Competitive Testing of the WHO 2010 versus the WHO 2017 Grading of Pancreatic Neuroendocrine Neoplasms: Data from a Large International Cohort Study

Approach to the Patient: Insulinoma

Insulinomas are hormone-producing pancreatic neuroendocrine neoplasms with an estimated incidence of 1 to 4 cases per million per year. Extrapancreatic insulinomas are extremely rare. Most insulinomas present with the Whipple triad: (1) symptoms, signs, or both consistent with hypoglycemia; (2) a low plasma glucose measured at the time of the symptoms and signs; and (3) relief of symptoms and signs when the glucose is raised to normal. Nonmetastatic insulinomas are nowadays referred to as "indolent" and metastatic insulinomas as "aggressive." The 5-year survival of patients with an indolent insulinoma has been reported to be 94% to 100%; for patients with an aggressive insulinoma, this amounts to 24% to 67%. Five percent to 10% of insulinomas are associated with the multiple endocrine neoplasia type 1 syndrome. Localization of the insulinoma and exclusion or confirmation of metastatic disease by computed tomography is followed by endoscopic ultrasound or magnetic resonance imaging for indolent, localized insulinomas. Glucagon-like peptide 1 receptor positron emission tomography/computed tomography or positron emission tomography/magnetic resonance imaging is a highly sensitive localization technique for seemingly occult, indolent, localized insulinomas. Supportive measures and somatostatin receptor ligands can be used for to control hypoglycemia. For single solitary insulinomas, curative surgical excision remains the treatment of choice. In aggressive malignant cases, debulking procedures, somatostatin receptor ligands, peptide receptor radionuclide therapy, everolimus, sunitinib, and cytotoxic chemotherapy can be valuable options.

A relook at gastroenteropancreatic neuroendocrine tumours as per 2019 WHO classification-A tertiary centre experience

INTRODUCTION

Neuroendocrine neoplasm of GIT (gastrointestinal tract) and pancreas is heterogenous with variable clinical features and disease outcomes. Despite multiple attempts of risk stratification by grading and staging, some have unpredictable clinical courses. Well-differentiated grade 3 neuroendocrine tumour (G3NET) is a recent subcategory introduced in the 2019 WHO classification based on morphology, molecular profile and prognosis distinguishing it from neuroendocrine carcinoma(NEC). This study aimed at describing the spectrum of NENs encountered in a tertiary centre with focus on reclassifying previously reported G3 tumours into G3 NET and NEC and comparing the survival between them.

METHODOLOGY

This is an 8-year retrospective study of all gastro-entero-pancreatic neuroendocrine neoplasms reclassified according to the 2019 WHO classification based on morphology and Ki-67 index with analysis of the survival rates between the categories. Minimum follow-up period was 20 months.

RESULTS

Eighty-six patients with NENs of gastro-entero-pancreas were included, with median age group of 40-60 years (age range 9 to 79 years) and male:female ratio of 1.7:1. The tumour grade correlated with the TNM staging and most of the syndromic NETs were low grade. Eleven percent of the tumours were reclassified as well-differentiated G3NETs. The survival of G3 NETs was higher than NEC.

CONCLUSION

Grading of NEN is vital for therapeutic decisions and for prognostication. Currently, morphology is the key to recognise the well-differentiated G3 NETs, but can be subject to interobserver variability. Molecular surrogates may play a role in accurately identifying these entities, the validity of which is warranted.

Site-specific trends in gastroenteropancreatic neuroendocrine neoplasms in Bavaria, Germany

INTRODUCTION

Neuroendocrine neoplasms (NEN) are rare and heterogeneous epithelial tumors, occurring throughout the body. For gastroenteropancreatic (GEP)-NEN, rising incidence rates were reported for the last decades, with underlying causes remaining largely unexplained. We evaluated NEN trends stratifying by their histologic subtypes.

METHODS

Incident cases of GEP-NEN diagnosed between 2005 and 2019 were retrieved from the prospective, population-based Bavarian Cancer Registry. GEP-NEN were divided in their histologic subtypes, that is, neuroendocrine tumors (NET) G1, NET G2/G3, other NET versus small-cell neuroendocrine carcinoma (NEC), large-cell NEC, and other NEC. We calculated annual age-standardized incidence rates (ASIRs) per 100,000 persons for the total of GEP-NEN, NEN histologic subtypes, and tumor sites. We used an annual percentage change (APC) approach including a joinpoint analysis to investigate NEN incidence trends.

RESULTS

ASIR of GEP-NEN rose from 2.2 in 2005 to 4.8 in 2019, characterized by a significant increase until 2012 (APC 2005-2012: 10.1%), followed by modest rise (APC 2012-2019: 1.5%). In the last decade, this increase was mainly driven by the rise of NET G1 and G2/G3, while incidence for NEC declined. Over the study period, ASIR increased significantly for all GEP-sites except the colon. APCs were largest for the stomach, the appendix, the pancreas, and the rectum.

CONCLUSIONS

This study found a significant increase in the incidence of GEP-NET. Though this development may partially be attributable to the increased use of advanced detection techniques and changes in NEN classification, further research should also focus on the identification of NEN risk factors.

Renal neuroendocrine tumors: clinical and molecular pathology with an emphasis on frequent association with ectopic Cushing syndrome

Renal neuroendocrine tumors (RenNETs) are rare malignancies with largely unknown biology, hormone expression, and genetic abnormalities. This study aims to improve our understanding of the RenNETs with emphasis of functional, hormonal, and genetic features. Surgically resected RenNETs (N = 13) were retrieved, and immunohistochemistry and next-generation sequencing (NGS) were performed in all cases. In addition, all published RenNETs were systematically reviewed. Our cohort (4 men and 9 women, mean age 42, mean tumor size 7.6 cm) included 2 patients with Cushing syndrome (CS). WHO grade (23% G1, 54% G2, and 23% G3) and tumor progression did not correlate. CS-associated RenNETs (CS-RenNETs) showed a solid and eosinophilic histology and stained for ACTH, while the remaining non-functioning tumors had a trabecular pattern and expressed variably hormones somatostatin (91%), pancreatic polypeptide (63%), glucagon (54%), and serotonin (18%). The transcription factors ISL1 and SATB2 were expressed in all non-functioning, but not in CS-RenNETs. NGS revealed no pathogenic alterations or gene fusions. In the literature review (N = 194), 15 (8%) of the patients had hormonal syndromes, in which CS being the most frequent (7/15). Large tumor size and presence of metastasis were associated with shorter patients' survival (p < 0.01). RenNETs present as large tumors with metastases. CS-RenNETs differ through ACTH production and solid-eosinophilic histology from the non-functioning trabecular RenNETs that produce pancreas-related hormones and express ISL1 and SATB2. MEN1 or DAXX/ARTX abnormalities and fusion genes are not detected in RenNETs, indicating a distinct yet unknown molecular pathogenesis.

Promising targetable biomarkers in pancreatic neuroendocrine tumours

INTRODUCTION

In the treatment scenario of PanNETs-targeted therapies are desired but limited, as rarity and heterogeneity on PanNETs pose limitations to their development.

AREAS COVERED

We performed a literature review searching for promising druggable biomarkers and potential treatments to be implemented in the next future. We focused on treatments which have already reached clinical experimentation, although in early phases. Six targets were identified, namely Hsp90, HIFa, HDACs, CDKs, uPAR, and DDR. Even though biological rational is strong, so far reported efficacy outcomes are quite disappointing. The reason of that should be searched in the patients' heterogeneity, lack of biomarker selection, poor knowledge of interfering mechanisms as well as difficulties in patients accrual. Moreover, different ways to assess treatment efficacy should be considered, other than response rate, in light of the more indolent nature of NETs.

EXPERT OPINION

Development of targeted treatments in PanNETs is still an uncovered area, far behind other more frequent cancers. Rarity of NETs led to accrual of unselected populations, possibly jeopardizing the drug efficacy. Better patients' selection, both in terms of topography, grading and biomarkers is crucial and will help understanding which role targeted therapies can really play in these tumors.

Controversy Over Liver Transplantation or Resection for Neuroendocrine Liver Metastasis: Tumor Biology Cuts the Deal

BACKGROUND

In patients with neuroendocrine liver metastasis (NELM), liver transplantation (LT) is an alternative to liver resection (LR), although the choice of therapy remains controversial. In this multicenter study, we aim to provide novel insight in this dispute.

METHODS

Following a systematic literature search, 15 large international centers were contacted to provide comprehensive data on their patients after LR or LT for NELM. Survival analyses were performed with the Kaplan-Meier method, while multivariable Cox regression served to identify factors influencing survival after either transplantation or resection. Inverse probability weighting and propensity score matching was used for analyses with balanced and equalized baseline characteristics.

