Hematopoietic stem cells (HSCs) are located in the bone marrow in a specific microenvironment referred as the hematopoietic stem cell niche, where HSCs interact with a variety of stromal cells. Though several components of the stem cell niche have been identified, the regulatory mechanisms through which such components regulate the stem cell fate are still unknown. In order to address this issue, we investigated how osteoblasts (OBs) can affect the molecular and functional phenotype of Hematopoietic Stem/Progenitor Cells (HSPCs) and vice versa. For this purpose, human CD34+ cells were cultured in direct contact with primary human OBs. Our data showed that CD34+ cells cultured with OBs give rise to higher total cell numbers, produce more CFUs and maintain a higher percentage of CD34+CD38- cells compared to control culture. Moreover, clonogenic assay and long-term culture results showed that co-culture with OBs induces a strong increase in mono/macrophage precursors coupled to a decrease in the erythroid ones. Finally, gene expression profiling (GEP) allowed us to study which signalling pathways were activated in the hematopoietic cell fraction and in the stromal cell compartment after coculture. Such analysis allowed us to identify several cytokine-receptor networks, such as WNT pathway, and transcription factors, as TWIST1 and FOXC1, that could be activated by co-culture with OBs and could be responsible for the biological effects reported above. Altogether our results indicate that OBs are able to affect HPSCs on 2 different levels: on one side, they increase the immature progenitor pool in vitro, on the other side, they favor the expansion of the mono/macrophage precursors at the expense of the erythroid lineage.

Bone morphogenetic protein 2(BMP2) is known to activate unfolded protein response (UPR) signal molecules in chondrogenesis. Inositol-requiring enzyme-1α (IRE1α),as one of three unfolded protein sensors in UPR signaling pathways, can be activated during ER stress. However, the influence on IRE1α in chondrocyte differentiation has not yet been elucidated. Here we present evidence demonstrating that overexpression of IRE1α inhibits chondrocyte differentiation, as revealed by reduced expression of collagen II (ColII), Sox9, collagen X (ColX), matrix metalloproteinase 13 (MMP-13), Indian hedgehog (IHH), Runx2 and enhanced expression of parathyroid hormone-related peptide (PTHrP). Furthermore, IRE1α-mediated inhibition of chondrogenesis depends on its enzymatic activity, since its point mutant lacking enzymatic activity completely loses this activity. The RNase and Kinase domains of IRE1α C-terminal are necessary for its full enzymatic activity and inhibition of chondrocyte differentiation. Mechanism studies demonstrate that granulin-epithelin precursor(GEP), a growth factor known to stimulate chondrogenesis, induced IRE1α expression in chondrogenesis. The expression of IRE1α is depended on GEP signaling, and IRE1α expression is hardly detectable in GEP(-/-) embryos. In addition, IRE1α inhibits GEP-mediated chondrocyte differentiation as a negative regulator. Altered expression of IRE1α in chondrocyte hypertrophy was accompanied by altered levels of IHH and PTHrP. Collectively, IRE1α may be a novel regulator of chondrocyte differentiation by 1) inhibition GEP-mediated chondrocyte differentiation as a negative regulator; 2) promoting IHH/PTHrP signaling.

Dysregulation of DNA (cytosine-5)-methyltransferase 1 (DNMT1) is associated with the pathogenesis of various types of cancer. It has been previously shown that DNMT1 is frequently expressed in diffuse large B-cell lymphoma (DLBCL), however its functions remain to be elucidated in the disease. In this study, we gene expression profiled (GEP) shRNA targeting DNMT1(shDNMT1)-treated germinal center B-cell-like DLBCL (GCB-DLBCL)-derived cell line (i.e. HT) compared with non-silencing shRNA (control shRNA)-treated HT cells. Independent gene set enrichment analysis (GSEA) performed using GEPs of shRNA-treated HT cells and primary GCB-DLBCL cases derived from two publicly-available datasets (i.e. GSE10846 and GSE31312) produced three separate lists of enriched gene sets for each gene sets collection from Molecular Signatures Database (MSigDB). Subsequent Venn analysis identified 268, 145 and six consensus gene sets from analyzing gene sets in C2 collection (curated gene sets), C5 sub-collection [gene sets from gene ontology (GO) biological process ontology] and Hallmark collection, respectively to be enriched in positive correlation with DNMT1 expression profiles in shRNA-treated HT cells, GSE10846 and GSE31312 datasets [false discovery rate (FDR) <0.05]. Cell cycle progression and DNA replication were among the significantly enriched biological processes (FDR <0.05). Expression of genes involved in the activation of cell cycle and DNA replication (e.g. CDK1, CCNA2, E2F2, PCNA, RFC5 and POLD3) were highly correlated (r>0.8) with DNMT1 expression and significantly downregulated (log fold-change <-1.35; p<0.05) following DNMT1 silencing in HT cells. These results suggest the involvement of DNMT1 in the activation of cell cycle and DNA replication in DLBCL cells.

