Microenvironmental Determinants of Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) belongs to the most lethal solid tumors in humans. A histological hallmark feature of PDAC is the pronounced tumor microenvironment (TME) that dynamically evolves during tumor progression. The TME consists of different non-neoplastic cells such as cancer-associated fibroblasts, immune cells, endothelial cells, and neurons. Furthermore, abundant extracellular matrix components such as collagen and hyaluronic acid as well as matricellular proteins create a highly dynamic and hypovascular TME with multiple biochemical and physical interactions among the various cellular and acellular components that promote tumor progression and therapeutic resistance. In recent years, intensive research efforts have resulted in a significantly improved understanding of the biology and pathophysiology of the TME in PDAC, and novel stroma-targeted approaches are emerging that may help to improve the devastating prognosis of PDAC patients. However, none of anti-stromal therapies has been approved in patients so far, and there is still a large discrepancy between multiple successful preclinical results and subsequent failure in clinical trials. Furthermore, recent findings suggest that parts of the TME may also possess tumor-restraining properties rendering tailored therapies even more challenging.

DYRK1B blockade promotes tumoricidal macrophage activity in pancreatic cancer.

OBJECTIVE: Highly malignant pancreatic ductal adenocarcinoma (PDAC) is characterised by an abundant immunosuppressive and fibrotic tumour microenvironment (TME). Future therapeutic attempts will therefore demand the targeting of tumours and stromal compartments in order to be effective. Here we investigate whether dual specificity and tyrosine phosphorylation-regulated kinase 1B (DYRK1B) fulfil these criteria and represent a promising anticancer target in PDAC. DESIGN: We used transplantation and autochthonous mouse models of PDAC with either genetic Dyrk1b loss or pharmacological DYRK1B inhibition, respectively. Mechanistic interactions between tumour cells and macrophages were studied in direct or indirect co-culture experiments. Histological analyses used tissue microarrays from patients with PDAC. Additional methodological approaches included bulk mRNA sequencing (transcriptomics) and proteomics (secretomics). RESULTS: We found that DYRK1B is mainly expressed by pancreatic epithelial cancer cells and modulates the influx and activity of TME-associated macrophages through effects on the cancer cells themselves as well as through the tumour secretome. Mechanistically, genetic ablation or pharmacological inhibition of DYRK1B strongly attracts tumoricidal macrophages and, in addition, downregulates the phagocytosis checkpoint and 'don't eat me' signal CD24 on cancer cells, resulting in enhanced tumour cell phagocytosis. Consequently, tumour cells lacking DYRK1B hardly expand in transplantation experiments, despite their rapid growth in culture. Furthermore, combining a small-molecule DYRK1B-directed therapy with mammalian target of rapamycin inhibition and conventional chemotherapy stalls the growth of established tumours and results in a significant extension of life span in a highly aggressive autochthonous model of PDAC. CONCLUSION: In light of DYRK inhibitors currently entering clinical phase testing, our data thus provide a novel and clinically translatable approach targeting both the cancer cell compartment and its microenvironment.

Type 1 Autoimmune Pancreatitis in Europe: Clinical Profile and Response to Treatment.

BACKGROUND & AIMS: Autoimmune pancreatitis (AIP) is an immune-mediated disease of the pancreas with distinct pathophysiology and manifestations. Our aims were to characterize type 1 AIP in a large pan-European cohort and study the effectiveness of current treatment regimens. METHODS: We retrospectively analyzed adults diagnosed since 2005 with type 1 or not-otherwise-specified AIP in 42 European university hospitals. Type 1 AIP was uniformly diagnosed using specific diagnostic criteria. Patients with type 2 AIP and those who had undergone pancreatic surgery were excluded. The primary end point was complete remission, defined as the absence of clinical symptoms and resolution of the index radiologic pancreatic abnormalities attributed to AIP. RESULTS: We included 735 individuals with AIP (69% male; median age, 57 years; 85% White). Steroid treatment was started in 634 patients, of whom 9 (1%) were lost to follow-up. The remaining 625 had a 79% (496/625) complete, 18% (111/625) partial, and 97% (607/625) cumulative remission rate, whereas 3% (18/625) did not achieve remission. No treatment was given in 95 patients, who had a 61% complete (58/95), 19% partial (18/95), and 80% cumulative (76/95) spontaneous remission rate. Higher (≥0.4 mg/kg/day) corticosteroid doses were no more effective than lower (<0.4 mg/kg/day) doses (odds ratio, 0.428; 95% confidence interval, 0.054-3.387) and neither was a starting dose duration >2 weeks (odds ratio, 0.908; 95% confidence interval, 0.818-1.009). Elevated IgG4 levels were independently associated with a decreased chance of complete remission (odds ratio, 0.639; 95% confidence interval, 0.427-0.955). Relapse occurred in 30% of patients. Relapses within 6 months of remission induction were independent of the steroid-tapering duration, induction treatment duration, and total cumulative dose. CONCLUSIONS: Patients with type 1 AIP and elevated IgG4 level may need closer monitoring. For remission induction, a starting dose of 0.4 mg/kg/day for 2 weeks followed by a short taper period seems effective. This study provides no evidence to support more aggressive regimens.

