Neuroendocrine neoplasms of the gut and pancreas: new insights

Hormone secreting gastro-entero-pancreatic neuroendocrine neoplasias (GEP-NEN): When to consider, how to diagnose?

Neuroendocrine neoplasms of the digestive system (GEP-NEN) represent a heterogeneous group of malignancies with various clinical presentation and prognosis. GEP-NENs can potentially affect all organs of the gastrointestinal tract; characteristically they share the biological property to produce and secrete peptides and neuroamines. About 30% of GEP-NENs are hormonally active and can cause specific clinical syndromes. The clinical presentation mainly depends on the primary site of the tumor and its functionality. Because of the wide spectrum of clinical symptoms and their misperceived rarity, diagnosis of GEP-NENs is often delayed for years and tumors are detected first in an advanced stage. Early identification of a specific hormonal syndrome can significantly impact tumor diagnosis and treatment, moreover the preoperative management of NEN hormonal release avoids potential life threatening hormonal crisis. However, GEP-NEN diagnostic work-up is challenging, it requires a multidisciplinary team and needs particular experience; standardized protocols and clinical experience are essential for a proper endocrine diagnostic work-up. In addition to the biochemical diagnostic, further radiologic and endoscopic imaging modalities are required moreover, somatostatin-receptor based functional imaging, using either Octreotide-scintigraphy or novel PET-based techniques with specific isotopes like Ga⁶⁸-DOTA-octreotate, plays an important role for the detection of the primary tumor as well as for the evaluation of the tumor extent.

The management of neuroendocrine tumours: A nutritional viewpoint

Nutritional status in patients with neuroendocrine tumours (NETs), especially of gastroenteropancreatic origin, can be deeply affected by excessive production of gastrointestinal hormones, peptides, and amines, which can lead to malabsorption, diarrhoea, steatorrhea, and altered gastrointestinal motility. Besides, the surgical and/or medical management of NETs can lead to alteration of gastrointestinal secretory, motor, and absorptive functions, with both dietary and nutritional consequences. Indeed, disease-related malnutrition is a frequently encountered yet both underrecognized and understudied clinical phenomenon in patients with NETs, with substantial prognostic and socioeconomic consequences. Most of these conditions can be alleviated by a tailored nutritional approach, also with the aim of improving the efficacy of cancer treatments. In this setting, skilled nutritionists can play a fundamental role in the multidisciplinary health care team in NETs management and their presence should be recommended. The aim of this review is to provide dietary advices for each specific condition in patients with NETs, underlining the importance of a nutritional approach to treat malnutrition in this setting. Further, we will provide preliminary evidence coming from our data on the assessment of nutritional status in a single cohort of patients with NETs.

Neuroendocrine Neoplasms: Dichotomy, Origin and Classifications

Neuroendocrine neoplasms (NENs) are heterogeneous tumors with a common phenotype. There are two fundamentally different groups of NENs: well-differentiated, low-proliferating NENs, called neuroendocrine tumors (NETs) or carcinoids, and poorly differentiated, highly proliferating NENs, called small- or large-cell neuroendocrine carcinomas (NECs). This NEN dichotomy is probably due to an origin from different neuroendocrine progenitor cells. The current World Health Organization (WHO) classification of gastrointestinal NENs uses the Ki67 proliferation index to grade NETs as G1 or G2, and NECs as G3. In the pancreas, NETs and NECs may overlap in their proliferation index, making the distinction between them difficult and leading to therapeutic uncertainties. Therefore, the WHO classification of pancreatic NENs (PanNENs) from 2017 introduced a new NET G3 category. Helpful for the distinction of NETs G3 from NECs is the expression of p53 and rb1 that is usually negative in PanNETs. Comparison of the WHO classification of digestive system NENs with other NEN classifications reveals site-specific differences in terminology and a general lack of grading systems. However, all classifications recognize the existence of the two major NEN families and provide a general basis for their prognostic and therapeutic stratification. A development of a common NEN classification across organs is desirable.

A single institution's 21-year experience with surgically resected pancreatic neuroendocrine tumors: an analysis of survival and prognostic factors

BACKGROUND

Pancreatic neuroendocrine tumors (pNETs) comprise a heterogeneous group of tumors with a varied biological behavior. In the present study, we analyzed the experience of 79 pNETs resected between 1999 and 2014. The pathologic prognostic factors (European Neuroendocrine Tumor Society, ENETS; and AJCC) classification, vascular invasion (VI), proliferation index (ki-67) and the presence of necrosis were retrospectively reviewed.

METHODS

The clinical data of 79 patients with pNETs who underwent surgery were retrospectively analyzed. Mortality rates and Kaplan-Meier estimates were used to evaluate survival over time for pathologic stages, tumor functionality, and vascular invasion. Cox proportional hazards models were used to calculate the hazard ratio regarding ENETS, AJCC staging, sex, tumor functionality and vascular invasion.

RESULTS

The male:female ratio was 40:39. Twenty-one patients (26%) had functional tumors and 58 (73.4%) had non-functional tumors, of which 35 (44.3%) were diagnosed incidentally. Seventeen Whipple procedures, 46 distal pancreatectomies (including 26 laparoscopic and 20 open procedures), 8 laparoscopic central pancreatectomies, 1 laparoscopic resection of the uncinated process and 7 enucleations (one laparoscopic) were performed. Vascular invasion and necrosis were observed in 29 of 75 cases (38.6%) and in 16 cases (29%), respectively. The comparison between survivor functions of ENETS staging categories showed statistically significant differences (p = 0.042). Mortality rate was higher in patients with non-functioning tumors compared with hormonally functioning tumors (p = 0.052) and in those with vascular invasion (p = 0.186).

CONCLUSIONS

In spite of the heterogeneity of pNETs, the ENETS TNM classification efficiently predicts long-term prognosis. The non-functioning tumors and the presence of vascular invasion are associated with poor prognosis.

Endocan expression is correlated with poor progression-free survival in patients with pancreatic neuroendocrine tumors

Endocan expression has been reported to be associated with aggressive tumor progression and poor outcomes in various cancers, such as breast cancer, renal cell cancer, lung cancer, gastric cancer, and pituitary adenomas. However, the prognostic significance of endocan in neuroendocrine tumors remains unknown. Thus, the aim of this study was to determine the correlation between endocan expression in pancreatic neuroendocrine tumor (PNET) tissues and progression-free survival. This study included 73 patients with confirmed PNETs who were treated in a single tertiary center in north Taiwan between 1992 and 2015. Immunohistochemical endocan expression and microvessel density (MVD) were examined, and the relationships between these parameters and other clinicopathological characteristics were analyzed. The abovementioned patients were divided into groups according to their endocan expression levels (≥1% or <1%) and median MVDs. Negative endocan expression (P = .002) and a high MVD (P < .001) were significant and favorable prognostic factors for progression-free survival. However, positive endocan expression was significantly associated with a low MVD (P = .037) and tumor mitosis (Ki-67 index) (P = .028). Multivariate Cox regression analysis showed that positive endocan expression (hazard ratio: 4.778, P = .018) and lymph node involvement (hazard ratio: 5.121, P = .005) were independent prognostic factors for tumor recurrence.In conclusion, endocan expression was correlated with poor clinical outcomes in PNETs. Our data indicated that endocan expression may be a reliable marker for predicting tumor recurrence in patients with PNETs.

A nation-wide retrospective epidemiological study of gastroenteropancreatic neuroendocrine neoplasms in china

BACKGROUND

Representative data on the gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) in Asian patients is rare, especially in China. This study aims to create a GEP-NENs profile of Chinese patients.

METHODS

This was a hospital-based, nation-wide, and multi-center 10-year (2001-2010) retrospective study which collected GEP-NEN patients' information in tertiary referral hospitals. All 2010 inpatient GEP-NEN cases with confirmed pathology in the selected hospitals were included. The primary GEP-NEN sites were measured and the epidemiological and clinical information of each tumor site were compared.

RESULTS

The most common primary sites for GEP-NEN were the pancreas (31.5%) and rectum (29.6%), followed by the cardia (11.6%) and body (15.4%) of stomach. Small intestinal and colonic NENs took up a relatively small proportion of all patients. Pancreatic and rectal NENs, rather than cardiac and gastric body NENs, tended to be found in younger (P<0.001), female (P<0.001), urban (P<0.001) residents with a higher education level (P=0.032) and were also diagnosed at earlier stage (P<0.001) and lower grade (P<0.001). Surgery remained the primary treatment method in all groups.

CONCLUSIONS

More studies on the commonality and heterogeneity of GEP-NENs are warranted to improve diagnosis efficiencies and treatment outcomes.

