The Gastroenteropancreatic Neuroendocrine Cell System and Its Tumors: The WHO Classification

Lymphadenectomy in pancreatic neuroendocrine neoplasms: Why are we still debating?

Pancreatic Neuroendocrine Neoplasms (PNEN) are rare tumours exhibiting very heterogeneous behaviour. For these reasons, studies with high level of evidence are lacking. Whether lymphadenectomy should be performed for PNEN is a matter of debate. In this review, we perform a critical analysis of the available literature regarding the clinical significance of lymphnode metastases, the importance of lymphadenectomy, and the implications on disease-specific survival.

Duodenal neuroendocrine neoplasms: a still poorly recognized clinical entity

BACKGROUND

Duodenal neuroendocrine neoplasms (dNENs) are rare tumors, which usually show good prognosis. The optimal management of these tumors is still far from being clearly understood because of their rarity and the poor level of knowledge about their natural history. Herein, we have reviewed the literature on dNENs to collect and analyze the current data on epidemiology, diagnosis and management of these rare tumors.

METHODS

Bibliographical searches were performed in PubMed, using the following keywords: duodenal neuroendocrine neoplasm; duodenum; gastrinoma; diagnosis; therapy; guidelines. We searched for all relevant articles published over the last 15 years. Non-English language papers were excluded.

RESULTS

We reviewed the pertinent articles about dNENs. Upper gastrointestinal endoscopy with biopsy is the cornerstone of the dNENs diagnostic process. Endoscopic ultrasound with fine-needle aspiration/biopsy should be performed in order to locally stage the disease and in all cases of non-diagnostic endoscopy. Endoscopic or complete surgical removal of the primary lesion is the recommended treatment and is generally achievable for the majority of the patients. A less aggressive approach may be suggested for well-differentiated low-stage tumors. After NEN removal, patients should be closely followed-up especially during the first 3 years by endoscopic examination, imaging tests and CgA measurements.

CONCLUSIONS

The multi-disciplinary approach and the preservation of the quality of life of the patients play a key role in the therapeutic process for dNENs. Further studies are needed to better define standardized guidelines specific to dNENs, including optimal management approaches and follow-up intervals.

Chromogranin A in the Follow-up of Gastroenteropancreatic Neuroendocrine Neoplasms: Is It Really Game Over? A Systematic Review and Meta-analysis

OBJECTIVES

Little is known about chromogranin A (CgA) during follow-up of gastroenteropancreatic neuroendocrine neoplasms. We hypothesized that serial CgA monitoring might be useful for the assessment of tumor progression, and we performed a systematic review of the literature and meta-analysis.

METHODS

A bibliographical search was performed in PubMed using "chromogranin A" and "neuroendocrine tumors" and "follow-up" and "biomarker" to identify all pertinent articles published in the last 10 years.

RESULTS

Eight studies were included in current meta-analysis. Chromogranin A as a follow-up marker shows sensitivity between 46% and 100% and specificity between 68% and 90%. The meta-analysis results showed an overall accuracy of 84% (95% confidence interval [CI], 81-86.6), a cumulative sensitivity of 74.6% (95% CI, 61.9-85.4), and a cumulative specificity of 84.7% (95% CI, 81.3-87.7). These data indicate that circulating CgA has a better overall accuracy in the follow-up setting; it can be used to rule the diagnosis of recurrence/progression in, rather than to rule it out.

CONCLUSIONS

Chromogranin A is more reliable when used to monitor disease progression and response to treatment and for the early detection of recurrence after treatment rather than in the diagnostic setting. It is more sensible to use this marker in those cases where the initial values were impaired.

Significance of TERT and ATRX mutations in glioma

Mutations of telomerase reverse transcriptase (TERT) and the α thalassemia/mental retardation syndrome X-linked (ATRX) genes have been the subject of numerous studies on the classification and prognosis of glioma. However, the association between TERT and ATRX in World Health Organization (WHO) grade II to IV glioma remains unclear. The present study utilized Sanger sequencing and immunohistochemical methods to detect the expression of the TERT promoter region, ATRX mutations and proliferation marker protein Ki-67 (Ki-67) protein expression in 179 cases of glioma. The current study analyzed these variables and their association with clinicopathological characteristics to further basic research and provide a theoretical basis for the clinical diagnosis and treatment of this type of tumor (1). The results demonstrated that TERT promoter mutations were negatively associated with ATRX. Additionally, Ki-67 protein expression in TERT wild-type samples was higher compared with samples with ATRX deletion. Overall, the results demonstrated, for the first time to the best of the authors' knowledge, that TERT promoter mutations are negatively associated with ATRX expression in WHO grade II to IV gliomas. These findings provide a theoretical basis for further basic research and may improve clinical diagnosis and treatment of glioma in the future.

Epidemiologic trends in neuroendocrine tumors: An examination of incidence rates and survival of specific patient subgroups over the past 20 years

INTRODUCTION

Neuroendocrine tumors (NETs) represent a small proportion of cancers, but are increasing in incidence due to incidental diagnosis. We examined NET incidence and survival over time in a population-based registry.

MATERIALS/METHODS

We identified all NET cases diagnosed between 1995 and 2014 in the Surveillance, Epidemiology, and End Results database, November 2016 submission. We determined incidence rates and calculated overall and cancer-specific survival curves in different subgroups stratified by grade, stage, and age at diagnosis.

RESULTS

We identified 85,133 patients with a diagnosis of NET between 1995 and 2014. Patients with grade 1, localized NETs had the best median overall survival (233 months, 95% confidence intervals [CI] not estimable) and 5-year cancer-specific survival (97.6%; 95% CI, 97.4%, 97.8%). The median overall survival decreased with age across the entire spectrum of ages, with patients >70 years having a particularly poor prognosis (28.0 months; 95% CI, 26.5, 29.5). Patients >70 years old often had distant (34.3%) or grade 3 disease (40.8%), but even elderly patients with lower grade and/or stage disease had worse median overall survival compared with younger subjects.

CONCLUSIONS

Age appears to be associated with a worse prognosis independent of NET stage, and grade at the time of diagnosis. Patients with grade 1, localized NETs have an excellent long-term prognosis. Further research is warranted on reducing intensity of surveillance in these patients.

Diagnostic imaging of gastrointestinal neuroendocrine tumours (GI-NETs): relationship between MDCT features and 2010 WHO classification

AIMS

We aimed to present our series of gastrointestinal neuroendocrine tumours (GI-NETs) in order to illustrate and highlight the associated contrast-enhanced multi-detector computed tomography (MDCT) features. We also attempted to identify a relationship between MDCT imaging and the 2010 World Health Organization (WHO) classification system.

MATERIALS AND METHODS

We selected all patients with pathologically proven GI-NETs diagnosed between January 2010 and August 2017. Only patients undergone contrast-enhanced MDCT imaging in the immediate preoperative period were included in our study. Later, two expert radiologists retrospectively assessed MDCT intestinal and extra-intestinal signs. We also analysed the relationship between MDCT imaging and the 2010 WHO classification.

RESULTS

A total of 20 patients (13 males, 7 females, age range 37-89 years, mean age 69.9 years) were included in our study. The majority of GI-NETs (85%) occurred in the small bowel and mainly in the terminal ileum. Forty-five percentage of our GI-NETs were diagnosed after an access to emergency medical service for obstruction symptoms or gastrointestinal bleeding. Regarding intestinal signs, 15/20 patients showed an intraluminal nodular mass and 5/20 a wall thickening. Extra-intestinal signs were present in 75% of cases. Desmoplastic reaction and lymph nodes metastases were significantly correlated with higher grade of GI-NETs.