RESULTS

Overall, 455 patients were analyzed, including 230 after LR and 225 after LT, with a median follow-up of 97 months [95% confidence interval (CI): 85-110 months]. Multivariable analysis revealed G3 grading as a negative prognostic factor for LR [hazard ratio (HR)=2.22, 95% CI: 1.04-4.77, P =0.040], while G2 grading (HR=2.52, 95% CI: 1.15-5.52, P =0.021) and LT outside Milan criteria (HR=2.40, 95% CI: 1.16-4.92, P =0.018) were negative prognostic factors in transplanted patients. Inverse probability-weighted multivariate analyses revealed a distinct survival benefit after LT. Matched patients presented a median overall survival (OS) of 197 months (95% CI: 143-not reached) and a 73% 5-year OS after LT, and 119 months (95% CI: 74-133 months) and a 52.8% 5-year OS after LR (HR=0.59, 95% CI: 0.3-0.9, P =0.022). However, the survival benefit after LT was lost if patients were transplanted outside Milan criteria.

CONCLUSIONS

This multicentric study in patients with NELM demonstrates a survival benefit of LT over LR. This benefit depends on adherence to selection criteria, in particular low-grade tumor biology and Milan criteria, and must be balanced against potential risks of LT.

Status of Surveillance and Nonsurgical Therapy for Small Nonfunctioning Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) occur in < 1/100,000 patients and most are nonfunctioning (NF). Approximately 5% occur as part of multiple endocrine neoplasia type 1. Anatomic and molecular imaging have a pivotal role in the diagnosis, staging and active surveillance. Surgery is generally recommended for nonfunctional pancreatic neuroendocrine tumors (NF-PNETs) >2 cm to prevent metastases. For tumors ≤2 cm, active surveillance is a viable alternative. Tumor size and grade are important factors to guide management. Assessment of death domain-associated protein 6/alpha-thalassemia/mental retardation X-linked and alternative lengthening of telomeres are promising novel prognostic markers. This review summarizes the status of surveillance and nonsurgical management for small NF-PNETs, including factors that can guide management.

Diagnostic, Prognostic, and Predictive Role of Ki67 Proliferative Index in Neuroendocrine and Endocrine Neoplasms: Past, Present, and Future

The introduction of Ki67 immunohistochemistry in the work-up of neuroendocrine neoplasms (NENs) has opened a new approach for their diagnosis and prognostic evaluation. Since the first demonstration of the prognostic role of Ki67 proliferative index in pancreatic NENs in 1996, several studies have been performed to explore its prognostic, diagnostic, and predictive role in other neuroendocrine and endocrine neoplasms. A large amount of information is now available and published results globally indicate that Ki67 proliferative index is useful to this scope, although some differences exist in relation to tumor site and type. In gut and pancreatic NENs, the Ki67 proliferative index has a well-documented and accepted diagnostic and prognostic role and its evaluation is mandatory in their diagnostic work-up. In the lung, the Ki67 index is recommended for the diagnosis of NENs on biopsy specimens, but its diagnostic role in surgical specimens still remains to be officially accepted, although its prognostic role is now well documented. In other organs, such as the pituitary, parathyroid, thyroid (follicular cell-derived neoplasms), and adrenal medulla, the Ki67 index does not play a diagnostic role and its prognostic value still remains a controversial issue. In medullary thyroid carcinoma, the Ki67 labelling index is used to define the tumor grade together with other morphological parameters, while in the adrenal cortical carcinoma, it is useful to select patients to treated with mitotane therapy. In the present review, the most important information on the diagnostic, prognostic, and predictive role of Ki67 proliferative index is presented discussing the current knowledge. In addition, technical issues related to the evaluation of Ki67 proliferative index and the future perspectives of the application of Ki67 immunostaining in endocrine and neuroendocrine neoplasms is discussed.

All Together Now: Standardization of Nomenclature for Neuroendocrine Neoplasms across Multiple Organs

Neuroendocrine neoplasms (NENs) span virtually all organ systems and exhibit a broad spectrum of behavior, from indolent to highly aggressive. Historically, nomenclature and grading practices have varied widely across, and even within, organ systems. However, certain core features are recapitulated across anatomic sites, including characteristic morphology and the crucial role of proliferative activity in prognostication. A recent emphasis on unifying themes has driven an increasingly standardized approach to NEN classification, as delineated in the World Health Organization's Classification of Tumours series. Here, we review recent developments in NEN classification, with a focus on NENs of the pancreas and lungs.

Venous invasion and lymphatic invasion are correlated with the postoperative prognosis of pancreatic neuroendocrine neoplasm

BACKGROUND

To determine treatment strategies corresponding to a wide range of pancreatic neuroendocrine neoplasms staging, easier-to-use and detailed prognostic classification is required.

METHODS

Patients with pancreatic neuroendocrine neoplasms who underwent curative-intent surgery at the University of Tokyo Hospital between 2000 and 2018 were retrospectively reviewed. The presence or absence of venous and lymphatic invasion was assessed. Multivariable analysis was performed to identify the risk factors of shorter overall survival and recurrence-free survival. Patients were classified into the following 3 groups: a lymphovascular invasion 0 group, whereby both venous and lymphatic invasion were negative; an lymphovascular invasion 1 group, where either of the 2 was positive; and an lymphovascular invasion 2 group, where both were positive. The survival curves and recurrence patterns of the 3 groups were compared.

RESULTS

Eighty-nine patients were analyzed. Multivariable analysis revealed that lymphatic invasion and Ki-67 index (≥ 3.0%) were independent prognostic factors of recurrence-free survival (hazard ratio: 5.2 and 3.6). Fifty-three patients were classified as lymphovascular invasion 0, 26 as lymphovascular invasion 1, and 10 as lymphovascular invasion 2. The recurrence-free survival curves of the 3 groups were significantly stratified (10-year recurrence-free survival: 89.1% in lymphovascular invasion 0, 57.1% in lymphovascular invasion 1, and 18.3% in lymphovascular invasion 2). Five-year cumulative liver and lymph node metastasis of lymphovascular invasion 0, lymphovascular invasion 1, and lymphovascular invasion 2 were well stratified at 0% and 3.8%, 15.8% and 23.1%, and 33.3% and 70.0%, respectively.

CONCLUSION

Postoperative prognosis of resected pancreatic neuroendocrine neoplasms could be finely classified by venous invasion and lymphatic invasion. Management after curative-intent surgery for pancreatic neuroendocrine neoplasms may be changed by this new classification.

An Insight on Functioning Pancreatic Neuroendocrine Neoplasms

Pancreatic neuroendocrine neoplasms (PanNENs) are rare neoplasms arising from islets of the Langerhans in the pancreas. They can be divided into two groups, based on peptide hormone secretion, functioning and nonfunctioning PanNENs. The first group is characterized by different secreted peptides causing specific syndromes and is further classified into subgroups: insulinoma, gastrinoma, glucagonoma, somatostatinoma, VIPoma and tumors producing serotonin and adrenocorticotrophic hormone. Conversely, the second group does not release peptides and is usually associated with a worse prognosis. Today, although the efforts to improve the therapeutic approaches, surgery remains the only curative treatment for patients with PanNENs. The development of high-throughput techniques has increased the molecular knowledge of PanNENs, thereby allowing us to understand better the molecular biology and potential therapeutic vulnerabilities of PanNENs. Although enormous advancements in therapeutic and molecular aspects of PanNENs have been achieved, there is poor knowledge about each subgroup of functioning PanNENs.Therefore, we believe that combining high-throughput platforms with new diagnostic tools will allow for the efficient characterization of the main differences among the subgroups of functioning PanNENs. In this narrative review, we summarize the current landscape regarding diagnosis, molecular profiling and treatment, and we discuss the future perspectives of functioning PanNENs.

Neuroendocrine Neoplasms of the Pancreas: Diagnostic Challenges and Practical Approach

Most pancreatic neuroendocrine neoplasms are slow-growing, and the patients may survive for many years, even after distant metastasis. The tumors usually display characteristic organoid growth patterns with typical neuroendocrine morphology. A smaller portion of the tumors follows a more precipitous clinical course. The classification has evolved from morphologic patterns to the current World Health Organization classification, with better-defined grading and prognostic criteria. Recent advances in molecular pathology have further improved our understanding of the pathogenesis of these tumors. Various issues and challenges remain, including the correct recognition of a neuroendocrine neoplasm, accurate classification and grading of the tumor, and differentiation from mimickers. This review focuses on the practical aspects during the workup of pancreatic neuroendocrine neoplasms and attempts to provide a general framework to help achieve an accurate diagnosis, classification, and grading.

The NET G3 enigma: dealing with a “new” entity

Neuroendocrine neoplasms of the gastroenteropancreatic system (GEP-NENs) have historically been graded into well-differentiated neuroendocrine tumors (NETs) G 1 and 2 and undifferentiated neuroendocrine carcinomas (NEC) G3 according to the proliferative index Ki-67, with the latter being larger than 20% for G3 NENs. However, clinical and pathological findings have suggested G3 NENs to be heterogeneous, and the most recent World Health Organization (WHO) classification has further subdivided G3 NENs into NET G3 with differentiated features and a usually lower Ki-67 (20–55%) as opposed to undifferentiated NECs. Currently, however, no standard approach to patients with NET G3 has been defined. As opposed to NET G1/G2, application of somatostatin analogues is not recommended, and the response to platinum-based chemotherapy is inferior when compared to NEC. The objective of this short review is to summarize pathological characteristics as well as therapeutic data obtained in patients with NET G3.