UNASSIGNED

Patients with inoperable and metastasized neuroendocrine tumors (NETs), particularly those with grades 1 and 2, usually receive treatment with somatostatin analogues (SSAs). Peptide receptor radionuclide therapy (PRRT) has gained momentum over the past two decades in patients who progress on SSAs. 177Lu-DOTATATE is currently the most widely used radiopeptide for PRRT. We reviewed the recent evidence on PRRT and the treatment of gastroentero-pancreatic neuroendocrine tumors (GEP-NETs).

UNASSIGNED

177Lu-DOTATATE can be used as neoadjuvant treatment in patients with inoperable GEP-NETs, who might be candidate for surgery after treatment and as adjuvant therapy after surgical intervention. Combination treatments of PRRT with chemotherapy or targeted agents as well as combinations of radionuclides in patients with NETs have been explored over the last few years. The majority of patients with NETs experience partial response or have disease stabilization, a small percentage has complete response, while some 30% of patients, however, will have disease progression. The safety and efficacy of retreatment with extra cycles of PRRT as salvage therapy have been evaluated in small retrospective series.

UNASSIGNED

Overall, there is evidence that disease control and quality of life improve significantly after 117Lu PRRT therapy. Clinical trials on this therapy are scarce, and there is a need for further studies to establish proper management guidelines.

Background: Myelofibrosis (MF) is a clonal disorder of hemopoietic stem/progenitor cells (HSPCs) with high prevalence in elderly patients and mutations in three driver genes (JAK2, MPL, or CALR). Around 10-15% of patients are triple-negative (TN) for the three driver mutations and display significantly worse survival. Circulating extracellular vesicles (EVs) play a role in intercellular signaling and are increased in inflammation and cancer. To identify a biomolecular signature of TN patients, we comparatively evaluated the circulating HSPCs and their functional interplay with the microenvironment focusing on EV analysis.

Methods: Peripheral blood was collected from MF patients (n = 29; JAK2^V617F mutation, n = 23; TN, n = 6) and healthy donors (HD, n = 10). Immunomagnetically isolated CD34⁺ cells were characterized by gene expression profiling analysis (GEP), survival, migration, and clonogenic ability. EVs were purified from platelet-poor plasma by ultracentrifugation, quantified using the Nanosight technology and phenotypically characterized by flow cytometry together with microRNA expression. Migration and survival of CD34⁺ cells from patients were also analyzed after in vitro treatments with selected inflammatory factors, i.e. (Interleukin (IL)-1β, Tumor Necrosis Factor (TNF)-α, IL6) or after co-culture with EVs from MF patients/HD.

Results: The absolute numbers of circulating CD34⁺ cells were massively increased in TN patients. We found that TN CD34⁺ cells show in vitro defective functions and are unresponsive to the inflammatory microenvironment. Of note, the plasma levels of crucial inflammatory cytokines are mostly within the normal range in TN patients. Compared to JAK2^V617F-mutated patients, the GEP of TN CD34⁺ cells revealed distinct signatures in key pathways such as survival, cell adhesion, and inflammation. Importantly, we observed the presence of mitochondrial components within plasma EVs and a distinct phenotype in TN-derived EVs compared to the JAK2^V617F-mutated MF patients and HD counterparts. Notably, TN EVs promoted the survival of TN CD34⁺ cells. Along with a specific microRNA signature, the circulating EVs from TN patients are enriched with miR-361-5p.

Conclusions: Distinct EV-driven signals from the microenvironment are capable to promote the TN malignant hemopoiesis and their further investigation paves the way toward novel therapeutic approaches for rare MF.

Keywords: Extracellular vesicles; Inflammation, microRNAs; Myelofibrosis.