CONCLUSIONS

The majority of GI-NETs appears as intraluminal mass often associated with extra-intestinal signs. We found a significantly correlation between higher grade of GI-NETs and extra-intestinal signs. MDCT imaging may be useful in predicting the pathological classification of GI-NETs.

Preoperative Imaging Overestimates the Tumor Size in Pancreatic Neuroendocrine Neoplasms Associated with Multiple Endocrine Neoplasia Type 1

BACKGROUND

Radiological tumor size of non-functioning pancreatic neuroendocrine neoplasms (Nf-pNENs) associated with multiple endocrine neoplasia type 1 (MEN1) is a crucial parameter to indicate surgery. The aim of this study was to compare radiological size (RS) and pathologic size (PS) of MEN1 associated with pNENs.

METHODS

Prospectively collected data of MEN1 patients who underwent pancreatic resections for pNENs were retrospectively analyzed. RS was defined as the largest tumor diameter measured on endoscopic ultrasound (EUS), magnetic resonance imaging (MRI) or computed tomography (CT). PS was defined as the largest tumor diameter on pathological analysis. Student's t test and linear regression analysis were used to compare the median RS and PS. p < 0.05 was considered significant.

RESULTS

Forty-four patients with a median age of 37 (range 10-68) years underwent primary pancreatic resections for pNENs. Overall, the median RS (20 mm, range 3-100 mm) was significantly larger than the PS (13 mm, range 4-110 mm) (p = 0.001). In patients with pNENs < 20 mm (n = 27), the size difference (median RS 15 mm vs PS 12 mm) was also significant (p = 0.003). However, the only modality that significantly overestimated the PS was EUS (median RS 14 mm vs 11 mm; p = 0.0002). RS overestimated the PS in 21 patients (21 of 27 patients, 78%). Five of 11 patients (12%) with a Nf-pNEN and a RS > 20 mm had in reality a PS < 20 mm. MRI was the imaging technique that best correlated with PS in the total cohort (r = 0.8; p < 0.0001), whereas EUS was the best correlating imaging tool in pNENs < 20 mm (r = 0.5; p = 0.0001).

CONCLUSION

Preoperative imaging, especially EUS, frequently overestimates the size of MEN1-pNENs, especially those with a PS < 20 mm. This should be considered when indicating surgery in MEN1 patients with small Nf-pNENs.

Laparoscopic resection of duodenal carcinoid: A feasible method: Single institute case series

Background

Duodenal carcinoids (neuroendocrine tumour) are rare tumour, but recently, increase in incidence has been noted. Various techniques for excision of tumour have been described in literature, but very few case reports and case series have mentioned about laparoscopic management of carcinoid tumour. We describe a case series of seven cases of duodenal non-periampullary carcinoids which was managed by laparoscopic method.

Aims

The aim of the study was to check feasibility of laparoscopic management of duodenal carcinoid and technique of surgery.

Settings and Design

This study design was a case series and prospective data were retrospectively collected.

Materials and Methods

A total of 7 patients were operated for carcinoid tumour of duodenum mainly involving first part by laparoscopic method from February 2016 to January 2017. All patients were followed up for minimum 1-year period and various pre-operative, intra-operative findings and post-operative outcome were noted.

Results

Out of seven patients, 6 patient were managed by laparoscopic duodenotomy and transduodenal excision whereas one patient required duodenectomy of first part. Mean operative time was 99 min, mean intraoperative blood loss was 55.7, mean hospital stay was 99.7 and no recurrence in a 1-year follow-up.

Conclusions

Laparoscopic excision of carcinoid tumour is safe, technically reproducible and feasible method.

Chemical Composition of Aqueous Ethanol Extract of Luffa cylindrica Leaves and Its Effect on Representation of Caspase-8, Caspase-3, and the Proliferation Marker Ki67 in Intrinsic Molecular Subtypes of Breast Cancer in Vitro

Breast cancer constitutes the second most prevalent cancer in Egypt, the problem needs more trends in treatment and treatment development either by regimen modification or introducing new drugs, and the main objective of this study is to screen the effects of the aqueous ethanol herbal extract of Luffa cylindrica leaves on different types of breast cancer cell lines representing different molecular subtypes of the disease. The major active constituents of the extract were tentatively identified by LC/MS which revealed the presence of phenolic compound derivatives and saponin that may be responsible in part for the activity of the extract. The emphasis was laid on the main apoptotic pathways as well as the extract effect on the normal cell line. Results of phytochemical investigation, cell cycle analysis, and molecular analysis of apoptotic and proliferative markers have shown effective anticancer activity against MCF-7, BT-474, and MDA-MB-231 cell lines which represent three subtypes of breast cancer, luminal A, luminal B, and triple negative, respectively. On the other hand, the effects on normal lung fibroblast cell line are less prominent at the dose used for treating breast cancer cell lines.

Unusual Sites of High-Grade Neuroendocrine Carcinomas: A Case Series and Review of the Literature

Case series

Patient: Female, 29 • Female, 69 • Female, 52 • Female, 71 • Male, 62 • Female, 67

Final Diagnosis: Neuroendocrine carcinoma

Symptoms: Abdominal pain

Medication: —

Clinical Procedure: —

Specialty: Oncology

Neuroendocrine Tumors of the Esophagus: State of the Art in Diagnostic and Therapeutic Management

INTRODUCTION

Neuroendocrine tumors (NETs) are a heterogeneous group of neoplasms composed of cells containing dense-core neuroendocrine secretory granules in their cytoplasm. NETs of the esophagus are exceedingly uncommon, with a parallel absence of data published on clinical features, prognosis, and proposed treatment strategies.

METHODS

As relevant classification is not well-established, knowledge acquired in NETs of lung and gastrointestinal sites usually guides esophageal NET management. Associated subtypes are divided based upon shared neuroendocrine features into small and large cell NET, typical and atypical carcinoid.

RESULTS

Common presenting symptoms include dysphagia, abdominal discomfort, weight loss, melena, and on occasion, signs of carcinoid syndrome. Endoscopic findings describe a polypoid, nodular elevated lesion with an overlying surface depicted as mostly smooth and glistening. Disease metastasis is assessed using anatomical imaging, including computed tomography (CT), endoscopic ultrasonography (EUS), and positron emission tomography (PET)-CT. Prognosis is influenced by the extent of lymph node metastasis and potential lymphovascular invasion. Furthermore, proliferative activity, estimated using mitotic count or Ki-67 immunostaining, has been suggested as a significant prognostic parameter.

CONCLUSION

Therapeutic approach depends on clinical staging. Nevertheless, currently, a specific treatment algorithm for esophageal NETs has not been elucidated. Endoscopic resection has been proposed in NETs less than 1 cm in size with absence of regional lymph node metastasis, while surgical excision combined with adjuvant chemotherapy remains the treatment of choice.

Clinical outcome and long-term survival of 150 consecutive patients with pancreatic neuroendocrine tumors: A comprehensive analysis by the World Health Organization 2010 grading classification

BACKGROUND AND OBJECTIVE

The World Health Organization (WHO) has revised its grading system for pancreatic neuroendocrine tumors (PNETs) in 2010 into three main group, which has not been widely and comprehensively evaluated. We aimed to validate the clinical valve of this system associated with the clinical outcome and long-term survival when applied to PNETs, which were rare and heterogeneous.

METHODS

We retrospectively collected and analyzed the data of 150 consecutive patients with PNETs who underwent a resection.

