Neuroendocrine Cancer, Therapeutic Strategies in G3 Cancers

Osteopontin is a prognostic circulating biomarker in patients with neuroendocrine neoplasms

PURPOSE

Osteopontin (OPN), also called secreted phosphoprotein 1 (SPP1) is a matricellular glycoprotein whose expression is elevated in various types of cancer and which has been shown to be involved in tumorigenesis and metastasis in many malignancies. Its role in neuroendocrine neoplasms (NEN) remains to be established. The aim of the study was to analyze plasma concentrations of OPN in patients with NEN and to explore its diagnostic and prognostic value as a clinical biomarker.

METHODS

OPN plasma concentrations were measured in a total of 38 patients with histologically proven NEN at three different time points during the course of disease and therapy (at the start of the study, after 3 and 12 months, respectively) as well as in healthy controls. Clinical and imaging data as well as concentrations of Chromogranin A (CgA) and Neuron Specific Enolase (NSE) were assessed.

RESULTS

OPN levels were significantly higher in patients with NEN compared to healthy controls. High-grade tumors (grade 3) showed the highest OPN levels. OPN levels were neither different between male and female patients nor between different primary tumor sites. OPN correlated significantly with corresponding NSE levels, while there was no correlation with Chromogranin A. High OPN levels above a cutoff value of 200 ng/ml at initial analysis predicted a worsened prognosis with significantly shorter progression-free survival of patients with NEN, which also held true within the subgroup of well-differentiated G1/G2 tumors.

CONCLUSION

Our data indicate that high baseline OPN levels in patients with NEN are predictive of an adverse outcome with shorter progression-free survival, even within the group of well differentiated G1/G2 tumors. Therefore, OPN may be used as a surrogate prognostic biomarker in patients with NEN.

Management of Localized Small- and Large-Cell Pancreatic Neuroendocrine Carcinoma in the National Cancer Database

BACKGROUND

The role of curative-intent resection and perioperative chemotherapy for nonmetastatic pancreatic neuroendocrine carcinoma (PanNEC) remains unclear due to their biological aggressiveness and rarity. This study aimed to evaluate the association of resection and perioperative chemotherapy with overall survival for nonmetastatic PanNEC.

STUDY DESIGN

Patients with localized (cT1-3, M0), small- and large-cell PanNEC were identified in the National Cancer Database from 2004 to 2017. The changing trends in terms of the annual proportions of resection and adjuvant chemotherapy were assessed. The survival of patients who received resection and those who received adjuvant chemotherapy were investigated using Kaplan-Meier estimates and Cox regression models.

RESULTS

In total, 199 patients with localized small- and large-cell PanNEC were identified; 50.3% of those were resected, and 45.0% of the resected patients received adjuvant chemotherapy. Rate of resection and adjuvant treatment has trended upward since 2011. The resected group was younger, was more often treated at academic institutions, had more distal tumors, and had a lower number of small-cell PanNEC. The median overall survival was longer in the resected group compared to the unresected group (29.4 months vs 8.6 months, p < 0.001). Resection was associated with improved survival in a multivariable Cox regression model adjusting for preoperative factors (adjusted hazard ratio 0.58, 95% CI 0.37 to 0.92), while adjuvant therapy was not.

CONCLUSIONS

This nationwide retrospective study suggests that resection is associated with improved survival in patients with localized PanNEC. The role of adjuvant chemotherapy needs more investigation.

Gastro-Enteric-Pancreatic Neuroendocrine Tumor Treatment: Actinium-225-DOTATATE and Combined Therapies

The role of lutetium-177-DOTATATE in advanced well-differentiated gastro-entero-pancreatic neuroendocrine tumors is well established. However, there is a scope for improving treatment outcomes. Actinium-225-DOTATATE is a form of targeted alpha therapy (TAT) that results in more efficient tumor cell killing owing to the substantially higher linear energy transfer of alpha particles. Systemic TAT is also safe given that the shorter path length of the alpha particles spares the surrounding healthy tissue and results in relatively fewer adverse events. Combination therapies with radiosensitizing and other chemotherapeutic agents have also gained popularity, especially in the setting of higher grade and fluorodeoxyglucose-avid tumors.

What have we learnt from the past - would treatment decisions for GEP-NET patients differ between 2012 to 2016 by the new recommendations in 2022?

BACKGROUND

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a heterogeneous group of tumors with a broad range of local and systemic treatment options. Still a lack of data regarding treatment sequences exists. The aim of this study was to analyse outcomes in GEP-NETs depending on stage and treatment steps and compare our treatment decisions to the latest treatment recommendations of European Society of Medical Oncology (ESMO) 2020 for GEP-NETs.