PITX2 as a Sensitive and Specific Marker of Midgut Neuroendocrine Tumors: Results from a Cohort of 1157 Primary Neuroendocrine Neoplasms.

As neuroendocrine tumors (NETs) often present as metastatic lesions, immunohistochemical assignment to a site of origin is one of the most important tasks in their pathologic assessment. Because a fraction of NETs eludes the typical expression profiles of their primary localization, additional sensitive and specific markers are required to improve diagnostic certainty. We investigated the expression of the transcription factor Pituitary Homeobox 2 (PITX2) in a large-scale cohort of 909 NET and 248 neuroendocrine carcinomas (NEC) according to the immunoreactive score (IRS) and correlated PITX2 expression groups with general tumor groups and primary localization. PITX2 expression (all expression groups) was highly sensitive (98.1%) for midgut-derived NET, but not perfectly specific, as non-midgut NET (especially pulmonary/duodenal) were quite frequently weak or moderately positive. The specificity rose to 99.5% for a midgut origin of NET if only a strong PITX2 expression was considered, which was found in only 0.5% (one pancreatic/one pulmonary) of non-midgut NET. In metastases of midgut-derived NET, PITX2 was expressed in all cases (87.5% strong, 12.5% moderate), whereas CDX2 was negative or only weakly expressed in 31.3% of the metastases. In NEC, a fraction of cases (14%) showed a weak or moderate PITX2 expression, which was not associated with a specific tumor localization. Our study independently validates PITX2 as a very sensitive and specific immunohistochemical marker of midgut-derived NET in a very large collective of neuroendocrine neoplasms. Therefore, our data argue toward implementation into diagnostic panels applied for NET as a firstline midgut marker.

Endoscopic retrograde cholangiopancreatography-obtained bile culture in acute cholangitis: retrospective analysis of bile cultures and risk factors in a tertiary care center.

BACKGROUND: Collection of bile aspirate during endoscopic retrograde cholangiopancreatography (ERCP) is essential to identify pathogens responsible for acute cholangitis. Limited data are available on the risk factors for the presence of multidrug-resistant organisms (MDRO) in bile. METHODS: We conducted this retrospective, single-center study to assess the prevalence and susceptibility rates of bacteria in bile cultures, and the risk factors for the presence of pathogens, MDRO, and fungi in bile. All consecutive patients who underwent biliary drainage for acute cholangitis from January 2017 to December 2019 were included. RESULTS: 443/1610 ERCPs were performed for acute cholangitis. Bile culture was collected in 91.4% (405/443), of which 86.7% were positive. Most common isolates were Enterococcus faecalis (37.6%) and Escherichia coli (32.8%). Vancomycin resistance was found in 9.9% of Enterococcus species (spp.); extended-spectrum beta-lactamases (ESBL) and carbapenemases in 11.2% and 0.9% of Enterobacteriaceae, respectively. The empiric antimicrobial therapy was changed in 26.4% (n = 107) of cases, with a clinical response in 90.7%. In multivariate analysis, biliary stenting was an independent risk factor for positive bile culture (odds ratio [OR] 9.43; P < 0.01). Independent risk factors for MDRO in bile were patient age>60 years (OR 2.51; P = 0.03), previous sphincterotomy (OR 2.57; P = 0.02), and biliary stenting (OR 2.80; P < 0.01). Previous sphincterotomy was the only risk factor for isolation of fungi in bile (OR 1.61; P = 0.04). CONCLUSIONS: Our study showed an increasing prevalence of Enterococcus spp. and MDRO. Bile cultures should be routinely collected in cholangitis and in patients with repeated ERCPs to allow more efficient antimicrobial treatment.

