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Inter- and intratumor heterogeneity is an important cause of treatment failure. In human pancreatic cancer (PC), heterogeneity has been investigated almost exclusively at the genomic and transcriptional level. Morphological heterogeneity, though prominent and potentially easily assessable in clinical practice, remains unexplored. This proof-of-concept study aims at demonstrating that morphological heterogeneity reflects structural and functional divergence. From the wide morphological spectrum of conventional PC, four common and distinctive patterns were investigated in 233 foci from 39 surgical specimens. Twenty-six features involved in key biological processes in PC were analyzed (immuno-)histochemically and morphometrically: cancer cell proliferation (Ki67) and migration (collagen fiber alignment, MMP14), cancer stem cells (CD44, CD133, ALDH1), amount, composition and spatial arrangement of extracellular matrix (epithelial proximity, total collagen, collagen I and III, fibronectin, hyaluronan), cancer-associated fibroblasts (density, αSMA), and cancer-stroma interactions (integrins α2, α5, α1, caveolin-1). All features differed significantly between at least two of the patterns. Stromal and cancer-cell-related features co-varied with morphology and allowed prediction of the morphological pattern. In conclusion, morphological heterogeneity in the cancer-cell and stromal compartments of PC correlates with structural and functional diversity. As such, histopathology has the potential to inform on the operationality of key biological processes in individual tumors.

Simple Summary The great majority, more than 90%, of patients with pancreatic ductal adenocarcinoma (PDAC) die within less than five years after detection of the disease, despite recent treatment advances. The poor prognosis is related to late diagnosis, aggressive disease progression, and tumor resistance to conventional chemotherapy. PDAC tumor tissue is characterized by dense fibrosis and poor nutrient availability. A large portion of the tumor is made up of stromal fibroblasts, the pancreatic stellate cells (PSCs), which are known to contribute to tumor progression in several ways. PSCs have been shown to act as an alternate energy source, induce drug resistance, and inhibit drug availability in tumor cells, however, the underlying exact molecular mechanisms remain unknown. In this literature review, we discuss recent available knowledge about the contributions of PSCs to the overall progression of PDAC via changes in tumor metabolism and how this is linked to therapy resistance. Abstract Pancreatic ductal adenocarcinoma (PDAC), also known as pancreatic cancer (PC), is characterized by an overall poor prognosis and a five-year survival that is less than 10%. Characteristic features of the tumor are the presence of a prominent desmoplastic stromal response, an altered metabolism, and profound resistance to cancer drugs including gemcitabine, the backbone of PDAC chemotherapy. The pancreatic stellate cells (PSCs) constitute the major cellular component of PDAC stroma. PSCs are essential for extracellular matrix assembly and form a supportive niche for tumor growth. Various cytokines and growth factors induce activation of PSCs through autocrine and paracrine mechanisms, which in turn promote overall tumor growth and metastasis and induce chemoresistance. To maintain growth and survival in the nutrient-poor, hypoxic environment of PDAC, tumor cells fulfill their high energy demands via several unconventional ways, a process generally referred to as metabolic reprogramming. Accumulating evidence indicates that activated PSCs not only contribute to the therapy-resistant phenotype of PDAC but also act as a nutrient supplier for the tumor cells. However, the precise molecular links between metabolic reprogramming and an acquired therapy resistance in PDAC remain elusive. This review highlights recent findings indicating the importance of PSCs in aiding growth-permissive metabolic reprogramming and gemcitabine chemoresistance in PDAC.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an extremely poor prognosis, and its treatment remains a challenge. As the existing in vitro experimental models offer only a limited resemblance to human PDAC, there is a strong need for additional research tools to better understand PDAC tumor biology, particularly the impact of the tumor stroma. Here, we report for the first time the establishment and characterization of human PDAC-derived paired primary monolayer cultures of (epithelial) cancer cells (PCCs) and mesenchymal stellate cells (PSCs) derived from the same tumor by the outgrowth method. Characterization of cell morphology, cytostructural, and functional profiles and proteomics-based secretome analysis were performed. All PCCs harbored KRAS and TP53 mutations, and expressed cytokeratin 19, ki-67, and p53, while the expression of EpCAM and vimentin was variable. All PSCs expressed &alpha, smooth muscle actin (&alpha, SMA) and vimentin. PCCs showed a significantly higher growth rate and proliferation than PSCs. Secretome analysis confirmed the distinct nature of PCCs as compared to PSCs and allowed identification of potential molecular regulators of PSC-conditioned medium (PSC-CM)-induced migration of PCCs. Paired primary cultures of PCCs and PSCs derived from the same tumor specimen represent a novel experimental model for basic research in PDAC tumor biology.