METHODS

Patients were included in this retrospective single-center analysis from 2012-2016. All patients suffering from a GEP-NET, who were screened, treated or evaluated at ENETS Center in Zurich, Switzerland were included in analysis. Patients with any other diagnosis of NET were not included. We used Kaplan Meier estimator as well as Cox regression to compare survival rates between different sites of localization, grades or stages and treatment sequences.

RESULTS

Overall, we identified 256 GEP-NETs, most in advanced stage (62%) and located in small intestine tract or pancreatic gland. Survival depended on stage, grade, primary site and duration of response for the early systemic treatment. On average patients underwent 2.6 different treatment modalities, mostly depending on stage and higher tumor grade. Surgery was performed early but also in advanced stages, usually followed by Somatostatine-Agonist modalities. In distant disease (Stage IV), we investigated a positive effect of PFS after treatment with Somatostatine Analogues (SSA) (hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.21 - 0.97; p = 0.04) and systemic treatment (HR, 0.51; 95% CI, 0.26 - 0.99; p = 0.047) if patients underwent prior surgery or endoscopic resection. Kaplan Meier distributions predict shorter OS in distant disease (Stage IV), (Figure. 1; HR, 2.06; 95% CI, 1.46 - 2.89; log-rank test, p < 0.001).

CONCLUSION

This retrospective analysis presents a great overview of all patients', disease and treatment characteristics of GEP-NETs at ENETS Center in Zurich, Switzerland. We illustrated survival (PFS) depending on implemented therapies. According to these findings, we formed a suggested treatment algorithm for advanced GEP-NETs, which does not differ from the latest treatment recommendation by ESMO guidelines for GEP-NETs. The results of this project may define GEP-NET patients' selection for upcoming clinical prospective studies.

Management of Appendix Neuroendocrine Neoplasms: Insights on the Current Guidelines

Appendiceal neuroendocrine neoplasms (ANENs) usually present as incidental findings at the time of appendectomy for acute appendicitis. They are rare, accounting for only 0.5-1% of intestinal neoplasms; they are found in 0.3-0.9% of all appendectomy specimens. They are usually sporadic tumors. There are several histological types including well-differentiated neuroendocrine tumors (NETs), poorly differentiated neuroendocrine carcinomas (NECs), and mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs). Histologic differentiation and the grade of well-differentiated NETs correlate with clinical behavior and prognosis. Management varies based on differentiation, aggressiveness, and metastatic potential. There is debate about the optimal surgical management for localized appendiceal NETs that are impacted by many factors including the tumor size, the extent of mesoappendiceal spread, lymphovascular invasion and perineural involvement. In addition, the data to guide therapy in metastatic disease are limited due to the paucity of these tumors. Here, we review the current advances in the management of ANENs within the context of a multidisciplinary approach to these tumors.

Prediction of the characteristics of aggressiveness of pancreatic neuroendocrine neoplasms (PanNENs) based on CT radiomic features

OBJECTIVES

To predict tumor grade (G1 vs. G2/3), presence of distant metastasis (M+), metastatic lymph nodes (N+), and microvascular invasion (VI) of pancreatic neuroendocrine neoplasms (PanNEN) based on preoperative CT radiomic features (RFs), by applying a machine learning approach aimed to limit overfit.

METHODS

This retrospective study included 101 patients who underwent surgery for PanNEN; the entire population was split into training (n = 70) and validation cohort (n = 31). Based on a previously validated methodology, after tumor segmentation on contrast-enhanced CT, RFs were extracted from unenhanced CT images. In addition, conventional radiological and clinical features were combined with RFs into multivariate logistic regression models using minimum redundancy and a bootstrap-based machine learning approach. For each endpoint, models were trained and validated including only RFs (RF_model), and both (radiomic and clinicoradiological) features (COMB_model).

RESULTS

Twenty-five patients had G2/G3 tumor, 37 N+, and 14 M+ and 38 were shown to have VI. From a total of 182 RFs initially extracted, few independent radiomic and clinicoradiological features were identified. For M+ and G, the resulting models showed moderate to high performances: areas under the curve (AUC) for training/validation cohorts were 0.85/0.77 (RF_model) and 0.81/0.81 (COMB_model) for M+ and 0.67/0.72 and 0.68/0.70 for G. Concerning N+ and VI, only the COMB_model could be built, with poorer performance for N+ (AUC = 0.72/0.61) compared to VI (0.82/0.75). For all endpoints, the negative predictive value was good (≥ 0.75).

CONCLUSIONS

Combining few radiomic and clinicoradiological features resulted in presurgical prediction of histological characteristics of PanNENs. Despite the limited risk of overfit, external validations are warranted.