RESULTS

Sixty-four males and 86 females with PNETs were enrolled in our study. The clinical stage from I to IV by European Neuroendocrine Tumor Society were respectively defined in 53, 60, 19 and 18 patients. Seventy-two patients were pathologically diagnosed as neuroendocrine tumor G1 (NET G1), 48 as neuroendocrine tumor G2 (NET G2) and 30 as neuroendocrine carcinoma G3 (NEC G3). Patients with a radical resection obtained a notably higher overall survival (OS) than that of patients who underwent a palliative surgery (P=0.001). The 5-year OS of patients with NET G1 was significantly higher than that of patients with NET G2 (P=0.015) and NEC G3 (P<0.001); the comparison of OS for patients with NET G2 and NEC G3 was also statistically significant (P=0.005). In both univariate and multivariate analysis, clinical staging by ENETS (stage I and II vs. stage III and IV), resection (radical vs. palliative) and WHO 2010 grading classification (NET G1 and G2 vs. NEC G3) were validated to be independent predictors for the survivals of PNETs.

CONCLUSION

The newly-updated WHO 2010 grading classification was prognostic for the OS of PNETs and could be widely adopted in clinical practice.

A 41-Year-Old Patient with a Rare Cause of Severe Abdominal Sepsis Misdiagnosed as PID

Infectious pelvic inflammatory disease is a common condition and a frequent cause of abdominal pain in a young female patient. In a patient who has not completed family planning, the diagnosis is often made with a low threshold and treatment started on a low suspicion of diagnosis to avoid a negative impact on fertility. Here, we present a case of a 41-year-old woman who was misdiagnosed with infectious pelvic inflammatory disease and treated ineffectively with antibiotics when the underlying condition of her persistent abdominal pain was a midgut neuroendocrine tumor that had caused bowel perforation and formation of an abscess in the pouch of Douglas.

The Risk Factors for Metastasis in Non-Ampullary Duodenal Neuroendocrine Tumors Measuring 20 mm or Less in Diameter

BACKGROUND/AIMS

The treatment strategy for non-ampullary duodenal neuroendocrine tumors (NAD-NETs) ≤20 mm in diameter has not been established. In this study, we aimed to evaluate the detailed characteristics of NAD-NETs ≤20 mm in diameter to clarify the risk factors of subsequent metastasis.

METHODS

The patients with NAD-NETs ≤20 mm in diameter who had been treated at 12 institutions between 1992 and 2013 were enrolled. Clinical records were retrieved, and histopathological findings of all cases were centrally reviewed by 2 pathologists.

RESULTS

We studied 49 patients with a mean follow-up period of 66.5 months. Thirty-five patients were initially treated with endoscopic resection (ER), and 14 with surgery. A univariate analysis revealed the ORs and 95% CIs of the risk factors for metastasis were lymphovascular invasion (12.5 [2.01-77.9]), multiple tumors (9.75 [1.46-65.4]), a tumor size of 11-20 mm (6.67 [1.21-36.6]), and World Health Organization grade G2 (7.13 [1.16-43.9]). Five-year overall and disease-specific survival rates were 86.1 and 97.2%, respectively.

CONCLUSION

This is the first study to demonstrate the risk factors of metastasis in NAD-NETs ≤20 mm in diameter. These findings may be helpful for determining the appropriate therapeutic approach and the clinical strategy of treatment following ER.

Survival outcomes and surgical intervention of small intestinal neuroendocrine tumors: a population based retrospective study

BACKGROUND

Small intestinal neuroendocrine tumors (SiNETs) without distant metastasis typically behave in an indolent manner, but there can be heterogeneity. We aimed to define the survival outcomes and impacts of surgical intervention.

METHODS

A retrospective cohort study was conducted by using data from the Surveillance, Epidemiology, and End Results (SEER) database. Clinicopathologic features were analyzed in 4407 patients between 2000 and 2012. The cancer specific survival (CSS) was calculated by the Kaplan-Meier method. Multivariable Cox regression models with hazard ratios (HRs) were constructed to analyze survival outcomes and risk factors.

RESULTS

The adjusted incidence of early SiNETs is 1.3/100,000. Tumors are most commonly located in the ileum and are small (≤ 2 cm). The 5-year and 10-year CSS rates were 95.0% and 88.5%, respectively. Age > 50 years, large tumor size (> 2cm), poor differentiation, advanced T classification, and absence of surgical treatment were independent predictors of poor survival. Stratified analysis indicated that surgery significantly improved survival in patients that were white (HR, 0.45), > 50 years old (HR, 0.61), had duodenal tumors (HR, 0.43), large tumors (> 2cm) (HR, 0.32), advanced T classification (T3: HR, 0.29; T4: HR, 0.18) or well differentiation (HR, 0.55). There was no significant survival difference between local resection and radical resection (P =0.884).

CONCLUSIONS

Early SiNETs have a favorable prognosis. Surgical resection may improve outcomes, particularly in older patients and those with large tumors. More aggressive resections couldn't improve outcomes.

Transcriptional alterations in hereditary and sporadic nonfunctioning pancreatic neuroendocrine tumors according to genotype

BACKGROUND

Nonfunctioning pancreatic neuroendocrine tumors (NFPanNETs) may be sporadic or inherited because of germline mutations associated with von Hippel-Lindau disease (VHL) or multiple endocrine neoplasia type 1 (MEN1). The clinical behavior of NFPanNETs is difficult to predict, even in tumors of the same stage and grade. The authors analyzed genotype-specific patterns of transcriptional messenger RNA (mRNA) levels of NFPanNETs to understand the molecular features that determine PanNET phenotype.

METHODS

Thirty-two samples were included for genome-wide mRNA gene expression analysis (9 VHL-associated, 10 MEN1-associated, and 9 sporadic NFPanNETs and 4 purified normal islet cell [NIC] samples). Validation of genes was performed by real-time polymerase chain reaction analysis and immunohistochemistry. Gene expression profiles were analyzed by tumor genotype, and pathway analysis was curated.

RESULTS

Consensus clustering of mRNA expression revealed separate clustering of NICs, VHL-associated NFPanNETs, and MEN1-associated NFPanNETs; whereas some sporadic tumors clustered with MEN1. Four of 5 MEN1-like sporadic PanNET subtypes had loss of heterozygosity at the MEN1 gene locus. Pathway analysis demonstrated subtype-specific pathway activation, comprising angiogenesis and immune response in VHL; neuronal development in MEN1; protein ubiquitination in the new MEN1/sporadic subtype; and cytokinesis and cilium/microtubule development in sporadic NFPanNETs. Among many genes, platelet-derived growth factor receptor β (PDGFRB), lymphoid enhancer-binding factor-1 (Lef-1), cyclin-dependent kinase 4 (CDK4), and CDK6 were upregulated in VHL or MEN1 NFPanNETs, providing potential subtype-specific treatment targets.

CONCLUSIONS

Distinct mRNA expression patterns were identified in sporadic-associated, VHL-associated, and MEN1-associated NFPanNETs. The current results uncover new pathways involved in NFPanNETs that are subtype-specific and provide potential new diagnostic or therapeutic targets based on tumor subtype. Cancer 2018;124:636-47. © 2017 American Cancer Society.

Incidence and survival trends for gastric neuroendocrine neoplasms: An analysis of 3523 patients in the SEER database

BACKGROUND

The aim of this study is to investigate trends in the incidence and survival of patients with gastric neuroendocrine neoplasms (g-NENs).