Neuroendocrine tumor G3 of bronchopulmonary origin and its classification

Neuroendocrine tumors (NET) with high proliferative activity (Ki-67 index >20% and/or mitotic counts >2 mm² ) are defined as NET G3 in the 2019 World Health Organization (WHO) classification of digestive system neuroendocrine neoplasms (NENs). NETs G3 occur mostly in the pancreas, colon, rectum, and stomach and only rarely in the small intestine and the appendix. In the bronchopulmonary system, similar tumors have also been recognized and were mostly classified as atypical carcinoid (AC) or large cell neuroendocrine carcinoma. Bronchopulmonary NENs that were classified as NETs G3 are characterized by histological and immunohistochemical similarities with carcinoids/NETs, and a clinical course that is more aggressive than with ACs and similar to that of neuroendocrine carcinomas. The morphomolecular and clinical features of bronchopulmonary neoplasms with a high proliferative activity were reviewed and a future classification system that is applicable for both digestive and bronchopulmonary NETs is proposed.

Ampullary Neuroendocrine Neoplasms: Identification of Prognostic Factors in a Multicentric Series of 119 Cases

Neuroendocrine neoplasms (NENs) of the major and minor ampulla are rare diseases with clinico-pathologic features distinct from non-ampullary-duodenal NENs. However, they have been often combined and the knowledge on prognostic factors specific to ampullary NENs (Amp-NENs) is limited. The aim of this study was to identify factors associated with metastatic potential and patient prognosis in Amp-NENs. We clinically and histologically investigated an international series of 119 Amp-NENs, comprising 93 ampullary neuroendocrine tumors (Amp-NETs) and 26 neuroendocrine carcinomas (Amp-NECs). Somatostatin-producing tubulo-acinar NET represented the predominant Amp-NET histologic subtype (58 cases, 62%, 12 associated with type 1 neurofibromatosis). Compared to Amp-NETs, Amp-NECs arose in significantly older patients and showed a larger tumor size, a more frequent small vessel invasion, a deeper level of invasion and a higher rate of distant metastasis, and, importantly, a tremendously worse disease-specific patient survival. In Amp-NETs, the WHO grade proved to be a strong predictor of disease-specific survival (hazard ratio: 12.61, p < 0.001 for G2 vs G1), as well as patient age at diagnosis > 60 years, small vessel invasion, pancreatic invasion, and distant metastasis at diagnosis. Although nodal metastatic disease was not associated with survival by itself, patients with > 3 metastatic lymph nodes showed a worse outcome in comparison with the remaining Amp-NET cases with lymphadenectomy. Tumor epicenter in the major ampulla, small vessel invasion, and tumor size > 16 mm were independent predictors of nodal metastases in Amp-NETs. In conclusion, we identified prognostic factors, which may eventually help guide treatment decisions in Amp-NENs.

Role of [18F]FDG PET/CT in the management of G1 gastro-entero-pancreatic neuroendocrine tumors

PURPOSE

Since the role of [¹⁸F]FDG PET/CT in low-grade gastroenteropancreatic (GEP) neuroendocrine neoplasia (NET) is not well established, this study was aimed to evaluate the role of [¹⁸F]FDG PET/CT in grade 1 (G1) GEP-NETs.

METHODS

This is a retrospective study including patients with G1 GEP-NETs who underwent [¹⁸F]FDG PET/CT.

RESULTS

55 patients were evaluated, including 24 (43.6%) with pancreatic NETs and 31 (56.4%) with gastrointestinal NETs. At the time of diagnosis, 28 (51%) patients had metastatic disease, and 50 (91%) patients were positive by 68-Ga sstr PET/CT. Overall, 27 patients (49%) had positive findings on [¹⁸F]FDG PET/CT. Following [¹⁸F]FDG PET/CT, therapeutic management was modified in 29 (52.7%) patients. Progression-free survival was longer in patients with negative [¹⁸F]FDG PET/CT compared with positive [¹⁸F]FDG PET/CT (median PFS was not reached and 24 months, respectively, p = 0.04). This significance was particularly evident in the pancreatic group (p = 0.008).

CONCLUSIONS

Despite having low proliferative activity, approximately half of GEP-NETs G1 showed positive [¹⁸F]FDG PET/CT, with a corresponding negative impact on patients' clinical outcomes. These data are in favor of a more "open" attitude toward the potential use of [¹⁸F]FDG PET/CT in the diagnostic work-up of G1 GEP-NETs, which may be used in selected cases to detect those at higher risk for an unfavorable disease course.

Survival According to Therapy Regimen for Small Intestinal Neuroendocrine Tumors

Introduction: Scarce data exist for therapy regimens other than somatostatin analogues (SSA) and peptide receptor radiotherapy (PRRT) for siNET. We analyzed real world data for differences in survival according to therapy. Patients and methods: Analysis of 145 patients, diagnosed between 1993 and 2018 at a single institution, divided in treatment groups. Group (gr.) 0: no treatment (n = 10), gr 1: TACE and/or PRRT (n = 26), gr. 2: SSA (n = 32), gr. 3: SSA/PRRT (n = 8), gr. 4: chemotherapy (n = 8), gr. 5: not metastasized (at diagnosis), surgery only (n = 53), gr. 6 = metastasized (at diagnosis), surgery only (n = 10). Results: 45.5% female, median age 60 years (range, 27–84). A total of 125/145 patients with a resection of the primary tumor. For all patients, 1-year OS (%) was 93.8 (95%-CI: 90–98), 3-year OS = 84.3 (CI: 78–90) and 5-year OS = 77.5 (CI: 70–85). For analysis of survival according to therapy, only stage IV patients (baseline) that received treatment were included. Compared with reference gr. 2 (SSA only), HR for OS was 1.49 (p = 0.47) for gr. 1, 0.72 (p = 0.69) for gr. 3, 2.34 (p = 0.19) for gr. 4. The 5 y OS rate of patients whose primary tumor was resected (n = 125) was 73.1%, and without PTR was 33.3% (HR: 4.31; p = 0.003). Individual patients are represented in swimmer plots. Conclusions: For stage IV patients in this analysis (limited by low patient numbers in co. 3/4), multimodal treatment did not significantly improve survival over SSA treatment alone. A resection of primary tumor significantly improves survival.

Orchestrating Treatment Modalities in Metastatic Pancreatic Neuroendocrine Tumors-Need for a Conductor

Simple Summary

Pancreatic neuroendocrine tumors (pNET) are a heterogeneous and challenging entity, and today’s guidelines offer a variety of treatment modalities, while surgery has a clear role for patients with resectable tumors and early stages, advanced, or metastatic pNET may benefit from treatments that were evaluated in randomized controlled studies during the last year. With this review, we aim to provide an updated view on treatment options for metastatic pNET.

Abstract

Pancreatic neuroendocrine tumors (pNETs) are a vast growing disease. Over 50% of these tumors are recognized at advanced stages with lymph node, liver, or distant metastasis. An ongoing controversy is the role of surgery in the metastatic setting as dedicated systemic treatments have emerged recently and shown benefits in randomized trials. Today, liver surgery is an option for advanced pNETs if the tumor has a favorable prognosis, reflected by a low to moderate proliferation index (G1 and G2). Surgery in this well-selected population may prolong progression-free and overall survival. Optimal selection of a treatment plan for an individual patient should be considered in a multidisciplinary tumor board. However, while current guidelines offer a variety of modalities, there is so far only a limited focus on the right timing. Available data is based on small case series or retrospective analyses. The focus of this review is to highlight the right time-point for surgery in the setting of the multimodal treatment of an advanced pancreatic neuroendocrine tumor.

Predictive Factors for Resistant Disease with Medical/Radiologic/Liver-Directed Anti-Tumor Treatments in Patients with Advanced Pancreatic Neuroendocrine Neoplasms: Recent Advances and Controversies

Simple Summary

Tumor resistance, both primary and acquired, is leading to increased complexity in the nonsurgical treatment of patients with advanced panNENs, which would be greatly helped by reliable prognostic/predictive factors. The importance in identifying resistance is being contributed to by the increased array of possible treatments available for treating resistant advanced disease; the variable clinical course as well as response to any given treatment approach of patients within one staging or grading system, the advances in imaging which are providing increasing promising results/parameters that correlate with grading/outcome/resistance, the increased understanding of the molecular pathogenesis providing promising prognostic markers, all of which can contribute to selecting the best treatment to overcome resistance disease. Several factors have been identified that have prognostic/predictive value for identifying development resistant disease and affecting overall survival (OS)/PFS with various nonsurgical treatments of patients with advanced panNENs. Prognostic factors identified for patients with advanced panNENs for both OS/PFSs include various clinically-related factors (clinical, laboratory/biological markers, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors. Particularly important prognostic factors for the different treatment modalities studies are the recent grading systems. Most prognostic factors for each treatment modality for OS/PFS are not specific for a given treatment option. These advances have generated several controversies and new unanswered questions, particularly those related to their possible role in predicting the possible sequence of different anti-tumor treatments in patients with different presentations. Each of these areas is reviewed in this paper.

