Classification and pathology of gastroenteropancreatic neuroendocrine neoplasms

Clinicopathological Findings and Treatment Outcomes of Patients with Primary Hepatobiliary Neuroendocrine Neoplasms: A Retrospective Single-institution Analysis

Objective Primary hepatobiliary neuroendocrine neoplasms (NENs) are rare tumors exhibiting several morphological and behavioral characteristics. Considering the lack of relevant data on this topic, we evaluated the clinicopathological features and treatment outcomes of patients with primary hepatobiliary NENs. Methods/Patients We examined 43 consecutive patients treated at the National Cancer Center Hospital with pathological diagnoses of primary hepatobiliary NEN between 1980 and 2016. Results Nine patients were diagnosed with neuroendocrine tumor (NET) G1, 9 with NET G2, and 25 with neuroendocrine carcinoma (NEC) based on the World Health Organization 2019 classification. Patients with NEC had primary sites across the hepatobiliary organs, although sites in patients with NET G1 and NET G2 only included the liver and ampulla of Vater. Patients with primary extrahepatic bile duct or ampulla of Vater NENs tended to be diagnosed earlier than patients with primary gallbladder NENs. The median survival times in the NET G1, NET G2, and NEC groups were 167.9, 97.4, and 11.1 months, respectively. A good performance status, absence of distant metastases, and low tumor grade were identified as independent predictors of a favorable prognosis. Conclusion The NET-to-NEC ratio and tumor stage distribution at the diagnosis differed depending on the primary site. Patients with G1 and G2 NETs who underwent surgical resection had good prognoses, whereas those with NEC exhibited more advanced disease and poorer prognoses. The performance status, staging classification, and tumor grade are important factors to consider when devising an appropriate treatment strategy and predicting the prognoses of patients with primary hepatobiliary NEN.

Hedinger Syndrome-Lessons Learnt: A Single-Center Experience

BACKGROUND

Hedinger syndrome (HS) or carcinoid heart disease (CD) is a rare and challenging manifestation of malignant neuroendocrine tumours (NETs) involving the heart. We aimed to report our experience with surgical strategies and midterm results in HS patients.

METHODS

Eleven patients (58 ± 11 (range 41 to 79 years); 5 females) with HS who underwent cardiac surgery in our department between 07/2005 and 05/2023 were analysed.

RESULTS

All patients showed a New York Heart Association (NYHA) class III-IV and in all the tricuspid valve (TV) was involved. Four patients received a TV replacement, and three TV reconstruction. Recently, to preserve the geometry and function of the compromised right ventricle (RV), we have applied the TV "bio-prosthesis in native-valve" implantation technique with the preservation of the valve apparatus (tricuspid valve implantation: TVI) in four cases. Concomitant procedures included pulmonary valve replacement in four, pulmonary implantation in one, and aortic valve replacement in three cases. To treat RV failure, we adapted a combined TandemHeart®-CytoSorb® haemoperfusion strategy in Patient #10 and venoarterial extracorporeal membrane oxygenation (V-A ECMO) support avoidance, after experiencing an ECMO-induced carcinoid-storm-related death in Patient #8. Mortality at 30 days was 18% (2/11). The median follow up was 2 ± 2.1 years (range 1 month to 6 years) with an overall mortality during the follow-up period of 72.7% (8/11).

CONCLUSIONS

HS surgery, despite being a high-risk procedure, can efficiently prolong survival, and represents a safe and feasible procedure. However, patient selection seems to be crucial. Further follow up and larger cohorts are needed.

Managing Metastatic Extrapulmonary Neuroendocrine Carcinoma After First-Line Treatment

PURPOSE OF REVIEW

Extrapulmonary neuroendocrine carcinoma (EP-NEC) is a rare, aggressive malignancy that can arise from any organ and frequently presents with distant metastases. Advanced disease has a poor prognosis with median overall survival (OS) rarely exceeding 1 year even with systemic therapy. The management paradigm of advanced/metastatic EP-NEC has been extrapolated from small cell lung cancer (SCLC) and commonly consists of 1st line therapy with etoposide and platinum (cisplatin or carboplatin), followed by alternative cytotoxic regimens at the time of progression. Only a minority of patients are able to receive 2nd line therapy, and cytotoxics derived from the SCLC paradigm such as topotecan or lurbinectedin have very limited activity. We aimed to evaluate emerging therapeutic options in the 2nd and later lines and survey potential future developments in this space.

RECENT FINDINGS

After a long period of stagnation in treatment options and outcomes, more promising regimens are gradually being utilized in the 2nd line setting including systemic therapy combinations such as FOLFIRI, FOLFOX, modified FOLFIRINOX, CAPTEM, and, more recently, novel checkpoint inhibitors such as nivolumab and ipilimumab. Simultaneously, advances in the understanding of disease biology are helping to refine patient selection and identify commonalities between NEC and their sites of origin which may eventually lead to additional targeted therapy options. While many questions remain, contemporary developments give grounds for optimism that improved outcomes for EP-NEC will soon be within reach.

Relation between WHO Classification and Location- and Functionality-Based Classifications of Neuroendocrine Neoplasms of the Digestive Tract

Practice of neuroendocrine neoplasms (NENs) of the digestive tract, which comprise of a highly diverse group of tumors with a rising incidence, faces multiple biological, diagnostic, and therapeutic issues. Part of these issues is due to misuse and misinterpretation of the classification and terminology of NENs of the digestive tract, which make it increasingly challenging to evaluate and compare the literature. For instance, grade 3 neuroendocrine tumors (NETs) are frequently referred to as neuroendocrine carcinomas (NECs) and vice versa, while NECs are, by definition, high grade and therefore constitute a separate entity from NETs. Moreover, the term NET is regularly misused to describe NENs in general, and NETs are frequently referred to as benign, while they should always be considered malignancies as they do have metastatic potential. To prevent misconceptions in future NEN-related research, we reviewed the most recent terminology used to classify NENs of the digestive tract and created an overview that combines the classification of these NENs according to the World Health Organization (WHO) with location- and functionality-based classifications. This overview may help clinicians and researchers in understanding the current literature and could serve as a guide in the clinic as well as for writing future studies on NENs of the digestive tract. In this way, we aim for the universal use of terminology, thereby providing an efficient foundation for future NEN-related research.

Small Bowel Imaging from Stepchild of Roentgenology to MR Enterography, Part II: The Reliable Disclosure of Crohn's Disease and Non-Inflammatory Small Bowel Disorder Plot through MRI Findings

MRE has become a standard imaging test for evaluating patients with small bowel pathology, but a rigorous methodology for describing and interpreting the pathological findings is mandatory. Strictures, abscess, inflammatory activity, sinus tract, wall edema, fistula, mucosal lesions, strictures, and mesentery fat hypertrophy are all indicators of small bowel damage in inflammatory and non-inflammatory small bowel disease, and they are all commonly and accurately explained by MRE. MRE is a non-invasive modality that accurately assesses the intra-luminal, parietal, and extra-luminal small bowel. Differential MRE appearance allows us to distinguish between Crohn's disease and non-inflammatory small bowel disorder. The purpose of this paper is to present the MRE pathological findings of small bowel disorder.

Transarterial chemoembolization (TACE) for neuroendocrine liver metastasis (NELM): Predictive value of volumetric arterial enhancement (VAE) on baseline MRI

BACKGROUND

Neuroendocrine tumors (NETs) belong to a rare family of tumors whose incidence has increased significantly over the past 50 years.

PURPOSE

To evaluate the prognostic value of volumetric arterial enhancement (VAE) on baseline magnetic resonance imaging (MRI) for patients with neuroendocrine liver metastasis (NELM) treated using transarterial chemoembolization (TACE).

MATERIAL AND METHODS

Between October 2012 and December 2018, VAE in 37 patients was measured with a semi-automatic volume of Interest (VOI) on subtracted T1 sequence in the arterial phase. Patients underwent 1-3 sectoral lipiodol TACE. Radiologic response using modified Response Evaluation Criteria in Solid Tumors (mRECIST) at the treatment cycle end and progression free survival were determined.

RESULTS

Median age was 68.0 (60.0; 73.0). Twenty-three patients (62%) had a partial response, 10 (27%) had stable disease, four (11%) had progressive disease. VAE was a significant (P<0.05) predictor of radiologic response. Median progression free survival was 13 months (IC 95: 8; 16). In univariate analysis, significant predictors of local progression were alkaline phosphatase (AP) (P=0.035), Ki-67 index (P=0.014), and VAE (P<0.01). VAE over 500ms and Ki-67 index over 3%were risk factors of progression (P=<0.01) in multivariate analysis.

CONCLUSION

VAE before TACE could be predictive of radiologic response and could be related to oncologic outcomes in patients with NELM.

