA root were reviewed to determine whether the classification is related to difficulty of LDP. Of the 50 assessed patients who underwent LDP, the relationship between the SPA and pancreatic parenchyma was the buried type in 30 (60.0%) and non-buried type in 20 (40.0%). The buried type was associated with a significantly longer median operative time than the non-buried type (285.0 vs. 235.5 min, respectively; P < 0.01). The median time required to isolate the SPA in the buried type (25.8 min; range, 4.0–101 min) was significantly longer than that in the non-buried type (7.0 min; range, 1.0–27.0 min) (P < 0.001). Preoperative 3D-CT around the pancreas is practical for predicting the difficulty of SPA isolation and determining the safety of the procedure.

Purpose In this systematic review, we aimed to clarify the useful anatomic structures and assess available surgical techniques and strategies required to safely perform minimally invasive anatomic liver resection (MIALR), with a particular focus on the hepatic veins (HVs). Methods A systematic review was conducted using MEDLINE/PubMed for English articles and Ichushi databases for Japanese articles through September 2020. The quality assessment of the articles was performed in accordance with the Scottish Intercollegiate Guidelines Network (SIGN). Results A total of 3,372 studies were obtained, and 59 were selected and reviewed. Due to the limited number of published comparative studies and case series, the degree of evidence from our review was low. Thirty-two articles examined the anatomic landmarks and crucial structures for approaching HVs. Regarding the direction of HV exposure, 32 articles focused on the techniques and advantages of exposing HVs from either the root or the periphery. Ten articles focused on the techniques to perform a segmentectomy 8 in particularly difficult cases of MIALR. In seven articles, bleeding control from HVs was also discussed. Conclusions This review may help experts reach a consensus regarding the best approach to the management of hepatic veins during MIALR.

Pancreatic cancer is the most lethal malignancy of the digestive organs. Although pancreatic resection is essential to radically cure this refractory disease, the multi-organ resection involved, as well as sequelae such as glucose tolerance insufficiency and severe complications impose a heavy burden on these patients. Since the late twentieth century, minimally invasive surgery has become more popular for the surgical management of digestive disease and pancreatic cancer. Minimally invasive pancreatic resection (MIPR), including pancreaticoduodenectomy and distal pancreatectomy, is now a treatment option for pancreatic cancer. Some evidence suggests that MIPR for pancreatic cancer provides comparable oncological outcomes to open surgery, with some advantages in perioperative outcomes. However, as this evidence is retrospective, prospective investigations, including randomized controlled trials, are necessary. Because neoadjuvant therapy for resectable or borderline-resectable pancreatic cancer and conversion surgery for initially unresectable pancreatic cancer has become more common, the feasibility of MIPR after neoadjuvant therapy or as conversion surgery requires further assessment. It is expected that progress in surgical techniques and devices, as well as the standardization of surgical procedures and widespread educational programs will improve the outcomes of MIPR.

Aim As the prognosis of patients who undergo resection for pancreatic cancer has improved, reports of remnant pancreatic cancer after pancreatic cancer resection have been increasing. Previous studies regarding early‐stage pancreatic cancer showed a high incidence of remnant pancreatic cancer in these patients. The aim of this study was to investigate the incidence of remnant pancreatic cancer according to the degree of progression of the initial pancreatic cancer. Methods Patients who underwent partial pancreatic resection for primary pancreatic cancer were retrospectively reviewed and divided into an early‐stage group and an advanced‐stage group according to the stage of the initial cancer. Patient characteristics and long‐term outcomes, including development of remnant pancreatic cancer, were compared between the two groups. Results This study included 321 patients who underwent partial pancreatectomy for pancreatic cancer; 32 patients in the early‐stage group and 289 patients in the advanced‐stage group. Remnant pancreatic cancer developed in 19 patients (5.9%); seven patients (21.9%) in the early‐stage group and 12 patients (4.5%) in the advanced‐stage group. The cumulative incidence of remnant pancreatic cancer according to the Kaplan–Meier method was comparable between the two groups (5‐year cumulative incidence: 20.6% vs 9.9%, early‐stage group vs advanced‐stage group; P = .1827). Conclusion Our results suggested that the potential for developing remnant pancreatic cancer was comparable between the early‐stage and the advanced‐stage groups. Therefore, the incidence of remnant pancreatic cancer may increase along with improved pancreatic cancer treatment., Remnant pancreatic cancer occasionally develops after pancreatic resection for pancreatic cancer. Although the proportion of patients who develop remnant pancreatic cancer was larger in early‐stage pancreatic cancer than advanced‐stage cancer, the potential for developing remnant pancreatic cancer was comparable between early‐stage cancer and advanced‐stage cancer.