Abstract

Purpose: Recent advances in the diagnosis, management and nonsurgical treatment of patients with advanced pancreatic neuroendocrine neoplasms (panNENs) have led to an emerging need for sensitive and useful prognostic factors for predicting responses/survival. Areas covered: The predictive value of a number of reported prognostic factors including clinically-related factors (clinical/laboratory/imaging/treatment-related factors), pathological factors (histological/classification/grading), and molecular factors, on therapeutic outcomes of anti-tumor medical therapies with molecular targeting agents (everolimus/sunitinib/somatostatin analogues), chemotherapy, radiological therapy with peptide receptor radionuclide therapy, or liver-directed therapies (embolization/chemoembolization/radio-embolization (SIRTs)) are reviewed. Recent findings in each of these areas, as well as remaining controversies and uncertainties, are discussed in detail, particularly from the viewpoint of treatment sequencing. Conclusions: The recent increase in the number of available therapeutic agents for the nonsurgical treatment of patients with advanced panNENs have raised the importance of prognostic factors predictive for therapeutic outcomes of each treatment option. The establishment of sensitive and useful prognostic markers will have a significant impact on optimal treatment selection, as well as in tailoring the therapeutic sequence, and for maximizing the survival benefit of each individual patient. In the paper, the progress in this area, as well as the controversies/uncertainties, are reviewed.

The classification of neuroendocrine neoplasms of the lung and digestive system according to WHO, 5th Edition: similarities, differences, challenges & unmet needs

Neuroendocrine neoplasms (NENs) are a group of disease entities sharing common morphological, ultrastructural and immunophenotypical features, yet with distinct biological behavior and clinical outcome, ranging from benign to frankly malignant. Accordingly, a spectrum of therapeutic options for each single entity is available, including somatostatin analogues (SSA), mTOR-inhibitors, peptide receptor radionuclide therapy (PRRT), non-platinum and platinum chemotherapy. In the last few decades, several attempts have been made in order to (1) better stratify these lesions refining the pathological classifications, so as to obtain an optimal correspondence between the scientific terminology and, the predictive and prognostic features of each disease subtype, and (2) achieve a global Classification encompassing NENs arising at different anatomical sites. Aim of this review is to analyze, compare and discuss the main features and issues of the latest WHO Classifications of NENs of the lung and the digestive system, in order to point out the strengths and limitations of our current understanding of these complex diseases.

A Case of Pancreatic Neuroendocrine Tumor G3 Which Responded Remarkably to Chemotherapy

Pancreatic neuroendocrine carcinoma (NEC) as classified in the World Health Organization (WHO) 2010 was reclassified in the WHO 2017 as either neuroendocrine tumor (NET) G3 or NEC. An accurate diagnosis based on the WHO 2017 classification is important in order treating this disease appropriately. We report a case diagnosed as NET G3 that responded remarkably well to treatment with streptozocin. The patient would likely not have received the streptozocin treatment if she had been diagnosed with NEC. The WHO 2017 classification is reasonable for the treatment of advanced pancreatic neuroendocrine neoplasms.

Time from first tumor manifestation to diagnosis in patients with GEP-NET: Results from a large German tertiary referral center

Patients with neuroendocrine tumors (NET) often go through a long phase between onset of symptoms and initial diagnosis.Assessment of time to diagnosis and pre-clinical pathway in patients with gastroenteropancreatic NET (GEP-NET) with regard to metastases and symptoms.Retrospective analysis of patients with GEP-NET at a tertiary referral center from 1984 to 2019; inclusion criteria: Patients ≥18 years, diagnosis of GEP-NET; statistical analysis using non-parametrical methods.Four hundred eighty-six patients with 488 tumors were identified; median age at first diagnosis (478/486, 8 unknown) was 59 years; 52.9% male patients. Pancreatic NET: 143/488 tumors; 29.3%; small intestinal NET: 145/488 tumors, 29.7%. 128/303 patients (42.2%) showed NET specific and 122/486 (25%) patients other tumor-specific symptoms. 222/279 patients had distant metastases at initial diagnosis (187/222 liver metastases). 154/488 (31.6%) of GEP-NET were incidental findings. Median time from tumor manifestation (e.g., symptoms related to NET) to initial diagnosis across all entities was 19.5 (95% CI: 12-28) days. No significant difference in patients with or without distant metastases (median 73 vs 105 days, P = .42).A large proportion of GEP-NET are incidental findings and only about half of all patients are symptomatic at the time of diagnosis. We did not find a significant influence of the presence of metastases on time to diagnosis, which shows a large variability with a median of <30 days.

Occupational injuries and psychological support in Chinese nurses: a cross-sectional study

OBJECTIVE

To assess the occupational injuries and psychological support received by nurses and to investigate the relationship between the two.

METHOD

This was a nation-wide cross-sectional study of nurses working across 1858 hospitals in China. Data were collected using an online structured, self-administered questionnaire between 2016 and 2017.

RESULTS

Nearly half of respondents had experienced aggressive behavior from patients or their attendants; 13.4% respondents had experienced aggressive behavior on more than three occasions. 78.96% respondents had experienced needle-stick injuries and 51.22% had experienced psychological trauma. 20.5% respondents believed that hospitals do not pay any attention to occupational safety. 86.1% respondents expressed the need for little or moderate psychological support. Nurses who had experienced aggressive behavior expressed a greater need for psychological support. Nurses working at hospitals that adequately addressed the occupational safety issues expressed the lowest need for psychological support.

CONCLUSION

We found a high prevalence of psychological stress and occupational injuries among nurses. Nursing managers need to address this issue and implement interventions to prevent and reduce injuries.

An analysis of 130 neuroendocrine tumors G3 regarding prevalence, origin, metastasis, and diagnostic features

Limited data exist on high-grade neuroendocrine tumors (NETs G3) which represent a new category among neuroendocrine neoplasms (NEN). We analyzed NETs G3 in a consultation series regarding prevalence, origin, metastasis, and diagnostic problems. Based on the WHO classification of digestive system tumors, 130 NETs G3 (9%) were identified in 1513 NENs. NET G3 samples were more often obtained from metastatic sites (69%) than NET G1/G2 samples (24%). NET G3 metastases presented most frequently in the liver (74%) and originated from the pancreas (38/90, 42%), followed by the lung (9%), ileum (7%), stomach (3%), rectum (1%), and rare sites (2%) such as the prostate and breast. The primaries remained unknown in 15%. NETs G3 had a median Ki67 of 30% that distinguished them from NECs (60%), though with great overlap. The expression of site-specific markers, p53, Rb1, and SST2 was similar in NETs G3 and NETs G1/G2, except for p53 and Rb1 which were abnormally expressed in 8% and 7% of liver metastases from NET G3 but not from NET G1/G2. NETs G3 were frequently referred as NECs (39%) but could be well distinguished from NECs by normal p53 (92% versus 21%) and Rb1 expression (93% versus 41%) expression. In conclusion, NETs G3 are frequently discovered as liver metastases from pancreatic or pulmonary primaries and are often misinterpreted as NEC. p53 and Rb1 are powerful markers in the distinction of NET G3 from NEC. Rarely, carcinomas from non-digestive, non-pulmonary organs with neuroendocrine features may present as NET G3.

A Subset of Large Cell Neuroendocrine Carcinomas in the Gastroenteropancreatic Tract May Evolve from Pre-existing Well-Differentiated Neuroendocrine Tumors

In the gastro-entero-pancreatic (GEP) tract, neuroendocrine neoplasms (NENs) include well differentiated neuroendocrine tumors (NETs) and high-grade NE carcinomas (NECs), which are thought to make up separate and mutually exclusive tumor entities. Little is known, however, as to whether there may be any pathogenetic link between them. Clustering analysis of a 10-gene panel generated from a previously reported next-generation sequencing analysis on 48 GEP-NENs with clinical annotations was used in the study. Unsupervised cluster analysis showed three histology-independent clusters, namely, C1, C2, and C3, which accounted for 44% of patients but the entire array of mutations. All but two NECs fell into the clusters, yet with different prevalence rates (p < 0.0001). A model was devised according to which NETs were likely to evolve into NECs upon progression of C3 into C1 and C2, despite different morphology. The median Ki-67 labeling index was 5% in C3 showing better prognosis and 50% in C1 and C2 experiencing worse prognosis, with an impressive intra-tumor heterogeneity of diversely proliferating tumor areas. This study suggests that a subset of large cell NECs in the gastroenteropancreatic tract may evolve from pre-existing well-differentiated NETs.