IL-17A-producing CD8+ T cells promote PDAC via induction of inflammatory cancer-associated fibroblasts.

OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) is characterised by an abundant desmoplastic stroma composed of cancer-associated fibroblasts (CAF) and interspersed immune cells. A non-canonical CD8+ T-cell subpopulation producing IL-17A (Tc17) promotes autoimmunity and has been identified in tumours. Here, we evaluated the Tc17 role in PDAC. DESIGN: Infiltration of Tc17 cells in PDAC tissue was correlated with patient overall survival and tumour stage. Wild-type (WT) or Il17ra-/- quiescent pancreatic stellate cells (qPSC) were exposed to conditional media obtained from Tc17 cells (Tc17-CM); moreover, co-culture of Tc17-CM-induced inflammatory (i)CAF (Tc17-iCAF) with tumour cells was performed. IL-17A/F-, IL-17RA-, RAG1-deficient and Foxn1nu/nu mice were used to study the Tc17 role in subcutaneous and orthotopic PDAC mouse models. RESULTS: Increased abundance of Tc17 cells highly correlated with reduced survival and advanced tumour stage in PDAC. Tc17-CM induced iCAF differentiation as assessed by the expression of iCAF-associated genes via synergism of IL-17A and TNF. Accordingly, IL-17RA controlled the responsiveness of qPSC to Tc17-CM. Pancreatic tumour cells co-cultured with Tc17-iCAF displayed enhanced proliferation and increased expression of genes implicated in proliferation, metabolism and protection from apoptosis. Tc17-iCAF accelerated growth of mouse and human tumours in Rag1-/- and Foxn1nu/nu mice, respectively. Finally, Il17ra-expressed by fibroblasts was required for Tc17-driven tumour growth in vivo. CONCLUSIONS: We identified Tc17 as a novel protumourigenic CD8+ T-cell subtype in PDAC, which accelerated tumour growth via IL-17RA-dependent stroma modification. We described a crosstalk between three cell types, Tc17, fibroblasts and tumour cells, promoting PDAC progression, which resulted in poor prognosis for patients.

Timeline of Development of Pancreatic Cancer and Implications for Successful Early Detection in High-Risk Individuals.

BACKGROUND & AIMS: To successfully implement imaging-based pancreatic cancer (PC) surveillance, understanding the timeline and morphologic features of neoplastic progression is key. We aimed to investigate the progression to neoplasia from serial prediagnostic pancreatic imaging tests in high-risk individuals and identify factors associated with successful early detection. METHODS: We retrospectively examined the development of pancreatic abnormalities in high-risk individuals who were diagnosed with PC or underwent pancreatic surgery, or both, in 16 international surveillance programs. RESULTS: Of 2552 high-risk individuals under surveillance, 28 (1%) developed neoplastic progression to PC or high-grade dysplasia during a median follow-up of 29 months after baseline (interquartile range [IQR], 40 months). Of these, 13 of 28 (46%) presented with a new lesion (median size, 15 mm; range 7-57 mm), a median of 11 months (IQR, 8; range 3-17 months) after a prior examination, by which time 10 of 13 (77%) had progressed beyond the pancreas. The remaining 15 of 28 (54%) had neoplastic progression in a previously detected lesion (12 originally cystic, 2 indeterminate, 1 solid), and 11 (73%) had PC progressed beyond the pancreas. The 12 patients with cysts had been monitored for 21 months (IQR, 15 months) and had a median growth of 5 mm/y (IQR, 8 mm/y). Successful early detection (as high-grade dysplasia or PC confined to the pancreas) was associated with resection of cystic lesions (vs solid or indeterminate lesions (odds ratio, 5.388; 95% confidence interval, 1.525-19.029) and small lesions (odds ratio, 0.890/mm; 95% confidence interval 0.812-0.976/mm). CONCLUSIONS: In nearly half of high-risk individuals developing high-grade dysplasia or PC, no prior lesions are detected by imaging, yet they present at an advanced stage. Progression can occur before the next scheduled annual examination. More sensitive diagnostic tools or a different management strategy for rapidly growing cysts are needed.