Hypoxia is a characteristic feature of the tumor microenvironment in pancreatic ductal adenocarcinoma (PDAC). We have recently explored new targeting molecules and pathways in PDAC cells under hypoxic conditions. In this study, we performed a microarray experiment to analyze the genes up-regulated in PDAC cell lines under hypoxia compared to normoxia, and identified human family with sequence similarity 115, member C (FAM115C) as a candidate gene for further study. Our data showed that FAM115C was overexpressed in PDAC cell lines under hypoxia, and FAM115C inhibition promoted PDAC cell migration and invasion in vitro. FAM115C inhibition did not affect tumor cell proliferation in PDAC. Immunohistochemically, FAM115C expression was observed ubiquitously in normal pancreas, pancreatic intraepithelial neoplasia (PanIN) and PDAC tissue, and it was located mainly in the nucleus but also in the cytoplasm of cells. In qPCR analysis, high expression of FAM115C was correlated with better prognosis in patients with PDAC. Our findings suggest that FAM115C could be a novel tumor suppressor associated with prolonged survival in patients with PDAC.

An 83-year-old woman underwent laparoscopic distal gastrectomy and Billroth Ⅱ reconstruction for gastric cancer. Since histopathological examination revealed that the lesion was Stage ⅢA, she had started taking S-1 as an adjuvant chemotherapy 7 weeks after gastrectomy. Seventeen days later after taking S-1 administration, she felt nauseous and self-interrupted. Nineteen days later, she was urgently hospitalized. Esophagogastroduodenoscopy(EGD)showed anastomotic lumen was open, but reconstructed small intestine mucosal damage was found, and reconstructed small intestine muscle layer was fused to anastomotic region. On 50th day of hospitalization, mucosa was regenerated and endoscopic balloon dilatation (EBD)was performed from 78th day. She was discharged on 151th day of hospitalization after 7 times of EBD. One year later, she does not need EBD and can be taken orally and has no recurrence.

The Brisbane 2000 Terminology for Liver Anatomy and Resections, based on Couinaud's segments, did not address how to identify segmental borders and anatomic territories of less than one segment. Smaller anatomic resections including segmentectomies and subsegmentectomies, have not been well defined. The advent of minimally invasive liver resection has enhanced the possibilities of more precise resection due to a magnified view and reduced bleeding, and minimally invasive anatomic liver resection (MIALR) is becoming popular gradually. Therefore, there is a need for updating the Brisbane 2000 system, including anatomic segmentectomy or less. An online "Expert Consensus Meeting: Precision Anatomy for Minimally Invasive HBP Surgery (PAM-HBP Surgery Consensus)" was hosted on February 23, 2021.The Steering Committee invited 34 international experts from around the world. The Expert Committee (EC) selected 12 questions and two future research topics in the terminology session. The EC created seven tentative definitions and five recommendations based on the experts' opinions and the literature review performed by the Research Committee. Two Delphi Rounds finalized those definitions and recommendations.This paper presents seven definitions and five recommendations regarding anatomic segmentectomy or less. In addition, two future research topics are discussed.The PAM-HBP Surgery Consensus has presented the Tokyo 2020 Terminology for Liver Anatomy and Resections. The terminology has added definitions of liver anatomy and resections that were not defined in the Brisbane 2000 system.

Background Primary gastric synovial sarcoma is extremely rare, only 44 cases have been reported so far, and there have been no reports of laparoscopic endoscopic cooperative surgery for this condition. Case presentation A 45-year-old male patient presented with gastric pain. Esophagogastroduodenoscopy was performed that led to the identification of an 8-mm submucosal tumor in the anterior wall of the antrum, and a kit-negative gastrointestinal stromal tumor was suspected following biopsy. On endoscopic ultrasonography, the boundary of the tumor, mainly composed of the second layer, was depicted as a slightly unclear low-echo region, and a pointless no echo region was scattered inside. A boring biopsy revealed synovial sarcoma. Positron emission tomography did not reveal fluorodeoxyglucose (18F-FDG) accumulation in the stomach or other organs. Thus, the patient was diagnosed with a primary gastric synovial sarcoma, and laparoscopic endoscopic cooperative surgery was performed. The tumor of the antrum could not be confirmed laparoscopically from the serosa, and under intraoperative endoscopy, it had delle on the mucosal surface, which was removed by a method that does not involve releasing the gastric wall. Immunohistochemistry showed that the spindle cells were positive for EMA, BCL-2 protein, TLE-1, and SS18-SSX fusion-specific antibodies but negative for KIT and DOG-1. The final pathological diagnosis was synovial sarcoma of the stomach. The postoperative course was good, and the patient was discharged from the hospital on the 11th postoperative day. Conclusion Resection with laparoscopic endoscopic cooperative surgery (LECS), which has not been reported before, was effective for small synovial sarcomas that could not be confirmed laparoscopically. With the combination of laparoscopic and endoscopic approaches to neoplasia with a non-exposure technique (CLEAN-NET) procedure, it was possible to excise the tumor with the minimum excision range of the gastric serosa without opening the stomach.