KEY POINTS

• Histology is the only tool currently available allowing characterization of PanNEN biological characteristics important for prognostic assessment; significant limitations to this approach exist. • Based upon preoperative contrast-enhanced CT images, a machine learning approach optimized to favor models' generalizability was successfully applied to train predictive models for tumor grading (G1 vs. G2/3), microvascular invasion, metastatic lymph nodes, and distant metastatic spread. • Moderate to high discriminative models (AUC: 0.67-0.85) based on few parameters (≤ 3) showing high negative predictive value (0.75-0.98) were generated and then successfully validated.

Radioligand therapy (RLT) as neoadjuvant treatment for inoperable pancreatic neuroendocrine tumors: a literature review

In the last 10 years, several literature reports supported radioligand therapy (RLT) in neoadjuvant settings for pancreatic neuroendocrine tumors (PanNETs). Indeed, primary tumor shrinkage has been frequently reported following RLT in unresectable or borderline resectable PanNETs. Moreover, RLT-induced intratumoral modifications facilitate surgery, both on primary tumor and metastasis, having a great impact on progression free survival (PFS), overall survival (OS) and quality of life (QoL). However, prospective controlled investigations are necessary to confirm preliminary data and to define the best RLT scheme and the ideal patient that, in a multidisciplinary approach, should be referred to neoadjuvant RLT.

DLL3 as an Emerging Target for the Treatment of Neuroendocrine Neoplasms

INTRODUCTION

Neuroendocrine neoplasms (NEN) are heterogeneous malignancies that can arise at almost any anatomical site and are classified as biologically distinct well-differentiated neuroendocrine tumors (NET) and poorly differentiated neuroendocrine carcinomas (NEC). Current systemic therapies for advanced disease, including targeted therapies, chemotherapy, and immunotherapy, are associated with limited duration of response. New therapeutic targets are needed. One promising target is delta-like ligand 3 (DLL3), an inhibitory ligand of the Notch receptor whose overexpression on the surface of NEN is associated with tumorigenesis.

METHODS

This article is a narrative review that highlights the role of DLL3 in NEN progression and prognosis, the potential for therapeutic targeting of DLL3, and ongoing studies of DLL3-targeting therapies. Classification, incidence, pathogenesis, and current management of NEN are reviewed to provide biological context and illustrate the unmet clinical needs.

DISCUSSION

DLL3 is overexpressed in many NENs, implicated in tumor progression, and is typically associated with poor clinical outcomes, particularly in patients with NEC. Targeted therapies using DLL3 as a homing beacon for cytotoxic activity mediated via several different mechanisms (eg, antibody-drug conjugates, T-cell engager molecules, CAR-Ts) have shown promising clinical activity in small-cell lung cancer (SCLC). DLL3 may be a clinically actionable target across NEN.

CONCLUSIONS

Current treatment options for NEN do not provide sustained responses. DLL3 is expressed on the cell surface of many NEN types and is associated with poor clinical outcomes. Initial clinical studies targeting DLL3 therapeutically in SCLC have been promising, and additional studies are expanding this approach to the broader group of NEN.

Systematic review of neuroendocrine carcinomas of the oropharynx

Data describing features and management of oropharyngeal neuroendocrine carcinomas (NEC) remain sparse. A systematic review was performed. Patients were stratified by treatment modality and examined for disease progression and survival outcomes. Ninety-four patients from 50 publications were included. Average age at diagnosis was 59.7 years (range 14-83). 73.4% were male. Most studies did not document HPV status. Forty patients (85.1%) were p16 positive, and 34 (85.0%) were HPV-ISH positive. Overall survival was 75.4% at 1 year, and 40.0% at 2 years. Of patients with locoregional disease, 33.8% developed distant metastasis. 12.5% of patients developed locoregional recurrence. Patients who developed distant metastases had worse overall survival (p = 0.0004). No significant difference was found between treatment modalities. Human papilloma virus may be associated with oropharyngeal NEC. Current treatments provide locoregional control, but distant metastases are common and confer low overall survival.

Treatment Approaches and Outcome of Patients with Neuroendocrine Neoplasia Grade 3 in German Real-World Clinical Practice

Simple Summary

Grade 3 neuroendocrine neoplasms (NEN G3) are a rare and heterogeneous subtype of NEN and include poorly differentiated neuroendocrine carcinomas and well-differentiated neuroendocrine tumors G3 (NET G3). Standard chemotherapy with platinum plus etoposide may not be appropriate for all subgroups, but more tailored approaches suffer from the lack of data. In our study, we provide real-world data from a large center-based cohort of the German NET Registry and hope to stimulate efforts to conduct clinical trials for well-defined entities.