Update on C-Cell Neuroendocrine Neoplasm: Prognostic and Predictive Histopathologic and Molecular Features of Medullary Thyroid Carcinoma

Medullary thyroid carcinoma (MTC) is a C-cell-derived epithelial neuroendocrine neoplasm. With the exception of rare examples, most are well-differentiated epithelial neuroendocrine neoplasms (also known as neuroendocrine tumors in the taxonomy of the International Agency for Research on Cancer [IARC] of the World Health Organization [WHO]). This review provides an overview and recent evidence-based data on the molecular genetics, disease risk stratification based on clinicopathologic variables including molecular profiling and histopathologic variables, and targeted molecular therapies in patients with advanced MTC. While MTC is not the only neuroendocrine neoplasm in the thyroid gland, other neuroendocrine neoplasms in the thyroid include intrathyroidal thymic neuroendocrine neoplasms, intrathyroidal parathyroid neoplasms, and primary thyroid paragangliomas as well as metastatic neuroendocrine neoplasms. Therefore, the first responsibility of a pathologist is to distinguish MTC from other mimics using appropriate biomarkers. The second responsibility includes meticulous assessment of the status of angioinvasion (defined as tumor cells invading through a vessel wall and forming tumor-fibrin complexes, or intravascular tumor cells admixed with fibrin/thrombus), tumor necrosis, proliferative rate (mitotic count and Ki67 labeling index), and tumor grade (low- or high-grade) along with the tumor stage and the resection margins. Given the morphologic and proliferative heterogeneity in these neoplasms, an exhaustive sampling is strongly recommended. Routine molecular testing for pathogenic germline RET variants is typically performed in all patients with a diagnosis of MTC; however, multifocal C-cell hyperplasia in association with at least a single focus of MTC and/or multifocal C-cell neoplasia are morphological harbingers of germline RET alterations. It is of interest to assess the status of pathogenic molecular alterations involving genes other than RET like the MET variants in MTC families with no pathogenic germline RET variants. Furthermore, the status of somatic RET alterations should be determined in all advanced/progressive or metastatic diseases, especially when selective RET inhibitor therapy (e.g., selpercatinib or pralsetinib) is considered. While the role of routine SSTR2/5 immunohistochemistry remains to be further clarified, evidence suggests that patients with somatostatin receptor (SSTR)-avid metastatic disease may also benefit from the option of ¹⁷⁷Lu-DOTATATE peptide radionuclide receptor therapy. Finally, the authors of this review make a call to support the nomenclature change of MTC to C-cell neuroendocrine neoplasm to align this entity with the IARC/WHO taxonomy since MTCs represent epithelial neuroendocrine neoplasms of endoderm-derived C-cells.

The Complex Histopathological and Immunohistochemical Spectrum of Neuroendocrine Tumors-An Overview of the Latest Classifications

Neuroendocrine neoplasms (NENs) originate from the neuroendocrine cell system, which may either take the shape of organoid cell aggregations or be composed of dispersed cells across various organs. Therefore, these tumors are heterogenous regarding the site of origin, functional status, degree of aggressiveness, and prognosis. When treating patients with neuroendocrine tumors, one of the most significant challenges for physicians is determining the correct tumor grade and thus classifying patients into risk categories. Over the years, the classification of these tumors has changed significantly, often causing confusion due to clinical, molecular, and immunohistochemical variability. This review aims to outline the latest NENs classifications regardless of their site of origin. Thus, an overview of the key histopathological and immunohistochemical characteristics of NENs could pave the way to validate possible predictive and prognostic markers and also guide the therapeutic conduct.

Evaluation of PD-L1 expression in a large set of gastroenteropancreatic neuroendocrine tumours and correlation with clinicopathological data

BACKGROUND

Targeting programmed death protein 1 (PD-1) or its ligand PD-L1 is a promising therapeutic approach for many types of cancer in which PD-L1 is overexpressed. However, data on PD-L1 expression levels in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are limited and contradictory.

METHODS

We evaluated PD-L1 expression in 457 archived, formalin-fixed, paraffin-embedded GEP-NEN samples from 175 patients by immunohistochemistry using the highly sensitive monoclonal anti-PD-L1 antibody 73-10. The immunostaining was semiquantitatively evaluated using a 12-point immunoreactivity score (IRS) taking both PD-L1-positive tumour cells and immune cells into account. Tumour samples with an IRS ≥ 3 were considered PD-L1-positive. Results were correlated with clinicopathological data and with the expression of several typical markers and receptors for neuroendocrine tumours.

RESULTS

Of the GEP-NEN samples, 73% were PD-L1-positive. The median IRS value across all samples was 4.0, corresponding to low expression. PD-L1 immunostaining was predominantly localised at the plasma membrane of the tumour cells. Positive correlations were observed between PD-L1 expression and tumour grading or Ki-67 index, between PD-L1 expression and the expression of chromogranin A, and between PD-L1 expression and the expression of each of the five somatostatin receptors. PD-L1 expression was lower in tumours with lymph node metastases at diagnosis than in those without regional metastasis and lower in high-stage than in earlier-stage tumours. No association was noted between PD-L1 expression and patient survival.

CONCLUSIONS

PD-L1 expression is common in GEP-NENs and increases with malignancy. Therefore, especially in high-grade GEP-NENs, targeting the PD-1/PD-L1 axis could be a promising additional therapeutic strategy.

NETest: serial liquid biopsies in gastroenteropancreatic NET surveillance

Objective

Up to now, serial NETest measurements in individuals assessing the disease course of gastroenteropancreatic neuroendocrine tumors (GEPNETs) at long-term follow-up and treatment response were not studied.

Design

The study was a longitudinal validation study of serial NETest measurements - a blood-based gene expression signature - in 132 patients with GEPNETs on therapy or watch-and-wait strategy.

Methods

Serial samples were collected during 46 (range: 6-71) months of follow-up. NETest scores were compared with Response Evaluation Criteria in Solid Tumors version 1.1-defined treatment response (e.g. no evidence of disease (NED), stable disease (SD) or progressive disease (PD)).

Results

Consecutive NETest scores fluctuated substantially (range: 0-100) over time in individuals with SD (n = 28) and NED (n = 30). Follow-up samples were significantly higher in SD (samples 3-5) and NED subgroups (samples 2-5) compared with baseline results, without changes in imaging. In 82% of untreated patients with PD, consecutive NETest scores consistently remained high. In patients undergoing systemic treatment, the median pre-treatment NETest score in treatment-responders was 76.5 (n = 22) vs 33 (n = 12) in non-responders (P = 0.001). Patients with low pre-treatment scores had 21 months reduced progression-free survival (10 vs 31 months; P = 0.01). The accuracy of the NETest for treatment response prediction was 0.73 (P = 0.009).

Conclusion

In patients not undergoing treatment, consecutive low NETest scores are associated with indolent behavior. Patients who develop PD exhibit elevated scores. Elevated results have important predictive value for treatment responsiveness and could be used for individualizing decisions on systemic therapy. The clinical value of follow-up NETest scores for patients who choose to watch and wait requires further study.

Surgical Outcomes, Long-Term Survivals and Staging Systems of World Health Organization G3 Pancreatic Neuroendocrine Tumors

Background: In 2017, the World Health Organization (WHO) defined a new category of pancreatic neuroendocrine neoplasms named G3 pancreatic neuroendocrine tumors (p-NETs), whose surgical outcomes, long-term survivals and staging systems have not been well documented. Methods: Data from eligible patients with G3 p-NETs defined using the WHO 2017 grading classification at our institute were retrospectively analyzed. Results: Our study enrolled 80 patients with WHO G3 p-NETs, including 50 women and 30 men. The accumulative 5-year overall survival (OS) of G3 p-NETs was 29.7%. The current staging system by the American Joint Committee on Cancer (AJCC) failed to discriminate the survival difference between Stage II and Stage III (p = 0.172), while notable differences with regard to the OS were statistically offered between each stage using the modified tumor−node−metastasis (mTNM) staging system (all p < 0.05). The OS of patients receiving surgical resection was significantly better than those with palliative operation (p < 0.05). Both the current AJCC system and proposed mTNM system were independent predictors for the OS of G3 p-NETs (p = 0.017 and p = 0.032, respectively). The 95% confidence intervals of the proposed mTNM staging system were smaller than that of the current AJCC system (0.626−8.217 and 0.329−10.013, respectively), indicating a relatively more accurate predictive ability. Conclusion: Our demonstration revealed that surgical resection was an independent predictor for the favorable prognosis of patients with G3 p-NETs. Moreover, the new mTNM staging system was more suitable and practical than the current AJCC system for stratifying G3 p-NETs into prognostic groups.

Real-world comparison of healthcare resource utilization and costs of [177Lu]Lu-DOTA-TATE in patients with progressive neuroendocrine tumors in England: a matched cohort analysis using data from the hospital episode statistics dataset

OBJECTIVE

To explore the healthcare resource utilization (HCRU) and costs for patients with progressive gastroenteropancreatic neuroendocrine tumors (GEP-NETs) treated with [¹⁷⁷Lu]Lu-DOTA-TATE and matched patients treated with somatostatin analogs (SSAs), chemotherapy, or targeted therapies.

METHODS

Hospital Episode Statistics (HES) dataset 2016-2018 was used to compare HCRU and costs between the two cohorts. The [¹⁷⁷Lu]Lu-DOTA-TATE cohort included patients assigned with a diagnosis code relevant to GEP-NET, a procedure code for imaging or SSAs, and a subsequent code for radionuclide therapy. The non-[¹⁷⁷Lu]Lu-DOTA-TATE cohort included patients assigned with a diagnosis code relevant to GEP-NET who had an increased frequency of SSAs or switched from SSAs to chemotherapy or targeted therapies. Cohorts were matched on propensity scores with sex, age at disease progression, and Charlson Comorbidity Index as parameters. Healthcare Resource Group codes were used for costing.

RESULTS

A total of 199 matched patients were included. The [¹⁷⁷Lu]Lu-DOTA-TATE cohort had lower overall costs (£1,882,028 vs. £3,016,321; p < .0001), non-elective inpatient spells (289 vs. 611 days) and costs (£849,569 vs. £1,707,109; p < .0001 for both), Accident & Emergency costs (£41,978 vs. £62,480; p = .0013), and average length of stay for overall inpatient spells (14.2 vs. 23.3 days; p = .1092) compared with the non-[¹⁷⁷Lu]Lu-DOTA-TATE cohort.

CONCLUSIONS

These analyses indicate significantly lower overall costs and HCRU for progressive GEP-NET patients treated with [¹⁷⁷Lu]Lu-DOTA-TATE. Current research reveals that future real-world analyses would further benefit from using additional databases linked to the HES dataset such as the Clinical Practice Research Datalink and/or National Cancer Registration and Analysis Service database.