Clinical Features and Prognosis of Patients with Carcinoid Syndrome and Carcinoid Heart Disease: A Retrospective Multicentric Study of 276 Patients.

INTRODUCTION: Carcinoid syndrome is the most frequent functional syndrome of neuroendocrine neoplasia. It is characterized by flushing, diarrhea, wheezing, hypotension, and exanthema and may cause carcinoid heart disease. METHODS: We assessed clinical characteristics and prognosis of patients with carcinoid syndrome and carcinoid heart disease in 276 patients from 3 referral centers. RESULTS: Carcinoid syndrome patients had a mean age of 57 years (range 21-84) and a normal BMI of 24.9 (SD 4.5; range 13.8-39.6). Most primaries were of small bowel or unknown primaries with distant metastasis in 94.6%. Flushing was the most frequent symptom in 74.3% of patients, followed by diarrhea in 68.8%, and wheezing in 40.9%. Pain was described by 45.3%, weakness by 23.5%, and weight loss of >10% in 6 months by 30.1% of patients. Carcinoid heart disease was diagnosed in 37.3% of patients (n = 104) by echocardiography and involved predominantly in the tricuspid valve. Combinations with other valve defects were common. Somatostatin analogs were taken by 80.4% of patients and 17% needed additional loperamide/opium tincture. Surgery and peptide receptor radiotherapy were most frequent treatments. The median survival of patients with carcinoid syndrome after diagnosis was 9 years. Prognosis was significantly impaired by male sex and diagnosis of carcinoid heart disease but surprisingly significantly increased by the presence of symptoms flushing and weakness. DISCUSSION/CONCLUSION: Carcinoid syndrome is associated with extensive disease and primaries in small bowels or of unknown primary. Weight loss, weakness, and pain are frequent, and carcinoid heart disease is diagnosed in more than one-third of patients.

Treatment of advanced gastroenteropancreatic neuroendocrine neoplasia, are we on the way to personalised medicine?

Gastroenteropancreatic neuroendocrine neoplasia (GEPNEN) comprises clinically as well as prognostically diverse tumour entities often diagnosed at late stage. Current classification provides a uniform terminology and a Ki67-based grading system, thereby facilitating management. Advances in the study of genomic and epigenetic landscapes have amplified knowledge of tumour biology and enhanced identification of prognostic and potentially predictive treatment subgroups. Translation of this genomic and mechanistic biology into advanced GEPNEN management is limited. 'Targeted' treatments such as somatostatin analogues, peptide receptor radiotherapy, tyrosine kinase inhibitors and mammalian target of rapamycin inhibitors are treatment options but predictive tools are lacking. The inability to identify clonal heterogeneity and define critical oncoregulatory pathways prior to therapy, restrict therapeutic efficacy as does the inability to monitor disease status in real time. Chemotherapy in the poor prognosis NEN G3 group, though associated with acceptable response rates, only leads to short-term tumour control and their molecular biology requires delineation to provide new and more specific treatment options.The future requires an exploration of the NEN tumour genome, its microenvironment and an identification of critical oncologic checkpoints for precise drug targeting. In the advance to personalised medical treatment of patients with GEPNEN, clinical trials need to be based on mechanistic and multidimensional characterisation of each tumour in order to identify the therapeutic agent effective for the individual tumour.This review surveys advances in NEN research and delineates the current status of translation with a view to laying the basis for a genome-based personalised medicine management of advanced GEPNEN.

Deciphering the complex interplay between pancreatic cancer, diabetes mellitus subtypes and obesity/BMI through causal inference and mediation analyses.