Abstract

Background: Neuroendocrine neoplasia grade 3 (NEN G3) represents a rare and heterogeneous cancer type with a poor prognosis. The aim of our study was to analyze real-world data from the German NET Registry with a focus on therapeutic and prognostic aspects. Methods: NEN G3 patients were identified within the German NET Registry. Demographic data and data on treatments and outcomes were retrieved. Univariate analyses were performed using the Kaplan–Meier-method. Multivariate analysis was performed using a Cox proportional hazard model. Results: Of 445 included patients, 318 (71.5%) were diagnosed at stage IV. Well-differentiated morphology (NET G3) was described in 31.7%, 60% of cases were classified as neuroendocrine carcinoma (NEC), and the median Ki67 value was 50%. First-line treatment comprised chemotherapy in 43.8%, with differences in the choice of regimen with regard to NET or NEC, and surgery in 41.6% of patients. Median overall survival for the entire cohort was 31 months. Stage, performance status and Ki67 were significant prognostic factors in multivariate analysis. Conclusions: The survival data of our national registry compare favorably to population-based data, probably mainly because of a relatively low median Ki67 of 50%. Nevertheless, the best first- and second-line approaches for specific subgroups remain unclear, and an international effort to fill these gaps is needed.

New insights in diagnosis and treatment of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are rare epithelial neoplasms derived from pluripotent endocrine cells along the gastrointestinal tract and pancreas. GEP-NENs are classified into well-differentiated neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas. Despite overlapping morphological features, GEP-NENs vary in molecular biology, epigenetic, clinical behavior, treatment response, and prognosis features and remain an unmet clinical challenge. In this review, we introduce recent updates on the histopathologic classification, including the tumor grading and staging system, molecular genetics, and systemic evaluation of the diagnosis and treatment of GEP-NENs at different anatomic sites, together with some insights into the diagnosis of challenging and unusual cases. We also discuss the application of novel therapeutic approaches for GEP-NENs, including peptide receptor radionuclide therapy, targeted therapy, and immunotherapy with immune checkpoint inhibitors. These findings will help improve patient care with precise diagnosis and individualized treatment of patients with GEP-NENs.

Unique Finding of a Primary Central Nervous System Neuroendocrine Carcinoma in a 5-Year-Old Child: A Case Report

Neuroendocrine tumors (NETs) are rare neoplasms predominantly arising in the gastrointestinal-tract or the lungs of adults. To date, only ten cases of primary central nervous system (CNS) NETs have been reported, with just three of them describing a neuroendocrine carcinoma (NECA) and none occurring in a child. We report on a previously healthy 5-year-old boy, who presented with headaches, nausea and vomiting, and was diagnosed with a left cerebellar solid mass with a cystic component. After gross-total resection, histology revealed a neuroendocrine carcinoma. Molecular analysis of the tumor tissue showed a KRAS-splice-site mutation (c451-3C &gt; T). The KRAS-mutation was discovered to be a maternal germline mutation, previously described as likely benign. After extensive search for an extracranial primary tumor, including Ga-68 DOTANOC-PET-CT, the diagnosis of a primary CNS NECA was established, and proton irradiation was performed. Unfortunately, the patient developed an in-field recurrence just 5 weeks after the end of radiotherapy. The tumor was re-resected with vital tumor tissue. Six cycles of chemotherapy were initiated, consisting of cisplatin, carboplatin, etoposide and ifosfamide. The patient remains disease free 22 months after the end of treatment, supporting the beneficial effect of platinum- and etoposide-based chemotherapy for this tumor entity.

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.

Cisplatin-Based versus Carboplatin-Based Chemotherapy for Extrapulmonary Neuroendocrine Carcinomas: A Real-World Study

OBJECTIVE

This study aimed to assess the survival differences between cisplatin/etoposide versus carboplatin/etoposide chemotherapy regimens in the management of patients with extrapulmonary neuroendocrine carcinomas (NECs).

METHODS

Administrative cancer care databases in the province of Alberta, Canada, were reviewed, and patients with extrapulmonary NECs (including those with small cell and large cell neuroendocrine carcinomas) who were treated with either cisplatin/etoposide or carboplatin/etoposide, 2004-2019, were reviewed. Kaplan-Meier survival estimates were used to compare the survival outcomes according to the type of platinum agent, and multivariable Cox regression analysis was used to assess the impact of the type of platinum agent on overall survival outcomes.

RESULTS

A total of 263 eligible patients were included in this analysis. These include 176 patients who received cisplatin/etoposide and 87 patients who received carboplatin/etoposide. Using Kaplan-Meier survival estimates, patients treated with cisplatin had better overall survival compared to patients treated with carboplatin (p = 0.005). Multivariable Cox regression analysis suggested that the following factors were associated with worse overall survival: higher Charlson comorbidity index (HR: 1.17; 95% CI: 1.05-1.30), gastrointestinal primary site (HR: 1.55; 95% CI: 1.12-2.14), stage IV disease (HR: 1.75; 95% CI: 1.28-2.38), and use of carboplatin (HR: 1.40; 95% CI: 1.02-1.92).

