Radical Resection in Entero-Pancreatic Neuroendocrine Tumors: Recurrence-Free Survival Rate and Definition of a Risk Score for Recurrence.

BACKGROUND: Surgery with radical intent is the only potentially curative option for entero-pancreatic neuroendocrine tumors (EP-NETs) but many patients develop recurrence even after many years. The subset of patients at high risk of disease recurrence has not been clearly defined to date. OBJECTIVE: The aim of this retrospective study was to define, in a series of completely resected EP-NETs, the recurrence-free survival (RFS) rate and a risk score for disease recurrence. PATIENTS AND METHODS: This was a multicenter retrospective analysis of sporadic pancreatic NETs (PanNETs) or small intestine NETs (SiNETs) [G1/G2] that underwent R0/R1 surgery (years 2000-2016) with at least a 24-month follow-up. Survival analysis was performed using the Kaplan-Meier method and risk factor analysis was performed using the Cox regression model. RESULTS: Overall, 441 patients (224 PanNETs and 217 SiNETs) were included, with a median Ki67 of 2% in tumor tissue and 8.2% stage IV disease. Median RFS was 101 months (5-year rate 67.9%). The derived prognostic score defined by multivariable analysis included prognostic parameters, such as TNM stage, lymph node ratio, margin status, and grading. The score distinguished three risk categories with a significantly different RFS (p < 0.01). CONCLUSIONS: Approximately 30% of patients with EP-NETs recurred within 5 years after radical surgery. Risk factors for recurrence were disease stage, lymph node ratio, margin status, and grading. The definition of risk categories may help in selecting patients who might benefit from adjuvant treatments and more intensive follow-up programs.

α-Synuclein strains cause distinct synucleinopathies after local and systemic administration.

Misfolded protein aggregates represent a continuum with overlapping features in neurodegenerative diseases, but differences in protein components and affected brain regions. The molecular hallmark of synucleinopathies such as Parkinson's disease, dementia with Lewy bodies and multiple system atrophy are megadalton α-synuclein-rich deposits suggestive of one molecular event causing distinct disease phenotypes. Glial α-synuclein (α-SYN) filamentous deposits are prominent in multiple system atrophy and neuronal α-SYN inclusions are found in Parkinson's disease and dementia with Lewy bodies. The discovery of α-SYN assemblies with different structural characteristics or 'strains' has led to the hypothesis that strains could account for the different clinico-pathological traits within synucleinopathies. In this study we show that α-SYN strain conformation and seeding propensity lead to distinct histopathological and behavioural phenotypes. We assess the properties of structurally well-defined α-SYN assemblies (oligomers, ribbons and fibrils) after injection in rat brain. We prove that α-SYN strains amplify in vivo. Fibrils seem to be the major toxic strain, resulting in progressive motor impairment and cell death, whereas ribbons cause a distinct histopathological phenotype displaying Parkinson's disease and multiple system atrophy traits. Additionally, we show that α-SYN assemblies cross the blood-brain barrier and distribute to the central nervous system after intravenous injection. Our results demonstrate that distinct α-SYN strains display differential seeding capacities, inducing strain-specific pathology and neurotoxic phenotypes.

Poorly differentiated thyroid carcinoma : An underdiagnosed entity.

Poorly differentiated thyroid carcinomas (PDTCs) are a rare subtype of thyroid carcinomas that are biologically situated between well-differentiated papillary/follicular thyroid carcinomas and anaplastic thyroid carcinomas (ATCs).The diagnosis of conventional as well as oncocytic poorly differentiated thyroid carcinoma is difficult and often missed in daily routine. The current WHO criteria to allow the diagnosis of PDTCs are based on the results of a consensus meeting held in Turin in 2006. Even a minor poorly differentiated component of only 10%of a given carcinoma significantly affects patient prognosis and the oncocytic subtype may even have a worse outcome. Immunohistochemistry is not much help and is mostly used to exclude a medullary thyroid carcinoma with calcitonin and to establish a follicular cell of origin via thyroglobulin staining.Due to the concept of stepwise dedifferentiation, there is a vast overlap of different molecular alterations like BRAF, RAS, CTNNB1, TP53 and others between different thyroid carcinoma subtypes. A distinctive molecular tumor profile is therefore currently not available.PDTCs have a unique miRNA signature, which separates them from other thyroid carcinomas. The average relapse free survival is less than one year and about 50% of patients die of the disease. Modern tyrosine kinase inhibitors offer in conjunction with powerful molecular diagnostic new chances in these difficult to treat carcinomas.