Background The concept of Minimally invasive anatomic liver resection (MIALR) is gaining popularity. However, specific technical skills need to be acquired to safely perform MIALR. The "Expert Consensus Meeting: Precision Anatomy for Minimally Invasive HBP Surgery (PAM-HBP Surgery Consensus)" was developed as a special program during the 32nd meeting of the Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS). Methods Thirty-four international experts gathered online for the consensus. A Research Committee performed a comprehensive literature review, classifying studies according to the Scottish Intercollegiate Guidelines Network (SIGN) method. Based on the literature review and experts' opinions, tentative recommendations were drafted and circulated among experts using online Delphi Rounds. Finally, formulated recommendations were presented online in the Expert Consensus Meeting of the JSHBPS on February 23rd, 2021. The final recommendations were validated and finalized by the 2nd Delphi Round in May 2021. Results Seven Clinical Questions (CQs) were selected, and 22 recommendations were formulated. All recommendations reached more than 85% consensus among experts at the final Delphi Round. Conclusions The Expert Consensus Meeting for safely performing MIALR has presented a set of clinical guidelines based on available literature and experts' opinions. We expect these guidelines to have a favorable effect on the safe implementation and development of MIALR.

Although the postoperative recurrence rate for pancreatic neuroendocrine tumors (PNETs) is reported to be 13.5%‐30%, the paucity of valuable biomarkers to predict recurrence poses a problem for the early detection of relapse. Hence, this study aimed to identify new biomarkers to predict the recurrence of PNETs. We performed RNA sequencing (RNA‐Seq) on RNA isolated from frozen primary tumors sampled from all localized G1/G2 PNETs resected curatively from 1998 to 2015 in our institution. We calculated differentially expressed genes (DEGs) in tumor with and without recurrence (≥3 years) for the propensity‐matched cohort. Gene ontology analysis for the identified DEGs was also performed. Furthermore, we evaluated the expression levels of candidate genes as recurrence predictors via immunostaining. Comparison of transcriptional levels in tumors with and without recurrence identified 166 DEGs. Up‐ and downregulated genes with high significance in these tumors were mainly related to extracellular organization and cell adhesion, respectively. We observed the top three upregulated genes, C‐type lectin domain family 3 member A (CLEC3A), matrix metalloproteinase‐7 (MMP7), and lipocalin2 (LCN2) immunohistochemically and compared their levels in recurrent and nonrecurrent tumors. Significantly higher recurrence rate was shown in patients with positive expression of CLEC3A (P = 0.028), MMP7 (P = 0.003), and LCN2 (P = 0.040) than that with negative expression. We identified CLEC3A, MMP7, and LCN2 known to be associated with the phosphatidylinositol‐3‐kinase/Akt pathway, as potential novel markers to predict the postoperative recurrence of PNETs.

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is characterized by cystic dilation of the pancreatic duct, caused by mucin hypersecretion, with slow progression via the adenoma-carcinoma sequence mechanism. Mutation of GNAS at codon 201 is found exclusively in IPMNs, occurring at a rate of 41-75%. Recent advances in molecular biological techniques have demonstrated that GNAS mutation might play a role in the transformation of IPMNs after the appearance of neoplastic cells, rather than in the tumorigenesis of IPMNs. GNAS mutation is observed frequently in the intestinal subtype of IPMNs with MUC2 expression, and less frequently in IPMNs with concomitant pancreatic ductal adenocarcinoma (PDAC). Research has focused on assessing GNAS mutation status in clinical practice using various samples. In this review, we discuss the clinical application of GNAS mutation assessment to differentiate invasive IPMNs from concomitant PDAC, examine the clonality of recurrent IPMNs in the remnant pancreas using resected specimens, and differentiate pancreatic cystic lesions using cystic fluid collected by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), duodenal fluid, and serum liquid biopsy samples.

Accumulation of evidence suggests that neoadjuvant chemotherapy improves the outcomes of borderline resectable pancreatic cancer (BRPC). Gemcitabine plus nab-paclitaxel (GnP) has been widely accepted as systemic chemotherapy for unresectable pancreatic cancer and reportedly results in remarkable tumor shrinkage. This study was performed to evaluate the safety and efficacy of neoadjuvant chemotherapy using neoadjuvant GnP for BRPC. The medical records of 57 patients who underwent treatment of BRPC from 2010 to 2017 were retrospectively reviewed. The patient characteristics and short- and intermediate-term outcomes were compared between the GnP and upfront surgery (UFS) groups. The GnP group comprised 31 patients and the UFS group comprised 26 patients. The patient characteristics were comparable with the exception of a higher prevalence of arterial involvement in the GnP group. Twenty-seven of the 31 patients (87%) in the GnP group and all 26 patients in the UFS group underwent resection. The GnP group showed a significantly shorter operation time (429 vs. 509.5 min, p = 0.0068), less blood loss (760 vs. 1324 ml, p = 0.0115), and a higher R0 resection rate (100% vs. 77%, p = 0.0100) than the UFS group. Postoperative complications and hospital stay were comparable between the two groups, and no treatment-related mortality occurred in either group. Both the disease-free survival and overall survival times were significantly longer in the GnP group (p = 0.0018 and p = 0.0024, respectively). Neoadjuvant GnP is a safe and effective treatment strategy for BRPC. It potentially improves patients’ prognosis and facilitates surgical procedures.