High expression of Ki-67 is an independent favorable prognostic factor for esophageal small cell carcinoma

BACKGROUND

The prognostic value of Ki-67 expression in small cell carcinoma of the esophagus (SCCE) has not been explored in any previous studies. Therefore, we conducted this retrospective study to investigate the prognostic role of Ki-67 in SCCE for the first time.

RESULTS

A total of 44 patients were included for analysis. The baseline clinicopathological data of these SCCE patients shared similar characteristics with previous studies. Ten patients were at stage I, 17 at stage II, and the remaining 17 were at stage III. Postoperatively, 23 patients received adjuvant therapy. Twenty-eight patients were found to have a high expression of Ki-67 (> 50%). After a median follow-up time of 54.8 months, the median survival time of those patients was 22.1 months. Early TNM stage, application of adjuvant therapy, and high expression of Ki-67 (Hazard Ratio = 0.314, 95% CI: 0.127-0.774; P = 0.012) were found to be favorable prognostic factors of patients with SCCE. In subgroup analysis, adjuvant therapy could only bring significant survival benefit for patients with high expression of Ki-67 (P = 0.008).

MATERIALS AND METHODS

Patients undergoing esophagectomy with lymphadenectomy for SCCE from January 2009 to January 2015 in our department were retrospectively analyzed. Data for analysis included demographic data, pathologic findings, tumor stage, adjuvant therapy, and survival time as well as Ki-67 index.

CONCLUSIONS

This study suggested that high expression of Ki-67 may not only serve as a favorable prognostic factor of SCCE but also an indication of providing adjuvant therapy for SCCE patients with surgical resection.

Imitators of chronic pancreatitis: diffuse neuroendocrine tumour of the pancreas

We report a rare case of diffuse replacement of the pancreas with neuroendocrine tumour mimicking chronic pancreatitis. A 55-year-old female with no significant past medical history initially presented with abdominal pain in 2006. A CT of the abdomen and pelvis was performed, revealing diffuse pancreatic parenchymal calcifications with mild pancreatic ductal dilatation and no discrete mass. She was diagnosed with chronic pancreatitis and followed clinically until 2015, where she presented with recurrent abdominal pain. A repeat CT and MRI of the abdomen were performed which revealed new hypoenhancing masses within the pancreas, particularly in the pancreatic tail. There was a persistent background of pancreatic parenchymal calcifications. The possibility of pancreatic neuroendocrine tumour was raised, and an indium-111 Octreotide scan was recommended. Diffuse intense uptake was identified throughout the pancreas on the indium-111 imaging. Given the concern for neuroendocrine tumour, a total pancreatectomy was performed, with histopathology revealing replacement of the pancreas with coalescing well-circumscribed nodules. Many of the nodules had numerous calcifications and localized amyloid deposition. Immunohistochemical stains of the neoplastic cells were strong for neuroendocrine markers chromogranin A and synaptophysin. Overall the findings were consistent with numerous neuroendocrine tumours of the pancreas, Grade II, as per the 2010 WHO criteria for neuroendocrine tumours of the pancreas. Neuroendocrine tumours of the pancreas are lesions that arise from the islet cells, with an approximate incidence of five cases per million people per year. Only one other case report has been documented in the literature by Singh et al demonstrating diffuse pancreatic neuroendocrine tumour replacing the entire pancreas. As diffuse pancreatic neuroendocrine tumour can look similar on imaging to chronic pancreatitis or other infiltrative processes, we wanted to present this case and some of the more specific imaging findings in distinguishing these entities.

Comprehensive immunohistochemical analysis of histone deacetylases in pancreatic neuroendocrine tumors: HDAC5 as a predictor of poor clinical outcome

Epigenetic factors contribute to carcinogenesis, tumor promotion, and chemoresistance. Histone deacetylases (HDACs) are epigenetic regulators that primarily cause chromatin compaction, leading to inaccessibility of promoter regions and eventually gene silencing. Many cancer entities feature overexpression of HDACs. Currently, the role of HDACs in pancreatic neuroendocrine tumors (pNETs) is unclear. We analyzed the expression patterns of all HDAC classes (classes I, IIA, IIB, III, and IV) in 5 human tissue microarrays representing 57 pNETs resected between 1997 and 2013 and corresponding control tissue. All pNET cases were characterized clinically and pathologically according to recent staging guidelines. The investigated cases included 32 (56.1%) female and 25 (43.9%) male pNET patients (total n=57, 47.4% immunohistochemically endocrine positive). Immunohistochemical profiling revealed a significant up-regulation of all HDAC classes in pNET versus control, with different levels of intensity and extensity ranging from 1.5- to >7-fold up-regulation. In addition, expression of several HDACs (HDAC1, HDAC2, HDAC5, HDAC11, and Sirt1) was significantly increased in G3 tumors. Correlation analysis showed a significant association between the protein expression of HDAC classes I, III, and IV and rate of the pHH3/Ki-67-associated mitotic and proliferation index. Furthermore, especially HDAC5 proved as a negative predictor of disease-free and overall survival in pNET patients. Overall, we demonstrate that specific members of all 4 HDAC classes are heterogeneously expressed in pNET. Moreover, expression of HDACs was associated with tumor grading, proliferation markers, and patient survival, therefore representing interesting new targets in pNET treatment.

Predictive value of preoperative peripheral blood neutrophil/lymphocyte ratio for lymph node metastasis in patients of resectable pancreatic neuroendocrine tumors: a nomogram-based study

Background

Neutrophil-to-lymphocyte ratio (NLR) is one of the systemic inflammation markers, which has prognostic values in many types of tumor. However, hardly any research has reported the relationship between NLR and pancreatic neuroendocrine tumors (PanNETs). In this study, we aimed to evaluate the predictive value of the preoperative peripheral blood NLR on the clinical outcomes in patients of resectable PanNETs.

Methods

Ninety-five cases of PanNETs registered in the First Affiliated Hospital of Zhejiang University between March 2009 and May 2016 and underwent pancreatic surgery were included in this study. Univariate and multivariate analyses were applied to identify the prognostic factors for PanNETs. Prognostic nomogram and its calibration curve then used R (version 3.3.2) to predict lymph node (LN) metastasis.

Results

Among these 95 patients, 52 (54.7%) patients were diagnosed as grade 1 (G1) NET (mitotic count <2/10 HPF, Ki-67 ≤2%), 32 (33.7%) as G2 NET (mitotic count 2–20/10 HPF, Ki-67 3–20%), and 11 (11.6%) as G3 NEC (mitotic count >20/10 HPF, Ki-67 >20%). Increased NLR was found to relate with advanced T stage, LN metastasis, tumor thrombus formation, and advanced grade (p < 0.05 for all). Multivariate logistic regression was performed and indicated that NLR (HR 6.74; p = 0.02) was an independent prognostic factor for LN metastasis. Furthermore, we developed a nomogram based on the combination of NLR, T stage, and grade for LN metastasis with a good discrimination ability with the AUC (area under the curve) of 0.885. This nomogram showed larger AUC than those using NLR (0.725), T stage (0.808), or grade (0.708) alone as a prognostic factor, which means this system achieved a more optional performance in predicting clinical outcomes. Finally, the Kaplan–Meier curve indicated that the recurrence-free survival (RFS) of patients with high NLR (NLR >1.40, RFS 61.1 ± 4.4 months) decreased significantly as compared with those of low NLR (NLR ≤1.40, RFS 63.8 ± 2.9 month, p < 0.05).

Conclusions

The preoperative NLR is a potential independent predictor for LN metastasis and RFS. Our nomogram highlighted the important role of NLR in prognosis, which might be considered as a convenient indicator for lymph node metastasis, especially during the initial diagnosis for resectable PanNETs.

Prognostic relevance of UCH-L1 and α-internexin in pancreatic neuroendocrine tumors

Prognostic biomarkers for the pancreatic neuroendocrine tumors are needed. Proteomic study on insulinoma has been rarely reported. We identified the differential expression of proteins between insulinoma and their paired tissues by proteomic analysis, and evaluated the prognostic significance of specific proteins in pancreatic neuroendocrine tumors including insulinoma. The differential expression of select proteins was validated in more than 300 tumors using immunohistochemical staining and western blot. Methylation of UCH-L1 promoter in tumors was examined by methylation specific PCR and validated by sequencing. The concurrent expression of UCH-L1 and α-internexin was correlated with the prognosis in 2 independent collectives of patients with tumors. Sixty-two and 219 proteins were significantly down-regulated and up-regulated in insulinomas, respectively. Demethylation of UCH-L1 promoter was associated with UCH-L1 expression in tumors (p = 0.002). The concurrent expression of UCH-L1 and α-internexin in pancreatic neuroendocrine tumors was significantly associated with better overall survival and disease-free survival in the combination of both cohorts (log rank p = 3.90 × 10⁻⁴ and p = 3.75 × 10⁻⁵, respectively) and in each of cohorts. The prognostic value of both proteins was also validated in patients with stage II and III tumors (p = 0.017 and p = 0.006, respectively). The proteins UCH-L1 and α-internexin could be independent prognostic biomarkers of pancreatic neuroendocrine tumors.