[Poorly differentiated thyroid carcinoma : An underdiagnosed entity. German version]. / Gering differenzierte Schilddrüsenkarzinome : Eine unterdiagnostizierte Entität.

Poorly differentiated thyroid carcinomas (PDTCs) are a rare subtype of thyroid carcinomas that are biologically situated between well-differentiated papillary/follicular thyroid carcinomas and anaplastic thyroid carcinomas (ATCs).The diagnosis of conventional as well as oncocytic poorly differentiated thyroid carcinoma is difficult and often missed in daily routine. The current WHO criteria to allow the diagnosis of PDTCs are based on the results of a consensus meeting held in Turin in 2006. Even a minor poorly differentiated component of only 10% of a given carcinoma significantly affects patient prognosis and the oncocytic subtype may even have a worse outcome. Immunohistochemistry is not much help and is mostly used to exclude a medullary thyroid carcinoma with calcitonin and to establish a follicular cell of origin via thyroglobulin staining.Due to the concept of stepwise dedifferentiation, there is a vast overlap of different molecular alterations like BRAF, RAS, CTNNB1, TP53 and others between different thyroid carcinoma subtypes. A distinctive molecular tumor profile is therefore currently not available.PDTCs have a unique miRNA signature, which separates them from other thyroid carcinomas.The average relapse free survival is less than one year and about 50% of patients die of the disease. Modern tyrosine kinase inhibitors offer in conjunction with powerful molecular diagnostic new chances in these difficult to treat carcinomas.

Expression of E-cadherin repressors SNAIL, ZEB1 and ZEB2 by tumour and stromal cells influences tumour-budding phenotype and suggests heterogeneity of stromal cells in pancreatic cancer.

BACKGROUND: There is evidence that tumour-stroma interactions have a major role in the neoplastic progression of pancreatic ductal adenocarcinoma (PDAC). Tumour budding is thought to reflect the process of epithelial-mesenchymal transition (EMT); however, the relationship between tumour buds and EMT remains unclear. Here we characterize the tumour-budding- and stromal cells in PDAC at protein and mRNA levels concerning factors involved in EMT. METHODS: mRNA in situ hybridisation and immunostaining for E-cadherin, ß-catenin, SNAIL1, ZEB1, ZEB2, N-cadherin and TWIST1 were assessed in the main tumour, tumour buds and tumour stroma on multipunch tissue microarrays from 120 well-characterised PDACs and associated with the clinicopathological features, including peritumoural (PTB) and intratumoural (ITB) budding. RESULTS: Tumour-budding cells showed increased levels of ZEB1 (P<0.0001) and ZEB2 (P=0.0119) and reduced E-cadherin and ß-catenin (P<0.0001, each) compared with the main tumour. Loss of membranous ß-catenin in the main tumour (P=0.0009) and tumour buds (P=0.0053), without nuclear translocation, as well as increased SNAIL1 in tumour and stromal cells (P=0.0002, each) correlated with high PTB. ZEB1 overexpression in the main tumour-budding and stromal cells was associated with high ITB (P=0.0084; 0.0250 and 0.0029, respectively) and high PTB (P=0.0005; 0.0392 and 0.0007, respectively). ZEB2 overexpression in stromal cells correlated with higher pT stage (P=0.03), lymphatic invasion (P=0.0172) and lymph node metastasis (P=0.0152). CONCLUSIONS: In the tumour microenvironment of phenotypically aggressive PDAC, tumour-budding cells express EMT hallmarks at protein and mRNA levels underlining their EMT-type character and are surrounded by stromal cells expressing high levels of the E-cadherin repressors ZEB1, ZEB2 and SNAIL1, this being strongly associated with the tumour-budding phenotype. Moreover, our findings suggest the existence of subtypes of stromal cells in PDAC with phenotypical and functional heterogeneity.

Pulmonary neuroendocrine (carcinoid) tumors: European Neuroendocrine Tumor Society expert consensus and recommendations for best practice for typical and atypical pulmonary carcinoids.