// Vegard Tjomsland 1, 2, * , Monica Aasrum 1, * , Thoralf Christoffersen 1 and Ivar P Gladhaug 2, 3 1 Department of Pharmacology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway 2 Department of Hepato-Pancreato-Biliary Surgery, Institute of Clinical Medicine, University of Oslo, Oslo, Norway 3 Department of Hepato-Pancreato-Biliary Surgery, Oslo University Hospital Rikshospitalet, Oslo, Norway * These authors contributed equally to this work Correspondence to: Ivar P Gladhaug, email: i.p.gladhaug@medisin.uio.no Keywords: pancreatic cancer, human pancreatic stellate cells, tumor-stroma interactions, HGF, cancer cell migration Received: November 10, 2016 Accepted: April 26, 2017 Published: May 11, 2017 ABSTRACT The pancreatic stellate cell (PSC) is the principal cell type of the desmoplastic stroma of pancreatic ductal adenocarcinoma (PDAC). PSCs interact with cancer cells and influence the progression of the disease through a complex network of signaling molecules including hepatocyte growth factor (HGF). Functional heterogeneity of PSCs within a tumor might conceivably influence tumor progression. We investigated PSC populations isolated from different human PDACs and examined the effects of PSC-conditioned medium on BxPC-3 and AsPC-1 pancreatic cancer cells. The different PSC populations exhibited a wide range of variation (120−3,000 pg/ml) in their ability to secrete HGF. Media from high-HGF-producing PSCs stimulated phosphorylation of Met, Gab1, and ERK in the cancer cells and induced increases in DNA synthesis and migration which were blocked by the Met inhibitor SU11274, indicating a role of HGF as a mediator. HGF levels produced by PSCs and the effects of PSC media on the cancer cells were increased by IL-1α and inhibited by TGFβ. The functional heterogeneity of PSCs in terms of HGF-mediated tumor-stroma interactions suggests that inhibition of the HGF pathway as a novel treatment approach in PDAC might have different effects in different subsets of patients.

Activated pancreatic stellate cells (PSCs) play a central role in the tumor stroma of pancreatic ductal adenocarcinoma (PDAC). Given the limited availability of patient-derived PSCs from PDAC, immortalized PSC cell lines of murine and human origin have been established, however, it is not elucidated whether differences in species, organ disease status, donor age, and immortalization alter the PSC phenotype and behavior compared to that of patient-derived primary PSC cultures. Therefore, a panel of commonly used PSC cultures was examined for important phenotypical and functional features: three primary cultures from human PDAC, one primary from normal human pancreas, and three immortalized (one from human, two from murine pancreas). Growth rate was considerably lower in primary PSCs from human PDAC. Basal collagen synthesis varied between the PSC cultures, and TGF-&beta, stimulation increased collagen synthesis only in non-immortalized cultures. Differences in secretome composition were observed along with a divergence in the DNA synthesis, migration, and response to gemcitabine of PDAC cell lines that were grown in conditioned medium from the various PSC cultures. The findings reveal considerable differences in features and functions that are key to PSCs and in the interactions with PDAC. These observations may be relevant to researchers when selecting the most appropriate PSC culture for their experiments.

Background The clinical relevance of the classification of ampullary adenocarcinoma (AC) into pancreatobiliary (PB) or intestinal (Int) subtypes has not been resolved. Methods Clinicopathological factors, survival, and localization and treatment of recurrence were investigated for patients with AC and duodenal adenocarcinoma (DC) treated by pancreatoduodenectomy from 2000 to 2015. Results A total of 109 AC (45 PB, 64 Int) and 71 DC (all Int) were identified. Median overall survival (OS) for ACPB vs DC vs ACInt was 43.6 vs 51 vs 75 months, respectively. ACPB had significantly shorter OS than ACInt (p = 0.036). However, for AC stage (HR = 2.39; 95 %CI 1.23–4.64, p = 0.010) was the only factor associated with mortality risk in multivariate analysis. Localization of recurrence (n = 88) was predominantly distant (ACPB 81.5%; ACInt 92%; DC 91.7%, p = 0.371). Post-recurrence survival (PRS) for ACPB, ACInt and DC did not differ (6.9 vs 9.2 vs 7.5 months, p = 0.755). Best supportive care or palliative chemotherapy were offered for recurrent disease to 44.5%/48.1% for ACPB, 40%/56% for ACInt, and 41.7%/52.8% for DC (p = 0.947). The choice of chemotherapy regimen varied considerably. Five patients underwent surgical resection or ablation with curative intent. All deaths among ACPB were caused by recurrent disease, whereas 29.4% of ACInt and 23.1% of DC deaths was non-cancer related or caused by other specific cancer. Conclusion ACPB, ACInt and DC have similar recurrence patterns and PRS. The difference in survival between ACPB and ACInt was not statistically significant when stratified by stage. The optimal chemotherapy in patients with recurrent AC remains undefined.