METHODS

and methods: Patients diagnosed with g-NENs (n = 3523) were identified from the Surveillance, Epidemiology and End Results (SEER) database. Patients diagnosed with g-NENs (n = 199) in our department were designated as a validation dataset. Nomograms were adopted to predict disease-specific survival (DSS) and overall survival (OS).

RESULTS

The incidence of g-NENs is steadily increasing over time at a rate higher than any other cancer [annual percentage change (APC) = 6.3%, 95% confidence interval (CI) 5.6-7.0]. The 1-, 3-, and 5-year DSS rates were 87%, 78.6% and 70.6%, respectively, and the corresponding OS rates were 84.3%, 71.9%, and 53.7%, respectively. The multivariate analysis identified age, sex, T stage, M stage, and histological type as independent prognostic factors for both DSS and OS (all P < .05). The concordance indexes of the nomograms for DSS and OS in the training dataset were superior to those of the traditional tumor-node-metastasis (TNM) staging system [0.899 and 0.849 versus 0.864 and 0.783]. Calibration plots of the nomograms showed that the probability of DSS and OS closely corresponded to the actual observations in both the SEER-based training dataset and our inpatient validation dataset.

CONCLUSION

The incidence of g-NENs has been steadily increasing at a rapid rate over the past four decades. The nomograms based on the analysis of the SEER database were superior to the TNM staging system in predicting the clinical outcomes for g-NEN patients.

The efficacy of chemotherapy and operation in patients with colorectal neuroendocrine carcinoma

BACKGROUND

Colorectal neuroendocrine carcinoma (CRNEC) is a rare type of malignancy and is quite aggressive with dismal prognosis. Neither large-scale retrospective studies nor prospective studies have been performed to evaluate the prognostic value of adjuvant chemotherapy in patients with CRNEC.

METHODS

Using the Surveillance, Epidemiology, and End Results-Medicare database, 318 elderly patients who were diagnosed with high-grade colorectal neuroendocrine tumors were included. The survival benefit was evaluated using a Cox proportional hazards model and propensity score-matched techniques.

RESULTS

Among patients with stage I-III CRNEC, there was also no significant difference in cancer-specific survival (CSS) (P = 0.898) or overall survival (OS) (P = 0.539) between the 5-fluorouracil (5-FU) and the no chemotherapy groups. Meanwhile, the etoposide + platinum (EP) regimen showed no improved survival in patients with stage I-III CRNEC compared with the no chemotherapy group. For stage IV CRNEC, there was no significant difference between operation group and no operation group in CSS (P = 0.317) or OS (P = 0.385). Both 5-FU and EP regimens improved the CSS (for 5-FU, hazard ratio [HR] = 0.257, 95% confidence interval [CI] = 0.134-0.491, P < 0.001; for EP, HR = 0.348, 95% CI = 0.192-0.631, P = 0.001) and OS (for 5-FU, HR = 0.274, 95% CI = 0.149-0.502, P < 0.001; for EP, HR = 0.345, 95% CI = 0.194-0.612, P < 0.001) of patients in stage IV CRNEC.

CONCLUSIONS

Our findings demonstrated that neither the 5-FU based nor EP chemotherapy regimens improved the CSS or OS for patients with stage I-III CRNEC. And for stage IV CRNEC, chemotherapy is an independent prognostic factor for CSS and OS, while operation could not improve the CSS or OS for patients with stage IV CRNEC.

A novel predictive model based on preoperative blood neutrophil-to-lymphocyte ratio for survival prognosis in patients with gastric neuroendocrine neoplasms

Purpose

Evaluate the predictive value of the preoperative blood neutrophil-to-lymphocyte ratio (NLR) on the clinical outcomes of patients with gastric neuroendocrine neoplasms (g-NENs) after radical surgery.

Results

The NLR was significantly higher in patients with g-NENs than in matched normal volunteers (P < 0.05). A higher blood NLR was not significantly associated with clinical characteristics (all P > 0.05). According to the multivariate analysis, the NLR was an independent prognostic factor of RFS and OS. Nomograms, including the NLR, Ki-67 index and lymph node ratio, had superior discriminative abilities to predict clinical outcomes. The recurrence rate was 37% (55/147). The median time to recurrence was 9 months; 48 (87%) patients experienced recurrence within the first 2 years. Both the NLR and Ki-67 index were correlated with liver metastases (both P < 0.05) and were also negatively correlated with recurrence time (both P < 0.05).

Materials And Methods

We enrolled 147 patients who were diagnosed with g-NENs and underwent radical surgery. Receiver operating characteristic curve analysis was used to identify the optimal value for blood NLR. Univariate and multivariate survival analysis were used to identify prognostic factors for g-NENs. A nomogram was adopted to predict RFS and OS after surgery.

Conclusions

As an independent prognostic factor for g-NENs, blood NLR can improve the predictability of RFS and OS. We recommend that g-NEN patients with a high blood NLR or high Ki-67 index undergo surveillance during the first month and then every 3 months for 2 years post-surgery.

Neuroendocrine Tumor Heterogeneity Adds Uncertainty to the World Health Organization 2010 Classification: Real-World Data from the Spanish Tumor Registry (R-GETNE)

BACKGROUND

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are a complex family of tumors of widely variable clinical behavior. The World Health Organization (WHO) 2010 classification provided a valuable tool to stratify neuroendocrine neoplasms (NENs) in three prognostic subgroups based on the proliferation index. However, substantial heterogeneity remains within these subgroups, and simplicity sometimes entails an ambiguous and imprecise prognostic stratification. The purpose of our study was to evaluate the prognostic impact of histological differentiation within the WHO 2010 grade (G) 1/G2/G3 categories, and explore additional Ki-67 cutoff values in GEP-NENs.

SUBJECTS, MATERIALS, AND METHODS

A total of 2,813 patients from the Spanish National Tumor Registry (RGETNE) were analyzed. Cases were classified by histological differentiation as NETs (neuroendocrine tumors [well differentiated]) or NECs (neuroendocrine carcinomas [poorly differentiated]), and by Ki-67 index as G1 (Ki-67 <2%), G2 (Ki-67 3%-20%), or G3 (Ki-67 >20%). Patients were stratified into five cohorts: NET-G1, NET-G2, NET-G3, NEC-G2, and NEC-G3.

RESULTS

Five-year survival was 72%. Age, gender, tumor site, grade, differentiation, and stage were all independent prognostic factors for survival. Further subdivision of the WHO 2010 grading improved prognostic stratification, both within G2 (5-year survival: 81% [Ki-67 3%-5%], 72% [Ki-67 6%-10%], 52% [Ki-67 11%-20%]) and G3 NENs (5-year survival: 35% [Ki-67 21%-50%], 22% [Ki-67 51%-100%]). Five-year survival was significantly greater for NET-G2 versus NEC-G2 (75.5% vs. 58.2%) and NET-G3 versus NEC-G3 (43.7% vs. 25.4%).

CONCLUSION

Substantial clinical heterogeneity is observed within G2 and G3 GEP-NENs. The WHO 2010 classification can be improved by including the additive effect of histological differentiation and the proliferation index.

IMPLICATIONS FOR PRACTICE

Gastroenteropancreatic neuroendocrine neoplasms are tumors of widely variable clinical behavior, roughly stratified by the World Health Organization (WHO) 2010 classification into three subgroups based on proliferation index. Real-world data from 2,813 patients of the Spanish Registry RGETNE demonstrated substantial clinical heterogeneity within grade (G) 2 and G3 neuroendocrine neoplasms. Tumor morphology and further subdivision of grading substantially improves prognostic stratification of these patients and may help individualize therapy. This combined, additive effect shall be considered in future classifications of neuroendocrine tumors and incorporated for stratification purposes in clinical trials.