The gastroenteropancreatic (GEP) system is the site of origin of about two thirds of all neuroendocrine neoplasms (NENs) of the human body. GEP-NENs encompass a wide spectrum of entities, from very indolent tumors to highly aggressive carcinomas. They represent a challenge for the oncologist and a correct diagnostic approach is crucial for the management of patients. The nomenclature and classification of these tumors have been a matter of debate for more than a century, since their first description by Siegfried Oberdorfer. The last WHO classification provided a robust and easy-to-use tool to prognostically stratify GEP-NENs, based on morphological aspects and on proliferation rate. This review examines current approaches to the diagnosis and prognostic classification of GEP-NENs, focusing on the critical use of morphological parameters and immunohistochemical stainings, including diagnostic, site-specific and prognostic markers. The key issues of the current classification are addressed, including the emerging topics about cases with discordant morphology and proliferative index. Finally, we attempted to highlight the diagnostic pitfalls and the caveats in the use of immunohistochemical stains.

While no specific genetic markers are required in the diagnosis of multiple myeloma (MM), multiple genetic abnormalities and gene signatures are used in disease prognostication and risk stratification. This is particularly important for the adequate identification of the high-risk MM group, which does not benefit from any of the current therapies, and novel approaches need to be proposed. Fluorescence in situ hybridization (FISH) has been employed for establishing risk-based stratification and still remains the most used genetic technique in the clinical routine. The incorporation of gene expression profiling (GEP) in the study of MM has shown to be a very powerful test in the patient stratification, but its incorporation in clinical routine depends on some technical and logistic resolutions. Thus, FISH still remains the gold standard test for detecting genomic abnormalities and outcome discrimination in MM.

Studies of guinea pig genomic and/or cDNA clones encoding the gastro-entero-pancreatic (GEP) hormones--insulin, glucagon and pancreatic polypeptide--as well as portions of the insulin receptor, are described. Multiple clustered substitutions (localized rapid mutation acceptance) altering the biological properties of both insulin and glucagon have been revealed, but this does not appear to be the case with either pancreatic polypeptide or those regions of guinea pig insulin receptor cDNAs that have been examined thus far. These findings suggest that novel selective pressures operative in the New World environment, in which these animals evolved in isolation from Old World mammalian species, have led to altered solutions to problems related to the regulation of growth and carbohydrate metabolism.

OBJECTIVE

Recent studies on gastroenteropancreatic neuroendocrine tumors (GEP-NETs) in the United States as well as the European studies demonstrate an increasing GEP-NETs incidence. Most information on the epidemiology of neuroendocrine tumors comes from western countries. However, the epidemiological profile of GEP-NETs in West China is still unclear. The aim of study was to reflect the regional features of GEP-NETs in Chengdu city of West China based on data from a single institution.

METHODS

West China Hospital (WCH), the largest university hospital located in Chengdu (West China) with population of 14.04 million, has established a serial of databases in recent years. According to the data from Medical Records Section of WCH and Chengdu Health Bureau, the total patients per year in WCH covered about 25.6-28% patients of Chengdu city during the 5 years. Therefore, we have used GEP-NETs diagnosed in WCH from 2009 to 2013 to reflect the regional epidemiological profile of GEP-NETs.

RESULTS

GEP-NETs proportion in WCH increased 1.6-folds during past 5 years from 1.28/10(5) to 2.03/10(5) , P < 0.05. The average duration of symptom before diagnosis was 16.8 months. About 46.6% (115/248) of GEP-NETs were metastatic. Seventy-seven percent (190/248) of patients were over 40 years. Proportions of GEP-NETs from primary sites were rectum 30.6% (76/248), pancreas 23.4% (58/248), gastric 13.3% (33/248) and esophagus 11.3% (28/248). Proportions of insulinoma, vipoma and nonfunctional pancreatic neuroendocrine tumors (P-NETs) were 43.1% (25/58), 1.7% (1/58) and 55.2% (32/58) separately in the P-NETs.

CONCLUSIONS

There is a distinct epidemiologic profile between West China and western countries based on a single institution data. The delayed diagnosis reflects inadequate disease awareness of GEP-NETs and paucity of research funding.