Classification of neuroendocrine neoplasms: lights and shadows

Neuroendocrine neoplasms (NENs) are a heterogeneous group of neoplastic proliferations showing different morphological features, immunophenotype, molecular background, clinical presentation, and outcome. They can virtually originate in every organ of the human body and their classification is not uniform among different sites. Indeed, as they have historically been classified according to the organ in which they primarily arise, the different nomenclature that has resulted have created some confusion among pathologists and clinicians. Although a uniform terminology to classify neuroendocrine neoplasms arising in different systems has recently been proposed by WHO/IARC, some issues remain unsolved or need to be clarified. In this review, we discuss the lights and shadows of the current WHO classifications used to define and characterize NENs of the pituitary gland, lung, breast and those of the head and neck region, and digestive and urogenital systems.

A tool to predict survival in stage IV entero-pancreatic NEN

PURPOSE

Well-differentiated stage IV neuroendocrine neoplasms (NEN) have an extremely heterogeneous, unpredictable clinical behavior. Survival prognostic markers, such as the recently proposed NEP-Score, would be very useful for better defining therapeutic strategies. We aim to verify NEP-Score applicability in an independent cohort of stage IV well-differentiated (WD) gastroentero-pancreatic (GEP) NEN, and identify a derivate prognostic marker taking into account clinical and pathological characteristics at diagnosis.

METHODS

Age, site of primary tumor, primary tumor surgery, symptoms, Ki67, timing of metastases of 27 patients (10 females; mean age at diagnosis 60.2 ± 2.9 years) with stage IV WD GEP NEN were evaluated to calculate the NEP-Score at the end of follow-up (NEP-T). We calculated the NEP-Score at diagnosis (NEP-D), which does not consider the appearance of new metastases during follow-up. Patients were subdivided according to whether they were alive or not at the end of follow-up (EOF) and an NEP-Score threshold was investigated to predict survival.

RESULTS

Mean NEP-T and mean NEP-D were significantly lower in 15 live patients as compared to 12 deceased patients (p < 0.01) at EOF. We identified an NEP-D = 116 as the cutoff that significantly predicts survival. No gender differences were identified.

CONCLUSIONS

In our series, we confirmed NEP-Score applicability. In addition, we propose NEP-D as a simple, quick and cheap prognostic score that can help clinicians in decision making. NEP-D threshold can predict NEN aggressiveness and may be used to define the best personalized therapeutic strategy.

Recent Advances in Digestive Tract Tumors: Updates From the 5th Edition of the World Health Organization "Blue Book"

CONTEXT.—

The World Health Organization Classification of Tumours: Digestive System Tumors, 5th edition, was published in 2019 and shows several impactful changes as compared with the 4th edition published in 2010. Changes include a revised nomenclature of serrated lesions and revamping the classification of neuroendocrine neoplasms. Appendiceal goblet cell adenocarcinoma is heavily revised, and intrahepatic cholangiocarcinoma is split into 2 subtypes. New subtypes of colorectal carcinoma and hepatocellular carcinoma are described. Precursor lesions are emphasized with their own entries, and both dysplastic and invasive lesions are generally recommended to be graded using a 2-tier system. Hematolymphoid tumors, mesenchymal tumors, and genetic tumor syndromes each have their own sections in the 5th edition. New hematolymphoid lesions include monomorphic epitheliotropic intestinal T-cell lymphoma; duodenal-type follicular lymphoma; intestinal T-cell lymphoma, not otherwise specified; and indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. This paper will provide an in-depth look at the changes in the 5th edition as compared with the 4th edition.

OBJECTIVE.—

To provide a comprehensive, in-depth update on the World Health Organization classification of digestive tumors, including changes to nomenclature, updated diagnostic criteria, and newly described entities.

DATA SOURCES.—

The 5th edition of the World Health Organization Classification of Tumours: Digestive System Tumours, as well as the 4th edition.

CONCLUSIONS.—

The World Health Organization has made many key changes in its newest update on tumors of the digestive system. Pathologists should be aware of these changes and incorporate them into their practice as able or necessary.

A [68Ga]Ga-DOTANOC PET/CT Radiomic Model for Non-Invasive Prediction of Tumour Grade in Pancreatic Neuroendocrine Tumours

Predicting grade 1 (G1) and 2 (G2) primary pancreatic neuroendocrine tumour (panNET) is crucial to foresee panNET clinical behaviour. Fifty-one patients with G1-G2 primary panNET demonstrated by pre-surgical [68Ga]Ga-DOTANOC PET/CT and diagnostic conventional imaging were grouped according to the tumour grade assessment method: histology on the whole excised primary lesion (HS) or biopsy (BS). First-order and second-order radiomic features (RFs) were computed from SUV maps for the whole tumour volume on HS. The RFs showing the lowest p-values and the highest area under the curve (AUC) were selected. Three radiomic models were assessed: A (trained on HS, validated on BS), B (trained on BS, validated on HS), and C (using the cross-validation on the whole dataset). The second-order normalized homogeneity and entropy was the most effective RFs couple predicting G2 and G1. The best performance was achieved by model A (test AUC = 0.90, sensitivity = 0.88, specificity = 0.89), followed by model C (median test AUC = 0.87, sensitivity = 0.83, specificity = 0.82). Model B performed worse. Using HS to train a radiomic model leads to the best prediction, although a “hybrid” (HS+BS) population performs better than biopsy-only. The non-invasive prediction of panNET grading may be especially useful in lesions not amenable to biopsy while [68Ga]Ga-DOTANOC heterogeneity might recommend FDG PET/CT.

The distinctive characteristics of the micro-vasculature and immune cell infiltration in cystic pancreatic neuroendocrine tumors

PURPOSE

Hypervascularity is a main characteristic of pancreatic neuroendocrine tumors (PanNETs), and cystic PanNETs (CPanNETs) are unique type of PanNETs in which the microenvironment remains unknown. We aim to compare the micro-vasculature features and immune cell infiltration between CPanNETs and solid PanNETs (SPanNETs).

METHODS

Data of 301 SPanNET and 36 CPanNET patients from a high-volume institution were evaluated. CD4, CD8, CD11c, CD15, CD20, CD68, CD34 and α-SMA expression levels were assessed by immunohistochemistry and immunofluorescent double staining. The microvessel density (MVD) and microvessel integrity (MVI) were examined.

RESULTS

MVD and MVI expression levels in CPanNETs were significantly higher than those in SPanNETs (p = 0.025 and 0.0092, respectively). CPanNETs had higher proportions of T1 (p = 0.023) and G1 (p = 0.052) than SPanNETs. In SPanNETs, higher MVD occurred in stages T1, N0 and G1 than in the T2/T3, N1 and G2 subgroups. In CPanNETs, CD34-MVD was uncorrelated with the T stage or grade. Higher CD34-MVD, but not MVI, was associated with better DFS (HR 0.3209, 95% CI 0.1259-0.8176, p = 0.004). There were significantly more peritumoral infiltrating immune cells than their intratumoral counterparts (p < 0.001 for each) in CPanNETs and SPanNETs. The mean number of peritumoral CD68 + TAM in CPanNETs was significantly lower than that in SPanNETs (p = 0.008). The counts of other peritumoral immune cells did not significantly differ between CPanNETs and SPanNETs.

CONCLUSIONS

CPanNETs had a microenvironment distinct from that of SPanNETs, including higher CD34-MVD, higher MVI and lower TAM. This specific microenvironment structure may partially help predicting the prognosis of patients with PanNET.

Gene Expression Profiling of Pancreas Neuroendocrine Tumors with Different Ki67-Based Grades

Simple Summary

Ki67-based grading is a major prognostic parameter for pancreatic neuroendocrine tumors. Gene expression profiles of these tumors have been explored, yet their relationship with Ki67-based tumor grade has only been superficially investigated. To fill this gap, we analyzed differentially expressed genes across 29 cases of different grades. Our data provided the first proof that the switch from lower to higher grades is associated with a profound change in the transcriptome. The comparison of multiple samples from the same patients, including primaries and metastasis, showed that the major determinant of difference was tumor grade, irrespective of the anatomic location or patient of origin. These data call for further investigation of this association and of the role of Ki67 in affecting chromosomal stability in neuroendocrine tumors of different grades, which may clarify the basis of tumor progression and provide clues on how to interfere with it.

Abstract

Pancreatic neuroendocrine tumors (PanNETs) display variable aggressive behavior. A major predictor of survival is tumor grade based on the Ki67 proliferation index. As information on transcriptomic profiles of PanNETs with different tumor grades is limited, we investigated 29 PanNETs (17 G1, 7 G2, 5 G3) for their expression profiles, mutations in 16 PanNET relevant genes and LINE-1 DNA methylation profiles. A total of 3050 genes were differentially expressed between tumors with different grades (p < 0.05): 1279 in G3 vs. G2; 2757 in G3 vs. G1; and 203 in G2 vs. G1. Mutational analysis showed 57 alterations in 11 genes, the most frequent being MEN1 (18/29), DAXX (7/29), ATRX (6/29) and MUTYH (5/29). The presence and type of mutations did not correlate with the specific expression profiles associated with different grades. LINE-1 showed significantly lower methylation in G2/G3 versus G1 tumors (p = 0.007). The expression profiles of matched primaries and metastasis (nodal, hepatic and colorectal wall) of three cases confirmed the role of Ki67 in defining specific expression profiles, which clustered according to tumor grades, independently from anatomic location or patient of origin. Such data call for future exploration of the role of Ki67 in tumor progression, given its involvement in chromosomal stability.