CONCLUSIONS

The current study suggested that cisplatin/etoposide might be associated with better overall survival compared to carboplatin/etoposide among patients with extrapulmonary NECs. It is unclear if this is related to differences in inherent responsiveness to the 2 platinum agents or due to differences in comorbidity burden between the 2 treatment groups.

Grade 3 Neuroendocrine Tumor (G3NET): An Unusual Tumor With A Histochemical Surprise

Given the rare occurrence and the indolent course of Neuroendocrine tumors (NETs), few epidemiological studies exist on these cancers. A small but interesting subset of these tumors are G3- Neuroendocrine Tumors. Grade 3 Neuroendocrine tumors (or G3-NETs) are unique in their intermediate prognosis. These grade discordant tumors lie in between high-grade poorly differentiated neuroendocrine carcinomas and grade 2 well-differentiated NETs, which have a worse and better prognosis than this rare entity, respectively. In this case report, we present a case of Grade 3 NET with an unusually high Ki67 index, diagnosed upon biopsy of metastasis visualized on imaging. Additionally, we review existing literature for characteristics, immunohistochemical markers, prognosis, and treatment modalities for the same.

Comparison of Design, Eligibility, and Outcomes of Neuroendocrine Neoplasm Trials Initiated From 2000 to 2009 vs 2010 to 2020

Importance

Neuroendocrine neoplasms (NENs) have historically been grouped homogenously in clinical trials, despite their heterogeneity. Given the adoption of a more advanced pathologic classification system and drug licensure of several targeted therapies over the last decade, information is needed on whether study characteristics of NEN studies have evolved.

Objective

To assess changes in study design, eligibility, accrual, sponsorship, and outcomes between phase II or III NEN clinical trials that began enrollment from 2000 to 2009 vs 2010 to 2020.

Design, Setting, and Participants

This quality improvement study used a systematic survey of completed studies published between January 1, 2000, and December 31, 2020. Therapeutic phase II and III NEN studies were identified through a database search of Medline (via PubMed), EMBASE (OvidSP), Cumulative Index of Nursing and Allied Health Literature (EBSCOhost), Web of Science (Clarivate), Cochrane Database of Systematic Reviews (Wiley), ClinicalTrials.gov (National Institutes of Health), EU Clinical Trials Register, and National Cancer Institute Clinical Trials. Data were analyzed between March and June 2021.

Main Outcomes and Measures

Study characteristic proportions between the 2 enrollment periods.

Results

Of 3243 identified studies, 119 studies met criteria for inclusion, of which 117 studies (54 studies that began enrollment between 2000-2009 and 63 studies that began enrollment between 2010-2020) included exact dates of enrollment and were compared. Studies that began enrollment after 2010, compared with studies that began enrollment from 2000 to 2009, were less likely to include all NENs (13 studies [21%] vs 34 studies [63%]; P < .001) and more likely to include select NENs (eg, gastrointestinal neuroendocrine tumors, 25 studies [40%] vs 11 studies [20%]; P = .02; pancreatic neuroendocrine tumors, 32 studies [51%] vs 16 studies [30%]; P = .02). Studies that began enrollment after 2010, compared with studies that began enrollment from 2000 to 2009, were more likely to specify tumor differentiation (59 studies [98%] vs 34 studies [63%]; P < .001) or Ki-67 index (23 studies [38%] vs 5 studies [9%]; P < .001) in inclusion criteria. Studies that began enrollment after 2010, compared with studies that began enrollment from 2000 to 2009, were more likely to use progression-free survival (22 studies [35%] vs 9 studies [18%]; P = .04) rather than objective response rate (19 studies [30%] vs 27 studies [53%]; P = .01) as a primary or coprimary end point.

Conclusions and Relevance

These findings suggest that NEN trials enrolling over the last decade were more focused on select tumor populations, compared with studies that began enrollment before 2010. Despite this shift, more than 20% of studies still included all NENs. Studying novel agents in specific disease populations may enhance drug development in the field.

Tri-modal management of primary small cell carcinoma of the pancreas (SCCP): a rare neuroendocrine carcinoma (NEC)

Background

Primary small cell carcinoma of the pancreas (SCCP) is a rare malignant neuroendocrine carcinoma (NEC). Typically, it presents with lymphovascular invasion as well as metastasis at the time of diagnosis which portends a dismal prognosis. Treatment is typically based on therapy used for other aggressive NECs such as small cell lung cancer. Although multimodal surgery, radiation and chemotherapy may improve prognosis, the outcome generally remains poor.