Value of diffusion-weighted magnetic resonance imaging in predicting World Health Organization grade in G1/G2 pancreatic neuroendocrine tumors

The present study aimed to investigate the value of diffusion-weighted magnetic resonance imaging (DWI) in the grading of well-differentiated pancreatic neuroendocrine tumors (PanNETs). A total of 44 patients with histologically proven well-differentiated PanNET [grade 1 (G1) and grade 2 (G2) according to the World Health Organization (WHO) criteria] underwent pretreatment magnetic resonance imaging (MRI), which was retrospectively analyzed. The location, size, cystic or solid appearance, boundary, presence or absence of tumor contrast enhancement, and MRI signal of the tumor were assessed. Apparent diffusion coefficients (ADCs) within the primary tumor were measured on ADC maps. Receiver operating characteristic curves were used to determine ADC cut-off values and the sensitivity and specificity of the grade prediction. Spearman's rank correlation was utilized to probe the association between ADC value and PanNET grade or pathological parameters. G1 tumors exhibited a well-circumscribed border more often than G2 tumors. No marked differences were observed between PanNET G1 and PanNET G2 for cystic or solid appearance, enhancement, and T1- and T2-weighted imaging signals. Marked hyperintensities were more common in PanNET G2 tumors than in PanNET G1 tumors (P<0.01). The mean ADC values were statistically different between the normal pancreas and G1 and G2 tumors (P<0.01), and between PanNET G1 and PanNET G2 (P<0.05). Correlation analysis showed that ADC value was negatively correlated with PanNET grade, mitotic count and Ki-67 proliferation index (P<0.05). The cut-off ADC value was 0.930×10^-3 mm²/sec, which identified G2 tumors with 82.4% sensitivity and 79.5% selectivity. ADC value therefore represents a non-invasive and valuable imaging parameter in predicting the WHO grade of tumors in well-differentiated PanNET.

Pancreatic neuroendocrine neoplasms at magnetic resonance imaging: comparison between grade 3 and grade 1/2 tumors

Background

The grading of pancreatic neuroendocrine neoplasms (PanNENs) is associated with the choice of treatment strategy. The aim of this study is to identify the magnetic resonance imaging (MRI) features in differentiating pancreatic neuroendocrine tumors (PanNETs) grade 1/2 (G1/G2) and pancreatic neuroendocrine carcinoma grade 3 (PanNEC G3).

Patients and methods

A total of 59 patients with histologically proven PanNENs and who underwent pretreatment MRI were retrospectively analyzed. Tumor location, size, boundary, cystic or solid appearance, enhancement degree, pancreatic duct dilatation, metastases and MRI signal were evaluated. Apparent diffusion coefficients (ADCs) were measured on ADC maps. Receiver operating characteristic curve was used to determine the cut off values and the sensitivity and specificity of prediction. Spearman correlation and logistic regression analysis were adopted to identify the association between MRI features and pathological parameters.

Results

A total of 47 lesions were PanNETs G1/G2 and 12 lesions were PanNEC G3. G1/G2 tumors were more common with well-circumscribed border compared with PanNEC G3. Ill- defined boundary, big size, necrosis, low-moderate enhancement, pancreatic duct dilatation, metastases and high diffusion-weighted imaging (DWI) intensity were more common in PanNEC G3 than in PanNETs G1/G2. The ADC values of PanNEC G3 were also significantly lower compared with the PanNETs G1/G2 and normal pancreatic parenchyma. The cut off value of ADC was 0.95×10⁻³ mm²/s for differentiating PanNEC G3 from PanNETs G1/G2 with 72.3% sensitivity and 91.6% specificity, respectively. Ki-67 index and mitosis count positively correlated with tumor size, pancreatic duct dilatation and metastases (P<0.05) and negatively correlated with ADC values (P<0.01), respectively. Regression analysis further showed that metastases and ADC value were associated with PanNENs grade.

Conclusion

Metastases and ADC value may have potential for differentiating PanNEC G3 from PanNETs G1/G2.

Spatial intratumoral heterogeneity of proliferation in immunohistochemical images of solid tumors

PURPOSE

The interactions of neoplastic cells with each other and the microenvironment are complex. To understand intratumoral heterogeneity, subtle differences should be quantified. Main factors contributing to heterogeneity include the gradient ischemic level within neoplasms, action of microenvironment, mechanisms of intercellular transfer of genetic information, and differential mechanisms of modifications of genetic material/proteins. This may reflect on the expression of biomarkers in the context of prognosis/stratification. Hence, a rigorous approach for assessing the spatial intratumoral heterogeneity of histological biomarker expression with accuracy and reproducibility is required, since patterns in immunohistochemical images can be challenging to identify and describe.

METHODS

A quantitative method that is useful for characterizing complex irregular structures is lacunarity; it is a multiscale technique that exhaustively samples the image, while the decay of its index as a function of window size follows characteristic patterns for different spatial arrangements. In histological images, lacunarity provides a useful measure for the spatial organization of a biomarker when a sampling scheme is employed and relevant features are computed. The proposed approach quantifies the segmented proliferative cells and not the textural content of the histological slide, thus providing a more realistic measure of heterogeneity within the sample space of the tumor region. The aim is to investigate in whole sections of primary pancreatic neuroendocrine neoplasms (pNENs), using whole-slide imaging and image analysis, the spatial intratumoral heterogeneity of Ki-67 immunostains. Unsupervised learning is employed to verify that the approach can partition the tissue sections according to distributional heterogeneity.

RESULTS

The architectural complexity of histological images has shown that single measurements are often insufficient. Inhomogeneity of distribution depends not only on percentage content of proliferation phase but also on how the phase fills the space. Lacunarity curves demonstrate variations in the sampled image sections. Since the spatial distribution of proliferation in each case is different, the width of the curves changes too. Image sections that have smaller numerical variations in the computed features correspond to neoplasms with spatially homogeneous proliferation, while larger variations correspond to cases where proliferation shows various degrees of clumping. Grade 1 (uniform/nonuniform: 74%/26%) and grade 3 (uniform: 100%) pNENs demonstrate a more homogeneous proliferation with grade 1 neoplasms being more variant, while grade 2 tumor regions render a more diverse landscape (50%/50%). Hence, some cases show an increased degree of spatial heterogeneity comparing to others with similar grade. Whether this is a sign of different tumor biology and an association with a more benign/malignant clinical course needs to be investigated further. The extent and range of spatial heterogeneity has the potential to be evaluated as a prognostic marker.

CONCLUSIONS

The association with tumor grade as well as the rationale that the methodology reflects true tumor architecture supports the technical soundness of the method. This reflects a general approach which is relevant to other solid tumors and biomarkers. Drawing upon the merits of computational biomedicine, the approach uncovers salient features for use in future studies of clinical relevance.

Clinicopathological, treatment, and prognosis study of 43 gastric neuroendocrine carcinomas

AIM

To provide more information and therapeutic methods about gastric neuroendocrine carcinomas (G-NECs) which occur rarely but are highly malignant and clinically challenging.

METHODS

We retrospectively analyzed the clinicopathological characteristics, treatments, and prognosis of 43 G-NEC patients at our hospital between January 2007 and December 2014. The diagnosis was based on the 2010 World Health Organization criteria.

RESULTS

Forty-three G-NECs containing 39 small cell carcinomas and 4 large cell NECs with Ki67 > 60% were included in this study, accounting for only 0.95% of all gastric carcinomas. The median patient age was 62 years (range, 33-82) and the male-to-female ratio was 4.4:1. All patients underwent surgery, including 38 curative resections and 5 palliative resections. Among these 43 patients, nearly half (48.84%) of these tumors were located in the cardiac region of the stomach, regional lymph node metastasis was found in 31 cases (72.09%), and liver metastasis was found in 6 cases (13.95%). Follow-up information was got for 40 patients. Twenty-three die of this disease with a median survival of 31 mo (range 1-90). The 1-year, 2-year, 3-year, and 5-year survival rate was 77.50%, 57.04%, 44.51%, and 35.05%, respectively. Survival was better in patients with tumor located in the cardiac region of the stomach, less than 7 lymph nodes metastasis and no liver metastasis. Five patients did not undergo postoperative chemotherapy, and the median survival time for these patients was 15 mo. For the remaining 34 patients who received postoperative chemotherapy, the median survival time was 44 mo and those received etoposide, cisplatin, and Paclitaxel survived the best. One patient with resected liver metastasis who received postoperative Capecitabine plus Oxaliplatin and Paclitaxel systemic chemotherapy plus octreotide LAR (30 mg intramuscularly, every 4 wk, for 2 years) has survived for 74 mo with no recurrence.