Simple Summary Pancreatic ductal adenocarcinoma (PDAC, also known as pancreatic cancer) is one of the deadliest tumor types, characterized by poor prognosis, profound chemoresistance and overall low survival. Gemcitabine remains the standard of care for all stages of PDAC, however, with poor clinical benefits which is considered to be due to reduced drug availability in tumor cells. Gemcitabine-induced cytotoxicity depends upon sufficient drug uptake followed by intracellular activation. Pancreatic stellate cells (PSCs), a major stromal component of PDAC, were recently reported to scavenge active metabolites of gemcitabine, thereby making it unavailable for cancer cells. Gemcitabine uptake and processing in both tumor cells and PSCs, as well as expression analysis of its molecular metabolic regulators, was investigated in this study. We observed heterogeneous gemcitabine-induced cytotoxicity in different pancreatic cancer cells whereas it was absent in PSCs. The gemcitabine-induced cytotoxicity in pancreatic cancer cells was driven by differential expression of its molecular regulators. Abstract Gemcitabine resistance in pancreatic ductal adenocarcinoma (PDAC) is attributed to cancer cell-intrinsic drug processing and the impact of the tumor microenvironment, especially pancreatic stellate cells (PSCs). This study uses human PDAC-derived paired primary cancer cells (PCCs) and PSCs from four different tumors, and the PDAC cell lines BxPC-3, Mia PaCa-2, and Panc-1, to assess the fate of gemcitabine by measuring its cellular uptake, cytotoxicity, and LC-MS/MS-based metabolite analysis. Expression analysis and siRNA-mediated knockdown of key regulators of gemcitabine (hENT1, CDA, DCK, NT5C1A) was performed. Compared to PSCs, both the paired primary PCCs and cancer cell lines showed gemcitabine-induced dose-dependent cytotoxicity, high uptake, as well as high and variable intracellular levels of gemcitabine metabolites. PSCs were gemcitabine-resistant and demonstrated significantly lower drug uptake, which was not influenced by co-culturing with their paired PCCs. Expression of key gemcitabine regulators was variable, but overall strong in the cancer cells and significantly lower or undetectable in PSCs. In cancer cells, hENT1 inhibition significantly downregulated gemcitabine uptake and cytotoxicity, whereas DCK knockdown reduced cytotoxicity. In conclusion, heterogeneity in gemcitabine processing among different pancreatic cancer cells and stellate cells results from the differential expression of molecular regulators which determines the effect of gemcitabine.

The aim of the study was to compare RNA sequencing data of sporadic nonfunctioning pancreatic neuroendocrine neoplasms (PNENs) to identify gene expression patterns that may be important for molecular differentiation of tumor aggressiveness.RNA sequencing was performed on samples of sporadic nonfunctioning PNENs, grouped as tumors with mild behavior (nonmetastatic and Ki675%) or aggressive behavior (metastatic and Ki67 ≥ 5%), on an Illumina Genome Analyzer II platform. Bioinformatic analyses were performed on the resulting data.Of 22,810 identified transcripts from protein-coding genes, a set of 309 genes were significantly differentially expressed between the 2 groups, of which 166 were upregulated and 143 downregulated in the aggressive disease group. Among the top protein-coding upregulated genes, we found genes encoding proteins involved in DNA packaging, ability to taste, chromosome structuring, cytoskeleton structuring, and cell-cell signaling. Among the top protein-coding downregulated genes, we found genes encoding proteins involved in neuronal differentiation, cytoskeleton structuring, cell-cell signaling, and immunological processes.A higher degree of tumor aggressiveness in sporadic nonfunctioning PNENs seems to be associated with upregulation of genes involved in regulation of the cell cycle and cell division. Small sample size and lack of a replication set are limitations of this study.

SMV/PV resection has become common practice in pancreatic surgery. The aim of this study was to evaluate the technical feasibility and surgical outcome of using cold-stored cadaveric venous allografts (AG) for superior mesenteric vein (SMV) and portal vein (PV) reconstruction during pancreatectomy.Patients who underwent pancreatic resection with concomitant vascular resection and reconstruction with AG between January 2006 and December 2014 were identified from our institutional prospective database. Medical records and pre- and postoperative CT-images were reviewed.Forty-five patients underwent SMV/PV reconstruction with AG interposition (n = 37) or AG patch (n = 8). The median operative time and blood loss were 488 min (IQR: 450-551) and 900 ml (IQR: 600-2000), respectively. Major morbidity (Clavien ≥ III) occurred in 16 patients. Four patients were reoperated (thrombosis n = 2, graft kinking/low flow n = 2) and in-hospital mortality occurred in two patients. On last available CT scan, 3 patients had thrombosis, all of whom also had local recurrence. Estimated cumulative patency rate (reduction in SMV/PV luminal diameter70% and no thrombosis) at 12 months was 52%.Cold-stored cadaveric venous AG for SMV/PV reconstruction during pancreatic surgery is safe and associated with acceptable long-term patency.

Background Pancreatoduodenectomy with venous resection is considered standard of care for patients with tumour involvement of the superior mesenteric/portal vein (SMV/PV) and deemed justified if an R0-resection can be achieved. The aim of this study was to provide a detailed pathology assessment of the site and extent of margin involvement in specimens resulting from pancreatoduodenectomy with venous resection. Methods Retrospective observational study including patients undergoing pancreatoduodenectomy with or without venous resection for pancreatic ductal adenocarcinoma between 2015 and 2017. Detailed histopathological mapping of the tumour and its relationship to the margins was undertaken. Results 98 patients met the inclusion criteria. An R0-resection, based on 1 mm clearance, was achieved in 16 of 73 patients without venous resection and in 1 of 25 patients with venous resection ( p = 0.063). The surface of the SMV-groove was the most frequently involved margin (23 of 25 patients with venous resection, 37 of 73 patients without venous resection; p < 0.001). The broad invasive tumour front as well as the absence of peripancreatic fat at the SMV-groove were the reasons for these findings. Conlusion An R0-resection following pancreatoduodenectomy with venous resection for ductal adenocarcinoma can rarely be achieved due to microscopical involvement of the SMV-groove.