Molecular deciphering of primary liver neuroendocrine neoplasms confirms its distinct existence with foregut-like profile

Isolated hepatic localizations of neuroendocrine tumors (NETs) are generally considered as metastatic NETs of unknown primary but could correspond to primary hepatic NETs (PHNETs), a poorly explored entity. We aimed to describe the clinicopathological and molecular features of PHNETs and compare them with other primary NETs. We assembled a retrospective cohort of patients managed for hepatic localization of NET without extra-hepatic primary tumor after exhaustive clinical, imaging and immunohistochemical characterization. We performed whole-exome sequencing with mutational and copy number analysis. Transcriptomic profiles were compared to pancreatic (n=31), small-bowel (n=22) and lung (n=15) NETs using principal component analysis, unsupervised clustering and gene-set enrichment analysis. Among 27 screened patients, 16 had PHNET (solitary tumor in 63%, median size 11 cm, G2 NETs in 81%) following clinical and pathological review. DNA analyses showed "foregut-like" genomic profiles with frequent alterations in pathways of Fanconi DNA repair (75%), histone modifiers (58%), adherens junctions (58%) and cell cycle control (50%). The most frequently involved genes were KMT2A (58%), ATM (42%), CDH1, CDKN2C, FANCF and MEN1 (33% each). Transcriptomic analyses showed that PHNETs clustered closer to foregut (pancreatic, lung) NETs than to midgut (small-bowel) NETs, while remaining a distinct entity with specific profile. Assessment of potentially predictive biomarkers suggested efficacy of treatments usually active in foregut NETs. In conclusion, PHNETs display a foregut-like molecular profile distinct from other types of NETs, with recurrent molecular alterations. Upon exhaustive work-up to exclude unrecognized primary tumor, PHNETs should not be considered metastatic NETs from an unknown primary. This article is protected by copyright. All rights reserved.

Surgical Outcomes and Prognostic Factors of G3 Pancreatic Neuroendocrine Carcinomas: A Consecutive Analysis Based on Previous Study Results

In 2017, the World Health Organization (WHO) officially defined pancreatic neuroendocrine neoplasms into well-differentiated tumors, namely G1/G2/G3 pancreatic neuroendocrine tumors, and poorly differentiated carcinomas referring to G3 pancreatic neuroendocrine carcinomas (p-NECs). However, the surgical outcomes and prognostic factors of G3 p-NECs are still unclear. Methods: We retrospectively collected and analyzed the data of eligible patients with G3 p-NECs defined by the WHO 2017 grading classification. Results: We eventually identified 120 patients with G3 p-NECs, including 72 females and 48 males, with a median age of 53 y. The 3-year overall survival (OS) of G3 p-NECs by Kaplan−Meier method was 37.3%. The 3-year OS for functional G3 p-NECs was 57.4%, which was statistically longer than 23.0% of non-functional ones (p = 0.002). Patients with surgical resection presented a significantly better 3-year OS than those with palliative operation (43.3% vs. 13.1%; p < 0.001). The 3-year OS for Stage Ⅰ, Stage Ⅱ, Stage Ⅲ, and Stage Ⅳ was 87.1%, 56.5%, 12.9%, and not applicable, respectively (p < 0.001). We demonstrated in a Cox regression model that palliative operation (p = 0.013), vascular infiltration (p = 0.039), lymph node involvement (p = 0.024), and distant metastasis (p = 0.016) were independent predictors of poor outcome for patients with surgically treated G3 p-NECs. Conclusion: Our data in the present analysis indicated that patients with G3 p-NECs could significantly benefit from surgical resection. Meanwhile, vascular infiltration, lymph node involvement, and distant metastasis were independent predictors of poor outcome for these patients.

Spannungsfeld endoskopische Resektionsverfahren bei GEP-NET // Endoscopic resection for GEP-NET

Neuroendokrine Tumoren des Verdauungstraktes (GEP-NET) sind eine seltene Tumorentität, die häufig als Zufallsbefund diagnostiziert werden. Ein großer Teil dieser Zufallsdiagnosen wird im Rahmen einer endoskopischen Untersuchung gestellt. Während die vollständige Entfernung des Tumors im Sinne einer kurativen chirurgischen Resektion nach onkologischen Kriterien das Standardvorgehen für lokalisierte Tumorerkrankungen ist, kann bei kleinen Tumoren ohne Hinweis und Risiko für eine lymphogene Metastasierung eine endoskopische Abtragung in gleicher Intention erfolgen. Während dies für Magen-, Duodenum- und Rektum-NET der Standard ist, sollten NET des Jejunums und Ileums aufgrund der hohen Metastasierungsrate trotz geringer Tumorgröße regelhaft nicht endoskopisch angegangen werden. Die Grenze für eine endoskopische Resektion ergibt sich sowohl durch die technische Machbarkeit im Sinne des Erreichens einer R0-Resektion, der erwarteten Komplikationen im Sinne von Blutung und Perforationen als auch durch das vermutete Risiko für eine lymphogene Metastasierung. Generell wird eine endoskopische Resektion bei Befunden < 1 cm regelhaft empfohlen, da sowohl die gute technische Machbarkeit als auch das geringe Metastasierungsrisiko für eine endoskopische Resektion sprechen. Bei allen Befunden über 2 cm Größe sind sowohl die technischen Erfolgsaussichten so niedrig als auch das Metastasierungsrisiko so hoch, dass in dieser Situation regelhaft ein chirurgisches Vorgehen erfolgen sollte. Es bleibt somit ein Graubereich bei der Tumorgröße zwischen 1 und 2 cm, wo sowohl endoskopische, aber auch chirurgische Resektionsverfahren sinnvoll eingesetzt werden können. Zunehmend kommen auch gemeinsame Eingriffe im Sinne eines endoskopisch-laparoskopischen Rendezvous-Verfahrens zum Einsatz – insbesondere im Duodenum bieten sich diese Eingriffe an, um eine minimale Resektion mit größtmöglicher R0-Erfolgsrate und niedriger Perforationsrate zu erreichen.

Childhood neuroendocrine tumors of the digestive system: A single center experience

The prevalence and incidence of neuroendocrine tumors (NETs) are increasing in the pediatric population. This increase can be associated with improved diagnostics and increased detection rates of the disease. We aimed to discuss the clinical and pathological characteristics of patients with this rare disease who were followed and treated at our center.The medical records of children (aged 0-18 years) with NETs of the digestive system, followed up and treated between 2007 and 2020 at Ondokuz Mayis University Faculty of Medicine, were reviewed.Overall, 16 patients (8 girls and 8 boys) were analyzed. Fifteen patients had NETs in the appendix; 14 of these had grade I NETs, and 1 had grade II NETs. No additional surgery was performed except for appendectomy. All patients were in complete remission at the last follow-up (median 38 months). The other patient, a 12-year-old girl, had a primary hepatic neuroendocrine carcinoma (grade III NET). Three cycles of neoadjuvant and adjuvant platinum-based chemotherapy were administered, and right hepatectomy was performed to remove the mass. The patient is being followed-up for approximately 3 years without disease recurrence.Most NETs are observed in adults, and most studies have focused on this population. Unlike adults, increasing awareness of the disease in the pediatric population (especially in cases of acute appendicitis), discovering therapeutic treatments, and sharing experiences are crucial for developing an optimal therapeutic approach for pediatric NETs.

Streptozocin/5-fluorouracil chemotherapy of pancreatic neuroendocrine tumours in the era of targeted therapy

PURPOSE

The role of streptozocin-based chemotherapy (STZ CTx) in advanced, well-differentiated pancreatic neuroendocrine tumours (PanNET) and the best sequence of treatments in advanced PanNET are unclear. We examined the outcomes after STZ CTx in patients who had been selected according to the current therapeutic guidelines.

METHODS

Data from 50 PanNET patients consecutively treated with STZ CTx between 2010 and 2018 were analysed. The endpoints of the study were the objective-response rate (ORR), progression-free survival (PFS), and overall survival (OS).

RESULTS

STZ CTx was the first-line treatment in 54% of patients. The PanNET grades were as follows: 6% G1, 88% G2, and 6% well-differentiated G3. The ORR was 38%. Stable disease was the best response in 38% of patients and 24% showed progressive disease. Treatment was discontinued because of toxicity in one patient. Median PFS and OS were 12 (95% confidence interval (CI), 8.5-15.5) and 38 months (95% CI, 20.4-55.6), respectively. In the Kaplan-Meier analysis, the median OS was 89 months (95% CI, 34.9-143.1) for STZ CTx as first-line therapy compared with 22 months (95% CI, 19.3-24.7; p = 0.001, log-rank test) for subsequent lines. Bone metastases negatively impacted survival (HR, 2.71, p = 0.009, univariate analysis, HR, 2.64, p = 0.015, multivariate analysis, and Cox regression).

CONCLUSIONS

In patients selected according to current guidelines, PFS, and OS after STZ CTx were lower than previously reported, whereas ORR was unchanged. First-line treatment was positively associated with OS and the presence of bone metastases was negatively associated with OS. Pre-treatment with targeted or peptide-receptor radionuclide therapy did not alter ORR, PFS, or OS.

Discordance between Histopathological grading and Dual Tracer PET-CT findings (68Ga-DOTATATE and FDG) in metastatic Neuroendocrine Neoplasms and outcome of 177Lu-DOTATATE PRRT: does in-vivo molecular PET imaging perform better from 'prediction of tumour biology' viewpoint?