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are rare and heterogeneous group of tumors presenting as localised or metastatic disease and in a subset with distinct clinical syndromes. Treatment is aimed at controlling the functional syndrome, eradicating the tumor, and/or preventing further tumor growth. Surgery is the treatment of choice in removing the primary tumor and/or reducing tumor burden but cannot be applied to all patients. Somatostatin analogs (SS-analogs) obtain control of functional syndromes in the majority of GEP-neuroendocrine tumors (NETs); phase III trials have shown that SS-analogs can be used as first-line antiproliferative treatment in patients with slow-growing GEP-NETs. The role of the recently approved serotonin inhibitor, telotristat ethyl, and gastrin receptor antagonist, netazepide, is evolving. Streptozotocin-based chemotherapy has been used for inoperable or progressing pancreatic NENs but the orally administered combination of capecitabine/temozolomide is becoming more popular due to its better tolerability and potential effect in other GEP-NENs. Phase III trials have shown efficacy of molecular targeted therapies in GEP-NETs and of radionuclide treatment in patients with midgut carcinoid tumors expressing somatostatin receptors. Most patients will develop disease progression necessitating further therapeutic options. A combination of currently available treatments along with the molecular signature of each tumor will guide future treatment.

For patients with neuroendocrine tumours (NETs) of the gastrointestinal tract and pancreas (GEP) (GEP-NETs), excellent care should ideally be provided by a multidisciplinary team of skilled health care professionals. In these patients, a combination of nuclear medicine imaging and conventional radiological imaging techniques is usually mandatory for primary tumour visualisation, tumour staging and evaluation of treatment. In specific cases, as in patients with occult insulinomas, sampling procedures can provide a clue as to where to localise the insulin-hypersecreting pancreatic NETs. Recent developments in these fields have led to an increase in the detection rate of primary GEP-NETs and their metastatic deposits. Radiopharmaceuticals targeted at specific tumour cell properties and processes can be used to provide sensitive and specific whole-body imaging. Functional imaging also allows for patient selection for receptor-based therapies and prediction of the efficacy of such therapies. Positron emission tomography/computed tomography (CT) and single-photon emission CT/CT are used to map functional images with anatomical localisations. As a result, tumour imaging and tumour follow-up strategies can be optimised for every individual GEP-NET patient. In some cases, functional imaging might give indications with regard to future tumour behaviour and prognosis.

BACKGROUND

Heart failure (HF) prevalence is increasing in the United States. Mechanical Circulatory Support (MCS) therapy is an option for Advanced HF (AdHF) patients. Perioperatively, multiorgan dysfunction (MOD) is linked to the effects of device implantation, augmented by preexisting HF. Early recognition of MOD allows for better diagnosis, treatment, and risk prediction. Gene expression profiling (GEP) was used to evaluate clinical phenotypes of peripheral blood mononuclear cells (PBMC) transcriptomes obtained from patients' blood samples. Whole blood (WB) samples are clinically more feasible, but their performance in comparison to PBMC samples has not been determined.

METHODS

We collected blood samples from 31 HF patients (57±15 years old) undergoing cardiothoracic surgery and 7 healthy age-matched controls, between 2010 and 2011, at a single institution. WB and PBMC samples were collected at a single timepoint postoperatively (median day 8 postoperatively) (25-75% IQR 7-14 days) and subjected to Illumina single color Human BeadChip HT12 v4 whole genome expression array analysis. The Sequential Organ Failure Assessment (SOFA) score was used to characterize the severity of MOD into low (≤ 4 points), intermediate (5-11), and high (≥ 12) risk categories correlating with GEP.

RESULTS

Results indicate that the direction of change in GEP of individuals with MOD as compared to controls is similar when determined from PBMC versus WB. The main enriched terms by Gene Ontology (GO) analysis included those involved in the inflammatory response, apoptosis, and other stress response related pathways. The data revealed 35 significant GO categories and 26 pathways overlapping between PBMC and WB. Additionally, class prediction using machine learning tools demonstrated that the subset of significant genes shared by PBMC and WB are sufficient to train as a predictor separating the SOFA groups.

CONCLUSIONS

GEP analysis of WB has the potential to become a clinical tool for immune-monitoring in patients with MOD.

OBJECTIVE

Uveal melanoma is the most common primary intraocular malignancy, and its metastases are deadly. Significant work has been done to elucidate the molecular framework that causes uveal melanoma development and metastasis. This review is intended to highlight the most recent breakthroughs in the molecular understanding of uveal melanoma.