No consensus exists on the optimal anticoagulation therapy after pancreatoduodenectomy with venous resection (PDVR). The aim of the study was to analyze perioperative outcomes of patients receiving low- vs high-dose anticoagulation therapy and to identify risk factors for postpancreatectomy hemorrhage in patients undergoing PDVR. Retrospective study of patients undergoing PDVR at a tertiary referral center between January 2006 and April 2017. Patients were investigated according to the dose of postoperative anticoagulation given (low- or high-dose low-molecular-weight heparin). Uni- and multivariate analysis were performed to assess risk factors for postpancreatectomy hemorrhage. A total of 141 patients underwent PDVR. Low-dose anticoagulation was given to 45 (31.9%) patients. Operative time (428 min vs 398 min, p = 0.025) and the use of interposition grafts (27% vs 11%, P = 0.033) were significantly higher in the high-dose group. There was no difference in the rate of early portal vein thrombosis (4.4% vs 4.2%, p = 0.939) or postpancreatectomy hemorrhage (13.3% vs 16.7%, p = 0.611) between the low- and high-dose groups. On multivariate analysis, serum bilirubin ≥ 200 μmol/L and clinically relevant postoperative fistula were the only factors associated with postpancreatectomy hemorrhage (OR 10.28, 95% CI 3.51–30.07, P

Pancreatic ductal adenocarcinoma (PDAC), commonly referred to as pancreatic cancer, ranks among the leading causes of cancer-related deaths in the Western world due to disease presentation at an advanced stage, early metastasis and generally a very limited response to chemotherapy or radiotherapy. Gemcitabine remains a cornerstone of PDAC treatment in all stages of the disease despite suboptimal clinical effects primarily caused by molecular mechanisms limiting its cellular uptake and activation and overall efficacy, as well as the development of chemoresistance within weeks of treatment initiation. To circumvent gemcitabine resistance in PDAC, several novel therapeutic approaches, including chemical modifications of the gemcitabine molecule generating numerous new prodrugs, as well as new entrapment designs of gemcitabine in colloidal systems such as nanoparticles and liposomes, are currently being investigated. Many of these approaches are reported to be more efficient than the parent gemcitabine molecule when tested in cellular systems and in vivo in murine tumor model systems; however, although promising, their translation to clinical use is still in a very early phase. This review discusses gemcitabine metabolism, activation and chemoresistance entities in the gemcitabine cytotoxicity pathway and provides an overview of approaches to override chemoresistance in pancreatic cancer.

Superior mesenteric vein/portal vein (SMV/PV) resection and reconstruction during pancreatic surgery are increasingly common. Several reconstruction techniques exist. The aim of this study was to evaluate characteristics of patients and clinical outcomes for SMV/PV reconstruction using interposed cold-stored cadaveric venous allograft (AG+) or primary end-to-end anastomosis (AG-) after segmental vein resections during pancreatic surgery.All patients undergoing pancreatic surgery with SMV/PV resection and reconstruction from 2006 to 2015 were identified. Clinical and histopathologic outcomes as well as preoperative and postoperative radiologic findings were assessed.A total of 171 patients were identified. The study included 42 and 71 patients reconstructed with AG+ and AG-, respectively. Patients in the AG+ group had longer mean operative time (506 minutes [standard deviation, 83 minutes] for AG+ vs 420 minutes [standard deviation, 91 minutes] for AG-; P .01) and more intraoperative bleeding (median, 1000 mL [interquartile range (IQR), 650-2200 mL] for AG+ vs 600 mL [IQR, 300-1000 mL] for AG-; P .01). Neoadjuvant therapy was administered more frequently for patients in the AG+ group (23.8% vs 8.5%; P = .02). Patients with AG+ had a longer length of tumor-vein involvement (median, 2.4 cm [IQR, 1.6-3.0 cm] for AG+ vs 1.8 cm [IQR, 1.2-2.4 cm] for AG-; P = .01), and a higher number of patients had a tumor-vein interface180 degrees (35.7% for AG+ vs 21.1% for AG-; P = .02). There was no difference in number of patients with major complications (42.9% for AG+ vs 36.6% for AG-; P = .51) or early failure at the reconstruction site (9.5% for AG+ vs 8.5% for AG-; P = 1). A subgroup analysis of 10 patients in the AG+ group revealed the presence of donor-specific antibodies in all patients.The short-term outcome of SMV/PV reconstruction with interposed cold-stored cadaveric venous allografts is comparable to that of reconstruction with primary end-to-end anastomosis. Graft rejection could be a contributing factor to severe stenosis in patients reconstructed with allograft.