CONCLUSION

G-NECs are mostly nonfunctioning, which lead to a delay in detection. Local and/or distant metastases were noticed in most patients when diagnosed, and they required postoperative medical treatment. Adjuvant etoposide, cisplatin plus Paclitaxel systemic chemotherapy is recommended for these patients.

Menin and Daxx Interact to Suppress Neuroendocrine Tumors through Epigenetic Control of the Membrane Metallo-Endopeptidase

Neuroendocrine tumors (NET) often harbor loss-of-function mutations in the MEN1 and DAXX tumor suppressor genes. Here, we report that the products of these genes, menin and Daxx, interact directly with each other to suppress the proliferation of NET cells, to a large degree by inhibiting expression of the membrane metallo-endopeptidase (MME). Menin and Daxx were required to enhance histone H3 lysine9 trimethylation (H3K9me3) at the MME promoter, as mediated partly by the histone H3 methyltransferase SUV39H1. Notably, the menin T429K mutation associated with a NET syndrome reduced Daxx binding, MME repression, and proliferation of NET cells. Conversely, inhibition of MME in NET cells repressed proliferation and tumor growth in vivo Our findings reveal a previously unappreciated cross-talk between two crucial tumor suppressor genes thought to work by independent pathways, focusing on MME as a common target of menin/Daxx to treat NET. Cancer Res; 77(2); 401-11. ©2016 AACR.

Malnutrition Predicts Clinical Outcome in Patients with Neuroendocrine Neoplasia

Malnutrition is a common problem in oncological diseases, influencing treatment outcomes, treatment complications, quality of life and survival. The potential role of malnutrition has not yet been studied systematically in neuroendocrine neoplasms (NEN), which, due to their growing prevalence and additional therapeutic options, provide an increasing clinical challenge to diagnosis and management. The aim of this cross-sectional observational study, which included a long-term follow-up, was therefore to define the prevalence of malnutrition in 203 patients with NEN using various methodological approaches, and to analyse the short- and long-term outcome of malnourished patients. A detailed subgroup analysis was also performed to define risk factors for poorer outcome. When applying malnutrition screening scores, 21-25% of the NEN patients were at risk of or demonstrated manifest malnutrition. This was confirmed by anthropometric measurements, by determination of serum surrogate parameters such as albumin as well as by bioelectrical impedance analysis (BIA), particularly phase angle α. The length of hospital stay was significantly longer in malnourished NEN patients, while long-term overall survival was highly significantly reduced. Patients with high-grade (G3) neuroendocrine carcinomas, progressive disease and undergoing chemotherapy were at particular risk of malnutrition associated with a poorer outcome. Multivariate analysis confirmed the important and highly significant role of malnutrition as an independent prognostic factor for NEN besides proliferative capacity (G3 NEC). Malnutrition is therefore an underrecognized problem in NEN patients which should systematically be diagnosed by widely available standard methods such as Nutritional Risk Screening (NRS), serum albumin assessment and BIA, and treated to improve both short- and long-term outcomes.

Intraarterial Liver-Directed Therapies: The Role of Interventional Oncology

BACKGROUND

Since the early 1990s, the minimally invasive image-guided therapies used in interventional oncology to treat hepatocellular carcinoma have continued to evolve. Additionally, the range of applications has been expanded to the treatment of hepatic metastases from colorectal cancer, neuroendocrine tumors, cholangiocarcinoma, breast cancer, melanoma, and sarcoma.

METHODS

We searched the literature to identify publications from 1990 to the present on various image-guided intraarterial therapies and their efficacy, as well as their role in the management of primary and secondary liver malignancies.

RESULTS

Chemoembolization and radioembolization are considered a standard of care in treating, delaying progression of disease, and downstaging to bridge to liver transplantation. Progression-free survival and overall survival outcomes are promising in patients with colorectal cancer and neuroendocrine tumors with liver metastases. Applications in the treatment of hepatic metastases from cholangiocarcinoma, breast cancer, melanoma, and sarcoma also show potential.

CONCLUSION

Interventional oncology and its image-guided intraarterial therapies continue to gain recognition as treatment options for primary and secondary liver cancers. Growing evidence supports their role as a standard of care alongside medical oncology, surgery, and radiation oncology.

The ENETS/WHO grading system for neuroendocrine neoplasms of the gastroenteropancreatic system: a review of the current state, limitations and proposals for modifications

The understanding of neuroendocrine neoplasms has evolved significantly since their initial descriptions in the 1800s to early 1900s. In the gastroenteropancreatic system, this group of malignant tumors is subdivided into well and poorly differentiated neuroendocrine neoplasms based on morphologic, proliferative and biologic differences. However, it has become increasingly apparent that well-differentiated neuroendocrine tumors are not a homogeneous group. Attempting to better predict outcome of these tumors has been the motivation behind numerous proposed classification systems, the evolution of which culminated with the currently used system, the ENETS/WHO classification. Herein, we review the genesis of this classification system and some of its shortcomings. In addition, we discuss some of the most recent proposals that suggest modifications to the current system.

The efficacy and safety of everolimus for the treatment of progressive gastroenteropancreatic neuroendocrine tumors: A multi-institution observational study in Taiwan

AIM

Everolimus is an inhibitor of mTOR, approved for treatment of advanced pancreatic neuroendocrine tumors (NETs). The purpose of this observational study was to evaluate the efficacy and safety of everolimus in treatment of progressive, advanced gastroenteropancreatic neuroendocrine tumors (GEP-NETs) in Taiwan.

METHODS

Fifty-three patients with progressive, advanced GEP-NETs who received everolimus treatment between January 2008 and August 2014 were selected. Patient characteristics, tumor features, safety profiles and treatment efficacy were retrospectively analyzed.

RESULTS

Mean follow-up duration was 23.7 (1.2-70) months and 37 of 53 patients (69.8%) remained alive at the end of study. The one- and two-year overall survival rates were 90.5% and 75.4%, respectively. The median progression-free survival (PFS) was 18.9 (95% confidence interval; 10.9-26.8) months. Partial response was observed in 15 (28.3%) patients, 29 (54.7%) patients had stable disease and nine (17%) patients had progressive disease. Patients with World Health Organization (WHO) grade I NETs, nonfunctional tumors and liver metastasis burden <10% had significantly better PFS with everolimus treatment. Adverse events observed were stomatitis (35.8%), hyperglycemia (22.6%) and rash (18.8%). Seven (15.4%) patients experienced severe adverse events (grade 3 or more), including hyperglycemia (4.4%), anemia (4.4%), fatigue (2.2%) and elevated liver function (2.2%). One (2.2%) patient died from grade 5 interstitial pneumonitis.

CONCLUSION

Everolimus was an effective treatment for Taiwanese patients with progressive advanced GEP-NETs. Patients with nonfunctional NETs had a trend toward longer PFS, whereas patients with liver metastases burden <10% had a trend toward longer overall survival time receiving everolimus treatment.

Genetic polymorphisms of interleukin 1β gene and sporadic pancreatic neuroendocrine tumors susceptibility

AIM: To evaluate the association between the interleukin 1β (IL-1β) polymorphisms and the pancreatic neuroendocrine tumor (pNET) development.

METHODS: A case-control study was conducted analyzing IL-1β polymorphisms using germline DNA collected in a population-based case-control study of pancreatic cancer (51 pNET cases, 85 pancreatic ductal adenocarcinoma cases, 19 intraductal papillary mucinous neoplasm and 98 healthy controls).

RESULTS: The distribution of genotypes for the -511 C/T polymorphism in the pNET patient groups showed significant difference compared to the control group. It is known that the carriers of the IL-1β -511T allele have increased concentrations of IL-1β. The -511 CT and TT high-expression genotypes were over-represented in pNET patients.

CONCLUSION: The findings of this study suggested a possible role of IL-1β -511 C/T genotypes in the pathogenesis of pNETs since the presence of the IL-1β -511 CT and TT genotypes and the T allele was associated with an increased risk of pNET only.