This study aimed at investigating the function and significance of CD110 expression in pancreatic cancer. We performed immunohistochemical staining for CD110 expression in tumor samples from 86 patients with pancreatic cancer. We evaluated clinical outcomes and other clinicopathological factors to determine the significance of CD110 on survival and liver metastasis. We examine thrombopoietin–CD110 signaling in cancer cell extravasation in vitro and in vivo. We investigated the effects of CD110 knockdown on liver metastasis in a splenic xenograft mouse model. CD110 expression in cancer cells was associated with low-histological-grade invasive ductal carcinoma, and patients with high CD110 expression had poorer prognosis (P = 0.0003). High CD110 expression was an independent predictor of liver metastasis (P = 0.0422). Knockdown of CD110 expression significantly attenuated cell migration and invasion. Treatment with thrombopoietin promoted pancreatic cancer cell extravasation. In the presence of thrombopoietin, CD110 increased cell viability through the activation of the ERK–MYC signaling pathway. Knockdown of CD110 expression inhibited liver metastases in the mouse model. CD110 promotes pancreatic cancer progression and it may serve as a predictive factor for liver metastasis.

Introduction: Although neoadjuvant treatment is recommended for patients with borderline resectable pancreatic cancer (BRPC), no standard neoadjuvant regimen has been established for BRPC with arterial involvement (BRPC-A), which is associated with a higher risk of margin-positive resection and poorer prognosis than BRPC with only venous involvement. Gemcitabine plus nab-paclitaxel (GnP) has been reported to significantly reduce tumor size in metastatic pancreatic cancer, and some retrospective studies suggested that neoadjuvant GnP for BRPC improved resectability and survival. Methods and analysis: A prospective multicenter single-arm phase II study is conducted to evaluate the safety and efficacy of GnP as neoadjuvant chemotherapy for BRPC-A. The primary endpoint is the R0 resection rate. The secondary endpoints are the neoadjuvant chemotherapy response rate, resection rate, pathological response rate, incidence rate of adverse events, and quality of life. Ethics and dissemination: This study protocol was approved by the institutional review board of Kyushu University (no. 181). The results will be published in a peer-reviewed journal and will be presented at medical meetings. Highlights: Strategy for borderline resectable pancreatic cancer involving arteries (BRPC-A). There is no standard regimen for neoadjuvant chemotherapy for BRPC-A. Gemcitabine plus nab-paclitaxel (GnP) shows significant tumor shrinkage. Neoadjuvant GnP for BRPC-A increases resectability and margin-negative resection.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a desmoplastic reaction caused by cancer-associated fibroblasts (CAFs), which provokes treatment resistance. CAFs are newly proposed to be heterogeneous populations with different functions within the PDAC microenvironment. The most direct sources of CAFs are resident tissue fibroblasts and mesenchymal stem cells, however, the origins and functions of CAF subtypes remain unclear. Here, we established allogeneic bone marrow (BM) transplantation models using spontaneous PDAC mice, and then investigated what subtype cells derived from BM modulate the tumor microenvironment and affect the behavior of pancreatic cancer cells (PCCs). BM-derived multilineage hematopoietic cells were engrafted in recipient pancreas, and accumulated at the invasive front and central lesion of PDAC. We identified BM macrophages-derived CAFs in tumors. BM-derived macrophages treated with PCC-conditioned media expressed CAF markers. BM-derived macrophages led the local invasion of PCCs in vitro and enhanced the tumor invasive growth in vivo. Our data suggest that BM-derived cells are recruited to the pancreas during carcinogenesis and that the specific subpopulation of BM-derived macrophages partially converted into CAF-like cells, acted as leading cells, and facilitated pancreatic cancer progression. The control of the conversion of BM-derived macrophages into CAF-like cells may be a novel therapeutic strategy to suppress tumor growth.

Pancreatic cancer is the most lethal malignancy of the digestive organs. Although pancreatic resection is essential to radically cure this refractory disease, the multi-organ resection involved, as well as sequelae such as glucose tolerance insufficiency and severe complications impose a heavy burden on these patients. Since the late twentieth century, minimally invasive surgery has become more popular for the surgical management of digestive disease and pancreatic cancer. Minimally invasive pancreatic resection (MIPR), including pancreaticoduodenectomy and distal pancreatectomy, is now a treatment option for pancreatic cancer. Some evidence suggests that MIPR for pancreatic cancer provides comparable oncological outcomes to open surgery, with some advantages in perioperative outcomes. However, as this evidence is retrospective, prospective investigations, including randomized controlled trials, are necessary. Because neoadjuvant therapy for resectable or borderline-resectable pancreatic cancer and conversion surgery for initially unresectable pancreatic cancer has become more common, the feasibility of MIPR after neoadjuvant therapy or as conversion surgery requires further assessment. It is expected that progress in surgical techniques and devices, as well as the standardization of surgical procedures and widespread educational programs will improve the outcomes of MIPR.