Background and Aim: Discordance between histopathological grading and dual tracer PET-CT (⁶⁸Ga-DOTATATE and FDG) findings in neuroendocrine tumours (NETs), though not typical, can be encountered in real-world scenario. The aim of this study was to assess patients with discordance between WHO 2017 grade predicted molecular PET-CT imaging and the actual dual tracer PET-CT findings (by exploring their histopathological, immunohistochemical and molecular imaging characteristics), with a view to identifying the prognostic determinants effecting outcome in a peptide receptor radionuclide therapy (PRRT) set-up. Methods: Thirty six patients of histopathologically proven inoperable, locally advanced/metastatic NETs, referred for PRRT were included in this study. The cohort was divided into two broad population groups: (a) those with discordance (between WHO 2017 grade predicted molecular imaging and the dual tracer PET-CT findings) and (b) control (showing both FDG and ⁶⁸Ga-DOTATATE uptake). The cohort was divided based on dual tracer PET-CT into: (i) metabolically FDG non-avid and SSTR expressing tumors, (ii) metabolically active and non-⁶⁸Ga-DOTATATE concentrating (SSTR expressing) and (iii) matched imaging characteristics with WHO 2017 grading system (showing both FDG and ⁶⁸Ga-DOTATATE concentrating disease) for statistical analysis. Statistical analyses were done on SPSS 23.0. Descriptive statistics was used to analyze categorical data, multivariate analysis was used to assess the correlation between different variables with progression free survival (PFS) and overall survival (OS). Kaplan-Meier was used for survival analysis to calculate median survival and to analyze the survival based on WHO 2017 grading and dual tracer PET. Cox proportional hazards regression analysis was used to determine predictors of survival (OS and PFS). Results: In the entire cohort (n = 36), 24 patients (66.7%) showed discordance whereas 12 patients (33.3%) were in the control group. Among the patients showing discordance: 14 patients (38.9%) had metabolically inactive and SSTR expressing disease and remaining 10 patients (27.8%) had FDG concentrating and SSTR non-expressing disease. Those in the control group, 12 patients (33.3%) had intermediate grade NETs and showed matched (⁶⁸Ga-DOTATATE and FDG concentrating lesions) disease. Multivariate analysis in patients with discordant findings demonstrated significant correlation of dual tracer PET with overall survival while no significant correlation could be established between WHO grade and overall survival in the discordant subgroups. No significant correlation could be appreciated between PFS and either dual tracer PET or WHO grading. The Kaplan-Meier survival analysis and Cox proportional hazards regression analysis demonstrated dual tracer PET-CT imaging to be significant prognostic determinant and predictor of outcome respectively. Conclusion: In summary, in NET patients with discordance between the two parameters, dual tracer PET-CT with FDG and ⁶⁸Ga-DOTATATE performed better than WHO grading, differentiation status and immunohistochemistry in prognosticating and predicting outcome.

Somatostatin and Its Receptor System in Colorectal Cancer

Somatostatin (SST)/somatotropin release-inhibiting factor (SRIF) is a well-known neuropeptide, widely distributed in the central and peripheral nervous systems, that regulates the endocrine system and affects neurotransmission via interaction with five SST receptors (SST1-5). In the gastrointestinal tract, the main SST-producing cells include intestinal enteroendocrine cells (EECs) restricted to the mucosa, and neurons of the submucosal and myenteric plexuses. The action of the SRIF system is based on the inhibition of endocrine and exocrine secretion, as well as the proliferative responses of target cells. The SST1–5 share common signaling pathways, and are not only widely expressed on normal tissues, but also frequently overexpressed by several tumors, particularly neuroendocrine neoplasms (NENs). Furthermore, the SRIF system represents the only peptide/G protein-coupled receptor (GPCR) system with multiple approved clinical applications for the diagnosis and treatment of several NENs. The role of the SRIF system in the histogenesis of colorectal cancer (CRC) subtypes (e.g., adenocarcinoma and signet ring-cell carcinoma), as well as diagnosis and prognosis of mixed adenoneuroendocrine carcinoma (MANEC) and pure adenocarcinoma, is poorly understood. Moreover, the impact of the SRIF system signaling on CRC cell proliferation and its potential role in the progression of this cancer remains unknown. Therefore, this review summarizes the recent collective knowledge and understanding of the clinical significance of the SRIF system signaling in CRC, aiming to evaluate the potential role of its components in CRC histogenesis, diagnosis, and potential therapy.

Gastroenteropancreatic neuroendocrine neoplasms G3: Novel insights and unmet needs

According to the 2019 WHO pathology grading system, high-grade gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) can be divided into well differentiated neuroendocrine tumors G3 (NETs G3) and poorly differentiated neuroendocrine carcinomas (NECs). GEP-NETs G3 and GEP-NECs present significant differences in driver genes and disease origin. NETs G3 and NECs have been confirmed to be two distinct diseases with different genetic backgrounds, however, this issue remains controversial. The prognosis of NETs G3 is significantly better than that of NECs. The differential diagnosis of GEP-NETs G3 and GEP-NECs should be combined with the patient's medical history, tumor histopathology, Ki-67 index, DAXX/ATRX, TP53 and Rb expression as well as other immunohistochemical indicators. In addition, the treatment strategies of these two subgroups are very different. Here, we summarize recent findings focused on the genomics, clinical manifestations, diagnosis, treatment and other aspects of high-grade GEP-NENs (G3). This review may help further our understanding of the carcinogenesis, diagnosis and treatment of GEP-NENs G3.

Neuroendocrine neoplasms of the pancreas: diagnosis and pitfalls

Common to neuroendocrine neoplasms of the pancreas is their expression of synaptophysin, chromogranin A, and/or INSM1. They differ, however, in their histological differentiation and molecular profile. Three groups can be distinguished: well-differentiated neuroendocrine neoplasms (neuroendocrine tumors), poorly differentiated neuroendocrine neoplasms (neuroendocrine carcinomas), and mixed neuroendocrine-non-neuroendocrine neoplasms. However, the expression of synaptophysin and, to a lesser extent, also chromogranin A is not restricted to the neuroendocrine neoplasms, but may also be in a subset of non-neuroendocrine epithelial and non-epithelial neoplasms. This review provides the essential criteria for the diagnosis of pancreatic neuroendocrine neoplasms including diagnostic clues for the distinction of high-grade neuroendocrine tumors from neuroendocrine carcinomas and an algorithm avoiding diagnostic pitfalls in the delineation of non-neuroendocrine neoplasms with neuroendocrine features from pancreatic neuroendocrine neoplasms.

Pancreatic Neuroendocrine Tumors: Molecular Mechanisms and Therapeutic Targets

Pancreatic neuroendocrine tumors (pNETs) are unique, slow-growing malignancies whose molecular pathogenesis is incompletely understood. With rising incidence of pNETs over the last four decades, larger and more comprehensive 'omic' analyses of patient tumors have led to a clearer picture of the pNET genomic landscape and transcriptional profiles for both primary and metastatic lesions. In pNET patients with advanced disease, those insights have guided the use of targeted therapies that inhibit activated mTOR and receptor tyrosine kinase (RTK) pathways or stimulate somatostatin receptor signaling. Such treatments have significantly benefited patients, but intrinsic or acquired drug resistance in the tumors remains a major problem that leaves few to no effective treatment options for advanced cases. This demands a better understanding of essential molecular and biological events underlying pNET growth, metastasis, and drug resistance. This review examines the known molecular alterations associated with pNET pathogenesis, identifying which changes may be drivers of the disease and, as such, relevant therapeutic targets. We also highlight areas that warrant further investigation at the biological level and discuss available model systems for pNET research. The paucity of pNET models has hampered research efforts over the years, although recently developed cell line, animal, patient-derived xenograft, and patient-derived organoid models have significantly expanded the available platforms for pNET investigations. Advancements in pNET research and understanding are expected to guide improved patient treatments.

Insulinoma-associated protein 1(INSM1) is a superior marker for the diagnosis of gastroenteropancreatic neuroendoerine neoplasms: a meta-analysis

PURPOSE

An increasing number of studies have shown that insulinoma-associated protein 1 (INSM1) is a robust marker for the diagnosis of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN). The overall diagnostic accuracy of INSM1 for GEP-NEN remains unclear. The purpose of this study is to estimate the diagnostic value of INSM1 for GEP-NEN through a meta-analysis.

METHODS

We searched relevant studies addressing the accuracy of INSM1 in the diagnosis of GEP-NEN from PubMed, Web of Science, Embase, Cochrane Library and China National Knowledge Infrastructure (CNKI) as well as from reference lists since the establishment of the database to January 12, 2021. Pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curves were used to comprehensively evaluate the diagnostic value of INSM1 for GEP-NEN. Statistical analysis was performed by Stata 15.0 and RevMan 5.4.

RESULTS

Nine studies with a total of 393 patients were included in the meta-analysis. The meta-analysis results showed that the pooled sensitivity and specificity of INSM1 for the diagnosis of GEP-NEN were 0.99 (95% CI: 0.87-1.00) and 0.96 (95% CI: 0.93-0.98), respectively. The PLR and NLR were 23.3 (95% CI: 13.3-40.8) and 0.01 (95% CI: 0.00-0.14), respectively. The DOR was 380.31 (95% CI: 164.14-881.21), and the area under the curve (AUC) of SROC curve was 0.98 (95% CI: 0.96-0.99).

CONCLUSIONS

The results show that INSM1 is an effective marker for the diagnosis of GEP-NEN with high sensitivity and specificity. INSM1 is recommended for clinical application to improve the diagnostic accuracy of GEP-NEN. However, more high-quality studies are needed to confirm these findings.