PPoma Review: Epidemiology, Aetiopathogenesis, Prognosis and Treatment

Generally, pancreatic polypeptide-secreting tumor of the distal pancreas (PPoma) is classified as a rare tumor, and may occur sporadically or be associated in families or with multiple endocrine neoplasia type 1 (NEM 1). It grows slowly, reaching large dimensions at the time of diagnosis and the symptomatology is fundamentally due to the mass effect, causing either non-specific abdominal pain or symptoms suggestive of obstruction of the pancreatic or biliary duct. Therefore, when detected, they are usually malignant, with metastases mainly in the liver. The combination of serum analysis of increased levels of chromogranin A and pancreatic polypeptide and pancreastatin is very useful with a sensitivity of up to 95%. However, in addition, scintigraphicexams with somatostatin analogues should be performed to better clarify the diagnosis. Surgical resection is the treatment of choice, despite surgical difficulty and because they are generally palliative due to the metastases. Surgeries for tumor volume reduction are also performed to relieve symptoms. Chemotherapy commonly uses streptozotocin and somatostatin analogues to treat residual disease. Unfortunately, the survival rates are still very low, less than 10%, and if metastases already exist, this percentage drops to 3%.

Primary well differentiated neuroendocrine tumor of the filum terminale. Case report and literature review

OBJECTIVE

To present a case of a well-differentiated primary intradural-extramedullary neuroendocrine tumor of the filum terminale and to conduct a literature review.

CASE

A 68-years old patient was assessed after presenting lower back pain and sciatica with ineffective pain relief. The patient presented an intradural-extramedullary lumbar lesion arising from the filum terminale, which was partially resected. The pathology diagnosis was a well-differentiated primary neuroendocrine tumor (carcinoid tumor). After a multidisciplinary evaluation, fractionated stereotactic radiotherapy was administered. No progression or metastatic spread was observed in successive assessments.

DISCUSSION

Neuroendocrine tumors are heterogeneous neoplasms derived predominantly from enterochromaffin cells, in which chemotherapy plays a very limited role. In contrast, radiotherapy has been described in partially resected lesions.

CONCLUSION

Well-differentiated primary neuroendocrine tumors with intradural-extramedullary lumbosacral location are an exceptional rarity. Isolated surgical resection, or associated with an adjuvant radiotherapy treatment in subtotal resections, could be considered an effective therapeutic strategy.

Molecular challenges of neuroendocrine tumors

Neuroendocrine tumors (NETs) are a very heterogeneous group that are thought to originate from the cells of the endocrine and nervous systems. These tumors develop in a number of organs, predominantly in the gastrointestinal and pulmonary systems. Clinical detection and diagnosis are reliable at the late stages when metastatic spread has occurred. However, traditional conventional therapies such as radiation and chemotherapy are not effective. In the majority of cases even surgical resection at that stage is unlikely to produce promising reusults. NETs present a serious clinical challenge, as the survival rates remain low, and as these rare tumors are very difficult to study, novel approaches and therapies are required. This review will highlight the important points of accumulated knowledge covering the molecular aspects of the role of neuroendocrine cells, hormonal peptides, the reasons for ectopic hormone production in NET, neuropeptides and epigenetic regulation as well as the other challenging questions that require further understanding.

Nomogram based on tumor-associated neutrophil-to-lymphocyte ratio to predict survival of patients with gastric neuroendocrine neoplasms

AIM

To assess the predictive value of the tumor-associated neutrophil-to-lymphocyte ratio in terms of the clinical outcomes of patients with gastric neuroendocrine neoplasms after radical surgery.

METHODS

Data were retrospectively collected from 142 patients who were diagnosed with gastric neuroendocrine neoplasms and who underwent radical gastrectomy at our department from March 2006 to March 2015. These data were retrospectively analyzed, and a receiver operating characteristic curve analysis was used to identify the optimal value of the tumor-associated neutrophil-to-lymphocyte ratio. Univariate and multivariate survival analyses were used to identify prognostic factors. A nomogram was then applied to predict clinical outcomes after surgery.

RESULTS

The tumor-associated neutrophil-to-lymphocyte ratio was significantly associated with tumor recurrence, especially with liver metastasis and lymph node metastasis (P < 0.05 for both), but not with clinical characteristics (P > 0.05 for all). A multivariate Cox regression analysis identified the tumor-associated neutrophil-to-lymphocyte ratio as an independent prognostic factor for recurrence-free survival and overall survival (P < 0.05 for both). The concordance index of the nomograms, which included the tumor-associated neutrophil-to-lymphocyte ratio, Ki-67 index, and lymph node ratio, was 0.788 (0.759) for recurrence-free survival (overall survival) and was higher than the concordance index of the traditional TNM staging system [0.672 (0.663)].

CONCLUSION

The tumor-associated neutrophil-to-lymphocyte ratio is an independent prognostic factor in patients with gastric neuroendocrine neoplasms. Nomograms that include the tumor-associated neutrophil-to-lymphocyte ratio, Ki-67 index, and lymph node ratio have a superior ability to predict clinical outcomes of postoperative patients.

Developing a multivariable prognostic model for pancreatic endocrine tumors using the clinical data warehouse resources of a single institution

OBJECTIVE: Current staging systems are not accurate for classifying pancreatic endocrine tumors (PETs) by risk. Here, we developed a prognostic model for PETs and compared it to the WHO classification system. METHODS: We identified 98 patients diagnosed with PET at NewYork-Presbyterian Hospital/Columbia University Medical Center (1999 to 2009). Tumor and clinical characteristics were retrieved and associations with survival were assessed by univariate Cox analysis. A multivariable model was constructed and a risk score was calculated; the prognostic strength of our model was assessed with the concordance index. RESULTS: Our cohort had median age of 60 years and consisted of 61.2% women; median follow-up time was 10.4 months (range: 0.1-99.6) with a 5-year survival of 61.5%. The majority of PETs were non-functional and no difference was observed between functional and non-functional tumors with respect to WHO stage, age, pathologic characteristics or survival. Distant metastases, aspartate aminotransferase-AST and surgical resection (HR=3.39, 95% CI: 1.38-8.35, p=0.008, HR=3.73, 95% CI: 1.20-11.57, p=0.023 and HR=0.20, 95% CI: 0.08-0.51, p<0.001 respectively) were the strongest predictors in the univariate analysis. Age, perineural and/or lymphovascular invasion, distant metastases and AST were the independent prognostic factors in the final multivariable model; a risk score was calculated and classified patients into low (n=40), intermediate (n=48) and high risk (n=10) groups. The concordance index of our model was 0.93 compared to 0.72 for the WHO system. CONCLUSION: Our prognostic model was highly accurate in stratifying patients by risk; novel approaches as such could thus be incorporated into clinical decisions.

Hindgut gastropancreatic neuroendocrine carcinoma mimicking hydatid disease

Primary neuroendocrine tumors of the colon are usually very rare and difficult to spot on a nonfunctional imaging. Metastatic lesions are mostly hypervascular, with only a small percentage appearing as cystic or hypovascular lesions. We present a case of a 34-year-old Hispanic female with a history of dull aching upper abdominal pain lasting for a few months. Initial abdominal ultrasound revealed multiple cystic lesions replacing the hepatic parenchyma concerning for a hydatid disease. Liver biopsy was obtained due to negative serology for hydatid disease, which surprisingly revealed a metastatic neuroendocrine tumor of unknown etiology. The primary disease was depicted within the sigmoid colon on a whole-body Octreotide single-photon emission computed tomography-computed tomography done following the biopsy.