Cases of “pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm” (IPMN) have multiple PDAC lesions more frequently than cases of “PDAC without IPMN”. However, the mechanism of carcinogenesis in this former disease category remains unknown. The main objective of this work was thus to investigate the effects of chronic inflammation on carcinogenesis in PDAC cases. We selected 31 “PDAC concomitant with IPMN” patients and 58 “PDAC without IPMN” patients and pathologically evaluated their background pancreatic parenchyma. Fibrosis and inflammation scores of background pancreas were higher in “PDAC concomitant with IPMN” than in “PDAC without IPMN” (P

"Mucoepidermoid carcinoma (MEC)" has been accepted as a synonym for pancreatic adenosquamous carcinoma (ASC). Pancreatic ASC can show salivary gland-type MEC-like morphology. CRTC1/3-MAML2 fusion gene is a characteristic molecular feature of MEC of the salivary gland. We conducted this study to clarify whether the pancreatic ASC with salivary gland-type MEC-like morphology (Pan-MEC) is a pancreatic counterpart of salivary gland-type MEC (Sal-MEC). We retrospectively analyzed 37 pancreatic ASCs including 16 Pan-MECs and 21 tumors without MEC-like features (ASC-NOS [not otherwise specified]), and we investigated (1) clinicopathologic features, (2) the presence of CRTC1/3-MAML2 fusion gene by reverse transcription polymerase chain reaction, (3) the presence of rearrangement of MAML2 gene by fluorescence in situ hybridization, and (4) mucin core proteins by immunohistochemistry. We also compared 16 Pan-MECs with 20 Sal-MECs by immunohistochemistry for mucin core protein. There were no significant differences of any clinicopathologic characteristics and survival analysis between the Pan-MECs and ASCs-NOS. Of note, the pancreatic ASCs (including Pan-MEC and ASC-NOS) were significantly more aggressive than conventional pancreatic ductal adenocarcinoma. In addition, all Pan-MECs were histologically high-grade. CRTC1/3-MAML2 fusion gene and MAML2 gene rearrangement were not detected in any ASCs including Pan-MECs. There were significant differences of MUC5AC and MUC6 between the Pan-MECs and Sal-MECs, but no significant differences of mucin core protein between the Pan-MECs and pancreatic ASCs-NOS. Pan-MEC is histologically and biologically high-grade and unrelated to CRTC1/3-MAML2 fusion gene, unlike Sal-MEC which is related to CRTC1/3-MAML2 fusion gene. Pan-MEC is not a pancreatic counterpart of CRTC1/3-MAML2 fusion gene-related Sal-MEC.

Although recent studies revealed that adipose tissue accelerates pancreatic tumor progression with excessive extracellular matrix, key players for desmoplasia in the adipose microenvironment remains unknown. Here, we investigated the roles of adipose tissue-derived stromal cells (ASCs) in desmoplastic lesions and tumor progression by in vitro and in vivo experiments. In a three-dimensional (3-D) organotypic fat invasion model using visceral fat from CAG-EGFP mice, GFP-positive fibroblastic cells infiltrated toward cancer cells. When tumor cells were inoculated into transplanted visceral fat pads in vivo, tumor weights and stromal components were enhanced compared to subcutaneous and orthotopic tumor cells inoculated without fat pads. Expression of αSMA in established human ASCs was lower compared to cancer associated fibroblasts, and the 3-D collagen matrices produced by ASCs cultured in cancer cell-conditioned medium changed from loose to dense structures that affected the motility of cancer cells. Microarray analyses revealed upregulation of S100A4 in ASCs, while S100A4-positive stromal cells were observed at extrapancreatic invasion sites of human pancreatic cancer. The present findings indicate that ASCs are recruited to extrapancreatic invasion sites and produce dense collagen matrices that lead to enhanced tumor progression. Both inhibition of ASCs recruitment and activation could lead to a novel antistromal therapy.

Preoperative nutritional and immunological patient factors have been found to be associated with prognostic outcomes of malignant tumors; however, the clinical significance of these factors in pancreatic ductal adenocarcinoma (PDAC) remains controversial.The aim of this study was to evaluate the prognostic value of nutritional and immunological factors in predicting survival of patients with PDAC.Retrospective studies of 329 patients who underwent surgical resection for PDAC and 95 patients who underwent palliative surgery were separately conducted to investigate the prognostic impact of tumor-related factors and patient-related factors, including Glasgow Prognostic Score (GPS), modified GPS, Prognostic Nutritional Index (PNI), neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio, and lymphocyte/monocyte ratio.In multivariate analysis for patients with surgical resection for PDAC, PNI was an independent factor for overall survival (OS) and disease-free survival. The median OS of patients with PNI ≤ 45 was significantly shorter than that of patients with PNI 45 (17.5 and 36.2 months, respectively; p 0.001). In multivariate analysis for patients undergoing palliative surgery for PDAC, only NLR was an independent prognosis factor. The median OS of patients with NLR 5 was significantly shorter than that of patients with NLR ≤ 5 (2.7 and 8.9 months, respectively; p 0.001).PNI in patients with surgical resection and NLR in patients with palliative surgery for PDAC may be useful prognostic factors.