BACKGROUND: Pulmonary carcinoids (PCs) are rare tumors. As there is a paucity of randomized studies, this expert consensus document represents an initiative by the European Neuroendocrine Tumor Society to provide guidance on their management. PATIENTS AND METHODS: Bibliographical searches were carried out in PubMed for the terms 'pulmonary neuroendocrine tumors', 'bronchial neuroendocrine tumors', 'bronchial carcinoid tumors', 'pulmonary carcinoid', 'pulmonary typical/atypical carcinoid', and 'pulmonary carcinoid and diagnosis/treatment/epidemiology/prognosis'. A systematic review of the relevant literature was carried out, followed by expert review. RESULTS: PCs are well-differentiated neuroendocrine tumors and include low- and intermediate-grade malignant tumors, i.e. typical (TC) and atypical carcinoid (AC), respectively. Contrast CT scan is the diagnostic gold standard for PCs, but pathology examination is mandatory for their correct classification. Somatostatin receptor imaging may visualize nearly 80% of the primary tumors and is most sensitive for metastatic disease. Plasma chromogranin A can be increased in PCs. Surgery is the treatment of choice for PCs with the aim of removing the tumor and preserving as much lung tissue as possible. Resection of metastases should be considered whenever possible with curative intent. Somatostatin analogs are the first-line treatment of carcinoid syndrome and may be considered as first-line systemic antiproliferative treatment in unresectable PCs, particularly of low-grade TC and AC. Locoregional or radiotargeted therapies should be considered for metastatic disease. Systemic chemotherapy is used for progressive PCs, although cytotoxic regimens have demonstrated limited effects with etoposide and platinum combination the most commonly used, however, temozolomide has shown most clinical benefit. CONCLUSIONS: PCs are complex tumors which require a multidisciplinary approach and long-term follow-up.

[What is new in the pathology of pancreatic neuroendocrine tumors?]. / Was ist neu in der Pathologie neuroendokriner Tumoren des Pankreas?

The diagnostics of pancreatic neuroendocrine tumors (PanNEN) have changed in recent years especially concerning the World Health Organization (WHO) classification, TNM staging and grading. Furthermore, some new prognostic and predictive immunohistochemical markers have been introduced. Most progress, however, has been made in the molecular pathogenesis of these neoplasms. Using next generation sequencing techniques, the mammalian target of rapamycin (mTOR) pathway, hypoxia and epigenetic changes were identified as key players in tumorigenesis. In this article the most important developments of morphological as well as immunohistochemical diagnostics together with the molecular background of PanNEN are summarized.

SwissScoring--a nationwide survey of NEMS assessing practices and its accuracy.

BACKGROUND: The nine equivalents of nursing manpower use score (NEMS) is used to evaluate critical care nursing workload and occasionally to define hospital reimbursements. Little is known about the caregivers' accuracy in scoring, about factors affecting this accuracy and how validity of scoring is assured. METHODS: Accuracy in NEMS scoring of Swiss critical care nurses was assessed using case vignettes. An online survey was performed to assess training and quality control of NEMS scoring and to collect structural and organizational data of participating intensive care units (ICUs). Aggregated structural and procedural data of the Swiss ICU Minimal Data Set were used for matching. RESULTS: Nursing staff from 64 (82%) of the 78 certified adult ICUs participated in this survey. Training and quality control of scoring shows large variability between ICUs. A total of 1378 nurses scored one out of 20 case vignettes: accuracy ranged from 63.7% (intravenous medications) to 99.1% (basic monitoring). Erroneous scoring (8.7% of all items) was more frequent than omitted scoring (3.2%). Mean NEMS per case was 28.0 ± 11.8 points (reference score: 25.7 ± 14.2 points). Mean bias was 2.8 points (95% confidence interval: 1.0-4.7); scores below 37.1 points were generally overestimated. Data from units with a greater nursing management staff showed a higher bias. CONCLUSION: Overall, nurses assess the NEMS score within a clinically acceptable range. Lower scores are generally overestimated. Inaccurate assessment was associated with a greater size of the nursing management staff. Swiss head nurses consider themselves motivated to assure appropriate scoring and its validation.

[Neuroendocrine neoplasms of the distal jejunum and ileum]. / Neuroendokrine Neoplasien des distalen Jejunums und Ileums.

Neuroendocrine neoplasms (NEN) of the distal jejunum and ileum derive from serotonin-producing enterochromaffin (EC) cells. Due to their low proliferation rate and their infiltrative growth, they are often discovered at an advanced disease stage when metastasis has already occurred. The biology of these tumours is different from other NEN of the digestive tract. In order to standardise and improve diagnosis and therapy, the guidelines for the diagnosis and clinical management of jejuno-ileal NEN as well as for the management of patients with liver and other distant metastases from NEN were revised by the European Neuroendocrine Tumour Society (ENETS) in 2012. This review focuses on aspects relevant for surgical pathology.