Case presentation

Here we present a primary SCCP managed with neoadjuvant multi-agent chemotherapy combined with radiotherapy and surgery

Conclusions

Multi-disciplinary therapy resulted in an ongoing 28 + month radiographic complete response and overall survival.

Prognostic Value of 18F-FDG PET in Neuroendocrine Neoplasm: A Systematic Review and Meta-analysis

OBJECTIVES

Accurate assessment of the prognosis is critical for the rational treatment of neuroendocrine neoplasms (NENs). We performed a systematic review and meta-analysis of the prognostic value of 18F-FDG PET for NENs.

PATIENTS AND METHODS

PubMed and Embase databases were searched up to September 2020 for studies that evaluated 18F-FDG PET as prognostic factors in patients with NENs with overall survival (OS) and event-free survival (EFS) as outcomes. Hazards ratios (HRs) comparing high and low FDG uptakes were pooled using the DerSimonian-Laird method. Publication bias was assessed and adjusted for using the trim-and-fill method. Metaregression and subgroup analyses were performed to explore the cause of heterogeneity.

RESULTS

Twenty-three studies (1799 patients) were included. The overall pooled HRs of high FDG uptake on EFS and OS were 2.84 (95% confidence interval [CI], 2.21-3.64) and 3.50 (95% CI, 2.42-4.12), respectively. Publication biases were present regarding both EFS and OS (P = 0.0342 and 0.0009, respectively). After adjustment, effect sizes remained significant for EFS and OS (adjusted HR, 2.26 [95% CI, 1.76-2.89]; 3.16 [95% CI, 2.42-4.12]). In metaregression analyses, the proportion of grade 3 tumors positively correlated with the HR of OS (adjusted P = 0.0422).

CONCLUSIONS

18F-FDG PET is a significant prognostic factor in patients with NENs. 18F-FDG PET might be a useful prognostic biomarker in conjunction with the histologic grade and can help select the optimal treatment.

Presentation and survival of gastro-entero-pancreatic neuroendocrine tumors in young adults versus older patients

BACKGROUND

A minority of patients with gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) is diagnosed at younger age. This population-based study explores the broad clinical and pathologic features of the youngest 5% of adult patients with GEP-NETs.

METHODS

A retrospective study of the National Cancer Database (NCDB) of patients with a primary GEP-NET was performed. Patients were stratified by age. Kaplan-Meier and multivariate Cox proportional hazards analyses were performed.

RESULTS

We identified 31,983 patients with a diagnosis of a GEP-NET and only 5% of patients were under the age of 35. Young patients were found to have greater proportions of localized, well differentiated disease. On multivariate analysis, young age, well differentiated histology, early stage, and surgical intervention were associated with lower risk of mortality.

CONCLUSIONS

Young patients with GEP-NETs tend to have earlier stage of presentation and well differentiated tumors, which may be most amenable to surgical intervention.

Fibroblast activation protein inhibitor (FAPi) positive tumour fraction on PET/CT correlates with Ki-67 in liver metastases of neuroendocrine tumours

AIM

Gallium-68-labelled inhibitors of the fibroblast activation protein (FAPi) enable positron emission tomography/computed tomography (PET/CT) imaging of fibroblast activation. We evaluated if [⁶⁸Ga]Ga-DATA5 m.SA.FAPi PET/CT is related to Ki-67 as a marker of tumour aggressiveness in patients with liver metastases of NET.

METHODS

Thirteen patients with liver metastases of a histologically confirmed NET who underwent PET/CT with [⁶⁸Ga]Ga-DATA5 m.SA.FAPi, [18F]FDG and [⁶⁸Ga]Ga-DOTA-TOC were retrospectively analyzed. PET-positive liver tumour volumes were segmented for calculation of volume, SUVmax and PET-positive tumour fraction (TF). PET parameters were correlated with Ki-67.

RESULTS

FDG_SUVmax correlated positively (rho = 0.543, p < 0.05) and DOTATOC_SUVmax correlated negatively (rho = -0.618, p < 0.05) with Ki-67, the correlation coefficients were in the moderate range. There was no significant correlation between FAPi_SUVmax and Ki-67 (rho = 0.382, p > 0.05). FAPi_TF correlated positively (rho = 0.770, p < 0.01) and DOTATOC_TF correlated negatively (rho = -0.828, p < 0.01) with Ki-67, both significantly with high correlation coefficients. FDG_TF also correlated significantly with Ki-67, with a moderate correlation coefficient (rho = 0.524, p < 0.05). The ratio FAPi_VOL:DOTATOC_VOL showed a significant and strong correlation with Ki-67 (rho = 0.808, p < 0.01).