Endoscopic management is presently the recommended first-line of treatment for biliary strictures. However, surgery still has an important role especially for biliary obstruction (BO) with duodenal obstruction. Even though endoscopic treatment for concurrent BO and gastric-outlet obstruction has been proposed, it is still not widespread. Duodenal obstruction is often associated with malignant BO which makes endoscopic treatment more challenging. Biliary and gastrointestinal double bypass with Roux-en-Y hepaticojejunostomy and gastrojejunostomy is the most common surgical intervention for malignant biliary and gastric-outlet obstruction. A variety of procedures of biliary bypass and gastrointestinal bypass have been reported. According to several studies, mortality rates range from 0% to 7%, while morbidity rates range from 3% to 50%. Higher morbidity was observed in symptomatic patients caused by the disease. Most common morbidity after double bypass was delayed gastric emptying. Recurrence of BO and gastric-outlet obstruction was less frequently seen after surgical bypass compared to after endoscopic treatment. Minimally invasive approach has been applied to double bypass. Studies showed that laparoscopic double bypass has a shorter hospital stay and reduced postoperative pain; however, due to its technical demand, it is still presently an uncommon procedure. Robotic bypass surgery may resolve this issue in the future. Further analyses of outcomes of both surgical and endoscopic treatments are necessary to establish better and suitable palliation options for concurrent biliary and duodenal obstruction caused by unresectable malignant tumors.

Background/Objectives It is often difficult to determine an adequate resection line during pancreatectomy for intraductal papillary mucinous neoplasm involving the main pancreatic duct during partial pancreatectomy. The aim of this study was to evaluate the usefulness of improved peroral pancreatoscopy using SpyGlass-DStm in the preoperative assessment of intraductal papillary mucinous neoplasm involving the main pancreatic duct. Methods We collected and retrospectively analyzed clinicopathological data from seven consecutive patients who underwent preoperative assessment of intraductal papillary mucinous neoplasm involving the main duct using SpyGlass-DStm. Results Good imaging quality of the intraductal protruding lesion was obtained in all seven patients, and only one adverse event was noted wherein a patient had mild pancreatitis. Six patients underwent pancreatectomy. In one patient, masked-type concomitant pancreatic ductal adenocarcinoma and low-length dysplastic lesion was found near the surgical margin, which was not detected by preoperative imaging modalities including SpyGlass-DStm. The sensitivity of targeting biopsy during SpyGlass-DStm to diagnose high-grade dysplasia was 0%. Conclusions SpyGlass-DStm can be safely performed in patients with intraductal papillary mucinous neoplasm involving the main duct, and has excellent visualization of the target lesion. However, challenges include poor diagnostic ability of targeting biopsy, and, therefore, intraoperative frozen section is still needed to obtain negative surgical margins.

Objective: The aim of this study was to evaluate the difficulty of endoscopic retrograde cholangiopancreatography (ERCP) procedures when performed in patients with different types of surgically altered gastrointestinal (GI) anatomies. Summary of background data: Clinical data of 102 consecutive patients with surgically altered GI anatomy who underwent ERCP using a double-balloon enteroscope or a regular gastroendoscope between January 2008 and March 2015 were retrospectively reviewed. Methods: The success rate of reaching the destination, the time until reaching the destination, the success rate of the procedures, and complications were assessed for each type of altered GI anatomy using a double-balloon enteroscope and a regular gastroendoscope. Results: A total of 180 ERCP procedures were performed. The total success rate of reaching the destination was 91% (164 of 180), and that of treatment was 88% (144 of 164). The success rate of reaching the destination in patients with Roux-en-Y hepaticojejunostomy (HJ + R-Y) was significantly lower than that of the other types of reconstruction. The time until reaching the destination was significantly longer in patients after R-Y reconstruction (gastrectomy or HJ) than that after Billroth-II gastrectomy or pancreatoduodenectomy. GI perforation occurred in 2 patients after R-Y reconstruction (1 patient after gastrectomy, and 1 patient after HJ). However, no other complications, such as severe pancreatitis, bleeding, or air embolism, were observed. Conclusions: ERCP for patients with surgically altered GI anatomy is feasible. Improvement of the success rate of reaching the destination in patients after HJ + R-Y and prevention of perforation in those with R-Y reconstruction are necessary.