Theranostics in neuroendocrine tumors: an overview of current approaches and future challenges

Neuroendocrine neoplasms (NENs) comprise a heterogeneous group of tumors, mainly localized in the gastrointestinal system. What characterizes NENs is the expression of hormone receptors on the tumor cell surface, making them accessible for diagnostic and therapeutic approaches (theranostics) using radiolabelled peptides. Somatostatin receptors subtype-two (SST2) play an important role in NENs since they are overexpressed and homogeneously distributed at the surface of the majority of NENs. Accordingly, targeting SST2 for diagnostic and therapeutic purposes has been established. Current research aims at upregulating its expression by epigenetic treatment or improving its targeting via use of alternative radioligands. In addition, recent data suggest a future role of SST antagonists as a diagnostic tool and a potential therapeutic option. Another promising target is the glucagon-like peptide-1 (GLP-1) receptor. Targeting GLP-1R using exendin-4 (GLP-1 analogue) has a high sensitivity for the localization of the often SST2-negative sporadic insulinomas and insulinomas in the context of multiple endocrine neoplasia type-1. Further options for patients with insufficient expression of SST2 involve metaiodobenzylguanidine (MIBG) and the molecular target C-X-C motif chemokine receptor-4 (CXCR4), which have been evaluated for potential theranostic approach in symptomatic NENs or dedifferentiated tumors. Recently, new targets such as the glucose-dependent insulinotropic polypeptide receptor (GIPR) and the fibroblast activation protein (FAP) have been identified in NENs. Finally, minigastrin - a ligand targeting the cholecystokinin-2 (CCK2) receptors in medullary thyroid carcinoma and foregut neuroendocrine tumors - may improve future management of these diseases with currently limited therapeutic options. This review summarises the current approaches and future challenges of diagnostic and therapeutic evaluations in neuroendocrine neoplasms.

Imaging of Pancreatic Neuroendocrine Neoplasms

Pancreatic neuroendocrine neoplasms (panNENs) represent the second most common pancreatic tumors. They are a heterogeneous group of neoplasms with varying clinical expression and biological behavior, from indolent to aggressive ones. PanNENs can be functioning or non-functioning in accordance with their ability or not to produce metabolically active hormones. They are histopathologically classified according to the 2017 World Health Organization (WHO) classification system. Although the final diagnosis of neuroendocrine tumor relies on histologic examination of biopsy or surgical specimens, both morphologic and functional imaging are crucial for patient care. Morphologic imaging with ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) is used for initial evaluation and staging of disease, as well as surveillance and therapy monitoring. Functional imaging techniques with somatostatin receptor scintigraphy (SRS) and positron emission tomography (PET) are used for functional and metabolic assessment that is helpful for therapy management and post-therapeutic re-staging. This article reviews the morphological and functional imaging modalities now available and the imaging features of panNENs. Finally, future imaging challenges, such as radiomics analysis, are illustrated.

Management of Small Bowel Neuroendocrine Tumors

Small bowel neuroendocrine tumors (SBNETS) are slow-growing neoplasms with a noted propensity toward metastasis and comparatively favorable prognosis. The presentation of SBNETs is varied, although abdominal pain and obstructive symptoms are the most common presenting symptoms. In patients with metastases, hypersecretion of serotonin and other bioactive amines results in diarrhea, flushing, valvular heart disease, and bronchospasm, termed carcinoid syndrome. The treatment of SBNETs is multimodal and includes surgery, liver-directed therapy, somatostatin analogues, targeted therapy, and peptide receptor radionuclide therapy.

Systemic Treatment of Gastroenteropancreatic Neuroendocrine Carcinoma

OPINION STATEMENT

Treatment recommendations for advanced gastroenteropancreatic neuroendocrine carcinomas (GEP-NEC) are based on uncontrolled, mainly retrospective data. Chemotherapy can offer palliative relief, but long-lasting complete responses or cures are rare. The European Neuroendocrine Tumour Society (ENETS) and European Society for Medical Oncology (ESMO) recommend platinum-based chemotherapy as first-line treatment. This has been the golden standard since the late 1980s and has been evaluated in mostly retrospective clinical studies. However, progression is inevitable for most patients. Unfortunately, data on effective second-line treatment options are scant, and ENETS and ESMO recommendations propose fluorouracil- or temozolomide-based chemotherapy schedules. As such, there is a huge unmet need for improved care. Improved knowledge on GEP-NEC biology may provide a pathway towards more effective interventions including chemotherapy, targeted gene therapy, peptide receptor radionuclide therapy, as well as immune checkpoint inhibitors. The review summarises this current state of the art as well as the most promising developments for systemic therapy in GEP-NEC patients.

The overriding role of surgery and tumor grade for long-term survival in patients with gastroenteropancreatic neuroendocrine neoplasms: A population-based cohort study

Background

Gastroenteropancreatic neuroendocrine neoplasms (GEP‐NENs) comprise a heterogeneous disease group. Factors that affect long‐term survival remain uncertain. Complete population‐representative cohorts with long‐term follow‐up are scarce.

Aim

To evaluate factors of importance for the long‐term survival.

Methods and results

An Observational population‐based study on consecutive GEP‐NEN patients diagnosed from 2003 to 2013, managed according to national guidelines. Univariable and multivariable survival analyses were performed to evaluate overall survival (OS) and to identify independent prognostic factors. One hundred ninety eligible patients (males, 58.9%) (median age, 60.0 years; range, 10.0–94.2 years) were included. The small bowel, appendix, and pancreas were the most common tumor locations. The World Health Organization (WHO) tumor grade 1–3 distributions varied according to the primary location and disease stage. Primary surgery with curative intent was performed in 66% of the patients. The median OS of the study population was 183 months with 5‐ and 10‐year OS rates of 66% and 57%, respectively. Only age, WHO tumor grade, and primary surgical treatment were independent prognostic factors for OS.

Conclusion

The outcomes of GEP‐NEN patients are related to several factors including age and primary surgical treatment. WHO tumor grading, based on the established criteria, should be routine in clinical practice. This may improve clinical decision‐making and allow the comparison of outcomes among different centers.

The value of MRI in identifying pancreatic neuroendocrine tumour G3 and carcinoma G3

AIM

To explore the magnetic resonance imaging (MRI) differences between pancreatic neuroendocrine tumour grade 3 (pNET-G3) and pancreatic neuroendocrine carcinoma grade 3 (pNEC-G3).

MATERIALS AND METHODS

Between 2009 and 2019, 31 patients underwent pNEN-G3 resection with preoperative MRI in two local hospitals in China. The 31 patients were assigned to a pNET-G3 group (n=13) or a pNEC-G3 group (n=18). The MRI findings between the groups were compared.

RESULTS

There was no statistically significant difference between the two groups in lesion size, clinical characteristics, or laboratory indexes. The lesions showed high or slightly higher signal on diffusion-weighted imaging and decreased apparent diffusion coefficient (ADC) values, which differed between the two groups (p=0.013). The difference between the groups regarding positive enhancement integral, arterial phase and portal phase signal enhancement ratio were statistically significant; however, the delayed phase signal enhancement ratio was not significantly different.

CONCLUSIONS

pNET-G3 and pNEC-G3 showed different characteristics on MRI. In particular, the ADC value and dynamic enhanced imaging could have an important role in distinguishing between the two.

Update in clinical management for gallbladder neuroendocrine carcinoma

BACKGROUND

Gallbladder neuroendocrine carcinoma (GB-NEC) is rare and there are few reports at present. We sought to review the current knowledge of GB-NEC and provide recommendations for clinical management.

METHODS

A systemic literature research was conducted in the websites of Pubmed, Medline, Web of Science, CNKI, Wanfang Data using the keywords including gallbladder combined with neuroendocrine carcinoma or neuroendocrine tumor or neuroendocrine neoplasm. Two reviewers independently screened the articles by reading the title, abstract and full-text.

RESULTS

In computed tomography (CT) and magnetic resonance imaging (MRI) examination, a well-defined margin, gallbladder replacing type with larger hepatic and lymphatic metastases could be helpful for differential diagnosis of GB-NEC and gallbladder adenocarcinoma (GB-ADC). Older age, unmarried status, large tumor size (>5 cm), positive margins, and distant Surveillance, Epidemiology and End result (SEER) stage are independently associated with poor survival. Surgical resection remains as the preferred and primary treatment. The potential survival benefit of lymphadenectomy for patients remains controversial. Platinum-based postoperative adjuvant chemotherapy may improve the survival. The efficacy of other treatments including immunotherapy, targeted therapy and somatostatin analogue needs further investigation.

CONCLUSION

Typical imaging features could be helpful for preoperative diagnosis. Age, margin status, tumor size, marital status, histopathologic subtype and SEER stage may be independent predictors for the survival. Remarkable advances regarding the treatment for GB-NEC have been achieved in recent years. Further studies are needed to investigate the survival benefit of lymphadenectomy for patients with GB-NEC.

Pancreatic neuroendocrine tumours: spectrum of imaging findings

Pancreatic neuroendocrine tumours (pNETs) are rare and heterogeneous group of neoplasms presenting with a wide variety of symptoms and biological behaviour, from indolent to aggressive ones. pNETs are stratified into functional or non-functional, because of their ability to produce metabolically active hormones. pNETs can be an isolate phenomenon or a part of a hereditary syndrome like von Hippel-Lindau syndrome or neurofibromatosis-1. The incidence has increased in the last years, also because of the improvement of cross-sectional imaging. Computed tomography (CT), magnetic resonance imaging (MRI) and functional imaging are the mainstay imaging modalities used for tumour detection and disease extension assessment, due to easy availability and better contrast/spatial resolution. Radiological imaging plays a fundamental role in detection, characterization and surveillance of pNETs and is involved in almost every stage of patients' management. Moreover, with specific indications and techniques, interventional radiology can also play a role in therapeutic management. Surgery is the treatment of choice, consisting of either partial pancreatectomy or enucleation of the primary tumour. This article reviews the radiologic features of different pNETs as well as imaging mimics, in order to help radiologists to avoid potential pitfalls, to reach the correct diagnosis and to support the multidisciplinary team in establishing the right treatment.