OBJECTIVES: To characterise the association between type 2 diabetes mellitus (T2DM) subtypes (new-onset T2DM (NODM) or long-standing T2DM (LSDM)) and pancreatic cancer (PC) risk, to explore the direction of causation through Mendelian randomisation (MR) analysis and to assess the mediation role of body mass index (BMI). DESIGN: Information about T2DM and related factors was collected from 2018 PC cases and 1540 controls from the PanGenEU (European Study into Digestive Illnesses and Genetics) study. A subset of PC cases and controls had glycated haemoglobin, C-peptide and genotype data. Multivariate logistic regression models were applied to derive ORs and 95% CIs. T2DM and PC-related single nucleotide polymorphism (SNP) were used as instrumental variables (IVs) in bidirectional MR analysis to test for two-way causal associations between PC, NODM and LSDM. Indirect and direct effects of the BMI-T2DM-PC association were further explored using mediation analysis. RESULTS: T2DM was associated with an increased PC risk when compared with non-T2DM (OR=2.50; 95% CI: 2.05 to 3.05), the risk being greater for NODM (OR=6.39; 95% CI: 4.18 to 9.78) and insulin users (OR=3.69; 95% CI: 2.80 to 4.86). The causal association between T2DM (57-SNP IV) and PC was not statistically significant (ORLSDM=1.08, 95% CI: 0.86 to 1.29, ORNODM=1.06, 95% CI: 0.95 to 1.17). In contrast, there was a causal association between PC (40-SNP IV) and NODM (OR=2.85; 95% CI: 2.04 to 3.98), although genetic pleiotropy was present (MR-Egger: p value=0.03). Potential mediating effects of BMI (125-SNPs as IV), particularly in terms of weight loss, were evidenced on the NODM-PC association (indirect effect for BMI in previous years=0.55). CONCLUSION: Findings of this study do not support a causal effect of LSDM on PC, but suggest that PC causes NODM. The interplay between obesity, PC and T2DM is complex.

Ramucirumab in combination with dacarbazine in patients with progressive well-differentiated metastatic pancreatic neuroendocrine tumors (RamuNET): study protocol for a multicenter single-arm trial.

BACKGROUND: Cytotoxic chemotherapy combinations and targeted agents represent established treatment concepts in advanced pancreatic neuroendocrine tumors (PNETs). However, response rates, side effects and outcome data strongly vary among these therapeutic approaches. Head-to-head comparisons between chemo- and molecular therapies are missing and secondary resistances frequently occur. The RamuNET trial aims to identify the effectiveness of dual treatment with DTIC and ramucirumab in progressive advanced PNET patients. METHODS: The RamuNET study is an investigator-initiated multicenter prospective single-arm trial to evaluate the efficacy of ramucirumab in combination with dacarbazine (DTIC) over a period of at least 6 months. Patients with progressive well-differentiated and metastatic pancreatic neuroendocrine tumors are eligible. The study aims to include 45 patients over a period of 24 months with a minimum follow-up of 24 months. The primary endpoint is disease control after 6 months. Secondary endpoints include progression-free survival, biochemical response, overall survival, quality of life and toxicity. Based on the hypothesis that 80% of the patients can achieve a disease control after 6 months, the sample size calculation follows an exact binomial single-stage design. H0: p < =p0 = 60% versus H1: p > =p1 = 80%, alpha = 0.05, beta = 0.1. DISCUSSION: This study investigates a new therapeutic approach using the combination of cytotoxic and targeted antiangiogenic therapy in advanced PNET. If positive, this trial will be the basis for a randomized two-arm study to investigate the combination of ramucirumab and DTIC against other established therapies in PNET. TRIAL REGISTRATION: EudraCT: 2017-001207-68 . Date of registration: 2018.01.03.

Management of patients with increased risk for familial pancreatic cancer: updated recommendations from the International Cancer of the Pancreas Screening (CAPS) Consortium.