Octreotide long-acting release (LAR) in combination with other therapies for treatment of neuroendocrine neoplasia: a systematic review

BACKGROUND

In the last decades, the incidence of neuroendocrine neoplasia (NEN) increased from 1 to 5 new diagnoses/100,000 persons/year. The synthetic somatostatin analogues (SSAs) represent the first-choice treatment for both functionally active and inactive gastro-enteric-pancreatic NEN. This systematic review examines the role of octreotide long-acting release (LAR) in combination with other therapies for NEN management.

METHODS

Primary outcomes were the disease control rate and the progression free survival (PFS), defined as the time between treatment initiation and progression of disease. Secondary outcomes were overall survival (OS) and safety.

RESULTS

This systematic review identified 13 studies, concerning the use of octreotide LAR in association with other therapies in advanced NENs and included 1,206 patients. Patients were treated with octreotide LAR in combination with other drugs, mainly with everolimus (404 patients, 35%), but even with Peptide Receptor Radionuclide Therapy, bevacizumab, interferon or fluoride-derivatives. Disease control was observed in 85% cases with SSAs in combination with other therapies; PFS ranged from 15 to 16.4 months and OS from 25 to 61.9 months. SSAs are very well tolerated drugs, with few side effects which are usually mild, not requiring drug withdrawn.

CONCLUSIONS

The review summarizes the effectiveness and available safety data on octreotide LAR in combination with other therapies in patients with NEN and may provide suggestions to address the therapeutic strategy. Further comparative head-to-head studies are needed to understand which is the best combination treatment for patients with progressive NEN after failure of first-line therapy.

Gastroenteropancreatic neuroendocrine neoplasms: A clinical snapshot

Our understanding about the epidemiological aspects, pathogenesis, molecular diagnosis, and targeted therapies of neuroendocrine neoplasms (NENs) have drastically advanced in the past decade. Gastroenteropancreatic (GEP) NENs originate from the enteroendocrine cells of the embryonic gut which share common endocrine and neural differentiation factors. Most NENs are well-differentiated, and slow growing. Specific neuroendocrine biomarkers that are used in the diagnosis of functional NENs include insulin, glucagon, vasoactive intestinal polypeptide, gastrin, somatostatin, adrenocorticotropin, growth hormone releasing hormone, parathyroid hormone-related peptide, serotonin, histamine, and 5-hydroxy indole acetic acid (5-HIAA). Biomarkers such as pancreatic polypeptide, human chorionic gonadotrophin subunits, neurotensin, ghrelin, and calcitonin are used in the diagnosis of non-functional NENs. 5-HIAA levels correlate with tumour burden, prognosis and development of carcinoid heart disease and mesenteric fibrosis, however several diseases, medications and edible products can falsely elevate the 5-HIAA levels. Organ-specific transcription factors are useful in the differential diagnosis of metastasis from an unknown primary of well-differentiated NENs. Emerging novel biomarkers include circulating tumour cells, circulating tumour DNA, circulating micro-RNAs, and neuroendocrine neoplasms test (NETest) (simultaneous measurement of 51 neuroendocrine-specific marker genes in the peripheral blood). NETest has high sensitivity (85%-98%) and specificity (93%-97%) for the detection of gastrointestinal NENs, and is useful for monitoring treatment response, recurrence, and prognosis. In terms of management, surgery, radiofrequency ablation, symptom control with medications, chemotherapy and molecular targeted therapies are all considered as options. Surgery is the mainstay of treatment, but depends on factors including age of the individual, location, stage, grade, functional status, and the heredity of the tumour (sporadic vs inherited). Medical management is helpful to alleviate the symptoms, manage inoperable lesions, suppress postoperative tumour growth, and manage recurrences. Several molecular-targeted therapies are considered second line to somatostatin analogues. This review is a clinical update on the pathophysiological aspects, diagnostic algorithm, and management of GEP NENs.

Sporadic non-functioning pancreatic neuroendocrine tumours: multicentre analysis

BACKGROUND

Outcomes after surgery for sporadic pancreatic neuroendocrine neoplasms (Pan-NENs) were evaluated.

METHODS

This multicentre study included patients who underwent radical pancreatic resection for sporadic non-functioning Pan-NENs. In survival analysis, the risk of mortality in this cohort was analysed in relation to that of the matched healthy Italian population. Relative survival (RS) was calculated as the rate between observed and expected survival. Factors related to RS were investigated using multivariable modelling.

RESULTS

Among 964 patients who had pancreatic resection for sporadic non-functioning Pan-NENs, the overall RS rate was 91.8 (95 per cent c.i. 81.5 to 96.5) per cent. 2019 WHO grade (hazard ratio (HR) 5.75 (s.e. 4.63); P = 0.030) and European Neuroendocrine Tumour Society (ENETS) TNM stage (6.73 (3.61); P < 0.001) were independent predictors of RS. The probability of a normal lifespan for patients with G1, G2, G3 Pan-NENS, and pancreatic neuroendocrine carcinomas (Pan-NECs) was 96.7, 54.8, 0, and 0 per cent respectively. The probability of a normal lifespan was 99.8, 99.3, 79.8, and 46.8 per cent for those with stage I, II, III, and IV disease respectively. The overall disease-free RS rate was 73.6 (65.2 to 79.5) per cent. 2019 WHO grade (HR 2.10 (0.19); P < 0.001) and ENETS TNM stage (HR 2.50 (0.24); P < 0.001) significantly influenced disease-free RS. The probability of disease-free survival was 93.2, 84.9, 45.2, and 6.8 per cent for patients with stage I, II, III, and IV disease, and 91.9, 45.2, 9.4, and 0.7 per cent for those with G1, G2, G3 Pan-NENS, and Pan-NECs, respectively.

CONCLUSION

A surgical approach seems without benefit for Pan-NECs, and unnecessary for small G1 sporadic Pan-NENs. Surgery alone may be insufficient for stage III-IV and G3 Pan-NENs.

Predicting the Survival Probability of Neuroendocrine Tumor Populations: Developing and Evaluating a New Predictive Nomogram

Purpose

The purpose of this study was to develop and initially validate a nomogram model in order to predict the 3-year and 5-year survival rates of neuroendocrine tumor patients.

Methods

Accordingly, 348 neuroendocrine tumor patients were enrolled as study objects, of which 244 (70%) patients were included in the training set to establish the nomogram model, while 104 (30%) patients were included in the validation set to verify the robustness of the model. First, the variables related to the survival rate were determined by univariable analysis. In addition, variables that were sufficiently significant were selected for constructing the nomogram model. Furthermore, the concordance index (C-index), receiver operating characteristic (ROC), and calibration curve analysis were used to evaluate the performance of the proposed nomogram model. The survival analysis was then used to evaluate the return to survival probability as well as the indicators of constructing the nomogram model.

Results

According to the multivariable analysis, lymphatic metastasis, international normalized ratio (INR), prothrombin time (PT), tumor differentiation, and the number of tumor metastases were found to be independent predictors of survival rate. Moreover, the C-index results demonstrated that the model was robust in both the training set (0.891) and validation set (0.804). In addition, the ROC results further verified the robustness of the model either in the training set (AUC = 0.823) or training set (AUC = 0.768). Furthermore, the calibration curve results showed that the model can be used to predict the 3-year and 5-year survival probability of neuroendocrine tumor patients. Meaningfully, five variables were found: lymphatic metastasis (p = 0.0095), international standardized ratio (p = 0.024), prothrombin time (p = 0.0036), tumor differentiation (p = 0.0026), and the number of tumor metastases (p = 0.00096), which were all significantly related to the 3-year and 5-year survival probability of neuroendocrine tumor patients.

Conclusion

In summary, a nomogram model was constructed in this study based on five variables (lymphatic metastasis, international normalized ratio (INR), prothrombin time (PT), tumor differentiation, and number of tumor metastases), which was shown to predict the survival probability of patients with neuroendocrine tumors. Additionally, the proposed nomogram exhibited good ability in predicting survival probability, which may be easily adopted for clinical use.

Tumor Heterogenity in Gastro-Entero-Pancreatic Neuroendocrine Neoplasia

Owing to the rarity and the biological and clinical heterogeneity of gastroenteropancreatic neuroendocrine neoplasia (GEP NEN), the management of these patients may be challenging for physicians. This review highlights the specific features of GEP NEN with particular attention on the role of Ki67 heterogeneity, the potential prognostic role of novel radiological techniques, and the clinical usefulness of functional imaging, including 68Ga-DOTA-SST PET/CT and 18F-FDG PET/CT. Understanding these specific features may help to plan proper and tailored follow-up programs and therapeutic approaches.