Do Canine Pancreatic Neuroendocrine Neoplasms Resemble Human Pancreatic Neuroendocrine Tumours? A Comparative Morphological and Immunohistochemical Investigation

Although canine pancreatic neuroendocrine neoplasms (PanNENs) have been proposed as a model for the counterpart human neoplasms, the type or grade of human PanNEN that they resemble is unclear. PanNENs in animals are classified as adenoma or carcinoma, whereas in humans they are classified as pancreatic neuroendocrine tumour (PanNET) if well-differentiated, or as pancreatic neuroendocrine carcinoma (PanNEC) if poorly differentiated. We evaluated 16 canine primary PanNENs and two metastases histologically and immunohistochemically, and graded them using the animal and human grading systems. All neoplasms had local or vascular invasion and were classified as pancreatic islet cell carcinomas according to the current WHO classification. The Ki-67 index was low in all cases (0.01-1.50%). All had cytoplasmic expression of synaptophysin and insulin but were immunonegative for glucagon, confirming a functional diagnosis of canine insulinoma. Membranous expression of SSTR2A and nuclear expression of ATRX, but no p53 expression, was found in all neoplasms. One primary tumour was diagnosed as a mixed neuroendocrine-non-neuroendocrine neoplasm, which is the first report of this neoplasm in dogs. The other 15 primary tumours and both metastatic tumours were graded as PanNET G1, according to the human WHO classification. We conclude that canine PanNENs share well-differentiated histomorphology, SSTR2A expression and absence of nuclear p53 immunolabelling with human PanNETs G1. However, they differ in ATRX gene expression and functionality, and seem to have a worse prognosis than human PanNETs G1, although their generally low Ki-67 index precludes more precise assessment of prognosis. Membranous SSTR2A expression renders canine PanNENs potentially amenable to treatment with somatostatin analogues or SSTR targeted in-vivo imaging methods.

Advances in Molecular Imaging and Radionuclide Therapy of Neuroendocrine Tumors

Neuroendocrine neoplasms make up a heterogeneous group of tumors with inter-patient and intra-patient variabilities. Molecular imaging can help to identify and characterize neuroendocrine tumors (NETs). Furthermore, imaging and treatment with novel theranostics agents offers a new, tailored approach to managing NETs. Recent advances in the management of NETs aim to enhance the effectiveness of targeted treatment with either modifications of known substances or the development of new substances with better targeting features. There have been several attempts to increase the detectability of NET lesions via positron emission tomography (PET) imaging and improvements in pretreatment planning using dosimetry. Especially notable is PET imaging with the radionuclide Copper-64. Increasing interest is also being paid to theranostics of grade 3 and purely differentiated NETs, for example, via targeting of the C-X-C motif chemokine receptor 4 (CXCR4). The aim of this review is to summarize the most relevant recent studies, which present promising new agents in molecular imaging and therapy for NETs, novel combination therapies and new applications of existing molecular imaging modalities in nuclear medicine.

Inflammation-related cytokines and their roles in gastroenteropancreatic neuroendocrine neoplasms

Proinflammatory counterworks are important at different stages of tumor development, particularly during invasion and metastasis. Immune cells and their signal molecules can influence all stages of tumor progression, as well as therapeutic intervention. Proinflammatory cytokines are known triggers of growth in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). In this study, we explored the immunohistochemical expression of tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), IL-2, and IL-6 in tissues from 43 GEP-NEN patients with tumors of gastric, duodenal, ileal, appendiceal, and colonic origin. The immunohistochemical expression of TNF-α was increased in tumor groups with high proliferation rates (Ki-67; p = 0.034), as well as in those with higher tumor grades (p = 0.05). Moreover, the immunohistochemical expression of TNF-α positively correlated with death outcomes (p = 0.016). Expression of IL-6, IL-1β, and IL-2 displayed similar immunohistochemical expression patterns regardless of Ki-67, although the expression between the ILs differed. Most GEP-NENs had high levels of IL-6 and lower levels of IL-1β and IL-2. Although further comprehensive studies are required for a complete understanding of activated mechanisms in proinflammatory protumoral microenvironment of GEP-NENs, TNF-α is a potential marker in the prognosis of those tumors.

CD57 as a routine neuroendocrine marker for liver metastasis

Background

The characterization of hepatic metastases as having neuroendocrine origins is essential and the main markers currently used are chromogranin A (CgA) and synaptophysin (Syn). However, these markers may exhibit certain limitations, and the use of CD56 and CD57 can also be considered, although, due to low specificity, their use is discouraged.

Aim

This study sought to compare the immunohistochemical expression of these markers in hepatic metastases of neuroendocrine neoplasms (NEN).

Materials and Methods

Eighteen samples, were used for immunohistochemical staining with CgA, Syn, CD56, and CD57 antibodies. The immunostaining reactions were compared according to its intensity (I), the percentage of labeled cells (P), and a final score (I × P). Statistical agreement between the markers was also evaluated.

Results

CD57 was expressed in the highest number of cases and also showed the most intense expression. CgA showed the highest number of cases with more than 80% positively stained area (72.2%), followed by CD57 (61.1%). The highest average score (I × P) was obtained for CD57 (9.1 ± 4.1). The best indices of agreement were between CgA and CD57 with respect to positivity (P = 0.021) and score (P = 0.014). According to the primary site, stomach/duodenum, lungs, and undetermined subgroups showed the highest average scores for CD57, followed by CgA. For the small bowel subgroup, the highest average score was obtained for CgA, followed by CD57.

Conclusion

Our results highlight the importance of CD57 in the evaluation of hepatic metastases of NEN and indicate that this marker should be included with CgA and Syn in routine diagnostic panels.

Clinical Features and Long-Term Survival of Metastatic Hepatic Neuroendocrine Neoplasms Secondary to Gastroenteropancreatic Site: An Analysis by Applying the Grading Classification

Method

Data of patients who were surgically treated and clinicopathologically diagnosed as (MH)-NENs secondary to (GEP)-NENs at West China Hospital of Sichuan University from January 2006 to December 2018 were retrospectively collected and analyzed by the grading classification for (GEP)-NENs.

Results

We identified 150 patients with (MH)-NENs secondary to (GEP)-NENs, including 10 patients with G1 NETs, 26 with G2 NETs, 33 with G3 NETs, and 81 with G3 NECs. There were significant differences between patients with G1/G2/G3 NETs and those with G3 NECs, such as age at diagnosis (P=0.041), synchronous liver lesion (P=0.032), incidental diagnosis (P=0.014), tumor largest diameter (P=0.047), vascular invasion (P=0.017), and extrahepatic metastatic disease (P=0.029). The estimated 3-year overall survival for patients with G1 NETs, G2 NETs, G3 NETs, and G3 NECs was 100%, 79.4%, 49.5%, and 20.7%, respectively (P < 0.001). The survival of G1 NETs or G2 NETs was significantly better than that of G3 NETs (P=0.013, P=0.037, respectively) and G3 NECs (P=0.001, P < 0.001; respectively). Patients with G3 NECs present notably worse survival than those with G3 NETs (P=0.012), while survival comparison between G1 NETs and G2 NETs was not statistically different (P=0.131). The grading classification for (GEP)-NENs was an effective independent predictor of survival for (MH)-NENs secondary to (GEP)-NENs (hazard ratio: 4.234; 95% confidence intervals: 1.984–6.763; P=0.003).

Conclusion

Our demonstration revealed that the grading classification for (GEP)-NENs could well stratify (MH)-NENs secondary to (GEP)-NENs into prognostic groups and supported its wide use in clinical practice.

Somatostatin Receptor PET/CT Imaging for the Detection and Staging of Pancreatic NET: A Systematic Review and Meta-Analysis

We investigated the diagnostic performance of Somatostatin Receptor Positron Emission Tomography/Computed Tomography (SSR-PET/CT) for the detection of primary lesion and initial staging of pancreatic neuroendocrine tumors (pNETs). A comprehensive literature search up to January 2020 was performed selecting studies in presence of: sample size ≥10 patients; index test (i.e., 68Ga-DOTATOC or 68Ga-DOTANOC or 68Ga-DOTATATE PET/CT); and outcomes (i.e., detection rate (DR), true positive, true negative, false positive, and false-negative). The methodological quality was evaluated with QUADAS-2. Pooled DR and pooled sensitivity and specificity for the identification of the primary tumor were assessed by a patient-based and a lesion-based analysis. Thirty-eight studies were selected for the qualitative analysis, while 18 papers were included in the meta-analysis. The number of pNET patients ranged from 10 to 142, for a total of 1143 subjects. At patient-based analysis, the pooled sensitivity and specificity for the assessment of primary pNET were 79.6% (95% confidence interval (95%CI): 71–87%) and 95% (95%CI: 75–100%) with a heterogeneity of 59.6% and 51.5%, respectively. Pooled DR for the primary lesion was 81% (95%CI: 65–90%) and 92% (95%CI: 80–97%), respectively, at patient-based and lesion-based analysis. In conclusion, SSR-PET/CT has high DR and diagnostic performances for primary lesion and initial staging of pNETs.

Repeat hepatectomy for liver metastases from bile duct neuroendocrine tumor: a case report

Background

Primary neuroendocrine tumor (NET) originating from the extrahepatic bile duct is rare, although liver metastasis from gastroenteropancreatic NET is frequently observed. We herein report a case who successfully underwent repeat hepatectomy for liver metastases from bile duct NET grade 2 (G2).