Predictive Factors for Lymph Node Metastasis and Prognostic Factors for Survival in Rectal Neuroendocrine Tumors

INTRODUCTION

Neuroendocrine tumors have malignant potential, and lymph node metastasis can occur. This study aimed to identify predictive factors of lymph node metastasis and prognostic factors for survival in rectal neuroendocrine tumors.

METHODS

Sixty-four patients underwent endoscopic or surgical treatment for rectal NET. The data on these patients were collected in our database prospectively and reviewed retrospectively.

RESULTS

Transanal excision was performed in 28 (43.8%) patients, endoscopic mucosal resection or submucosal dissection was performed in 15 (23.4%) patients, and radical resection was performed in 21 (31.8%) patients. Lymph node and distant metastasis was present in 16 (25.0%) and fir (7.8%) patients. The significant risk factors for lymph node metastasis identified in the multivariable analyses were tumor size (≥ 2 cm, p = 0.003) and tumor grade (G2, p < 0.001; G3, p = 0.008). In patients with a tumor smaller than 2 cm, the risk factors for lymph node metastasis included the tumor grade, mitosis count, and Ki-67 index. The median follow-up period was 30.0 months, and recurrence developed in four (6.8%) patients. The significant prognostic factors for survival included tumor size, T stage, lymph node metastasis, and tumor grade.

CONCLUSION

Tumor grade combined with tumor size is an important predictive factor for lymph node metastasis and could serve as a prognostic factor for survival outcomes.

Gastroenteropancreatic-origin neuroendocrine carcinomas: Three case reports with favorable responses following localized radiotherapy and a review of literature

RATIONALE

The radiotherapy (RT) responses of gastroenteropancreatic (GEP)-origin neuroendocrine tumors remain unclear. We report cases of favorable response after localized RT of GEP-origin neuroendocrine carcinomas (GEP-NECs).

PATIENT CONCERNS

1. An 82-year-old male presented with a lower esophageal mass. Positron emission tomography computed tomography (PET-CT) scan showed a lower esophageal mass and gastrohepatic lymph nodes. 2. A 52-year-old female presented with abdominal discomfort. CT scan showed a 9.8 cm-sized enhancing mass in the lesser sac abutting the stomach, pancreas and liver. 3. A 54-year-old male patient presented with anal pain and bleeding. CT scan showed a remnant mass in the perirectal area after trans-anal excision.

DIAGNOSES

The diagnoses of GEP-NECs were pathologically confirmed by biopsy or excision, and immunohistochemical stainings of Ki-67, CD56, synaptophysin and chromogranin-A.

INTERVENTIONS

1. The patient was treated with definitive RT. 2. The patient was treated with RT after two cycles of etoposide-cisplatin chemotherapy. 3. The patient was treated with adjuvant RT.

OUTCOMES

1. Complete remission was achieved based on CT scan four months after RT. 2. CT scan showed partial regression of the mass with a 5 cm-diameter at six months after RT. Adjuvant chemotherapy was administered after RT. 3. The residual mass was almost completely regressed at CT scan four months after RT.

LESSONS

In cases of GEP-NECs, RT can be a useful treatment modality with favorable tumor response for patients with inoperable conditions or those suffering from bulky tumor masses.

Diagnosis and Management of Upper Gastrointestinal Neuroendocrine Tumors

Upper gastrointestinal neuroendocrine tumors (NETs) are rare tumors which are increasingly recognised by practising endoscopists. After confirmation by endoscopic biopsies of these focal lesions, many questions may arise. As NETs are less frequently encountered compared to other malignancies or gastrointestinal pathology, many endoscopists may not fully understand the natural history, diagnosis and management of these tumors. In this review, we aim to update the practising endoscopist on the key clinical features and management of patients with upper gastrointestinal NET.

Ki67 labeling index: assessment and prognostic role in gastroenteropancreatic neuroendocrine neoplasms

In 1983, a monoclonal antibody, Ki67, was generated, that labeled the nuclei of proliferating non-neoplastic and neoplastic cells. The name Ki67 derived from the city of Kiel (Ki) where the antibody was produced in the university department of pathology and refers to the number of the original clone (67). Systematic assessment of the proliferative activity of tumors using Ki67 started in the 1990s, when Ki67, which only worked on frozen tissue, was complemented by the antibody MIB-1 that also worked in formalin-fixed tissues. Pancreatic neuroendocrine neoplasms (PanNENs) were the first endocrine tumors whose proliferative activity was assessed with Ki67. This approach was so successful that Ki67 was included as prognostic marker in the 2000 and 2004 WHO classifications of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). In 2010, the WHO classification of GEP-NENs introduced a three-tiered grading, originally proposed by ENETS in 2006 that was mainly based on the Ki67 index. As it has subsequently been shown that the Ki67 index is the most reliable factor in the prognostic evaluation of GEP-NENs, especially of PanNENs, the 2017 WHO classification of PanNENs requires its use and strongly recommends exact assessment of the proportion Ki67-labeled cells as basis for the calculation of the Ki67 index. Problems in assessing the Ki67 index include intertumoral and intratumoral staining heterogeneity and counting methods. Despite such problems, the Ki67 index has emerged as indispensable for the prognostic and therapeutic stratification of the majority of GEP-NENs and can barely be replaced by counting mitoses. In future, however, it can be anticipated that the Ki67 cut-offs experience refinement in relation to the type of tumor, its location, and its response to therapy. It is also possible that the prognostic risk of an individual tumor is calculated for each Ki67 unit and not for an "a priori" fixed Ki67 class.

Expression of the Cholecystokinin-B Receptor in Neoplastic Gastric Cells

Gastric cancer is an important disease due to its high mortality. Despite the decline in frequency, most cases are discovered late in its course, and most of the cancer patients die within a few years of diagnosis. In addition to Helicobacter pylori gastritis, gastrin is considered an important factor in the development of this disease, and thus, cholecystokinin-B receptor (CCKBR) becomes of interest. The aim of our study was to explore whether CCKBR is expressed in stomach cancers. Thirty-seven tumors from 19 men and 18 women diagnosed with either adenocarcinoma or neuroendocrine neoplasm (NENs) were included in this study. The tumors were classified into 29 adenocarcinomas and eight NENs. Immunohistochemistry with antibodies against chromogranin A (CgA), synaptophysin and CCKBR, and in situ hybridization with probes against CgA, CCKBR and histidine decarboxylase were used to further explore these tumors. Thirty-three (89%) of the tumors expressed CCKBR protein, whereas only 20 (54%) of all tumors expressed CCKBR mRNA. Of the 20 tumors expressing CCKBR mRNA, eight were NENs and 12 were adenocarcinoma. The highest amount of CCKBR was expressed in NEN. Interestingly, a high degree of co-expression of CCKBR and CgA was observed when the two markers were examined together with in situ hybridization. In conclusion, we found that all eight NENs expressed CCKBR and neuroendocrine markers in a majority of tumor cells. The same markers were also expressed in a proportion of adenocarcinomas supporting the view that gastrin is important in the development of gastric cancer.