Risk factors for pancreas and lung neuroendocrine neoplasms: a case-control study

PURPOSE

Neuroendocrine neoplasia (NEN) has been displaying an incremental trend along the last two decades. This phenomenon is poorly understood, and little information is available on risk factor for neuroendocrine neoplasia development. Aim of this work is to elucidate the role of potentially modifiable risk factors for pancreatic and pulmonary NEN.

METHODS

We conducted a case-control study on 184 patients with NEN (100 pancreas and 84 lung) and 248 controls. The structured questionnaire included 84 queries on socio-demographic, behavioral, dietary and clinical information.

RESULTS

Increased risk was associated with history of cancer ("other tumor", lung OR = 7.18; 95% CI: 2.55-20.20 and pancreas OR = 5.88; 95% CI: 2.43-14.22; "family history of tumor", lung OR = 2.66; 95% CI: 1.53-4.64 and pancreas OR = 1.94; 95% CI: 1.19-3.17; "family history of lung tumor", lung OR = 2.56; 95% CI: 1.05-6.24 and pancreas OR = 2.60; 95% CI: 1.13-5.95). Type 2 diabetes mellitus associated with an increased risk of pancreatic NEN (OR = 3.01; 95% CI: 1.15-7.89).

CONCLUSIONS

Besides site-specific risk factors, there is a significant link between neuroendocrine neoplasia and cancer in general, pointing to a shared cancer predisposition.

O-positive blood type is associated with prolonged recurrence-free survival following curative resection of pancreatic neuroendocrine tumors

BACKGROUND

The ABO blood group may influence the development and progression of cancer. In particular, the prognosis of patients with blood type O is better for pancreatic adenocarcinoma, although this has not been extensively explored in pancreatic neuroendocrine tumors (PanNET).

OBJECTIVE

To assess the influence of the ABO and Rhesus blood types on the risk of recurrence in patients who underwent curative intent PanNET surgical resection.

METHODS

All consecutive patients operated on for well-differentiated panNET in an expert center from 2003 to 2018 were retrospectively included. Blood group, Rhesus system, demographic and clinical data were collected. The primary endpoint was recurrence free survival (RFS). Factors associated with RFS were explored using Cox proportional hazard models.

RESULTS

Overall, 300 patients (male 43%) were included, median age 54 years old (IQR 45-64). The ABO blood group distribution was similar to that of the French population. There was no association between blood group and tumor features. The median postoperative follow-up was 43.9 months (17.0-77.8). The 5- and 10-year RFS rates were 85 ± 4% and 71 ± 13% in O RhD + patients, versus 72 ± 4% and 63 ± 6% otherwise, respectively (p = 0.035). The O RhD + blood group was associated with a decreased risk of recurrence (HR 0.34, 95% CI [0.15-0.75]), p = 0.007 in multivariable analysis adjusted for age, ki67, functioning syndrome, resection margins, tumor size, lymph node status, oncogenetic syndrome.

CONCLUSIONS

After curative-intent surgical resection for PanNET, patients with a non-O RhD + blood group may have an increased risk of recurrence and could benefit from closer follow-up.

Neuroendocrine neoplasia of the gastrointestinal tract revisited: towards precision medicine

Over the past 5 years, a number of notable research advances have been made in the field of neuroendocrine cancer, specifically with regard to neuroendocrine cancer of the gastrointestinal tract. The aim of this Review is to provide an update on current knowledge that has proven effective for the clinical management of patients with these tumours. For example, for the first time in the tubular gastrointestinal tract, well-differentiated high-grade (grade 3) tumours and mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are defined in the WHO classification. This novel classification enables efficient identification of the most aggressive well-differentiated neuroendocrine tumours and helps in defining the degree of aggressiveness of MiNENs. The Review also discusses updates to epidemiology, cell biology (including vesicle-specific components) and the as-yet-unresolved complex genetic background that varies according to site and differentiation status. The Review summarizes novel diagnostic instruments, including molecules associated with the secretory machinery, novel radiological approaches (including pattern recognition techniques), novel PET tracers and liquid biopsy combined with DNA or RNA assays. Surgery remains the treatment mainstay; however, peptide receptor radionuclide therapy with novel radioligands and new emerging medical therapies (including vaccination and immunotherapy) are evolving and being tested in clinical trials, which are summarized and critically reviewed here.

Distinct DNA Methylation Signatures in Neuroendocrine Tumors Specific for Primary Site and Inherited Predisposition

PURPOSE

To compare the deoxyribonucleic acid (DNA) methylation signature of neuroendocrine tumors (NETs) by primary tumor site and inherited predisposition syndromes von Hippel-Lindau disease (VHL) and multiple endocrine neoplasia type 1 (MEN1).

METHODS

Genome-wide DNA methylation (835 424 CpGs) of 96 NET samples. Principal components analysis (PCA) and unsupervised hierarchical clustering analyses were used to determine DNA methylome signatures.

RESULTS

Hypomethylated CpGs were significantly more common in VHL-related versus sporadic and MEN1-related NETs (P < .001 for both comparisons). Small-intestinal NETs (SINETs) had the most differentially methylated CpGs, either hyper- or hypomethylated, followed by duodenal NETs (DNETs) and pancreatic NETs (PNETs, P < .001 for all comparisons). There was complete separation of SINETs on PCA, and 3 NETs of unknown origin clustered with the SINET samples. Sporadic, VHL-related, and MEN1-related PNETs formed distinct groups on PCA, and VHL clustered separately, showing pronounced DNA hypomethylation, while sporadic and MEN1-related NETs clustered together. MEN1-related PNETs, DNETs, and gastric NETs each had a distinct DNA methylome signature, with complete separation by PCA and unsupervised clustering. Finally, we identified 12 hypermethylated CpGs in the 1A promoter of the APC (adenomatous polyposis coli) gene, with higher methylation levels in MEN1-related NETs versus VHL-related and sporadic NETs (P < .001 for both comparisons).

CONCLUSIONS

DNA CpG methylation profiles are unique in different primary NET types even when occurring in MEN1-related NETs. This tumor DNA methylome signature may be utilized for noninvasive molecular characterization of NETs, through DNA methylation profiling of biopsy samples or even circulating tumor DNA in the near future.

Gastro-entero-pancreatic neuroendocrine neoplasia: The rules for non-operative management

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) with favorable pathological and clinical features may be considered as indolent lesions, and therefore be amenable to conservative management. According to the primary tumor site, different non-aggressive approaches, based on endoscopic resection or simple active surveillance, can be proposed to selected patients fulfilling specific criteria. Tumor size, Ki67 proliferative index and depth of invasion are markers that can be used in order to identify these subjects. Patients with type I gastric NENs <1 cm as well as those with non-ampullary duodenal NENs <1 cm with no associated syndrome can be safely managed by endoscopic resection. On the other hand, an active surveillance approach is preferred over surgery for patients with asymptomatic, non-functioning pancreatic NENs ≤2 cm without dilation of the main pancreatic duct or bile duct. As far as NENs of the appendix are concerned, appendectomy should be considered as curative when a R0 resection has been achieved in the presence of a tumor ≤1.5 cm, graded as G1 and without lymphovascular invasion. Finally, G1 rectal NENs ≤1 cm without invasion of the muscular layer can be safely treated by endoscopic resection. Therefore, surgeons should be aware of the existence of indolent GEP-NENs, in order to avoid unnecessary operations with associated postoperative complications.

Genetic analysis of the cooperative tumorigenic effects of targeted deletions of tumor suppressors Rb1, Trp53, Men1, and Pten in neuroendocrine tumors in mice

Genetic alterations of tumor suppressor genes (TSGs) are frequently observed to have cumulative or cooperative tumorigenic effects. We examined whether the TSGs Rb1, Trp53, Pten and Men1 have cooperative effects in suppressing neuroendocrine tumors (NETs) in mice. We generated pairwise homozygous deletions of these four genes in insulin II gene expressing cells using the Cre-LoxP system. By monitoring growth and examining the histopathology of the pituitary (Pit) and pancreas (Pan) in these mice, we demonstrated that pRB had the strongest cooperative function with PTEN in suppressing PitNETs and had strong cooperative function with Menin and TRP53, respectively, in suppressing PitNETs and PanNETs. TRP53 had weak cooperative function with PTEN in suppressing pituitary lesions. We also found that deletion of Pten singly led to prolactinomas in female mice, and deletion of Rb1 alone led to islet hyperplasia in pancreas. Collectively, our data indicated that pRB and PTEN pathways play significant roles in suppressing PitNETs, while the Menin-mediated pathway plays a significant role in suppressing PanNETs. Understanding the molecular mechanisms of these genes and pathways on NETs will help us understand the molecular mechanisms of neuroendocrine tumorigenesis and develop effective preclinical murine models for NET therapeutics to improve clinical outcomes in humans.