Specific cell populations leading the local invasion of cancer are called "leading cells". However, the underlying mechanisms are unclear. Here, we identified leading cells in pancreatic cancer and determined how these cells lead and promote cancer cell invasion in the extracellular matrix (ECM). Using three-dimensional matrix remodeling assay, we found that pancreatic stellate cells (PSCs) frequently invaded the collagen matrix with pancreatic cancer cells (PCCs), which invaded behind the invading PSCs. In addition, invading PSCs changed the alignment of collagen fibers, resulting in ECM remodeling and an increase in the parallel fibers along the direction of invading PSCs. Endo180 expression was higher in PSCs than in PCCs, Endo180 knockdown in PSCs attenuated the invasive abilities of PSCs and co-cultured PCCs, and decreased the expression level of phosphorylated myosin light chain 2 (MLC2). In mouse models, Endo180-knockdown PSCs suppressed tumor growth and changes in collagen fiber orientation in co-transplantation with PCCs. Our findings suggest that PSCs lead the local invasion of PCCs by physically remodeling the ECM, possibly via the function of Endo180, which reconstructs the actin cell skeleton by phosphorylation of MLC2.

The aim of this study was to assess the feasibility of prophylactic pancreatojejunostomy after enucleation or limited pancreatic resection regarding the risk of postoperative pancreatic fistula (PF). We retrospectively reviewed the medical records of 32 patients who underwent enucleation or limited pancreatic resection and compared the clinical parameters between patients with ( n = 10) and without ( n = 22) prophylactic pancreatojejunostomy. Prophylactic pancreatojejunostomy was performed in patients with a possible high risk ofPF. No operation-related mortality occurred. Operation time was significantly longer ( P < 0.01) and blood loss significantly greater ( P < 0.01) in patients with pancreatojejunostomy. Overall complications were more frequent ( P = 0.02) and postoperative hospital stay was significantly longer ( P = 0.02) in patients with pancreatojejunostomy. However, other assessed factors including the prevalence of postoperative PF did not differ between groups. In conclusion, prophylactic pancreatojejunostomy is feasible, and its efficacy in preventing PF after enucleation or limited pancreatic resection in high-risk patients will require further study.

Introduction and importance Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is often found incidentally during examination for other diseases. In addition to the risk of malignant transformation, patients with IPMN are at risk of developing pancreatic cancer. We report a case of pancreatic tail cancer that developed separately from a preexisting IPMN after minimally invasive esophagectomy for cancer of the esophagogastric junction and was resected successfully by laparoscopic distal pancreatectomy. Case presentation A 72-year-old man underwent thoracoscopic and laparoscopic esophagectomy for esophagogastric junction cancer. He had undergone surgery for ascending colon cancer 20 years ago. At that time, IPMN was confirmed in the pancreatic body by a preoperative examination. Computed tomography was regularly performed for postoperative work-up and follow-up of the IPMN, and a solid lesion with cystic components was detected in the pancreatic tail 9 months after the operation. On detailed examination, pancreatic ductal adenocarcinoma concomitant with IPMN, accompanied by a retention cyst, was considered. Laparoscopic distal pancreatectomy was successfully performed after neoadjuvant chemotherapy. Pathological diagnosis of the lesion in the pancreatic tail was of an invasive intraductal papillary mucinous carcinoma (ypT3ypN0yM0 ypStageIIA). Clinical discussion If an IPMN is detected during preoperative examination for malignancies of other organs, careful follow-up is necessary due to the high risk of pancreatic cancer development. Furthermore, initial operation with minimally invasive surgery may reduce adhesion and facilitate subsequent surgeries. Conclusion We have provided evidence that supports the importance of a careful follow-up of IPMNs, even if they are low risk., Highlights • Intraductal papillary mucinous neoplasm of the pancreas is found incidentally. • A pre-existing neoplasm led to pancreatic tail cancer in one patient. • Due to careful follow-up of the neoplasm, the secondary cancer was detected rapidly. • It was resected successfully by laparoscopic distal pancreatectomy. • Careful follow is necessary if this neoplasm is detected.

Background Circumportal pancreas is a rare congenital pancreatic anomaly. The aim of this study was to clarify the clinical characteristics of patients with circumportal pancreases undergoing pancreatectomy. Methods The medical records of 508 patients who underwent pancreatectomy were retrospectively reviewed. The prevalence of circumportal pancreas and related anatomical variations were assessed. Surgical procedures and postoperative outcomes were compared in patients with and without circumportal pancreas. Results Circumportal pancreas was observed in 9 of the 508 patients (1.7%). In all nine patients, the portal vein was completely encircled by the pancreatic parenchyma above the level of the splenoportal junction, and the main pancreatic duct ran dorsal to the portal vein. The rate of variant hepatic artery did not differ significantly in patients with and without circumportal pancreas. Pancreatic fistula developed more frequently in patients with than without circumportal pancreas (44% vs. 14%, p = 0.03), but other clinical parameters did not differ significantly in these two groups. Conclusions Despite being rare, circumportal pancreas may increase the risk of postoperative pancreatic fistula in patients undergoing pancreatectomy. However, a prospective, large-cohort study is necessary to determine the real incidence of relevant anatomical variations and the definitive clinical significance of this rare anomaly.