Background Pancreatoduodenectomy with superior mesenteric–portal vein resection has become a common procedure in pancreatic surgery. The aim of this study was to compare standard pancreatoduodenectomy with pancreatoduodenectomy plus venous resection at a high-volume centre, and to examine trends in management and outcome over a decade for the latter procedure. Methods This retrospective observational study included all patients undergoing pancreatoduodenectomy with or without venous resection at Oslo University Hospital between January 2006 and December 2015. Trends were evaluated by assessing preoperative clinical and radiological characteristics, as well as perioperative outcomes in three time intervals (early, intermediate and late). Results A total of 784 patients had a pancreatoduodenectomy, of whom 127 (16·2 per cent) underwent venous resection. Venous resection resulted in a longer operating time (median 422 versus 312 min; P = 0·001) and greater estimated blood loss (EBL) (median 700 versus 500 ml; P = 0·004) than standard pancreatoduodenectomy. The rate of severe complications was significantly higher for pancreatoduodenectomy with venous resection (37·0 versus 26·3 per cent; P = 0·014). The overall burden of complications, evaluated using the Comprehensive Complication Index (CCI), did not differ (median score 8·7 versus 8·7; P = 0·175). Trends in venous resection over time showed a significant reduction in EBL (median 1050 versus 375 ml; P = 0·001) and duration of hospital stay (median 14 versus 9 days; P = 0·011) between the early and late periods. However, despite an improvement in the intermediate period, severe complication rates returned to baseline in the late period (18 of 43 versus 9 of 42 versus 20 of 42 patients in early, intermediate and late periods respectively; P = 0·032), as did CCI scores (median 20·9 versus 0 versus 20·9; P = 0·041). Conclusion Despite an initial improvement in severe complications for venous resection during pancreatoduodenectomy, this was not maintained over time. Every fourth patient with venous resection needed relaparotomy, most frequently for bleeding.

The pathogenesis of sporadic pancreatic neuroendocrine neoplasms (PNENs) is poorly understood. To gain insight into the genetic mechanisms underlying this tumor entity, we performed genome-wide screening of 16 surgical specimens from 15 patients with sporadic PNEN, combining G-band karyotyping and high resolution comparative genomic hybridization (HR-CGH). G-banding revealed abnormal karyotypes in 2 of 10 tumor samples analyzed. DNA copy number changes were detected in 13 samples, whereas three tumors showed a balanced genome. Gains were more frequent than losses in the nonfunctioning tumors (n=13). Common gains were scored at 5p12–13, 4q13–24, 5p15, 5q11–31, and 9q21–22. Common losses were scored at 11p11, 11p14–15, 11q23, 11p12–13, and 11q22. The average number of copy aberrations (ANCA index) was 12 for 13 nonfunctioning primary tumors, 4.8 for the nonfunctioning tumors with low Ki-67 (≥5%), 21.2 for the tumors with high Ki-67 (

Gastrointestinal cancers include malignancies arising in the esophagus, liver and bile ducts, gallbladder, pancreas, stomach, small intestine, colon and rectum. Their incidence and mortality differ significantly, however, together they account for approximately one-fifth of the cancer incidence and nearly one-fourth of the cancer related deaths in the US.1 Colorectal and gastric cancers are the most common gastrointestinal tumors worldwide, accounting for ∼2.2 million new cases and an estimated 1.3 million deaths annually.2 When these malignancies are detected at an early, localized stage, the 5-year survival is 90% and 63%, respectively.3 However, more than 60% of the patients with colorectal cancer and 75% of the patients with gastric cancer have regional or distant metastases at the time of diagnosis, resulting in a significant drop in survival.3 Cholangiocarinoma and pancreatic cancer are less prevalent.2,4 However, these malignancies are often “clinically silent” and thus diagnosed at an advanced stage with a corresponding poor prognosis.2,4 Early detection, particularly of colorectal and gastric cancer, may significantly reduce the number of gastrointestinal cancer deaths, and identification of suitable biomarkers for this purpose is therefore warranted. In humans, DNA methylation occurs predominantly at the 5′ position of cytosine, within CpG dinucleotides. Approximately 70% of the human genes have a CpG island—an enrichment of such dinucleotides—in the promoter region.5 In normal cells these islands are usually unmethylated, but several of them become hypermethylated in cancer and this is associated with repressed or lost gene expression.6 Using genome-wide analyzes, DNA methylation was recently shown to be more frequent than genetic changes in colorectal cancer.7 In addition to being frequent, aberrant DNA methylation has been shown to be an early event in tumorigenesis.8 Finally, several examples of genes with promoter DNA hypermethylation have been detected in various bodily fluids from cancer patients, including bile, feces, plasma and urine,9–13 indicating that methylation biomarkers may be useful for non- or minimally invasive cancer diagnostics. Although cancer is a highly heterogeneous disease, comprising more than 200 different conditions, it is believed that tumors arising in the gastrointestinal tract share several molecular alterations. Gut derived adenocarcinomas have indeed been found to display similar copy-number changes, forming tissue-specific clusters when various cancer types were clustered according to amplification activated oncogenes.14,15 Gastrointestinal tumors further show extremely high frequencies of transition mutations at CpG dinucleotides,16 and several genes, including APC, MLH1, MGMT, p16INK4a, CDH1, SFRP1, RASSF1A and VIM have been shown to be epigenetically dysregulated across malignancies of the gastrointestinal tract.17–21 With increased focus on cross-tumor analysis, exemplified by The Cancer Genome Atlas (TCGA) Pan-Cancer project, more shared abnormalities among the gastrointestinal cancers are expected to be uncovered. In the present study we have investigated whether the recently identified methylation biomarkers for cholangiocarcinoma (CDO1, DCLK1, ZSCAN18 and SFRP1)22 were methylated also in other malignancies of the gastrointestinal tract. The promoter methylation frequency of these genes, in addition to ZNF331, previously shown to be methylated across several gastrointestinal cancer cell lines,22 was analyzed in tissue samples from colorectal-, gastric- and pancreatic cancer patients.