RESULTS

Monosomy of chromosome 3 and class 2 gene-expression profile are well-known indicators of melanoma metastasis. However, some patients with disomy 3 and class 1 gene expression profiling (GEP) still develop metastasis. Disomy 3 tumors may be further classified based upon the presence of an SF3B1 mutation. The role of SF3B1 gene is unclear at this time but may be related to the development of late metastases among disomy 3 uveal melanoma. Class 1 GEP tumors have recently been subdivided into class 1a and class 1b, with class 1b tumors carrying a slightly higher risk of metastasis. Among patients with either class 1 or class 2 GEP, the expression of preferentially expressed antigen in melanoma (PRAME) is an independent risk factor for the development of metastasis. Mutation of GNAQ is the most commonly observed mutation in uveal melanoma, regardless of chromosome 3 status or GEP class. Inhibitors or GNAQ may be targets for therapeutic intervention in uveal melanoma. MicroRNA molecules are small noncoding RNA molecules that have been recently demonstrated to function in RNA silencing and posttranscriptional regulation of gene expression. These molecules may play a role in the development of uveal melanoma metastasis.

CONCLUSIONS

New findings such as the presence or absence of PRAME, mutations in the SF3B1 gene and microRNA dysregulation have added new layers to our understanding of uveal melanoma. These new concepts will enhance our ability to prognosticate tumor metastasis and may provide targets for therapeutic intervention.

BACKGROUND

Gastroenteropancreatic neuroendocrine tumours (GEP NETs) are a heterogenous group of tumours of various clinical presentations. Proliferative activity of tumour cells is an essential parameter determining the course of the disease and affecting the prognosis. The Ki-67 antigen is an important marker of cell proliferation, which shows activity in all the phases of the cell cycle, excluding the G0 phase.

OBJECTIVE

To assess the expression of Ki-67 in GEP NETs and to examine the association of Ki-67 with the stage of the tumour (tumour size, presence of metastases) and the hormonal function of the tumour.

METHODS

We included 61 patients with GEP NETs (25 males and 36 females aged between 20 and 82 years [mean age: 56 years]). The proliferative activity was examined in paraffin blocks containing surgically removed tumour samples and in core-needle biopsies of primary and metastatic tumours. The presence of the Ki-67 antigen was assessed by immunohistochemistry using MIB‑1 monoclonal antibodies. Based on the Ki-67 proliferative index we determined the tumour grade. In addition, we determined the tumour stage according to the TNM classification. In all the subjects we determined the levels of the non-specific NET marker (chromogranin A) and of specific NET markers (serotonin, insulin and gastrin in the blood and 5‑hydroxyindoleacetic acid [5‑HIAA] in 24-hour urine).

RESULTS

The diagnoses of low-grade (Ki‑67 ≤ 2%), intermediate-grade (Ki-67 3-20%) and high-grade (Ki‑67>> 20%) NET were established in 38, 12 and 11 patients, respectively. Metastatic disease was diagnosed in 36/61 patients. A significantly higher expression of K-67 was observed in patients with metastatic disease (p = 0.01). A positive correlation was demonstrated between Ki-67 and the stage of the disease (p = 0.01) and between the histologic grade of the tumour and the stage of the disease (p = 0.01). No association between Ki-67 and the levels of chromogranin A, serotonin, insulin, gastrin and 5-HIAA was shown. There was also no difference in Ki-67 expression relative to the location of the primary tumour and the tumour size.

CONCLUSIONS

The Ki-67 proliferative index is an essential parameter predicting the course of GEP-NETs.

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is an indolent lymphoma, but can transform into diffuse large B cell lymphoma (DLBCL), showing a more aggressive clinical behavior. Little is known about these cases on the molecular level. Therefore, the aim of the present study was to characterize DLBCL transformed from NLPHL (LP-DLBCL) by gene expression profiling (GEP). GEP revealed an inflammatory signature pinpointing to a specific host response. In a coculture model resembling this host response, DEV tumor cells showed an impaired growth behavior. Mechanisms involved in the reduced tumor cell proliferation included a downregulation of MYC and its target genes. Lack of MYC expression was also confirmed in 12/16 LP-DLBCL by immunohistochemistry. Furthermore, CD274/PD-L1 was upregulated in DEV tumor cells after coculture with T cells or monocytes and its expression was validated in 12/19 cases of LP-DLBCL. Thereby, our data provide new insights into the pathogenesis of LP-DLBCL and an explanation for the relatively low tumor cell content. Moreover, the findings suggest that treatment of these patients with immune checkpoint inhibitors may enhance an already ongoing host response in these patients.