NETest in advanced high-grade gastroenteropancreatic neuroendocrine neoplasms.

Molecular blood biomarkers are lacking for high-grade (HG) gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN). To histologically distinguish between neuroendocrine carcinoma (NEC), neuroendocrine tumors G3 (NET G3), adenocarcinoma and MINEN is often challenging. The mRNA-based NETest has diagnostic, prognostic and predictive value in neuroendocrine tumors G1-2 but has not been studied in HG GEP-NEN. Patients with advanced HG GEP-NEN were prospectively included in an observational study. A blood sample was collected before the start of chemotherapy and pseudonymised before NETest was performed. NETest results are expressed as an activity index (NETest score) from 0 to 100. The normal score cut-off is 20. Histological sections were pseudonymised before centralized pathological re-evaluation. Samples from 60 patients were evaluable with the NETest. Main primary tumor sites were colon (14), rectum (12), pancreas (11) and esophagus (7). Re-classification: 30 NEC, 12 NET G3, 3 HG-NEN ambiguous morphology, 8 MiNEN, 3 adenocarcinomas with neuroendocrine differentiation (ADNE), 3 adenocarcinomas and 1 NET G2. Elevated NETest (>20) was seen in 38/45 (84%) HG GEP-NEN, all 17 large-cell NEC (100%), 11/13 (85%) small-cell NEC, all ambiguous cases and 7/12 (64%) NET G3. NETest was elevated in 5/8 (63%) MiNEN, 2/3 ADNE, however not in 3 adenocarcinomas. Median survival was 10.2 months (9.6-10.8 95%CI) for evaluable HG GEP-NEN treated with palliative chemotherapy (n = 39), and survival was significantly shorter in patients with NETest >60 with an OS of only 6.5 months. This is the first study to evaluate use of the NETest in advanced HG GEP-NEN. The NETest was almost always elevated in GEP-NEC and in all large-cell NEC. The NETest was also frequently elevated in NET G3 and MiNEN, however cases were limited. Baseline NETest was not predictive for benefit of chemotherapy, however a NETest >60 was prognostic with a shorter survival for patients receiving chemotherapy.

Characterization of MENX-associated pituitary tumours.

AIMS: The aim of this study is to evaluate the pathological features, serum hormone levels and ex vivo cultures of pituitary adenomas that occur in rats affected by MENX syndrome. MENX is multiple endocrine neoplasia syndrome caused by a germline mutation in the cell cycle inhibitor p27. Characterization of MENX adenomas is a prerequisite to exploit this animal model for molecular and translational studies of pituitary adenomas. METHODS: We investigated MENX pituitary adenomas with immunohistochemistry, double immunofluorescence, electron microscopy, reverse transcription polymerase chain reaction (RT-PCR), measurement of serum hormone levels and ex vivo cultures. RESULTS: Adenomas in MENX rats belong to the gonadotroph lineage. They start from 4 months of age as multiple neoplastic nodules and progress to become large lesions that efface the gland. Adenomas are composed of chromophobic cells predominantly expressing the glycoprotein alpha-subunit (αGSU). They show mitotic activity and high Ki67 labelling. A few neoplastic cells co-express gonadotropins and the transcription factor steroidogenic factor 1, together with growth hormone or prolactin and Pit-1, suggesting that they are not fully committed to one cell lineage. Ex vivo cultures show features similar to the primary tumour. CONCLUSIONS: Our results suggest that p27 function is critical to regulate gonadotroph cells growth. The MENX syndrome represents a unique model to elucidate the physiological and molecular mechanisms mediating the pathogenesis of gonadotroph adenomas.

Efficient and stable transduction of dopaminergic neurons in rat substantia nigra by rAAV 2/1, 2/2, 2/5, 2/6.2, 2/7, 2/8 and 2/9.