Specimen grossing is a key step in the pathology examination of pancreatic resection specimens. Optimal display of pathologic changes and extensive tissue sampling are important determinants of the quality of pathology reporting. Divergence in macroscopic examination practice has led to considerable variation in the reporting of factors that are of clinical and prognostic significance. This article provides a detailed account of the macroscopic examination procedure with reference to current (inter-)national guidelines and recommendations.

Pancreatic neuroendocrine tumors (PNET) are rare neoplasms with better prognosis than most pancreatic malignancies. Surgery of locally advanced PNET remains controversial, and the role of vascular reconstruction in this patient group has yet to be defined. The aim of this study was to evaluate the feasibility and outcome of pancreatic resections with vascular reconstruction in patients with locally advanced PNET.Retrospective analysis of patients who underwent pancreatic surgery with vascular reconstruction for locally advanced PNET at a single institution. Furthermore, a review of the relevant literature on the topic was performed.Seven patients who had undergone vascular reconstruction for locally advanced PNET were identified. Four patients had liver metastases at time of surgery. Postoperative complications developed in four patients with no mortality. Median follow-up time of all patients was 21 (range, 3-58) months. Three patients had disease in remission after 58, 42 and 3 months, respectively. One patient died 35 months postoperatively due to progressive disease, whereas three patients had progression of disease after 21, 9, and 4 months postoperatively.Pancreatic surgery with vascular reconstruction in patients with locally advanced PNET is feasible with acceptable outcome.

As most pancreatic neuroendocrine tumors (PNET) are relatively small and solitary, they may be considered well suited for removal by a minimally invasive approach. There are few large series that describe laparoscopic surgery for PNET. The primary aim of this study was to describe the feasibility, outcome, and histopathology associated with laparoscopic pancreatic surgery (LS) of PNET in a large series.All patients with PNET who underwent LS at a single hospital from March 1997 to April 2011 were included retrospectively in the study.A total of 72 patients with PNET underwent 75 laparoscopic procedures, out of which 65 were laparoscopic resections or enucleations. The median operative time of all patients who underwent resections or enucleations was 175 (60-520) min, the median blood loss was 300 (5-2700) ml, and the median length of hospital stay was 7 (2-27) days. The overall morbidity rate was 42%, with a surgical morbidity rate of 21% and postoperative pancreatic fistula (POPF) formation in 21%. Laparoscopic enucleations were associated with a higher rate of POPF than were laparoscopic resections. Five-year disease-specific survival rate was 90%. The T stage, R stage, and a Ki-67 cutoff value of 5% significantly predicted 5-year survival.LS of PNET is feasible with acceptable morbidity and a good overall disease-specific long-term prognosis.

Background The most abundant cells in the extensive desmoplastic stroma of pancreatic adenocarcinomas are the pancreatic stellate cells, which interact with the carcinoma cells and strongly influence the progression of the cancer. Tumor stroma interactions induced by IL-1α/IL-1R1 signaling have been shown to be involved in pancreatic cancer cell migration. TGFβ and its receptors are overexpressed in pancreatic adenocarcinomas. We aimed at exploring TGFβ and IL-1α signaling and cross-talk in the stellate cell cancer cell interactions regulating pancreatic adenocarcinoma cell migration. Methods Human pancreatic stellate cells were isolated from surgically resected pancreatic adenocarcinomas and cultured in the presence of TGFβ or pancreatic adenocarcinoma cell lines. The effects of TGFβ were blocked by inhibitors or amplified by silencing the endogenous inhibitor of SMAD signaling, SMAD7. Pancreatic stellate cell responses to IL-1α or to IL-1α-expressing pancreatic adenocarcinoma cells (BxPC-3) were characterized by their ability to stimulate migration of cancer cells in a 2D migration model. Results In pancreatic stellate cells, IL-1R1 expression was found to be down-regulated by TGFβ and blocking of TGFβ signaling re-established the expression. Endogenous inhibition of TGFβ signaling by SMAD7 was found to correlate with the levels of IL-1R1, indicating a regulatory role of SMAD7 in IL-1R1 expression. Pancreatic stellate cells cultured in the presence of IL-1α or in co-cultures with BxPC-3 cells enhanced the migration of cancer cells. This effect was blocked after treatment of the pancreatic stellate cells with TGFβ. Silencing of stellate cell expression of SMAD7 was found to suppress the levels of IL-1R1 and reduce the stimulatory effects of IL-1α, thus inhibiting the capacity of pancreatic stellate cells to induce cancer cell migration. Conclusions TGFβ signaling suppressed IL-1α mediated pancreatic stellate cell induced carcinoma cell migration. Depletion of SMAD7 upregulated the effects of TGFβ and reduced the expression of IL-1R1, leading to inhibition of IL-1α induced stellate cell enhancement of carcinoma cell migration. SMAD7 might represent a target for inhibition of IL-1α induced tumor stroma interactions.