Well-differentiated bronchial neuroendocrine tumors (B-NETs) are rare. They represent 1-5 % of all lung cancers. The incidence of these neoplasms has risen over the past 30 years and, especially for advanced or metastatic disease, management is complex and requires a multidisciplinary approach. Treatment with somatostatin analogs (SSAs) is the most important first-line therapy, in particular in well-differentiated NETs with high somatostatin type receptor (SSTR) expression. In these tumors, the role of mammalian target of rapamycin (m-TOR) inhibitors and the potential utility of other target therapies remain unclear while chemotherapy represents the gold standard treatment only for aggressive forms with low SSTR expression. Peptide receptor radionuclide therapy (PRRT) is an emerging treatment modality for advanced NETs. There are many cumulative evidences about the effectiveness and tolerability of this therapeutic approach, especially in gastro-entero-pancreatic (GEP)-NETs. For B-NETs, scientific research is moving more slowly. Here, we performed a review in order to evaluate the efficacy and toxicity of PRRT with a focus on patients with inoperable or metastatic well-differentiated B-NETs.

In this review, we evaluate radiological techniques currently used to localize gastroenteropancreatic (GEP) endocrine tumors. We also describe the visualization, using intravenous administration of two isotope-labelled somatostatin analogs (123-I-Tyr3-octreotide and 111In-DTPA-octreotide), of islet cell tumors in 25 patients and carcinoids in 39 patients. The primary tumor as well as previously unrecognized distant metastases were visualized in 20 of the 25 patients (80%) and in 37 of the 39 (95%). Parallel in vitro detection of somatostatin receptors on those tumors also visualized in vivo showed that ligand binding to the tumor in vivo represents binding to specific somatostatin receptors. The detection of somatostatin receptors on tumors in vivo predicted a good suppressive effect of octreotide on hormonal hypersecretion by these tumors. It is an easy, quick and harmless procedure, valuable in the localization of primary endocrine pancreatic tumors and their often radiologically and clinically unrecognized metastases. Future prospective controlled studies comparing this procedure with other radiological investigative techniques should demonstrate its sensitivity and specificity and determine the place of somatostatin receptor imaging in the localization of GEP endocrine tumors.

The potential of neuroendocrine neoplasms (NEN) to respond to checkpoint inhibitors is largely unknown and full of great expectations. Immunohistochemical (IHC) studies of programmed cell death ligand 1 (PD-L1) expression in the tumor microenvironment and its implications in predicting the response to checkpoint inhibition is a very active subject. Currently, the combined analysis of PD-L1 expression and tumor-associated immune cell (TAIC) infiltration is considered the best predictive marker of therapeutic response. Here we investigated the expression of PD-L1 on tumor cells (TC) and tumor-infiltrating immune cells (IC) by IHC in 68 NEN samples with a high proliferation rate (Ki-67 >20%) from 57 patients and in 22 samples we correlated it with TAIC density by assessing intratumoral infiltration of CD3+, CD8+, and CD68+ cells. Furthermore, the tumor microenvironment was evaluated according to the classification of Teng et al. We detected PD-L1 expression in 31.6% of NEN G3. Its expression usually was weak and more IC than TC expressed PD-L1. The proportion of tumors positive for PD-L1 was comparable in NEN from different sites of origin but varied depending on tumor differentiation and disease extension. No positive IHC staining was found in 3 well-differentiated neuroendocrine tumors (NETs) with a proliferation rate above 20% (NET G3). When analyzing TAIC, we rarely (18.2%) detected intratumoral CD8+ cells, whereas infiltration by CD3+ and CD68+ cells was more common (45.5 and 59.1%, respectively). By combining CD3+ cells and PD-L1 status, we identified the immune ignorant phenotype of tumor microenvironment as being the most common phenotype, supporting the concept of a preferably combined immunotherapeutic approach in neuroendocrine carcinoma (NEC).