Racial disparities in pancreatic neuroendocrine tumors survival: a SEER study

Pancreatic neuroendocrine tumor (pancreatic NETs), is an important cause of cancer‐related death worldwide. No study has rigorously explored the impact of ethnicity on pancreatic NETs. We aimed to demonstrate the relationship between ethnicity and the survival of patients with pancreatic NETs. We used the SEER database to identify patients with pancreatic NETs from 2004 to 2013. Kaplan–Meier methods and Cox proportional hazard models were used to evaluate the impact of race on survival in pancreatic NETs patients. A total of 3850 patients were included: 3357 Non‐Blacks, 493 Blacks. We stratified races as “Black” and “White/Other.” Blacks were more likely to be diagnosed with later stages of tumors (P = 0.021). As for the treatment, the access to surgery seemed to be more limited in Blacks than non‐Black patients (P = 0.012). Compared with non‐Black patients, Black patients have worse overall survival (OS) (HR = 1.17, 95% CI: 1.00–1.37, P = 0.046) and pancreatic neuroendocrine tumors specific survival (PNSS) (HR = 1.22, 95% CI: 1.01–1.48, P = 0.044). Multivariate Cox analysis identified that disease extension at the time of diagnosis and surgical status contributed to the ethnical survival disparity. Black patients whose stages at diagnosis were localized had significantly worse OS (HR = 2.09, 95% CI: 1.18–3.71, P = 0.011) and PNSS (HR = 3.79, 95% CI: 1.62–8.82, P = 0.002). As for the patients who did not receive surgery, Blacks also have a worse OS (HR = 1.18, 95% CI: 1.00–1.41, P = 0.045). The Black patients had both worse OS and PNSS compared to non‐Black patients. The restricted utilization of surgery, and the advanced disease extension at the time of diagnosis are the possible contributors to poorer survival of Blacks with pancreatic NETs.

Immunohistochemical Characterization of the Origins of Metastatic Well-differentiated Neuroendocrine Tumors to the Liver

Metastatic neoplasms of unknown primary site pose a major challenge to patient management. As targeted therapies are now being tailored to neuroendocrine tumors (NETs) of different primary sites, identifying the origin of metastatic NETs has become increasingly important. Compared with more extensive efforts on metastatic adenocarcinomas of unknown primary, the literature on metastatic NETs (often to the liver) is relatively sparse and most studies are based on primary tumors. We sought to study metastatic well-differentiated NETs to the liver to identify markers that predict the site of origin. Eighty-five metastatic NETs to the liver were retrieved from the pathology archive. The primary sites were determined based on either pathologic review of the primary tumors (in most cases) or radiologic/clinical findings. Immunohistochemical labeling for TTF1, CDX2, ISL1, NKX2.2, and PDX1 was performed on either tissue microarrays or whole sections. The primary sites of the NETs in the study cohort included: pancreas (35%), small intestine (32%), rectum (8%), stomach (2%), bile duct (1%), lung (9%), and unknown primary (12%). We found predominant expression of TTF1 in lung carcinoid (63%), CDX2 in small intestinal (89%) and ISL1 in pancreatic NETs (77%), respectively. NKX2.2 was mainly expressed in NETs of the digestive organs. PDX1 was detected in a small percentage of pancreatic, small intestinal and the single bile duct NET. There was no statistically significant association between tumor grade (World Health Organization G1 vs. G2) and the expression of any of the above markers. The 3-marker panel (TTF1, CDX2, and ISL1) had sensitivities of 81%, 89%, and 63%, specificities of 100%, 94%, and 100%, positive predictive values of 100%, 89%, and 100%, and negative predictive values of 84%, 94%, and 96% in separating metastatic NETs into 3 major primary sites: pancreas/rectum, small intestine, and lung, respectively, with an overall accuracy of 82%. Furthermore, this panel predicted a primary site for 6 of the 10 NETs of unknown primary, which reduced the NETs of unknown primary from 12% to 5%. Thus, through immunohistochemical study of a large series of metastatic NETs to the liver, we have demonstrated the utility of a 3-marker panel for the identification of one or more potential primary sites of most metastatic NETs, which could provide practical guidance in patient management.

Combination therapies for primary hepatic neuroendocrine carcinoma: a case report

Background

Primary hepatic neuroendocrine carcinomas are extremely rare. Because of the rarity of PHNEC, its clinical features and treatment outcomes are not well understood. A proper diagnosis and the correct therapeutic approach therefore remain clinically challenging.

Case presentation

A 67-year-old man was admitted to our department because of a liver tumor. Computed tomography revealed a single liver tumor 50 mm in diameter and located in the S3 region. Biopsy and imaging findings resulted in a diagnosis of primary hepatic neuroendocrine carcinoma. Left lateral segmentectomy was performed. Immunohistochemically, the tumor cells were positive for synaptophysin, chromogranin A, and CD56. Ki-67 was positive in > 90% of the tumor cells. The final diagnosis was primary hepatic neuroendocrine carcinoma. The patient suffered two episodes of lymph node recurrence. Nonetheless, the tumor was excised to prolong survival. Thus, after lymphadenectomy, he received adjuvant chemotherapy for 6 months. Two years after surgery, the patient remains alive and in good general condition.

Conclusions

In most cases, primary hepatic neuroendocrine carcinoma, while extremely rare, has a poor prognosis. At present, surgical resection is a priority for curative treatment, but in patients with recurrence, combined therapies are recommended.

Imaging of Neuroendocrine Tumors: Indications, Interpretations, Limits, and Pitfalls

Imaging is critical in the diagnosis, prognosis, and management of neuroendocrine tumors (NETs). NETs share common imaging features, but each type exhibits unique features. Computed tomography scans or MRI of the abdomen is used to assess tumor burden routinely. Functional imaging with octreotide scan or gallium-68 somatostatin analog PET is used selectively to confirm diagnosis and guide therapy. Clinicians and radiologists should be familiar with the indications and interpretations of imaging modalities. Novel functional imaging modalities likely will be developed to detect small NETs, predict prognosis, guide therapeutic choices, and design novel therapies.

Evaluation of treatment for rectal neuroendocrine tumors sized under 20 mm in comparison with the WHO 2010 guidelines

Rectal neuroendocrine tumor (NET) is a relatively rare lesion of the gastrointestinal tract, but the prospective examination with colonofiberoscopy or endoscopic ultrasound has increased the frequency of its detection. It is often difficult to determine the optimal treatment for NETs sized <20 mm in the clinical setting. Other clinicopathological variables are not considered in the current guidelines and staging systems. Although the effects of lymphovascular invasion are not covered by the World Health Organization (WHO) 2010 guidelines or tumor-node-metastasis (TNM) staging system, this may be promising for the establishment of improved guidelines and staging systems, particularly for early-stage colorectal carcinoids. The aim of the present study was to evaluate rectal NETs sized <20 mm in comparison with the WHO 2010 guidelines. Between January 2005 and December 2013, 40 consecutive patients [26 men and 14 women; median age, 59.3 years (range, 34-81 years)] who underwent endoscopic resection of rectal NETs, and 12 patients undergoing surgical resection of rectal NETs, were enrolled in this retrospective study. The median tumor size was 7.4 mm (range, 3-15 mm). The locations of the NET were the rectosigmoid colon (n=3), the upper rectum (n=13), and the lower rectum (n=25). The NETs were classified by size as 0-5 (n=7), 6-10 (n=29) and 11-15 mm (n=4). The surgical procedures performed included low anterior resection plus esophagectomy (n=1), laparoscopic low anterior resection (n=7) and laparoscopic intersphincteric resection (n=4). Only 1 patient had lymph node metastasis (tumor sized 6-10 mm, with lymphovascular invasion). NET recurrence was not detected in any of the patients. According to the WHO guidelines, the tumors were classified as grade (G)1 (n=8), G2 (n=3) and G1/G2 (n=1). The tumor in the patient with lymph node metastasis was G1. NETs sized <10 mm may be curatively treated by endoscopic resection. However, NETs with either lymphovascular invasion or sized >1 cm carry a risk for metastasis equivalent to that of adenocarcinomas. Therefore, it is mandatory to histologically examine lymphovascular invasion in specimens retrieved via endoscopic resection to determine the necessity for further radical surgery with regional lymph node dissection. The treatment of NETs sized <20 mm as presently defined in the WHO 2010 guidelines requires further evaluation.