BACKGROUND: This study aimed to evaluate the role of surgery for patients with high-grade pancreatic neuroendocrine carcinoma (hgPNEC) in a large Nordic multicenter cohort study. Prior studies evaluating the role of surgery for patients with hgPNEC are limited, and the benefit of the surgery is uncertain.METHODS: Data from patients with a diagnosis of hgPNEC determined between 1998 and 2012 were retrospectively registered at 10 Nordic university hospitals. Kaplan-Meier curves were used to compare the overall survival of different treatment groups, and Cox-regression analysis was used to evaluate factors potentially influencing survival.RESULTS: The study registered 119 patients. The median survival period from the time of metastasis was 23 months for patients undergoing initial resection of localized nonmetastatic disease and chemotherapy at the time of recurrence (n = 14), 29 months for patients undergoing resection of the primary tumor and resection/radiofrequency ablation of synchronous metastatic liver disease (n = 12), and 13 months for patients with synchronous metastatic disease given systemic chemotherapy alone (n = 78). The 3-year survival rate after surgery of the primary tumor and metastatic disease was 69 %. Resection of the primary tumor was an independent factor for improved survival after occurrence of metastatic disease.CONCLUSIONS: Patients with resected localized nonmetastatic hgPNEC and later metastatic disease seemed to benefit from initial resection of the primary tumor. Patients selected for resection of the primary tumor and synchronous liver metastases had a high 3-year survival rate. Selected patients with both localized hgPNEC and metastatic hgPNEC should be considered for radical surgical treatment.

Pancreatic ductal adenocarcinoma is characterized by a prominent fibroinflammatory stroma with both tumor-promoting and tumor-suppressive functions. The pancreatic stellate cell (PSC) is the major cellular stromal component and the main producer of extracellular matrix proteins, including collagens, which are degraded by metalloproteinases (MMPs). PSCs interact with cancer cells through various factors, including transforming growth factor (TGF)β and interleukin (IL)-1α. The role of TGFβ in the dual nature of tumor stroma, i.e., protumorigenic or tumor suppressive, is not clear. We aimed to investigate the roles of TGFβ and IL-1α in the regulation of MMP profiles in PSCs and the subsequent effects on cancer cell migration. Human PSCs isolated from surgically resected specimens were cultured in the presence of pancreatic cancer cell lines, as well as IL-1α or TGFβ. MMP production and activities in PSCs were quantified by gene array transcripts, mRNA measurements, fluorescence resonance energy transfer–based activity assay, and zymography. PSC-conditioned media and pancreatic cancer cells were included in a collagen matrix cell migration model. We found that production of IL-1α by pancreatic cancer cells induced alterations in MMP and tissue inhibitors of matrix metalloproteinase (TIMP) profiles and activities in PSCs, upregulated expression and activation of MMP1 and MMP3, and enhanced migration of pancreatic cancer cells in the collagen matrix model. TGFβ counteracted the effects of IL-1α on PSCs, reestablished PSC MMP and TIMP profiles and activities, and inhibited migration of cancer cells. This suggests that tumor TGFβ has a role as a suppressor of stromal promotion of tumor progression through alterations in PSC MMP profiles with subsequent inhibition of pancreatic cancer cell migration.

Fusion transcripts arising from the combination of exons residing on neighboring genes on the same chromosome may give rise to chimeric or novel proteins. Such read-through transcripts have been detected in different cancers where they may be of pathogenetic interest. In this study, we describe for the first time the expression of a read-through transcript in insulinomas, a functioning neuroendocrine pancreatic neoplasm. The read-through transcript INS-IGF2, composed of exons from the two genes proinsulin precursor (INS) and insulin‑like growth factor 2 (IGF2), both mapping to chromosomal subband 11p15.5, was highly expressed in the two insulinomas analyzed. More precisely, version 2 of the INS-IGF2 transcript was expressed, indicating possible expression of the chimeric INS-IGF2 protein. We further identified a novel splice variant of the INS-IGF2 read-through transcript in one of the insulinomas, composed of exon 1 of INS3 and exons of IGF2. In the same tumor, we found high expression of INS3 and the presence of the A allele at SNP rs689. SNP rs689 has been previously described to regulate splicing of the INS transcript, indicating that this regulatory mechanism also affects splicing of INS-IGF2. The identification of the INS-IGF2 read-through transcript specifically in tumor tissue but not in normal pancreatic tissue suggests that high expression of INS-IGF2 could be neoplasia‑specific. These results may have potential clinical applications given that the read-through transcript could be used as a biomarker in insulinoma patients.

Pancreatic neuroendocrine neoplasms (PNENs) are rare, accounting for less than 5% of all pancreatic tumors. High-grade pancreatic neuroendocrine carcinomas (hgPNECs) represent about 5% of all PNENs. They show highly aggressive behavior with dismal prognosis. Throughout the last two decades, there has been a notable progress in basic and clinical research of PNENs and a therapeutic trend towards both more aggressive and minimally invasive surgery. Despite these advances, hgPNECs as a distinct clinical entity remains largely unexplored among surgeons. This review of current development in pathology reporting and surgical treatment of hgPNECs aims at increasing the awareness of an evolving field in pancreatic surgery.