CONCLUSION

The ratio FAPi_VOL:DOTATOC_VOL might serve as a clinical parameter for the assessment of dedifferentiation and aggressiveness of liver metastases in patients with NET. [⁶⁸Ga]Ga-DATA5 m.SA.FAPi might hold potential for identification of high-risk patients. Further studies are warranted to evaluate its prognostic significance in comparison to [¹⁸F]FDG in patients with NET.

Diagnostic and Predictive Role of DLL3 Expression in Gastroenteropancreatic Neuroendocrine Neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are a rare and heterogeneous subgroup of tumors with a challenging management because of their extremely variable biological and clinical behaviors. Due to their different prognosis, there is an urgent need to identify molecular markers which would enable to discriminate between grade 3 neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs), despite both being diagnosed mainly on the basis of proliferation index and cell differentiation. DLL3, a negative Notch regulator, is a promising molecular target highly expressed in several tumors with neuroendocrine features. We conducted a retrospective analysis of DLL3, RB1, and PD-L1 expression by immunohistochemistry (IHC), in formalin-fixed, paraffin-embedded (FFPE) samples from 47 patients with GEP-NENs. Then, we correlated the results with patients' clinical features and outcome. The absence of DLL3 expression in 5 well-differentiated GEP-NETs with high-grade features (G3 NET), and the presence of DLL3 in 76.9% of poorly-differentiated NECs (G3 NEC), highlights DLL3 expression as a marker of G3 NECs (p = 0.007). DLL3 expression was correlated with RB1-loss (p < 0.001), negative ⁶⁸ Ga-PET/CT scan (p = 0.001), and an unfavorable clinical outcome, with important implications for treatment response and patient's follow-up. Median progression-free survival (PFS) and overall survival (OS) were 22.7 months (95% CI 6.1-68.8) and 68.8 months (95% CI 26.0-78.1), respectively, in patients with DLL3-negative tumor compared with 5.2 months (95% CI 2.5-18.5) and 9.5 months (95% CI 2.5-25.2), respectively, in patients with DLL3-positive tumor (PFS p = 0.0083, OS p = 0.0071). Therefore, combined with morphological cell analysis, DLL3 could represent a valuable histological marker, for the diagnosis of poorly differentiated NECs. The high percentage of DLL3 expression in NEC patients also highlights a potential opportunity for a DLL3 targeted therapy in this tumor subset.

Evaluation of MGMT gene methylation in neuroendocrine neoplasms

Unresectable neuroendocrine neoplasms (NENs) often poorly respond to standard therapeutic approaches. Alkylating agents, in particular temozolomide, commonly used to treat high-grade brain tumors including glioblastomas, have recently been tested in advanced or metastatic NENs, where they showed promising response rates. In glioblastomas, prediction of response to temozolomide is based on the assessment of the methylation status of the MGMT gene, as its product, O-6-methylguanine-DNA methyltransferase, may counteract the damaging effects of the alkylating agent. However, in NENs, such a biomarker has not been validated yet. Thus, we have investigated MGMT methylation in 42 NENs of different grades and from various sites of origin by two different approaches: in contrast to methylation-specific PCR (MSP), which is commonly used in glioblastoma management, amplicon bisulfite sequencing (ABS) is based on high resolution next-generation sequencing and interrogates several additional CpG sites compared to those covered by MSP. Overall, we found MGMT methylation in 74% (31/42) of the NENs investigated. A higher methylation degree was observed in well-differentiated tumors and in tumors originating in the gastrointestinal tract. Comparing MSP and ABS results, we demonstrate that the region analyzed by the MSP test is sufficiently informative of the MGMT methylation status in NENs, suggesting that this predictive parameter could routinely be interrogated also in NENs.

Poorly Differentiated Neuroendocrine Larynx Carcinoma: Clinical Features and miRNAs Signature-A New Goal for Early Diagnosis and Therapy?

Laryngeal neuroendocrine carcinomas (LNECs) are rare and highly heterogeneous malignancies presenting a wide range of pathological and clinical manifestations. Herein, we retrospectively characterize ten patients diagnosticated with LNEC, five of which were defined as well-moderately differentiated neuroendocrine carcinomas, and five that were defined as poorly differentiated neuroendocrine carcinomas, according to the latest WHO classification. Clinical features were analyzed and compared between the two subgroups together with a microRNA study which evidenced a peculiar signature likely related to poorly differentiated larynx neuroendocrine carcinomas. These findings may offer new useful insights for clinicians to improve diagnosis efficiency, therapy response, and patients' outcome for this aggressive neoplasm.