Hot Spot TERT Promoter Mutations Are Rare in Sporadic Pancreatic Neuroendocrine Neoplasms and Associated with Telomere Length and Epigenetic Expression Patterns

Cancer cells activate a telomere maintenance mechanism like telomerase in order to proliferate indefinitely. Telomerase can be reactivated by gain-of-function Telomerase Reverse Transcriptase (TERT) promoter mutations (TPMs) that occur in several cancer subtypes with high incidence and association with diagnosis, prognosis and epigenetics. However, such information about TPMs in sporadic pancreatic neuroendocrine neoplasms (pNENs) including tumor (pNET) and carcinoma (pNEC) is less well defined. We have studied two hot spot TPMs and telomere length (TL) in pNEN and compared the results with clinicopathological information and proliferation-associated miRNA/HDAC expression profiles. DNA was isolated from formalin-fixed paraffin-embedded (FFPE) tissue of 58 sporadic pNEN patients. T allele frequency of C250T and C228T TPM was analyzed by pyrosequencing, relative TL as telomeric content by qPCR. In total, five pNEN cases (9%) including four pNETs and one pNEC were identified with TPMs, four cases with exclusive C250T as predominant TPM and one case with both C250T and C228T. T allele frequencies of DNA isolated from adjacent high tumor cell content FFPE tissue varied considerably, which may indicate TPM tumor heterogeneity. Overall and disease-free survival was not associated with TPM versus wild-type pNEN cases. Binary category analyses indicated a marginally significant relationship between TPM status and longer telomeres (p = 0.086), and changes in expression of miR449a (p = 0.157), HDAC4 (p = 0.146) and HDAC9 (p = 0.149). Future studies with larger patient cohorts are needed to assess the true clinical value of these rare mutations in pNEN.

CD56 Expression Is Associated with Biological Behavior of Pancreatic Neuroendocrine Neoplasms

Purpose

CD56 is a neural cell adhesion molecule that plays a role in the cohesiveness of neuroendocrine cells. The aim of this study was to explore the biological values of CD56 expression in pancreatic neuroendocrine neoplasms (PNENs) and its role in predicting PNENs grades.

Patients and Methods

A total of 138 patients with histological-proven PNENs was included (66 G1, 46 G2 and 26 G3). The clinicopathological characteristics, including mitosis count, ki67 index, chromogranin A (CgA), synaptophysin (Syn) and CD56 expression, were evaluated. We assessed the diagnostic performance of markers in predicting PNEN G3 and the association between CD56 expression and risk of G3 or organs invasion.

Results

Lack of CD56 immunoreaction (CD56-) was more common in PNEN G3 than G1/G2 (31% vs 0–2%, p < 0.01). The sizes of CD56- tumors were larger than CD56 positive tumors in PNEN G3 (p < 0.01). The odds ratio (OR) of CD56- expression was 13.6 [95% confidence interval (CI): 2.1–88.1] in predicting PNEN G3. The OR of CD56- expression was 6.5 (95% CI: 1.1–38.6) and 31.9 (95% CI: 1.09–938.3) in predicting organs invasion and neuroendocrine carcinoma in PNEN G3, respectively. Tumor size (area under the curve [AUC] = 0.77 and size+CD56- expression [AUC = 0.84]) had acceptable performance in predicating PNEN G3.

Conclusion

Lack of CD56 immunoreaction may be a predictor and biological behavior marker for PNEN G3.

Outcome after pancreatectomy for neuroendocrine neoplams according to the WHO 2017 grading system: A retrospective multicentric analysis of 138 consecutive patients

AIM

The aim of this study was to evaluate the new World Health Organization (WHO) 2017 grading system and the others clinicopathological factors in pancreatic neuroendocrine tumor (panNET) operated patients.

METHODS

Histological staging was based on the WHO 2017 grading system. Outcome after surgery and predictors of overall survival (OS) and disease free survival (DFS) were evaluated.

RESULTS

A total of 138 patients underwent surgical resection with a severe morbidity and mortality rates of 14.5% and 0.7% respectively. Five years OS differed according to WHO 2017: 95% among 58 patients with NETG1, 82% in 68 patients with NETG2, 35% in 7 patients with NETG3 and 0% in 5 patients with NECG3 (P<0.0001). Independent predictors of worse OS were age>60 y.o (P=0.014), synchronous metastasis (P=0.005) and WHO 2017 with significant differences between NETG1 versus NETG2 (P=0.005), NETG3 (P<0.001) and NECG3 (P<0.001). Independent predictors of worse DFS were symptomatic NET (P=0.038), pN+ status (P=0.027) and WHO 2017 with significant differences between NETG1 versus NETG3 (P=0.014) and NECG3 (P=0.009).

CONCLUSION

The WHO 2017 grading system is a useful tool for patient prognosis after panNET resection and the tailoring of therapeutic strategy. Surgery could provide good results in NETG3 patients.

Soluble Urokinase Plasminogen Activator Receptor (suPAR) Concentrations Are Elevated in Patients with Neuroendocrine Malignancies

Neuroendocrine neoplasia (NEN) comprises heterogeneous tumors that are challenging to diagnose and, especially in cases of poorly differentiated (G3) NEN, are associated with very limited survival. Novel biomarkers allowing an early diagnosis as well as an optimal selection of suitable treatment options are urgently needed to improve the outcome of these patients. Recently, alterations of soluble urokinase-type plasminogen activator receptor (suPAR) serum levels were described in various types of cancers. However, the role of circulating suPAR as a biomarker in patients with NEN is unknown. In this study, we measured suPAR serum levels in a large and well-characterized cohort of 187 patients with NEN (neuroendocrine carcinomas (NEC) n = 30; neuroendocrine tumors (NET), n = 157) as well as 44 healthy controls. suPAR concentrations were significantly elevated in patients compared to controls. However, suPAR concentrations were independent of tumor-related factors such as the proliferation activity according to Ki-67, tumor grading, TNM (TNM classification of malignant tumors) stage, somatostatin receptor expression or clinical features such as functional or nonfunctional disease and the presence of tumor relapse. Interestingly, suPAR concentrations in NET patients were similar when compared to those measured in NEC patients. In contrast to previous results from other malignancies, in our analysis suPAR levels were not a significant predictor of overall survival. In conclusion, our data suggests that suPAR serum concentrations are elevated in NEN patients but do not allow prediction of outcome.

Grading Solid Pseudopapillary Tumors of the Pancreas: the Fudan Prognostic Index

BACKGROUND

Ki-67 has been shown to predict outcome of patients with solid pseudopapillary tumor of the pancreas (SPTP) but has not been incorporated into a formal classification system to predict recurrence-free survival (RFS).

METHODS

This is a retrospective cohort study of patients with histologically confirmed diagnosis of SPTP who had at least 1 year of follow-up at two tertiary academic centers. Survival data were assessed by Kaplan-Meier method and multivariable Cox regression model. Prognostic performance was compared among various systems.

RESULTS

A total of 193 consecutive patients were included, ranging in age from 12 to 70 years (median 33 years). Seven patients (3.6%) developed tumor recurrence. The 3-, 5-, and 10-year RFS rates were estimated at 96.9%, 96.1%, and 94.8%, respectively. For the AJCC staging system, patients with stage I had similar prognosis to those with stage II. For the ENETS staging system, patients with stage I to III had similar prognosis. Grade based on Ki-67 was superior to both the AJCC and ENETS systems for predicting survival. Multivariate analysis revealed that large tumor size [> 10 cm; hazard ratio (HR), 6.177 95% confidence interval (CI), 1.289-29.603; P = 0.023] and Ki-67 (HR, 17.199 95% CI, 4.001-73.930; P < 0.001) were independent predictors for RFS. The Fudan Prognostic Index based on the combination of Ki-67 and tumor size showed excellent discrimination for RFS and was more accurate and informative than other grading/staging systems.

CONCLUSION

The Fudan Prognostic Index better predicts RFS compared with either Ki-67 alone or the current AJCC and ENETS TNM-based staging systems.

Advances in the Diagnosis and Management of Well-Differentiated Neuroendocrine Neoplasms

Neuroendocrine neoplasms constitute a diverse group of tumors that derive from the sensory and secretory neuroendocrine cells and predominantly arise within the pulmonary and gastrointestinal tracts. The majority of these neoplasms have a well-differentiated grade and are termed neuroendocrine tumors (NETs). This subgroup is characterized by limited proliferation and patients affected by these tumors carry a good to moderate prognosis. A substantial subset of patients presenting with a NET suffer from the consequences of endocrine syndromes as a result of the excessive secretion of amines or peptide hormones, which can impair their quality of life and prognosis. Over the past 15 years, critical developments in tumor grading, diagnostic biomarkers, radionuclide imaging, randomized controlled drug trials, evidence-based guidelines, and superior prognostic outcomes have substantially altered the field of NET care. Here, we review the relevant advances to clinical practice that have significantly upgraded our approach to NET patients, both in diagnostic and in therapeutic options.