Laparoscopic versus open distal pancreatectomy for pancreatic cancer

BACKGROUND

Surgical resection is currently the only treatment with the potential for long-term survival and cure of pancreatic cancer. Surgical resection is provided as distal pancreatectomy for cancers of the body and tail of the pancreas. It can be performed by laparoscopic or open surgery. In operations on other organs, laparoscopic surgery has been shown to reduce complications and length of hospital stay as compared with open surgery. However, concerns remain about the safety of laparoscopic distal pancreatectomy compared with open distal pancreatectomy in terms of postoperative complications and oncological clearance.

OBJECTIVES

To assess the benefits and harms of laparoscopic distal pancreatectomy versus open distal pancreatectomy for people undergoing distal pancreatectomy for pancreatic ductal adenocarcinoma of the body or tail of the pancreas, or both.

SEARCH METHODS

We used search strategies to search the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Science Citation Index Expanded and trials registers until June 2015 to identify randomised controlled trials (RCTs) and non-randomised studies. We also searched the reference lists of included trials to identify additional studies.

SELECTION CRITERIA

We considered for inclusion in the review RCTs and non-randomised studies comparing laparoscopic versus open distal pancreatectomy in patients with resectable pancreatic cancer, irrespective of language, blinding or publication status..

DATA COLLECTION AND ANALYSIS

Two review authors independently identified trials and independently extracted data. We calculated odds ratios (ORs), mean differences (MDs) or hazard ratios (HRs) along with 95% confidence intervals (CIs) using both fixed-effect and random-effects models with RevMan 5 on the basis of intention-to-treat analysis when possible.

MAIN RESULTS

We found no RCTs on this topic. We included in this review 12 non-randomised studies that compared laparoscopic versus open distal pancreatectomy (1576 participants: 394 underwent laparoscopic distal pancreatectomy and 1182 underwent open distal pancreatectomy); 11 studies (1506 participants: 353 undergoing laparoscopic distal pancreatectomy and 1153 undergoing open distal pancreatectomy) provided information for one or more outcomes. All of these studies were retrospective cohort-like studies or case-control studies. Most were at unclear or high risk of bias, and the overall quality of evidence was very low for all reported outcomes.Differences in short-term mortality (laparoscopic group: 1/329 (adjusted proportion based on meta-analysis estimate: 0.5%) vs open group: 11/1122 (1%); OR 0.48, 95% CI 0.11 to 2.17; 1451 participants; nine studies; I(2) = 0%), long-term mortality (HR 0.96, 95% CI 0.82 to 1.12; 277 participants; three studies; I(2) = 0%), proportion of people with serious adverse events (laparoscopic group: 7/89 (adjusted proportion: 8.8%) vs open group: 6/117 (5.1%); OR 1.79, 95% CI 0.53 to 6.06; 206 participants; three studies; I(2) = 0%), proportion of people with a clinically significant pancreatic fistula (laparoscopic group: 9/109 (adjusted proportion: 7.7%) vs open group: 9/137 (6.6%); OR 1.19, 95% CI 0.47 to 3.02; 246 participants; four studies; I(2) = 61%) were imprecise. Differences in recurrence at maximal follow-up (laparoscopic group: 37/81 (adjusted proportion based on meta-analysis estimate: 36.3%) vs open group: 59/103 (49.5%); OR 0.58, 95% CI 0.32 to 1.05; 184 participants; two studies; I(2) = 13%), adverse events of any severity (laparoscopic group: 33/109 (adjusted proportion: 31.7%) vs open group: 45/137 (32.8%); OR 0.95, 95% CI 0.54 to 1.66; 246 participants; four studies; I(2) = 18%) and proportion of participants with positive resection margins (laparoscopic group: 49/333 (adjusted proportion based on meta-analysis estimate: 14.3%) vs open group: 208/1133 (18.4%); OR 0.74, 95% CI 0.49 to 1.10; 1466 participants; 10 studies; I(2) = 6%) were also imprecise. Mean length of hospital stay was shorter by 2.43 days in the laparoscopic group than in the open group (MD -2.43 days, 95% CI -3.13 to -1.73; 1068 participants; five studies; I(2) = 0%). None of the included studies reported quality of life at any point in time, recurrence within six months, time to return to normal activity and time to return to work or blood transfusion requirements.

AUTHORS' CONCLUSIONS

Currently, no randomised controlled trials have compared laparoscopic distal pancreatectomy versus open distal pancreatectomy for patients with pancreatic cancers. In observational studies, laparoscopic distal pancreatectomy has been associated with shorter hospital stay as compared with open distal pancreatectomy. Currently, no information is available to determine a causal association in the differences between laparoscopic versus open distal pancreatectomy. Observed differences may be a result of confounding due to laparoscopic operation on less extensive cancer and open surgery on more extensive cancer. In addition, differences in length of hospital stay are relevant only if laparoscopic and open surgery procedures are equivalent oncologically. This information is not available currently. Thus, randomised controlled trials are needed to compare laparoscopic distal pancreatectomy versus open distal pancreatectomy with at least two to three years of follow-up. Such studies should include patient-oriented outcomes such as short-term mortality and long-term mortality (at least two to three years); health-related quality of life; complications and the sequelae of complications; resection margins; measures of earlier postoperative recovery such as length of hospital stay, time to return to normal activity and time to return to work (in those who are employed); and recurrence of cancer.

Identification of tumorigenic cells and therapeutic targets in pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PanNETs) are a type of pancreatic cancer with limited therapeutic options. Consequently, most patients with advanced disease die from tumor progression. Current evidence indicates that a subset of cancer cells is responsible for tumor development, metastasis, and recurrence, and targeting these tumor-initiating cells is necessary to eradicate tumors. However, tumor-initiating cells and the biological processes that promote pathogenesis remain largely uncharacterized in PanNETs. Here we profile primary and metastatic tumors from an index patient and demonstrate that MET proto-oncogene activation is important for tumor growth in PanNET xenograft models. We identify a highly tumorigenic cell population within several independent surgically acquired PanNETs characterized by increased cell-surface protein CD90 expression and aldehyde dehydrogenase A1 (ALDHA1) activity, and provide in vitro and in vivo evidence for their stem-like properties. We performed proteomic profiling of 332 antigens in two cell lines and four primary tumors, and showed that CD47, a cell-surface protein that acts as a "don't eat me" signal co-opted by cancers to evade innate immune surveillance, is ubiquitously expressed. Moreover, CD47 coexpresses with MET and is enriched in CD90(hi)cells. Furthermore, blocking CD47 signaling promotes engulfment of tumor cells by macrophages in vitro and inhibits xenograft tumor growth, prevents metastases, and prolongs survival in vivo.

Natural history and outcome in Chinese patients with gastroenteropancreatic neuroendocrine tumours: - a 17-year retrospective analysis

BACKGROUND

There is rising incidence of gastroenteropancreatic neuroendocrine tumours (GEP- NETs) in many parts of the world, but epidemiological data from Asian populations is rare.

METHODS

We conducted a retrospective study in a tertiary medical centre in Hong Kong, using updated diagnostic criteria. The presentation, clinical features, and disease outcome were reviewed for all patients with GEP-NETs confirmed histopathologically at the Prince of Wales Hospital, the Chinese University of Hong Kong, between 1996 and 2013, according to the latest 2010 World Health Organization Classification.

RESULTS

Among 126 patients, GEP- NETs were found in pancreas (34.9 %), rectum (33.3 %), and stomach (8.7 %), and most of them were non- functional GEP- NETs (91.3 %), mostly of grade 1 (G1) (87.3 %), and about 20 % had metastases on presentation. Age under 55 years, G1 tumours and absence of metastases were significant favourable predictors for survival in univariate analysis; whereas G2/3 tumours, size ≥2 cm, and metastases were significant predictors for disease progression (p < 0.05). In multivariate analysis, age and metastases on presentation were significant predictors of mortality (respective hazard ratios [HR] 1.05 [95 % confidence interval {CI} 1.02-1.08] and 6.52 [95 % CI 3.22-13.2]) and disease progression (respective HRs 1.05 [95 % CI 1.02-1.07] and 4.12 [95 % CI 1.96-8.68]), while higher tumour grade also independently predicted disease progression (HR 5.17 [95 % CI 2.05-13.05]) (all p < 0.05).

CONCLUSION

Non-functional tumours with non-specific symptoms account for the vast majority of GEP-NETs in this Chinese series. Multidisciplinary approach in the management of patients with GEP-NETs may help improve the treatment efficacy and outcome.