Case presentation

A 75-year-old man presented with jaundice and was suspected of perihilar cholangiocarcinoma by computed tomography (CT) and magnetic resonance imaging (MRI). He underwent extended left hepatectomy, extrahepatic bile duct resection, and hepaticojejunostomy. Pathological findings showed a NET G2 of the biliary tract arising from the common bile duct. Two years and 11 months after surgery, a liver metastasis was detected and hepatectomy was performed. During the surgery, another liver metastasis was detected, and limited liver resection for the two lesions was performed. Pathological findings showed four liver metastases of NET G2. Five years and 4 months after the first surgery (2 years and 5 months after the second hepatectomy), four liver metastases were detected. Thereafter, he received somatostatin analogues for 1 year. Although the size of tumors increased slightly, the number did not change. He underwent limited liver resections and was diagnosed with 7 liver metastases of NET G2. Finally, another hepatectomy (fourth hepatectomy) was performed and long-term survival without recurrence was obtained for as long as 8 years after the first surgery.

Conclusions

Repeat hepatectomy is a good option to obtain long-term survival for liver metastases from bile duct NET G2 in select patients.

Morphological imaging and CT histogram analysis to differentiate pancreatic neuroendocrine tumor grade 3 from neuroendocrine carcinoma

PURPOSE

To compare morphological imaging features and CT texture histogram parameters between grade 3 pancreatic neuroendocrine tumors (G3-NET) and neuroendocrine carcinomas (NEC).

MATERIALS AND METHODS

Patients with pathologically proven G3-NET and NEC, according to the 2017 World Health Organization classification who had CT and MRI examinations between 2006-2017 were retrospectively included. CT and MRI examinations were reviewed by two radiologists in consensus and analyzed with respect to tumor size, enhancement patterns, hemorrhagic content, liver metastases and lymphadenopathies. Texture histogram analysis of tumors was performed on arterial and portal phase CT images. images. Morphological imaging features and CT texture histogram parameters of G3-NETs and NECs were compared.

RESULTS

Thirty-seven patients (21 men, 16 women; mean age, 56±13 [SD] years [range: 28-82 years]) with 37 tumors (mean diameter, 60±46 [SD] mm) were included (CT available for all, MRI for 16/37, 43%). Twenty-three patients (23/37; 62%) had NEC and 14 patients (14/37; 38%) had G3-NET. NECs were larger than G3-NETs (mean, 70±51 [SD] mm [range: 18 - 196mm] vs. 42±24 [SD] mm [range: 8 - 94mm], respectively; P=0.039), with more tumor necrosis (75% vs. 33%, respectively; P=0.030) and lower attenuation on precontrast (30±4 [SD] HU [range: 25-39 HU] vs. 37±6 [SD] [range: 25-45 HU], respectively; P=0.002) and on portal venous phase CT images (75±18 [SD] HU [range: 43 - 108 HU] vs. 92±19 [SD] HU [range: 46 - 117 HU], respectively; P=0.014). Hemorrhagic content on MRI was only observed in NEC (P=0.007). The mean ADC value was lower in NEC ([1.1±0.1 (SD)]×10^-3 mm²/s [range: (0.91 - 1.3)×10^-3 mm²/s] vs. [1.4±0.2 (SD)]×10^-3 mm²/s [range: (1.1 - 1.6)×10^-3 mm²/s]; P=0.005). CT histogram analysis showed that NEC were more heterogeneous on portal venous phase images (Entropy-0: 4.7±0.2 [SD] [range: 4.2-5.1] vs. 4.5±0.4 [SD] [range: 3.7-4.9]; P=0.023).

CONCLUSION

Pancreatic NECs are larger, more frequently hypoattenuating and more heterogeneous with hemorrhagic content than G3-NET on CT and MRI.

The Effects of Genetic and Epigenetic Alterations of BARD1 on the Development of Non-Breast and Non-Gynecological Cancers

Breast Cancer 1 (BRCA1) gene is a well-characterized tumor suppressor gene, mutations of which are primarily found in women with breast and ovarian cancers. BRCA1-associated RING domain 1 (BARD1) gene has also been identified as an important tumor suppressor gene in breast, ovarian, and uterine cancers. Underscoring the functional significance of the BRCA1 and BARD1 interactions, prevalent mutations in the BRCA1 gene are found in its RING domain, through which it binds the RING domain of BARD1. BARD1-BRCA1 heterodimer plays a crucial role in a variety of DNA damage response (DDR) pathways, including DNA damage checkpoint and homologous recombination (HR). However, many mutations in both BARD1 and BRCA1 also exist in other domains that significantly affect their biological functions. Intriguingly, recent genome-wide studies have identified various single nucleotide polymorphisms (SNPs), genetic alterations, and epigenetic modifications in or near the BARD1 gene that manifested profound effects on tumorigenesis in a variety of non-breast and non-gynecological cancers. In this review, we will briefly discuss the molecular functions of BARD1, including its BRCA1-dependent as well as BRCA1-independent functions. We will then focus on evaluating the common BARD1 related SNPs as well as genetic and epigenetic changes that occur in the non-BRCA1-dominant cancers, including neuroblastoma, lung, and gastrointestinal cancers. Furthermore, the pro- and anti-tumorigenic functions of different SNPs and BARD1 variants will also be discussed.

Altered miRNAs Expression Correlates With Gastroenteropancreatic Neuroendocrine Tumors Grades

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare and heterogeneous tumors that present a wide spectrum of different clinical and biological characteristics. Currently, tumor grading, determined by Ki-67 staining and mitotic counts, represents the most reliable predictor of prognosis. This time-consuming approach fails to reach high reproducibility standards thus requiring novel approaches to support histological evaluation and prognosis. In this study, starting from a microarray analysis of paraffin-embedded tissue specimens, we defined the miRNAs signature for poorly differentiated NETs (G3) compared to well-differentiated NETs (G1 and G2) consisting of 56 deregulated miRNAs. We identified 8 miRNAs that were expressed in all GEP-NETs grades but at different level. Among these miRNAs, miR-96-5p expression level was progressively higher from grade 1 to grade 3; inversely, its target FoxO1 expression decreased from grade 1 to grade 3. Our results reveal that the miRNAs expression profile of GEP-NET is correlated with the tumor grade, showing a potential advantage of miRNA quantification that could aid clinicians in the classification of common GEP-NETs subtypes. These findings could reliably support the histological evaluation of GEP-NETs paving the way toward personalized treatment approaches.

Clinicopathological features and outcome of esophageal neuroendocrine tumor: A retrospective multicenter survey by the digestive endoscopy society of Taiwan

BACKGROUND & AIMS

Esophageal neuroendocrine tumors (NET) are very rare and mostly carcinomic, carrying poor prognosis. There is still no guideline or consensus on the treatment for esophageal NET.

METHODS

Patients with histologically-proven esophageal neuroendocrine tumor were recruited from 9 hospitals in Taiwan between 2002 and 2017. Clinical, laboratory, radiological, endoscopic, pathological data, treatment strategies, follow-up periods, and survivals were collected retrospectively.

RESULTS

In total, 39 esophageal NET were analyzed and 38 were neuroendocrine carcinoma (NEC). Sixteen (41%) patients had mixed components with either adenocarcinoma (N = 9, 23%) or squamous-cell carcinoma (SCC) (N = 7, 18%). 64.1% of the patients experienced dysphagia and ulcerative mass was the most comment endoscopic finding. There was a higher proportion of drinkers (54.1%), betel chewers (21.6%) and smokers (64.9%) among the patients than in the general population in Taiwan. Five patients (12.8%) had been diagnosed with other cancers. Definite chemoradiotherapy (N = 14, 35.9%) and surgery (N = 7, 17.9%) were the major treatment. Patients with Ki-67% above the median level (50%) in the tumors tended to have worse survival (P = 0.06). However, presence of mixed component was not a significant survival predictor in our study (P = 0.56).

CONCLUSION

Mixed component of an esophageal NET is commonly observed. Staged workup and the principle of treatment can follow that for the common cancer type of esophagus. The risk factors and behaviors of esophageal NEC in Taiwan seem to be similar to that of esophageal SCC.

Genetic and epigenetic alterations in pancreatic neuroendocrine tumors

Neuroendocrine tumors (NETs) are a heterogenous group of tumors that originate from neuroendocrine cells, mainly in the pancreas and the gastrointestinal and bronchopulmonary tracts. There has been considerable progress in our understanding of the genetic and epigenetic changes associated with pancreatic NETs (PNETs). The main genetic alterations that drive PNETs include genetic alterations in MEN1, VHL and genes involved in the mTOR pathway, DAXX and/or ATRX mutations and their association with alternative telomere lengthening, and genes involved in DNA damage repair and chromatin modification. The epigenetic alterations in PNETs are also common based on genome-wide DNA methylation profiling studies, with a high rate of CpG hypermethylation in MEN1-associated PNETs compared to sporadic and VHL-associated PNETs. Moreover, the dysregulated DNA methylation status is associated with distinct gene expression profiles. This article reviews the commonly and recently discovered genetic and epigenetic changes that are associated with PNETs, inherited PNETs, and genotype-phenotype associations, and it discusses their clinical relevance.

Prognostic importance of lymph node yield after curative resection of gastroenteropancreatic neuroendocrine tumours

BACKGROUND

The prognostic significance of lymph nodes (LNs) metastases and the optimum number of LN yield in gastroenteropancreatic neuroendocrine tumours (GEP NETs) undergoing curative resection is still debatable. Many studies have demonstrated that cure rate for patients with GEP NETs can be improved by the resection of the primary tumour and regional lymphadenectomy

AIM

To evaluate the effect of lymph node (LN) status and yield on relapse-free survival (RFS) and overall survival (OS) in patients with resected GEP NETs.

METHODS

Data on patients who underwent curative resection for GEP NETs between January 2002 and March 2017 were analysed retrospectively. Grade 3 tumours (Ki67 > 20%) were excluded. Univariate Cox proportional hazard models were computed for RFS and OS and assessed alongside cut-point analysis to distinguish a suitable binary categorisation of total LNs retrieved associated with RFS.