BACKGROUND AND AIM: The International Cancer of the Pancreas Screening Consortium met in 2018 to update its consensus recommendations for the management of individuals with increased risk of pancreatic cancer based on family history or germline mutation status (high-risk individuals). METHODS: A modified Delphi approach was employed to reach consensus among a multidisciplinary group of experts who voted on consensus statements. Consensus was considered reached if ≥75% agreed or disagreed. RESULTS: Consensus was reached on 55 statements. The main goals of surveillance (to identify high-grade dysplastic precursor lesions and T1N0M0 pancreatic cancer) remained unchanged. Experts agreed that for those with familial risk, surveillance should start no earlier than age 50 or 10 years earlier than the youngest relative with pancreatic cancer, but were split on whether to start at age 50 or 55. Germline ATM mutation carriers with one affected first-degree relative are now considered eligible for surveillance. Experts agreed that preferred surveillance tests are endoscopic ultrasound and MRI/magnetic retrograde cholangiopancreatography, but no consensus was reached on how to alternate these modalities. Annual surveillance is recommended in the absence of concerning lesions. Main areas of disagreement included if and how surveillance should be performed for hereditary pancreatitis, and the management of indeterminate lesions. CONCLUSIONS: Pancreatic surveillance is recommended for selected high-risk individuals to detect early pancreatic cancer and its high-grade precursors, but should be performed in a research setting by multidisciplinary teams in centres with appropriate expertise. Until more evidence supporting these recommendations is available, the benefits, risks and costs of surveillance of pancreatic surveillance need additional evaluation.

Surgery with Radical Intent: Is There an Indication for G3 Neuroendocrine Neoplasms?

BACKGROUND: While platinum-based chemotherapy represents the standard treatment for advanced grade 3 (G3) neuroendocrine neoplasms (NENs) according to the European Neuroendocrine Tumor Society guidelines, the role of radical-intended surgery in these patients, as well as the use of adjuvant chemotherapy, are still controversial. The aim of the present work is to describe, in a retrospective series of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) G3, the overall survival (OS) rate and risk factors for death after radical surgery. Secondary aims are the description of median recurrence-free survival (RFS) and of the role of adjuvant chemotherapy. PATIENTS AND METHODS: Multicenter analysis of a series of stage I-III GEP-NEN G3 patients receiving radical surgery (R0/R1) with/without adjuvant chemotherapy was performed. RESULTS: Sixty patients from eight neuroendocrine tumor (NET) referral centers, with median follow-up of 23 months (5-187 months) were evaluated. While 28.6% of cases had NET G3, 71.4% had neuroendocrine carcinoma G3 (NEC G3). The 2-year OS rate after radical surgery was 64.5%, with a statistically significant difference in terms of Ki67 threshold (cut-off 55%, P = 0.03) and tumor differentiation (NEC G3 vs. NET G3, P = 0.03). Median RFS after radical surgery was 14 months, and 2-year RFS rate was 44.9%. Use of adjuvant chemotherapy provided no benefit in terms of either OS or RFS in this series. CONCLUSIONS: Surgery with radical intent might represent a valid option for GEP-NEN G3 patients with locoregional disease, especially with Ki67 value ≤ 55%.

International consensus guidelines on interventional endoscopy in chronic pancreatitis. Recommendations from the working group for the international consensus guidelines for chronic pancreatitis in collaboration with the International Association of Pancreatology, the American Pancreatic Association, the Japan Pancreas Society, and European Pancreatic Club.

BACKGROUND/OBJECTIVES: This paper is part of the international consensus guidelines on chronic pancreatitis, presenting for interventional endoscopy. METHODS: An international working group with experts on interventional endoscopy evaluated 26 statements generated from evidence on 9 clinically relevant questions. The Grading of Recommendations Assessment, Development, and Evaluation approach was used to evaluate the level of evidence. To determine the level of agreement, a nine-point Likert scale was used for voting on the statements. RESULTS: Strong consensus was obtained for 15 statements relating to nine questions including the recommendation that endoscopic intervention should be offered to patients with persistent severe pain but not to those without pain. Endoscopic decompression of the pancreatic duct could be used for immediate pain relief, and then offered surgery if this fails or needs repeated endoscopy. Endoscopic drainage is preferred for portal-splenic vein thrombosis and pancreatic fistula. A plastic stent should be placed and replaced 2-3 months later after insertion. Endoscopic extraction is indicated for stone fragments remaining after ESWL. Interventional treatment should be performed for symptomatic/complicated pancreatic pseudocysts. Endoscopic treatment is recommended for bile duct obstruction and afterwards surgery if this fails or needs repeated endoscopy. Surgery may be offered if there is significant calcification and/or mass of the pancreatic head. Percutaneous endovascular treatment is preferred for hemosuccus pancreaticus. Surgical treatment is recommended for duodenal stenosis due to chronic pancreatitis. CONCLUSIONS: This international expert consensus guideline provides evidenced-based statements concerning indications and key aspects for interventional endoscopy in the management of patients with chronic pancreatitis.