Management of follow-up of neuroendocrine neoplasias

Neuroendocrine neoplasias (NEN) comprise heterogeneous epithelial neoplasms with a large variety of clinical presentations, treatment options and outcomes. Since potentially all NEN bear malignant potential it is important for long-term clinical management and improvement of outcome to decide on successful and oncologically and economically meaningful follow-up strategies. Evidence-based outcome data validating specific follow-up strategies are, however, not available to date and thus outcome data, known prognostic factors and clinical experience guide the decisions on follow-up regimens. The review summarizes general recommendations as well as specific considerations based on tumor entities, clinicopathological tumor characteristics and clinical experience. Follow-up shall serve the patient to improve outcome, benefit from more effective therapies and suffer less from unnecessary and/or toxic therapeutic interventions and finally preserve or gain a good quality of life.

Detection of neuroendocrine tumors using promoter-specific secreted Gaussia luciferase

Accurate detection of neuroendocrine (NE) tumors is critically important for better prognosis and treatment outcomes in patients. To demonstrate the efficacy of using an adenoviral vector for the detection of NE tumors, we have constructed a pair of adenoviral vectors which, in combination, can conditionally replicate and release Gaussia luciferase into the circulation after infecting the NE tumors. The expression of these two vectors is regulated upstream by an INSM1-promoter (insulinoma-associated-1) that is specifically active in NE tumors and developing NE tissues, but silenced in normal adult tissues. In order to retain the tumor-specificity of the INSM1 promoter, we have modified the promoter using the core insulator sequence from the chicken β-globin HS4 insulator and the neuronal restrictive silencing element (NRSE). This modified INSM1-promoter can retain NE tumor specificity in an adenoviral construct while driving a mutated adenovirus E1A gene (∆24E1A), the Metridia, or Gaussia luciferase gene. The in vitro cell line and mouse xenograft human tumor studies revealed the NE specificity of the INSM1-promoter in NE lung cancer, neuroblastoma, medulloblastoma, retinoblastoma, and insulinoma. When we combined the INSM1-promoter driven Gaussia luciferase with ∆24E1A, the co-infected NE tumor secreted higher levels of Gaussia luciferase as compared to the INSM1p-Gaussia virus alone. In a mouse subcutaneous xenograft tumor model, the combination viruses secreted detectable level of Gaussia luciferase after infecting an INSM1-positive NE lung tumor for ≥12 days. Therefore, the INSM1-promoter specific conditional replicating adenovirus represents a sensitive diagnostic tool to aid clinicians in the detection of NE tumors.

Surgical Management of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) are uncommon tumors with a range of clinical behavior. Some PNETs are associated with symptoms of hormone secretion, with increased systemic levels of insulin, gastrin, glucagon, or other hormones. More commonly, PNETs are nonfunctional, without hormone secretion. Surgical resection is the mainstay of therapy, particularly for localized disease. Surgical therapy must be tailored to tumor and clinical characteristics. Resection may be particularly indicated in the setting of hormone hypersecretion. Small, incidental PNETs are increasingly managed nonoperatively. Surgery may also be indicated in some instances of metastatic disease, if all metastatic foci may be removed.

A Cross-Species Analysis in Pancreatic Neuroendocrine Tumors Reveals Molecular Subtypes with Distinctive Clinical, Metastatic, Developmental, and Metabolic Characteristics

Seeking to assess the representative and instructive value of an engineered mouse model of pancreatic neuroendocrine tumors (PanNET) for its cognate human cancer, we profiled and compared mRNA and miRNA transcriptomes of tumors from both. Mouse PanNET tumors could be classified into two distinctive subtypes, well-differentiated islet/insulinoma tumors (IT) and poorly differentiated tumors associated with liver metastases, dubbed metastasis-like primary (MLP). Human PanNETs were independently classified into these same two subtypes, along with a third, specific gene mutation-enriched subtype. The MLP subtypes in human and mouse were similar to liver metastases in terms of miRNA and mRNA transcriptome profiles and signature genes. The human/mouse MLP subtypes also similarly expressed genes known to regulate early pancreas development, whereas the IT subtypes expressed genes characteristic of mature islet cells, suggesting different tumorigenesis pathways. In addition, these subtypes exhibit distinct metabolic profiles marked by differential pyruvate metabolism, substantiating the significance of their separate identities.

SIGNIFICANCE

This study involves a comprehensive cross-species integrated analysis of multi-omics profiles and histology to stratify PanNETs into subtypes with distinctive characteristics. We provide support for the RIP1-TAG2 mouse model as representative of its cognate human cancer with prospects to better understand PanNET heterogeneity and consider future applications of personalized cancer therapy.

Blood and tissue neuroendocrine tumor gene cluster analysis correlate, define hallmarks and predict disease status

A multianalyte algorithmic assay (MAAA) identifies circulating neuroendocrine tumor (NET) transcripts (n=51) with a sensitivity/specificity of 98%/97%. We evaluated whether blood measurements correlated with tumor tissue transcript analysis. The latter were segregated into gene clusters (GC) that defined clinical 'hallmarks' of neoplasia. A MAAA/cluster integrated algorithm (CIA) was developed as a predictive activity index to define tumor behavior and outcome. We evaluated three groups. Group 1: publically available NET transcriptome databases (n=15; GeneProfiler). Group 2: prospectively collected tumors and matched blood samples (n=22; qRT-PCR). Group 3: prospective clinical blood samples, n=159: stable disease (SD): n=111 and progressive disease (PD): n=48. Regulatory network analysis, linear modeling, principal component analysis (PCA), and receiver operating characteristic analyses were used to delineate neoplasia 'hallmarks' and assess GC predictive utility. Our results demonstrated: group 1: NET transcriptomes identified (92%) genes elevated. Group 2: 98% genes elevated by qPCR (fold change >2, P<0.05). Correlation analysis of matched blood/tumor was highly significant (R(2)=0.7, P<0.0001), and 58% of genes defined nine omic clusters (SSTRome, proliferome, signalome, metabolome, secretome, epigenome, plurome, and apoptome). Group 3: six clusters (SSTRome, proliferome, metabolome, secretome, epigenome, and plurome) differentiated SD from PD (area under the curve (AUC)=0.81). Integration with blood-algorithm amplified the AUC to 0.92±0.02 for differentiating PD and SD. The CIA defined a significantly lower SD score (34.1±2.6%) than in PD (84±2.8%, P<0.0001). In conclusion, circulating transcripts measurements reflect NET tissue values. Integration of biologically relevant GC differentiate SD from PD. Combination of GC data with the blood-algorithm predicted disease status in >92%. Blood transcript measurement predicts NET activity.

Clinical presentation in insulinoma predicts histopathological tumour characteristics

BACKGROUND

Insulinomas are rare neuroendocrine tumours (NETs) of the pancreas, characterized clinically by neuroglycopenic symptoms during periods of substrate deficiency. The gold standard test for diagnosing an insulinoma is a 72-h fast. However, the prognostic value of parameters in the standardized 72-h fast on histopathological tumour criteria and clinical presentation has not been examined.

METHODS

In thirty-three patients diagnosed with an insulinoma records, and data were investigated retrospectively. Histopathological tumour characteristics, including staging, grading and size, were reviewed. Grading was performed using Ki-67 index. Cut-off values for classical grading (G(clas)) were set at G1(clas) ≤ 2%, G2(clas) 3-20% & G3(clas) >20% and for modified grading (G(mod)) at G1(mod) <5%, G2(mod) 5-20% & G3(mod) >20%.

RESULTS

When G(mod) criteria were applied, the initial blood glucose was lower in GII/III(mod) patients compared to GI(mod) (2.8 ± 0.8 vs 3.8 ± 1.3 mmol/l; P = 0.046). Basal and end of fast levels of insulin (basal insulin 71 ± 61 vs 20 ± 16 mU/l; P < 0.001; end of fast insulin 77 ± 51 vs 21 ± 20 mU/l; P < 0.001) and c-peptide (basal c-peptide 5.4 ± 2.4 vs 2.7 ± 1.6 μg/l; P = 0.004; end of fast c-peptide 5.3 ± 2.4 vs 2.5 ± 1.4 μg/l; P = 0.001) were significantly higher in GII/III(mod) than in GI(mod). No differences between the groups were observed when G(clas) criteria were applied. Additionally, close correlations were observed between insulin concentration, Ki-67 index and tumour size.

CONCLUSION

This study shows an impact of histopathological tumour characteristics in patients suffering from an insulinoma on clinical presentation during a standardized 72-h fast. Lower initial blood glucose levels and higher concentrations of insulin and c-peptide are associated with worse tumour grading and larger tumour size.