Background Primary adenocarcinomas removed by pancreatoduodenectomy originate from the duodenum (DC), ampulla (AC), distal bile duct (DBC), or pancreas (PC). Pathobiology, staging, survival, and adjuvant chemotherapy vary among these cancers. The proximity of the structures of possible origin renders it difficult to obtain a correct diagnosis, which might lead to inconsistencies in reported data and inappropriate adjuvant treatment. Methods Records of 207 patients undergoing pancreatoduodenectomy (1998–2009) for periampullary adenocarcinoma were reviewed. Routine histopathology reports of tumour origin performed by multiple pathologists were independently re-evaluated based on predetermined criteria by two experienced pancreatic pathologists. Results Slide review changed the diagnosis in 55 (27%) patients. After reclassification, final distribution was 29 (14%) DC, 52 (25%) AC, 57 (28%) DBC, and 69 (33%) PC. The diagnosis was revised in 4 (14%) DC, 7 (17%) AC, 30 (53%) DBC and 14 (19%) PC. The underestimation of DBC during routine histopathology was caused by misinterpretation of DBC either PC or AC. Misclassification of PC was mainly due to erroneous diagnosis of AC. Reassignment of tumour origin caused no significant changes in survival within cancer type, but resulted in a significant difference in survival between DBC and PC (p = 0.004). Conclusion Specialist slide review resulted in reassignment of tumour origin in 27% of periampullary adenocarcinomas. Distal bile duct cancer was found to be most frequently misdiagnosed (53%). Correct diagnosis of tumour origin is crucial for data quality, appropriate adjuvant therapy, and patient inclusion in clinical trials.

Lymph node ratio (LNR) may be more useful than nodal (N) status in prognostic subclassification of adenocarcinomas after pancreatoduodenectomy. Ampullary (AC), biliary (DBC), and pancreatic (PC) adenocarcinomas are biologically distinct, and nodal involvement may have different prognostic importance among these separate cancers. We included 179 consecutive pancreatoduodenectomies for PC, AC, or DBC, and performed standardized histopathologic evaluation, including prospective registration and retrospective reevaluation of the cancer origin. Associations between histopathologic variables and LNR, N status, and number of metastatic nodes were evaluated. Unadjusted and adjusted survival analysis was performed. Overall 5 year survival was 6 % for PC (n = 72), 26 % for DBC (n = 46), and 46 % for AC (n = 61). Lymph node involvement was more frequent in PC (75 %) than in AC (48 %) and DBC (57 %). In PC, N status did not discriminate between prognostic groups (N1 vs. N0; p = 0.31). However, increasing LNR was associated with poorer survival in unadjusted analysis, as well as when adjusting for margin involvement, degree of differentiation, and tumor diameter (p = 0.032; hazard ratio 1.87, 95 % confidence interval 1.06–3.31). In AC and DBC, N status clearly discriminated between subgroups of patients with different long-term survival in unadjusted and adjusted survival analysis (N1 vs. N0; p

Background Assessment of the origin of adenocarcinoma in pancreatoduodenectomy specimens (pancreatic, ampullary or biliary) and resection margin status is not performed in a consistent manner in different centres. The aim of this review was to identify the impact of such variations on patient outcome. Methods A systematic literature search for articles on pancreatic, ampullary, distal bile duct and periampullary cancer was performed, with special attention to data on resection margin status, pathological examination and outcome. Results The frequent reclassification of tumour origin following slide review, and the wide variation in published incidence of pancreatic (33–89 per cent), ampullary (5–42 per cent) and distal bile duct (5–38 per cent) cancers indicate that the histopathological distinction between the three cancer groups is less accurate than generally believed. Recent studies have shown that the wide range of rates of microscopic margin involvement (R1) in pancreatoduodenectomy specimens (18–85, 0–27 and 0–72 per cent respectively for pancreatic, ampullary and distal bile duct cancers) is mainly caused by differences in pathological assessment rather than surgical practice and patient selection. As a consequence of the existing inconsistency in reporting of these data items, the clinical significance of microscopic margin involvement in each of the three cancer groups remains unclear. Conclusion Inaccurate and inconsistent distinction between pancreatic, ampullary and distal bile duct cancer, combined with inaccuracies in resection margin assessment, results in obfuscation of key clinicopathological data. Specimen dissection technique plays a key role in the quality of the assessment of both tumour origin and margin status. Unless the pathological examination is meticulous and standardized, comparison of results between centres and observations in multicentre trials will remain of limited value.

Verbeke C S, Knapp J & Gladhaug I P (2011) Histopathology 59, 1111–1121 Tumour growth is more dispersed in pancreatic head cancers than in rectal cancer: implications for resection margin assessment Aims: The UK definition of microscopic resection margin involvement (R1) in pancreatic head cancer, based on tumour lying

Westgaard A, Clausen OPF, Gladhaug IP. Survival estimates after pancreatoduodenectomy skewed by non-standardized histopathology reports. APMIS 2011; 119: 689–700. Survival estimates may be biased if quality control on histopathology is insufficient. We evaluated the effects of standardizing histopathology for pancreatoduodenectomy specimens and compared survival estimates based on standardized vs non-standardized histopathological evaluation. Microscopic slides and histopathological reports from 311 consecutive pancreatoduodenectomies (1980–2004) were reviewed, including 104 adenocarcinomas (1980–1997) resected before and 123 adenocarcinomas (1998–2004) resected after standardizing histopathology. Histopathological factors were re-evaluated for all primary adenocarcinomas (n = 227). The most frequent histological types were pancreatobiliary-type (n = 145) and intestinal-type (n = 73). Standardized histopathology was associated with sampling more blocks and nodes (p