Testing of Helicobacter pylori by Endoscopic Biopsy: The Clinical Dilemma of Suppressive Conditions.

BACKGROUND AND AIMS: Testing for Helicobacter pylori is frequently conducted during esophagogastroduodenoscopy (EGD). Suppressive conditions such as the intake of proton-pump inhibitors (PPIs), preceded antibiotic treatment or recent upper gastrointestinal bleeding impair H. pylori test quality. The aim of our study was to evaluate the frequency and pattern of H. pylori suppressive conditions in a large patient collective undergoing elective EGD in a German university hospital. METHODS: The trial was performed as a single-center study. Only elective EGD from inpatients and outpatients were included. Prior to endoscopy, H. pylori suppressive conditions were collected using a standardized questionnaire. If H. pylori testing was indicated according to the guidelines, always both histology and helicobacter urease test were performed in analogy to the Sydney classification. RESULTS: One thousand six hundred and thirty-one patients were included (median 61 years, 36.0% outpatients, 64.0% inpatients). Overall, 76.5% of patients were under H. pylori suppressive conditions. The main suppressive condition was the intake of PPIs (70.7%). In 819 (50.2%) of all included cases, H. pylori testing was performed. The following were the results: 17.3% (142) had a positive H. pylori testing and 82.7% (677) were negative. Of those with negative result, 70.0% were tested under suppressive conditions. CONCLUSION: Guidelines recommend H. pylori testing under non-suppressive conditions. However, this does not always meet the clinical practice. Our data show that de facto, many patients undergoing elective EGD are tested for H. pylori under suppressive conditions coming along with a higher risk of potentially false negative results. Particularly, concerning this issue, further research is needed to improve and clarify everyday clinical practice.

DYRK1B regulates Hedgehog-induced microtubule acetylation.

The posttranslational modification (PTM) of tubulin subunits is important for the physiological functions of the microtubule (MT) cytoskeleton. Although major advances have been made in the identification of enzymes carrying out MT-PTMs, little knowledge is available on how intercellular signaling molecules and their associated pathways regulate MT-PTM-dependent processes inside signal-receiving cells. Here we show that Hedgehog (Hh) signaling, a paradigmatic intercellular signaling system, affects the MT acetylation state in mammalian cells. Mechanistically, Hh pathway activity increases the levels of the MT-associated DYRK1B kinase, resulting in the inhibition of GSK3ß through phosphorylation of Serine 9 and the subsequent suppression of HDAC6 enzyme activity. Since HDAC6 represents a major tubulin deacetylase, its inhibition increases the levels of acetylated MTs. Through the activation of DYRK1B, Hh signaling facilitates MT-dependent processes such as intracellular mitochondrial transport, mesenchymal cell polarization or directed cell migration. Taken together, we provide evidence that intercellular communication through Hh signals can regulate the MT cytoskeleton and contribute to MT-dependent processes by affecting the level of tubulin acetylation.

Long-term outcome of surgical resection in patients with gastroenteropancreatic neuroendocrine neoplasia: results from a German nation-wide multi-centric registry.

BACKGROUND: Neuroendocrine neoplasia (NEN) are rare and heterogenous tumours. Few data exist on the impact of surgical therapy. MATERIALS AND METHODS: This is a retrospective analysis of prospectively collected data of gastroenteropancreatic NEN in the German NET-Registry (1999-2012). It focuses on patients without distant metastases (limited disease, LD, stage I-IIIB). RESULTS: Data of 2239 patients with NEN were recorded. Median age was 59 years, the gender ratio was 1:1.3 (f:m). A total of 986 patients (44%) had LD, and the 5-year survival rate (5 years) was 77% for all and 90% for patients with LD. A total of 1635 patients (73%) received a surgical therapy (1st to 6th line); the 5 and 10 ysr were 83/65% after and 59/35% without surgery for all patients (p < .001). The resection margins in the LD patients were 76%, 16%, and 3% for R0, R1 and R2, respectively. The 10 ysr was 84%, 59% and 42% for R0, R1 and R2 resections, respectively (p = .021 R0/R1, p < .001 R0/R2). The R0 resection rate was 75% for G1/G2 NET and 67% for G3 NEC. CONCLUSION: The rate of complete tumour resection (R0) in LD is independent of tumour grading, and R0 resection is the key determinant of long-term survival, as demonstrated by the 10 ysr. of 84%. All NEN patients with limited disease should be considered for operation, if possible, as the best 10-year survival is shown after an R0 resection.