Gastrointestinal manifestations of neuroendocrine tumours: their investigation and management

The incidence of neuroendocrine tumours (NETs) is on the rise in the UK. Patients with NETs need to be managed by a team of clinical specialties. There are a number of challenging gastrointestinal (GI) manifestations related to NETs that can occur in these patients, but a limited literature base exists to guide clinicians.Whilst life expectancy can be several years for patients with NETs, the GI symptoms can have a significant impact on their quality of life. It is therefore imperative to be familiar with the common GI manifestations associated with NETs, so symptoms can be appropriately managed with an overall aim of restoring the patient's quality of life.

Molecular imaging in the investigation of hypoglycaemic syndromes and their management

There has been recent progress in molecular imaging using a variety of cellular targets for the investigation of adult non-diabetic hypoglycaemic syndromes and its integration into patient management. These targets include peptide receptors (somatostatin receptors (SSTRs) and glucagon-like peptide-1 receptor (GLP-1R)) the amine precursor uptake and decarboxylation system utilising the diphydroxyphenylaline (DOPA) analogue 6-[¹⁸F]-l-fluoro-l-3,4-dihydroxyphenylalanine (¹⁸F-FDOPA), and glycolytic metabolism with 2-[¹⁸F]fluoro-2-deoxy-d-glucose (FDG). Accurate preoperative localisation and staging is critical to enable directed surgical excision or enucleation with minimal morbidity and preservation of residual pancreatic function. Benign insulinoma has near ubiquitous dense GLP-1R expression enabling accurate localisation with radiolabelled-exendin-4 compounds (e.g. ⁶⁸Ga-NOTA-exendin-4 PET/CT), whilst the rarer and more difficult to manage metastatic insulinoma typically express SSTR and is preferably imaged with radiolabelled-SSTR analogues such as ⁶⁸Ga-DOTA-octreotate (DOTATATE) PET/CT for staging and assessment of suitability for peptide receptor radionuclide therapy (PRRT). Similar to other metastatic neuroendocrine tumours, FDG PET/CT is used in the setting of higher-grade metastatic insulinoma to provide important prognostic information that can guide treatment and determine suitability for PRRT. Interestingly, these three tracers appear to represent a spectrum of differentiation, which we conceptually describe as the 'triple-flop' phenomenon, with GLP-1R > SSTR > FDG in benign insulinoma and the opposite in higher-grade disease. This paper will review the clinical syndromes of adult hypoglycaemia (including a practical overview of the differential diagnoses to be considered), comparison of techniques for insulinoma localisation with emphasis on molecular imaging before discussing its implications for management of metastatic insulinoma.

Recent updates on grading and classification of neuroendocrine tumors

Neuroendocrine tumors (NETs) are originating from neuroendocrine cells in diffuse endocrine systems. NETs are diagnosed by characteristic histologic features and immunoprofiles. Recent 2010 WHO classification for gastroenteropancreatic NETs introduced grading system based on mitotic count and Ki-67 proliferation index. Gastroenteropancreatic NETs are classified as NET grade 1, NET grade 2, and neuroendocrine carcinoma (NET grade 3). However, the carcinoid is still used in classification of NETs of the lung and uterine cervix. Some issues with grading system such as methodologies for evaluation of Ki-67 index and subclassification of neuroendocrine carcinoma (NET grade 3) are arising. The importance of Ki-67 labeling index is emerging in differential diagnosis of lung carcinoids. In this review, we focus on recent grading and classification of NETs and related issues in various organs, including gastrointestinal tract, pancreas, lung, and female reproductive organs.

Clinicopathological characteristics of biliary neuroendocrine neoplasms: a multicenter study

OBJECTIVES

This study assessed the clinicopathological features, therapeutic approaches, and prognosis of patients with biliary neuroendocrine neoplasm (NENs).

MATERIALS AND METHODS

Multicenter retrospective study of patients with biliary tract NENs in the gallbladder, the extrahepatic bile duct, or the ampulla of Vater between 2005 and 2014.

RESULTS

Total of 43 patients were included in the study. The median age was 62 years (range: 29-84 years) and 58.1% of the patients were male. The tumors occurred in the gallbladder (n = 11), the extrahepatic bile duct (n = 5) or the ampulla of Vater (n = 27). The liver was the most common metastatic site. Based on the 2010 World Health Organization classification, more patients with gallbladder NENs (11/11 (100%)) had neuroendocrine carcinoma G3 than those with NENs in the ampulla of Vater (10/27 (37.1%)). The median progression free survival time (39.3 vs 5.1 months, p = 0.001) and median overall survival time (46.9 vs 7.9 months, p < 0.001) were significantly longer in patients with ampulla of Vater NENs than gallbladder NENs. A 2010 World Health Organization classification of neuroendocrine carcinoma G3 was independently related to poor overall survival (hazard ratio (HR), 27.1; 95% confidence intervals (CI), 2.81-260.68; p = 0.004).

CONCLUSION

The 2010 World Health Organization classification of neuroendocrine carcinoma G3 was the only factor related to poor prognosis in patients with biliary neuroendocrine neoplasms.

Prognostic factors in ectopic Cushing's syndrome due to neuroendocrine tumors: a multicenter study

OBJECTIVE

Evidence is limited regarding outcome of patients with ectopic Cushing's syndrome (ECS) due to neuroendocrine tumors (NETs).

DESIGN

We assessed the prognostic factors affecting the survival of patients with NETs and ECS.

METHODS

Retrospective analysis of clinicopathological features, severity of hormonal syndrome, treatments from a large cohort of patients with NETs and ECS collected from 17 Italian centers.

RESULTS

Our series included 110 patients, 58.2% female, with mean (±s.d.) age at diagnosis of 49.5 ± 15.9 years. The main sources of ectopic ACTH were bronchial carcinoids (BC) (40.9%), occult tumors (22.7%) and pancreatic (p)NETs (15.5%). Curative surgery was performed in 56.7% (70.2% of BC, 11% of pNETs). Overall survival was significantly higher in BC compared with pNETs and occult tumors (P = 0.033) and in G1-NETs compared with G2 and G3 (P = 0.007). Negative predictive factors for survival were severity of hypercortisolism (P < 0.02), hypokalemia (P = 0.001), diabetes mellitus (P = 0.0146) and distant metastases (P < 0.001). Improved survival was observed in patients who underwent NET removal (P < 0.001). Adrenalectomy improved short-term survival.

CONCLUSIONS

Multiple factors affect prognosis of ECS patients: type of NET, grading, distant metastases, severity of hypercortisolism, hypokalemia and diabetes mellitus. BCs have the highest curative surgical rate and better survival compared with occult tumors and pNETs. Hypercortisolism plays a primary role in affecting outcome and quality of life; therefore, prompt and vigorous treatment of hormonal excess by NET surgery and medical therapy should be a key therapeutic goal. In refractory cases, adrenalectomy should be considered as it affects outcome positively at least in the first 2 years.