Neuroendocrine Carcinomas of the Gastroenteropancreatic System: A Comprehensive Review

To date, empirical literature has generally been considered lacking in relation to neuroendocrine carcinomas (NECs), the highly malignant subgroup of neuroendocrine neoplasms. NECs are often found in the lungs or the gastroenteropancreatic (GEP) system and can be of small or large cell type. Concentrating on GEP-NECs, we can conclude that survival times are poor, with a median of only 4–16 months depending on disease stage and primary site. Further, this aggressive disease appears to be on the rise, with incidence numbers increasing while survival times are stagnant. Treatment strategies concerning surgery are often undecided and second-line chemotherapy is not yet established. After an analysis of over 2600 articles, we can conclude that there is indeed more empirical literature concerning GEP-NECs available than previously assumed. This unique review is based on 333 selected articles and contains detailed information concerning all aspects of GEP-NECs. Namely, the classification, histology, genetic abnormalities, epidemiology, origin, biochemistry, imaging, treatment and survival of GEP-NECs are described. Also, organ-specific summaries with more detail in relation to disease presentation, diagnosis, treatment and survival are presented. Finally, key points are discussed with directions for future research priorities.

A retrospective review of diagnosis and treatment modalities of neuroendocrine tumors (excluding primary lung cancer) in 10 oncological institutions of the East German Study Group of Hematology and Oncology (OSHO), 2010-2012

RATIONALE

There is a paucity of data on the incidence of neuroendocrine tumors (NET) outside pulmonary primaries and on treatment modalities applied to patients with NET in clinical practice. Only very little therapeutic progress has been made with respect to response and overall survival, particularly among patients with poorly differentiated, WHO grade 3 neuroendocrine carcinomas (G3-NEC). We sought to document the incidence and treatment modalities in patients with NET/NEC within a period of 2 years.

METHODS

We conducted a retrospective data analysis using a simple documentation file to be completed in written form or electronically, including localization, WHO grading, treatment modalities, and specific therapeutic regimens applied. Primary lung cancer was excluded. The time period to be covered was 2010 through 2012. Individual patient data such as names or age were not documented, so that no ethics committee approval was required.

RESULTS

Ten different hospital- or practice-based institutions contributed their data. One to 35 patients were documented per institution, summing up to 149 patients with 154 tumor localizations. Midgut (n = 46), foregut (n = 42), hindgut (n = 17), lung (n = 9), bladder (n = 8), unknown primary (n = 11), and other including prostate and liver (n = 21) were documented as tumor sites. Histological gradings were G1 (n = 71), G2 (n = 27), G3 (n = 34), undifferentiated "G4" (n = 4), and not specified (n = 13). Treatment modalities were surgical resection (n = 102), chemotherapy (n = 49), somatostatin analogs (n = 39), radiotherapy (n = 22), receptor-directed radionuclide therapy (n = 12), and systemic tyrosine kinase inhibition (n = 5). Chemotherapy was given to patients not only with G3-NEC (n = 31), but also with G2 (n = 12) and G1 NET (n = 7). Somatostatin analogs as well as receptor-directed radionuclides were applied to patients throughout all gradings.

CONCLUSIONS

NET and NEC are not very rare tumor entities, but are diagnosed with very different frequencies, possibly depending upon the alertness of pathologists and clinicians. Chemotherapy, receptor-directed radionuclide application, and somatostatin analog therapy are applied without a clear correlation to different histologic gradings. Diagnostic and therapeutic progress in the field of NETs/carcinomas is urgently needed.

Contrast enhancement pattern on multidetector CT predicts malignancy in pancreatic endocrine tumours

OBJECTIVES

Preoperative suspicion of malignancy in pancreatic neuroendocrine tumours (pNETs) is mostly based on tumour size. We retrospectively reviewed the contrast enhancement pattern (CEP) of a series of pNETs on multiphasic multidetector computed tomography (MDCT), to identify further imaging features predictive of lesion aggressiveness.

METHODS

Sixty pNETs, diagnosed in 52 patients, were classified based on CEP as: type A showing early contrast enhancement and rapid wash-out; type B presenting even (B1) or only (B2) late enhancement. All tumours were resected allowing pathologic correlations.

RESULTS

Nineteen pNETs showed type A CEP (5-20 mm), 29 type B1 CEP (5-80 mm) and 12 type B2 (15-100 mm). All tumours were classified as well differentiated tumours, 19 were benign (WDt-b), 15 with uncertain behaviour (WDt-u) and 26 carcinomas (WDC). None of A lesions were malignant (12 WDt-b; 7 WDt-u), all B2 lesions were WDC, 7 B1 lesions were WDt-b, 8 WDt-u and 14 WDC; 4/34 (12 %) lesions ≤2cm were WDC. CEP showed correlation with all histological prognostic indicators.

CONCLUSIONS

Correlating with the lesion grading and other histological prognostic predictors, CEP may preoperatively suggest the behaviour of pNETs, assisting decisions about treatment. Moreover CEP allows recognition of malignant small tumours, incorrectly classified on the basis of their dimension.

Vascular endothelial growth factor (VEGF) pathway and neuroendocrine neoplasms (NENs): prognostic and therapeutic considerations

Neuroendocrine neoplasms (NENs) consist of a large heterogeneous group of epithelial tumors with neuroendocrine differentiation, as proved by immune reactivity for neuroendocrine markers. From the very first studies of vascular endothelial growth factor (VEGF) pathway, VEGF has been considered an important prognostic marker in NENs. Consequently, a number of preclinical experiences and clinical trials have examined the efficacy of VEGF-targeted therapeutics in NENs. Bevacizumab and sorafenib were clinically tested in NENs and they showed modest activity, while on the other hand, they present significant toxicity problems. More interesting in gastroenteropancreatic (GEP)-NENs seems to be the demonstrated efficacy of sunitinib. Preclinical as well as clinical sunitinib data in this regard provide a new hope in that direction. The use of other novel VEGF-targeted agents like aflibercept as well as VEGFR-TKI is being investigated in a number of phase II studies; the results of which are greatly awaited. Additionally, the use of potential biomarkers to select patients for VEGF-targeted therapy may be considered for further clinical evaluation. Thus, this article reviews the basic science as well as clinical data of VEGF signaling in advanced NENs with special emphasis on the different VEGF-targeting agents tested previously in this disease and the future prospective in that field.

Genetic polymorphisms of inflammatory response gene TNF-α and its influence on sporadic pancreatic neuroendocrine tumors predisposition risk

The diagnosed incidence of pancreatic neuroendocrine tumors (pNETs) is increasing; however, their etiology remains poorly understood. PNETs are a rare, heterogeneous group of tumors arising from the endocrine cells of the pancreas, and genetic risk factors for sporadic pNETs are inadequately understood. It is known that pNETs secrete biogenic amines, hormones and growth factors, tumor necrosis factor-a (TNF-α) being one of them. Furthermore, cytokines and other proinflammatory mediators have been implicated in inflammatory pancreatic diseases including pancreatitis and cancer. The aim of our study was to analyze TNF-α promoter gene polymorphisms as risk factors for pNETs using germline DNA collected in a population-based case-control study of pancreatic cancer [42 pNET cases, 78 pancreatic ductal adenocarcinoma (PDAC) cases, 17 intraductal papillary mucinous neoplasm (IPMN) and 98 healthy controls] conducted in the Athens, Greece and Izmir, Turkey areas. For subsequent analysis, we excluded cases and controls with known genetic syndromes. The CC genotype at the -1031 position was more frequent in pNET and IPMN patients (p=0.0002 and p=0.009, respectively), suggesting its possible role in pNET development. Furthermore, the AA genotype at the -308 position was overrepresented in IPMN cases (p=0.03), and AA genotype at the -238 position was more frequent in PDAC cases (p=0.03) compared to healthy individuals. With regard to tumor characteristics, no statistically significant association was detected. Our findings suggest the putative role of TNF-α -1031 polymorphism in the development of pNET and IPMN, whereas the -308 polymorphism seems to be overrepresented among IPMN cases and -238 polymorphism among PDAC cases.

KRAS and DAXX/ATRX gene mutations are correlated with the clinicopathological features, advanced diseases, and poor prognosis in Chinese patients with pancreatic neuroendocrine tumors

Background and Aim: Pancreatic neuroendocrine tumor (pNET) is a clinically rare and heterogeneous group of tumors; its pharmacogenetic characteristics are not fully understood. This study was designed to examine the relationship between key gene variations and disease development and prognosis among Chinese patients with pNET.

Methods: Various pNET associated genes such as DAXX/ATRX, KRAS, MEN1, PTEN, TSC2, SMAD4/DPC, TP53 and VHL were analyzed in high-throughput sequencing. The links between the gene mutations and the clinicopathological features and prognosis of the patients were determined.