RESULTS

A total of 217 patients were included in the study. The median age was 59 years (21-97 years) and 51% (n = 111) were male. Primary tumour sites were small bowel (42%), pancreas (25%), appendix (18%), rectum (7%), colon (3%), gastric (2%), others (2%). Median follow up times for all patients were 41 mo (95%CI: 36-51) and 71 mo (95%CI: 63–76) for RFS and OS respectively; 50 relapses and 35 deaths were reported. LNs were retrieved in 151 patients. Eight or more LNs were harvested in 106 patients and LN positivity reported in 114 patients. Three or more positive LNs were detected in 62 cases. The result of univariate analysis suggested perineural invasion (P = 0.0023), LN positivity (P = 0.033), LN retrieval of ≥ 8 (P = 0.047) and localisation (P = 0.0049) have a statistically significant association with shorter RFS, but there was no effect of LN ratio on RFS: P = 0.1 or OS: P = 0.75. Tumour necrosis (P = 0.021) and perineural invasion (P = 0.016) were the only two variables significantly associated with worse OS. In the final multivariable analysis, localisation (pancreas HR = 27.33, P = 0.006, small bowel HR = 32.44, P = 0.005), and retrieval of ≥ 8 LNs (HR = 2.7, P = 0.036) were independent prognostic factors for worse RFS.

CONCLUSION

An outcome-oriented approach to cut-point analysis can suggest a minimum number of adequate LNs to be harvested in patients with GEP NETs undergoing curative surgery. Removal of ≥ 8 LNs is associated with increased risk of relapse, which could be due to high rates of LN positivity at the time of surgery. Given that localisation had a significant association with RFS, a prospective multicentre study is warranted with a clear direction on recommended surgical practice and follow-up guidance for GEP NETs.

Prognostic role of lymphocyte-to-monocyte ratio in pancreatic neuroendocrine neoplasms

OBJECTIVES

Systemic inflammation markers have been demonstrated to be associated with prognosis in various tumors. In this study, we aimed to assess the value of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio (LMR), systemic immune-inflammation index and the counts of lymphocyte, monocyte and neutrophil in predicting prognosis among patients with resected pancreatic neuroendocrine neoplasms (pNENs).

METHODS

A total of 174 patients were included in the study. Univariate and multivariate analyses were performed to evaluate the predictive roles of inflammation markers for relapse-free survival (RFS) and overall survival (OS) in pNEN patients.

RESULTS

The optimal cut-off values of NLR, LMR and lymphocyte count were 1.9, 5.0 and 1.4 × 109/L, respectively, determined by the X-tile software. RFS was found to be significantly longer in patients with NLR ≤1.9 (P = 0.041), LMR >5.0 (P < 0.001) and lymphocyte count >1.4 × 109/L (P = 0.002) in comparison to those with NLR >1.9, LMR ≤5.0 and lymphocyte count ≤1.4 × 109/L, respectively. Multivariate analysis revealed that LMR (hazard ratio 0.30, 95% CI 0.11-0.85, P = 0.023) was an independent predictor for RFS, but not NLR or lymphocyte count. For long-term survival analysis, patients with NLR ≤1.9 (P = 0.016) were found to be associated with favorable OS, but NLR was not an independent factor validated by multivariate analysis.

CONCLUSIONS

Preoperative LMR is an independent systemic inflammation marker to predict relapses in pNEN patients who underwent curative resections, whose clinical value needs to be verified in further large sample-based prospective studies.

Survivals of patients with pancreatic neuroendocrine carcinomas: An in-depth analysis by the American Joint Committee on Cancer 8th tumor-node-metastasis staging manual

Recently, the American Joint Committee on Cancer (AJCC) 8th staging manual stipulated the World Health Organization (WHO) G3 pancreatic neuroendocrine carcinomas (p-NECs) should all be classified by the system for pancreatic exocrine adenocarcinomas, which had ignored the heterogeneity of G3 p-NECs. We focused on demonstrating whether the heterogeneous subgroups of G3 p-NECs would influence the accurate application of AJCC 8th staging systems.G3 p-NECs were divided into well-differentiated and poorly-differentiated subgroups, whose clinical features and overall survival (OS) were compared. Survival analysis by applying 2 new AJCC 8th staging systems to well-differentiated G3 p-NECs were performed to validate whether these subgroup patients should also be staged by the system proposed for all G3 p-NECs.We enrolled 172 patients who were histopathologically diagnosed as G3 p-NECs, including 64 well-differentiated G3 p-NECs and 108 poorly-differentiated ones, whose patient demographics and tumor characteristics present no notably differences (P > .05), except their Ki-67 index and mitotic rate (P = .031, P = .025; respectively). The estimated OS of well-differentiated G3 p-NECs was significantly better than those of poorly-differentiated tumors (P < .001). When applying the new AJCC system for all G3 p-NECs to well-differentiated G3 tumors, 18, 22, 12, and 12 patients were respectively distributed in the new AJCC Stage I, Stage II, Stage III, and Stage IV. Using the AJCC 8th staging system for WHO G1/G2 pancreatic neuroendocrine tumors (p-NETs) to well-differentiated G3 p-NECs, there were 5, 25, 22, and 12 patients classified from the new AJCC Stage I to Stage IV, respectively. The system for G1/G2 p-NETs could significantly differentiate the survival differences between each new stage of well-differentiated G3 p-NECs (P < .05), while comparisons of survivals between Stage II with Stage III or Stage III with Stage IV by the system for G3 p-NECs were not statistically different (P = .334, P = .073; respectively).G3 p-NECs were heterogeneous with well-differentiated and poorly-differentiated subgroups. Both AJCC 8th staging systems proposed for all G3 p-NECs and G1/G2 p-NETs were practical for well-differentiated G3 p-NECs, while the one originally applied to G1/G2 p-NETs appeared to be superior in performance due to its better prognostic stratification and more accurate predicting ability.

Preoperative Prediction of Pancreatic Neuroendocrine Neoplasms Grading Based on Enhanced Computed Tomography Imaging: Validation of Deep Learning with a Convolutional Neural Network

INTRODUCTION

The pathological grading of pancreatic neuroendocrine neoplasms (pNENs) is an independent predictor of survival and indicator for treatment. Deep learning (DL) with a convolutional neural network (CNN) may improve the preoperative prediction of pNEN grading.

METHODS

Ninety-three pNEN patients with preoperative contrast-enhanced computed tomography (CECT) from Hospital I were retrospectively enrolled. A CNN-based DL algorithm was applied to the CECT images to obtain 3 models (arterial, venous, and arterial/venous models), the performances of which were evaluated via an eightfold cross-validation technique. The CECT images of the optimal phase were used for comparing the DL and traditional machine learning (TML) models in predicting the pathological grading of pNENs. The performance of radiologists by using qualitative and quantitative computed tomography findings was also evaluated. The best DL model from the eightfold cross-validation was evaluated on an independent testing set of 19 patients from Hospital II who were scanned on a different scanner. The Kaplan-Meier (KM) analysis was employed for survival analysis.

RESULTS

The area under the curve (AUC; 0.81) of arterial phase in validation set was significantly higher than those of venous (AUC 0.57, p = 0.03) and arterial/venous phase (AUC 0.70, p = 0.03) in predicting the pathological grading of pNENs. Compared with the TML models, the DL model gave a higher (although insignificantly) AUC. The highest OR was achieved for the p ratio <0.9, the AUC and accuracy for diagnosing G3 pNENs were 0.80 and 79.1% respectively. The DL algorithm achieved an AUC of 0.82 and an accuracy of 88.1% for the independent testing set. The KM analysis showed a statistical significant difference between the predicted G1/2 and G3 groups in the progression-free survival (p = 0.001) and overall survival (p < 0.001).

CONCLUSION

The CNN-based DL method showed a relatively robust performance in predicting pathological grading of pNENs from CECT images.

A competing-risks nomogram and recursive partitioning analysis for cause-specific mortality in patients with esophageal neuroendocrine carcinoma

The objective of this study is to estimate the probability of cause-specific mortality using a competing-risks nomogram and recursive partitioning analysis in a large population-based cohort of patients with esophageal neuroendocrine carcinoma. The surveillance, epidemiology and end results database was used to identify 162 patients diagnosed with esophageal neuroendocrine carcinoma from 1998 to 2014. We estimated a cumulative incidence function for cause-specific mortality. A nomogram was constructed by using a proportional subdistribution hazard model, validated using bootstrap cross-validation, and evaluated with a decision curve analysis to assess its clinical utility. Finally, we performed risk stratification using a recursive partitioning analysis to divide patients with esophageal neuroendocrine carcinoma into clinically useful prognostic groups. Tumor location, distant metastasis, surgery, radiotherapy, and chemotherapy were significantly associated with cause-specific mortality. The calibration plots demonstrated good concordance between the predicted and actual outcomes. The discrimination performance of a Fine-Gray model was evaluated by using the c-index, which was 0.723 for cause-specific mortality. The decision curve analysis ranged from 0.268 to 0.968 for the threshold probability at which the risk model provided net clinical benefits relative to hypothetical all-screening and no-screening scenarios. The risk groups stratified by a recursive partitioning analysis allowed significant distinction between cumulative incidence curves. We determined the probability of cause-specific mortality in patients with esophageal neuroendocrine carcinoma and developed a nomogram and recursive partitioning analysis stratification system based on a competing-risks model. The nomogram and recursive partitioning analysis appear to be suitable for risk stratification of cause-specific mortality in patients with esophageal neuroendocrine carcinoma and will help clinicians to identify patients at increased risk of cause-specific mortality to guide treatment and surveillance decisions.