Dysfunction of the nigrostriatal system is the major cause of Parkinson's disease (PD). This brain region is therefore an important target for gene delivery aiming at disease modeling and gene therapy. Recombinant adeno-associated viral (rAAV) vectors have been developed as efficient vehicles for gene transfer into the central nervous system. Recently, several serotypes have been described, with varying tropism for brain transduction. In light of the further development of a viral vector-mediated rat model for PD, we performed a comprehensive comparison of the transduction and tropism for dopaminergic neurons (DNs) in the adult Wistar rat substantia nigra (SN) of seven rAAV vector serotypes (rAAV 2/1, 2/2, 2/5, 2/6.2, 2/7, 2/8 and 2/9). All vectors were normalized by titer and volume, and stereotactically injected into the SN. Gene expression was assessed non-invasively and quantitatively in vivo by bioluminescence imaging at 2 and 5 weeks after injection, and was found to be stable over time. Immunohistochemistry at 6 weeks following injection revealed the most widespread enhanced green fluorescence protein expression and the highest number of positive nigral cells using rAAV 2/7, 2/9 and 2/1. The area transduced by rAAV 2/8 was smaller, but nevertheless almost equal numbers of nigral cells were targeted. Detailed confocal analysis revealed that serotype 2/7, 2/9, 2/1 and 2/8 transduced at least 70% of the DNs. In conclusion, these results show that various rAAV serotypes efficiently transduce nigral DNs, but significant differences in transgene expression pattern and level were observed.

Glucagon-like peptide-1 (GLP-1) receptors are not overexpressed in pancreatic islets from patients with severe hyperinsulinaemic hypoglycaemia following gastric bypass.

AIMS/HYPOTHESIS: Glucagon-like peptide-1 (GLP-1) receptors are highly overexpressed in benign insulinomas, permitting in vivo tumour visualisation with GLP-1 receptor scanning. The present study sought to evaluate the GLP-1 receptor status in vitro in other pancreatic disorders leading to hyperinsulinaemic hypoglycaemia, specifically after gastric bypass surgery. METHODS: Fresh frozen pancreatic tissue samples (n=7) from six gastric bypass surgery patients suffering from hyperinsulinaemic hypoglycaemia were evaluated for GLP-1 receptor content using in vitro receptor autoradiography, and compared with normal pancreas and with pancreatic insulinoma tissues. RESULTS: GLP-1 receptor analysis of the pancreatic tissues, which histopathologically were compatible with nesidioblastosis and originated from post-bypass hypoglycaemic patients, revealed a mean density value of GLP-1 receptors in the islets of 1,483 ± 183 dpm/mg tissue. Pharmacological characterisation indicated the presence of specific GLP-1 receptors. The density of islet GLP-1 receptor in post-gastric bypass patients did not differ from that of normal pancreas (1,563 ± 104 dpm/mg tissue, n = 10). Receptor density in pancreatic acini was low in post-bypass and control conditions. In contrast, benign insulinomas showed a high density of GLP-1 receptors, with a mean value of 8,302 ± 1,073 dpm/mg tissue (n = 6). CONCLUSIONS/INTERPRETATION: In contrast to insulinoma, hyperinsulinaemic hypoglycaemia after gastric bypass surgery is not accompanied by overexpression of GLP-1 receptor in individual islets. Thus, patients with post-gastric bypass hyperinsulinaemic hypoglycaemia are not candidates for GLP-1 receptor imaging in vivo using radiolabelled exendin. These GLP-1 receptor data support the notion that the islet pathobiology of post-gastric bypass hypoglycaemia is distinctly different from that of benign insulinomas.

A model of ischemic isolated acute liver failure in pigs: standardizing monitoring and treatment.

BACKGROUND: Acute liver failure (ALF) models in pigs have been widely used for evaluating newly developed liver support systems. But hardly any guidelines are available for the surgical methods and the clinical management. METHODS: The study validated several standard operating procedures describing in detail the surgical method and intensive care monitoring and treatment (control of potassium, glucose and bicarbonate levels, cardiovascular and intracranial pressure monitoring, etc.). ALF was induced in animals with a mean of 56 kg. Two surgical methods were compared: ligation of hepatic arteries with either end-to-side portacaval shunt (ESPS) and bile duct ligation or side-to-side portacaval shunt (SSPS) without bile duct ligation. RESULTS: During total portal vein clamping, the animals in the ESPS group developed severe hypotension, splanchnic congestion and metabolic acidosis. One animal died after approximately 1.5 h. This model therefore represents a multiorgan failure model rather than an isolated ALF model. In the SSPS group, none of these side effects were observed, while clinical, laboratory and histopathological signs of ALF were evident. CONCLUSIONS: A reproducible model in pigs representing ALF can be established with the help of the standardized monitoring and treatment procedures presented.