Results: The somatic mutation frequencies of the DAXX/ATRX, KRAS, MEN1, mTOR pathway genes (PTEN and TSC2), SMAD4/DPC, TP53, and VHL in Chinese pNET patients were 54.05%, 10.81%, 35.14%, 54.05%, 2.70%, 13.51%, and 40.54%, respectively, while the same figures in Caucasians pNET patients were 43%, 0%, 44%, 15%, 0%, 3%, and 0%, respectively. The numbers of mutated genes were from 0 to 6; 4 patients with more than 3 mutated genes had higher proliferation (Ki-67) index or nerve vascular invasion or organ involvement, but only 9 of 27 patients with 3 or few mutated genes had such features. Mutations in KRAS and DAXX/ATRX, but not other genes analyzed, were associated with a shortened survival.

Conclusion: The mutation rates of these genes in Chinese pNET patients are different from those in Caucasians. A higher number of gene mutations and the DAXX/ATRX and KRAS gene mutations are correlated with a poor prognosis of patients with pNET.

Chromogranin A is a reliable serum diagnostic biomarker for pancreatic neuroendocrine tumors but not for insulinomas

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) are a group of rare tumors. Chromogranin A (CgA) was considered as the most practical and useful serum tumor marker in PNET patients. But peripheral blood levels of CgA are not routinely tested in Chinese patients with PNETs. This study was to assess the diagnostic value of CgA in Chinese patients with PNETs especially in patients with insulinomas.

METHODS

Eighty-nine patients with PNETs including 57 insulinomas and 32 non-insulinoma PNETs as well as 86 healthy participants were enrolled in this study between September 2003 and June 2013. Serum levels of CgA were measured by ELISA method. Expression of CgA protein was detected in 26 PNET tissues including 14 insulinomas by immunohistochemical staining.

RESULTS

Serum levels of CgA in 89 PNET patients were significantly higher than that in healthy controls (P = 7.2 × 10-9). Serum levels of CgA in 57 patients with insulinomas (median 64.8 ng/ml, range 25-164) were slightly higher than the levels in healthy controls (median 53.4 ng/ml, range 39-94) but much lower than the levels in 32 patients with non-insulinoma PNETs (median 193 ng/ml, range 27-9021), P = 0.001. The serum CgA levels were reduced in 16 of 17 patients with insulinomas after tumor resection. ROC curve showed that CgA values at 60 ng/ml distinguished patients with insulinomas from healthy controls but its sensitivity and specificity were 66.7% and 73.3%, respectively. In contrast, CgA values at 74 ng/ml distinguished patients with non-insulinoma PNETs from healthy controls, and the sensitivity and specificity were 65.6% and 91.9%, respectively. Except for two insulinomas with negative staining of CgA, 12 insulinoma tissues showed positive staining of CgA.

CONCLUSION

CgA is a reliable serum diagnostic biomarker for PNETs but not for insulinomas.

Small bowel neuroendocrine tumors: the benefits of surgical intervention

Well-differentiated SI NETs are on the rise. Due in part to the indolent nature of these tumors, patients typically have a delay in diagnosis and present with metastatic disease. Surgeries for symptoms of either chronic intermittent small bowel obstruction and/or ischemia or from carcinoid syndrome have proven to provide excellent palliation. Most recently, several series have demonstrated an improved survival in those patients in whom the primary, locoregional disease has been resected. Several newer adjuncts have been developed to aid in the hepatic directed therapies such as ablation therapies, embolization and Y spheres. The ability to cytoreduce 70% or more of the hepatic tumor burden has been shown to not only to provide a biochemical and as such a clinical response, but also appears to prolong survival. All patients with SI NETs should be assessed in a multidisciplinary clinic and the first line of therapy should always be to assess surgical resectabilty.

Loss of 11p11 is a frequent and early event in sporadic nonfunctioning pancreatic neuroendocrine neoplasms

The pathogenesis of sporadic pancreatic neuroendocrine neoplasms (PNENs) is poorly understood. To gain insight into the genetic mechanisms underlying this tumor entity, we performed genome-wide screening of 16 surgical specimens from 15 patients with sporadic PNEN, combining G-band karyotyping and high resolution comparative genomic hybridization (HR-CGH). G-banding revealed abnormal karyotypes in 2 of 10 tumor samples analyzed. DNA copy number changes were detected in 13 samples, whereas three tumors showed a balanced genome. Gains were more frequent than losses in the nonfunctioning tumors (n=13). Common gains were scored at 5p12–13, 4q13–24, 5p15, 5q11–31, and 9q21–22. Common losses were scored at 11p11, 11p14–15, 11q23, 11p12–13, and 11q22. The average number of copy aberrations (ANCA index) was 12 for 13 nonfunctioning primary tumors, 4.8 for the nonfunctioning tumors with low Ki-67 (≥5%), 21.2 for the tumors with high Ki-67 (<5%), 2.5 for small tumors (<3.5 cm), and 17.8 for large tumors (≥3.5 cm). There was a statistically significant difference in the ANCA index between the groups defined by Ki-67 and tumor size. Nonfunctioning tumors with low Ki-67, no distant metastasis and small size had few aberrations detected by HR-CGH, but frequent loss of material from chromosomal band 11p11. The present study indicates the existence of distinct cytogenetic patterns in sporadic nonfunctioning PNEN. Loss of chromosomal band 11p11 might indicate a primary pathogenetic event in these tumors.

The 2010 WHO classification of digestive neuroendocrine neoplasms: a critical appraisal four years after its introduction

This paper briefly illustrates the basis, rules of application, and present outcome of the current World Health Organization (WHO) classification for neuroendocrine neoplasms. Established in 2010 upon the proposal from the European Neuroendocrine Tumor Society (ENETS), the WHO 2010 fostered some definitional changes (most notably the use of neuroendocrine tumor (NET) instead of carcinoid) and indicated the tools of grading and staging. Specific rules for its application were also defined. The data generated from the use of WHO 2010 classification substantially endorsed its rules and prognostic efficacy. In addition, the application demonstrated some issues, among which are the possible re-definition of the cutoff for grading G1 vs G2, as well as the possible identification of cases with somewhat different clinical behavior within the G3 neuroendocrine cancer class. Overall, since the recent introduction of WHO 2010 grading and staging, it appears wise to keep the current descriptors to avoid unnecessary confusion and to generate comparable data. Homogenous data on large series are ultimately needed to solve such issues.

Clinical application of microRNA testing in neuroendocrine tumors of the gastrointestinal tract

It is well documented that dysregulation of microRNAs is a hallmark of human cancers. Thus, this family of small non-coding regulatory molecules represents an excellent source of sensitive biomarkers. Unique microRNAs expression profiles have been associated with different types and subsets of gastrointestinal tumors including gastroenteropancreatic neuroendocrine tumors (GEP-NETs). GEP-NETs are a heterogeneous group of epithelial neoplasms with neuroendocrine differentiation. At present, early detection and surgical resection of GEP-NETs represent the best chance for a cure. Thus, clinically useful biomarkers for GEP-NETs that strongly correlate with early detection are urgently needed. The purpose of this review is to summarize the role of miRNAs in GEP-NET carcinogenesis and their possible use as novel diagnostic, prognostic and predictive biomarkers.

CUX1: a modulator of tumour aggressiveness in pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms (PNENs) constitute a rare tumour entity, and prognosis and treatment options depend on tumour-mediating hallmarks such as angiogenesis, proliferation rate and resistance to apoptosis. The molecular pathways that determine the malignant phenotype are still insufficiently understood and this has limited the use of effective combination therapies in the past. In this study, we aimed to characterise the effect of the oncogenic transcription factor Cut homeobox 1 (CUX1) on proliferation, resistance to apoptosis and angiogenesis in murine and human PNENs. The expression and function of CUX1 were analysed using knockdown and overexpression strategies in Ins-1 and Bon-1 cells, xenograft models and a genetically engineered mouse model of insulinoma (RIP1Tag2). Regulation of angiogenesis was assessed using RNA profiling and functional tube-formation assays in HMEC-1 cells. Finally, CUX1 expression was assessed in a tissue microarray of 59 human insulinomas and correlated with clinicopathological data. CUX1 expression was upregulated during tumour progression in a time- and stage-dependent manner in the RIP1Tag2 model, and associated with pro-invasive and metastatic features of human insulinomas. Endogenous and recombinant CUX1 expression increased tumour cell proliferation, tumour growth, resistance to apoptosis, and angiogenesis in vitro and in vivo. Mechanistically, the pro-angiogenic effect of CUX1 was mediated via upregulation of effectors such as HIF1α and MMP9. CUX1 mediates an invasive pro-angiogenic phenotype and is associated with malignant behaviour in human insulinomas.