The tumor cells in diffuse large B-cell lymphomas (DLBCL) are considered to originate from germinal center derived B-cells (GCB) or activated B-cells (ABC). Gene expression profiling (GEP) is preferably used to determine the cell of origin (COO), however, GEP is not widely applied in clinical practice and consequently, several algorithms based on immunohistochemistry (IHC) have been developed. Our aim was to evaluate the concordance of COO assignment between the Lymph2Cx GEP assay and the IHC-based Hans algorithm to decide which model is the best survival predictor. GEP and IHC were performed in 359 homogenously treated Swedish and Danish DLBCL patients in a retrospective multicenter cohort. The overall concordance between GEP and IHC algorithm was 72%; GEP classified 85% of cases assigned as GCB by IHC as GCB, while 58% classified as non-GCB by IHC were categorized as ABC by GEP. There were significant survival differences (overall survival and progression-free survival) if cases were classified by GEP, whereas if cases were categorized by IHC only progression-free survival differed significantly. Importantly, patients assigned as non-GCB/ABC both by IHC and GEP had the worst prognosis, which was also significant in multivariate analyses. Double expression of MYC and BCL2 was more common in ABC cases and was associated with a dismal outcome. In conclusion, to determine COO both by IHC and GEP is the strongest outcome predictor to identify DLBCL patients with the worst outcome. This article is protected by copyright. All rights reserved.

To investigate whether screening for malnutrition using the validated malnutrition universal screening tool (MUST) identifies specific characteristics of patients at risk, in patients with gastro-entero-pancreatic neuroendocrine tumours (GEP-NET).

Cross-sectional study.

University Hospitals Coventry & Warwickshire NHS Trust; European Neuroendocrine Tumour Society Centre of Excellence.

Patients with confirmed GEP-NET (n=161) of varying primary tumour sites, functioning status, grading, staging and treatment modalities.

To identify disease and treatment-related characteristics of patients with GEP-NET who score using MUST, and should be directed to detailed nutritional assessment.

MUST score was positive (≥1) in 14% of outpatients with GEP-NET. MUST-positive patients had lower faecal elastase concentrations compared to MUST-negative patients (244±37 vs 383±20 µg/g stool; p=0.018), and were more likely to be on treatment with long-acting somatostatin analogues (65 vs 38%, p=0.021). MUST-positive patients were also more likely to have rectal or unknown primary NET, whereas, frequencies of other GEP-NET including pancreatic NET were comparable between MUST-positive and MUST-negative patients.

Given the frequency of patients identified at malnutrition risk using MUST in our relatively large and diverse GEP-NET cohort and the clinical implications of detecting malnutrition early, we recommend routine use of malnutrition screening in all patients with GEP-NET, and particularly in patients who are treated with long-acting somatostatin analogues.

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of mature T-cell malignancies with approximately one-third of cases designated as PTCL-not otherwise specified (PTCL-NOS). Using gene expression profiling (GEP), we have previously defined two major molecular subtypes of PTCL-NOS; PTCL-GATA3 and PTCL-TBX21 that have distinct biological differences in oncogenic pathways and prognosis. In the current study, we generated an immunohistochemistry (IHC) algorithm to identify the two subtypes in paraffin tissue using antibodies to key transcriptional factors (GATA3 and TBX21) and their target proteins (CCR4 and CXCR3). In a training cohort of 49 cases of PTCL-NOS with corresponding GEP data, the two subtypes identified by the IHC algorithm matched the GEP results with high sensitivity (85%) and showed a significant difference in overall survival (OS) (p=0.03). The IHC algorithm classification showed high inter-observer reproducibility among pathologists and was validated in a second PTCL-NOS cohort (n=124), where a significant difference in OS between the PTCL-GATA3 and PTCL-TBX21 subtypes was confirmed (p=0.003). In multivariate analysis, a high International Prognostic Index score (3-5) and the PTCL-GATA3 subtype identified by IHC were independent adverse predictors of OS (p= 0.0015). Additionally, the two IHC-defined subtypes were significantly associated with distinct morphological features (p&lt;0.001), and there was a significant enrichment of an activated CD8+ cytotoxic phenotype in the PTCL-TBX21 subtype (p= 0.03). The IHC algorithm will aid in identifying the two subtypes in clinical practice, which will aid the future clinical management of patients and facilitate risk stratification in clinical trials.

Pulmonary carcinoids (PCs) display the common features of all well-differentiated neuroendocrine neoplasms (NEN) and are classified as low- and intermediate-grade malignant tumours (i.e. typical (TC) and atypical carcinoid (AC), respectively). There is a paucity of randomised studies dedicated to advanced PCs and management principles are drawn from the larger gastroenteropancreatic (GEP) NEN experience. There is growing evidence that NEN anatomic subgroups have different biology and different responses to treatment and, therefore, should be investigated as separate entities in clinical trials. In this review, we discuss the existing evidence and limitations of tumour classification, diagnostics and staging, prognostication and treatment in the setting of PC with focus on unmet medical needs and directions for the future.