Pancreatic cancer is characterized by increased hyperplasia of fibrotic tissue, termed desmoplasia, and lymph node metastasis is an independent prognostic factor in this disease. However, there are no reports focused on desmoplasia in pancreatic cancer lymph node metastases. The present study evaluated a range of factors and investigated their association with poor prognosis in pancreatic cancer cases with lymph node metastasis, including the degree of desmoplasia in lesions. To identify the poor prognostic factors associated with lymph node metastasis, the present study retrospectively reviewed the clinical data of 65 patients with lymph node metastases that underwent surgical pancreatic cancer resection between 2007 and 2012 at a single institution. The investigation focused on the degree of fibrosis in metastatic lesions in 216 lymph nodes, and investigated associations with prognosis or clinicopathological findings. The ratios of the fibrotic area in metastatic lymph node lesions were evaluated and classified into three categories, high (≥70%), moderate (10–70%) and low (

Management of intraductal papillary mucinous neoplasm is controversial, and several guidelines have aimed to establish an adequate strategy for surgical resection and surveillance. We compared various intraductal papillary mucinous neoplasm guidelines and considered new matters that are pivotal for improved treatment of intraductal papillary mucinous neoplasm. We identified and compared 11 published guidelines, three of which were major guidelines that mainly referred to the diagnosis and treatment of intraductal papillary mucinous neoplasm (International Association of Pancreatology 2012 guidelines, European Study Group on Cystic Tumours of the Pancreas 2013 guidelines, and American Gastroenterological Association 2015 guidelines). The main concerns of these three guidelines were indication for surgery and follow up of non‐resected lesions. Among the differences between the three guidelines, the period of surveillance recommended was the most controversial matter. Meanwhile, several nomograms have been proposed to improve the diagnosis of intraductal papillary mucinous neoplasm from the level of experts' experiences to that of rational systems. We discuss the adequate strategy of surveillance for intraductal papillary mucinous neoplasm with and without pancreatectomy and nomograms aiming to predict the risk of malignancy in patients with intraductal papillary mucinous neoplasm., In this review, we summarize current available guidelines for IPMN, and discuss concerns that are pivotal for improvement of the guidelines.

Laparoscopic surgery as a treatment for congenital biliary dilatation is uncommon. We herein present a series of laparoscopic surgeries for congenital biliary dilatation performed in our institution and review our experience with this approach over a long period of time. Medical records of 36 consecutive patients who underwent laparoscopic surgery for congenital biliary dilatation from 1996 to 2015 were retrospectively reviewed. Data on patient demographics, operative time, blood loss, hospital stay, and complications were evaluated. A comparison between the former period (Group A, 1996–2005) and the latter period (Group B, 2006–2015) was performed. The patients comprised 23 females and 13 males with a median age of 34 years. The median operative time, blood loss, and hospital stay was 493 min, 154 g, and 11 days, respectively. Total early and late complications occurred in 7 (19%) and 2 (5%) patients, respectively. A comparison between Groups A and B revealed no significant difference in operative time or complications, but operative blood loss, open conversion, and hospital stay were significantly lower in Group B than in Group A (P

Pancreatic cancer progression involves components of the tumor microenvironment, including stellate cells, immune cells, endothelial cells, and the extracellular matrix. Although peripancreatic fat is the main stromal component involved in extra-pancreatic invasion, its roles in local invasion and metastasis of pancreatic cancer remain unclear. This study investigated the role of adipose tissue in pancreatic cancer progression using genetically engineered mice (Pdx1-Cre; LSL-KrasG12D; Trp53R172H/+) and an in vitro model of organotypic fat invasion. Mice fed a high fat diet had significantly larger primary pancreatic tumors and a significantly higher rate of distant organ metastasis than mice fed a standard diet. In the organotypic fat invasion model, pancreatic cancer cell clusters were smaller and more elongated in shape and showed increased fibrosis. Adipose tissue-derived conditioned medium enhanced pancreatic cancer cell invasiveness and gemcitabine resistance, as well as inducing morphologic changes in cancer cells and increasing the numbers of lipid droplets in their cytoplasm. The concentrations of oleic, palmitoleic, and linoleic acids were higher in adipose tissue-derived conditioned medium than in normal medium, with these fatty acids significantly enhancing the migration of cancer cells. Mature adipocytes were smaller and the concentration of fatty acids in the medium higher when these cells were co-cultured with cancer cells. These findings indicate that lipolytic and fibrotic changes in peripancreatic adipose tissue enhance local invasiveness and metastasis via adipocyte-released fatty acids. Inhibition of fatty acid uptake by cancer cells may be a novel therapy targeting interactions between cancer and stromal cells.