The Immune Microenvironment in Pancreatic Cancer.

The biology of solid tumors is strongly determined by the interactions of cancer cells with their surrounding microenvironment. In this regard, pancreatic cancer (pancreatic ductal adenocarcinoma, PDAC) represents a paradigmatic example for the multitude of possible tumor-stroma interactions. PDAC has proven particularly refractory to novel immunotherapies, which is a fact that is mediated by a unique assemblage of various immune cells creating a strongly immunosuppressive environment in which this cancer type thrives. In this review, we outline currently available knowledge on the cross-talk between tumor cells and the cellular immune microenvironment, highlighting the physiological and pathological cellular interactions, as well as the resulting therapeutic approaches derived thereof. Hopefully a better understanding of the complex tumor-stroma interactions will one day lead to a significant advancement in patient care.

Stromal biology and therapy in pancreatic cancer: ready for clinical translation?

Pancreatic ductal adenocarcinoma (PDA) is notoriously aggressive and hard to treat. The tumour microenvironment (TME) in PDA is highly dynamic and has been found to promote tumour progression, metastasis niche formation and therapeutic resistance. Intensive research of recent years has revealed an incredible heterogeneity and complexity of the different components of the TME, including cancer-associated fibroblasts, immune cells, extracellular matrix components, tumour vessels and nerves. It has been hypothesised that paracrine interactions between neoplastic epithelial cells and TME compartments may result in either tumour-promoting or tumour-restraining consequences. A better preclinical understanding of such complex and dynamic network systems is required to develop more powerful treatment strategies for patients. Scientific activity and the number of compelling findings has virtually exploded during recent years. Here, we provide an update of the most recent findings in this area and discuss their translational and clinical implications for basic scientists and clinicians alike.

Brain metastases in patients with neuroendocrine neoplasms: risk factors and outcome.

BACKGROUND: Brain metastases (BM) are rarely reported in patients with neuroendocrine carcinoma (NEC) of non-lung origin and neuroendocrine tumors (NET) of the gastroenteropancreatic (GEP) or bronchopulmonary system. However, symptomatic brain metastases are associated with dismal prognosis, so early detection and treatment could be advisable. METHODS: We retrospectively analyzed 51 patients with GEP-NEN and bronchopulmonary NEN excluding small cell lung cancer. All patients were treated at the University Hospital Marburg and Halle (Saale) between 2000 and 2017. The median overall survival (mOS) and mOS after diagnosis of brain metastases (BM) were calculated using Kaplan-Meier analysis. Risk factors for poor prognosis were evaluated using univariate and multivariate Cox regression method. RESULTS: Overall, 51 patients with a median age of 58 years presented BM. Lung (n = 23, 45.1%) was the most frequent primary localization. Most patients had NEC (n = 31, 60.8%), including 26 carcinomas (51%) with Ki-67 indices > 55%. Singular BM were present in 16 patients (31.4%), but 21 patients (41.2%) had multiple lesions. Overall, the median period from first diagnosis of the tumor disease up to diagnosis of brain metastasis was 5.0 months. Palliative radiation was the most common therapy (n = 31, 60.8%). Median OS after initial diagnosis and diagnosis of BM was 23.0 and 11.0 months, respectively. Univariate and multivariate analysis for prognostic indicators depicted differentiation (NEC HR 4.2, 95% CI 1.1-16.1) and age (≥60 HR 3.0, 95% CI 1.2-7.5) as markers for poor outcome. CONCLUSIONS: Overall, the risk for symptomatic brain metastases is low in GEP-NEN and bronchopulmonary NEN patients. Age above 60 and poor tumor differentiation may deteriorate the overall survival. Therefore, screening for brain metastases could be advisable in NEC patients.