Treatment Outcomes of Well-Differentiated High-Grade Neuroendocrine Tumors

INTRODUCTION

Recent classification of neuroendocrine neoplasms has defined well-differentiated high-grade neuroendocrine tumors (NET G3) as a distinct entity from poorly differentiated neuroendocrine carcinoma. The optimal treatment for NET G3 has not been well-described. This study aimed to evaluate metastatic NET G3 response to different treatment regimens.

MATERIALS AND METHODS

This was a retrospective study of patients with NET G3 within the Mayo Clinic database. Patients' demographics along with treatment characteristics, responses, and survival were assessed. Primary endpoints were progression-free survival (PFS) and overall survival. Secondary endpoints were objective response rate (ORR) and disease control rate (DCR).

RESULTS

Treatment data was available in 30 patients with median age of 59.5 years at diagnosis. The primary tumor was mostly pancreatic (73.3%). Ki-67 index was ≥55% in 26.7% of cases. Treatments included capecitabine + temozolomide (CAPTEM) (n = 20), lutetium 177 DOTATATE (PRRT; n = 10), Platinum-etoposide (EP; n = 8), FOLFOX (n = 7), and everolimus (n = 2). CAPTEM exhibited ORR 35%, DCR 65%, and median PFS 9.4 months (95% confidence interval, 2.96-16.07). Both EP and FOLFOX showed similar radiographic response rates with ORR 25.0% and 28.6%; however, median PFS durations were quite distinct at 2.94 and 13.04 months, respectively. PRRT had ORR of 20%, DCR of 70%, and median PFS of 9.13 months.

CONCLUSION

Among patients with NET G3, CAPTEM was the most commonly used treatment with clinically meaningful efficacy and disease control. FOLFOX or PRRT are other potentially active treatment options. EP has some activity in NET G3, but responses appear to be short-lived. Prospective studies evaluating different treatments effects in patients with NET G3 are needed to determine an optimal treatment strategy.

IMPLICATIONS FOR PRACTICE

High-grade well-differentiated neuroendocrine tumors (NET G3) are considered a different entity from low-grade NET and neuroendocrine carcinoma in terms of prognosis and management. The oral combination of capecitabine and temozolomide is considered a good option in the management of metastatic NET G3 and may be preferred. FOLFOX is another systemic option with reasonable efficacy. Similar to other well-differentiated neuroendocrine tumors, peptide receptor radionuclide therapy seems to have some efficacy in these tumors.

Theranostics in Oncology-Thriving, Now More than Ever

Tracing its roots back to the 1940s, theranostics in nuclear oncology has proved successful mainly due to the beneficial effects of image-guided therapeutic concepts for patients afflicted with a variety of different cancers. The majority of these treatments are not only characterized by substantial prolongation of progression-free and overall survival, but are also generally safe, rendering theranostic agents as an attractive treatment option in various clinical scenarios in oncology. In this Special Issue Novel Theranostic Agents, nine original articles from around the globe provide further evidence on the use of the theranostic concept for neuroendocrine neoplasm (NEN), prostate cancer (PC), meningioma, and neuroblastoma. The investigated diagnostic and therapeutic radiotracers target not only established structures, such as somatostatin receptor, prostate-specific membrane antigen or norepinephrine transporter, but also recently emerging targets such as the C-X-C motif chemokine receptor 4. Moreover, the presented original articles also combine the concept of theranostics with in-depth read-out techniques such as radiomics or novel reconstruction algorithms on pretherapeutic scans, e.g., for outcome prediction. Even 80 years after its initial clinical introduction, theranostics in oncology continues to thrive, now more than ever.

A novel risk factor panel predicts early recurrence in resected pancreatic neuroendocrine tumors

BACKGROUND

Pancreatic neuroendocrine tumors (PanNETs) are indolent pancreatic tumors derived from neuroendocrine cells in pancreatic islets. To date, reliable predictors for identifying patients at high risk for recurrence after curative cancer resection are lacking. We aimed to determine independent predictors for high-risk PanNETs and patient outcomes after surgery.

METHODS

We analyzed relevant clinicopathological parameters in 319 consecutive patients of derivation cohort 1 and 106 patients of validation cohort 2 who underwent pancreatectomy and were diagnosed with PanNETs. Association of tumor characteristics with recurrence-free survival (RFS) and overall survival (OS) was evaluated using Cox regression.

RESULTS

PanNET grade 3 (G3), pancreatic duct dilatation, and perineural invasion were independent prognostic factors for RFS and were significantly associated with early recurrence (within 1.5 years) of PanNETs after curative resection (P = 0.019, P < 0.001, and P < 0.001, respectively). Using these factors, we established a novel risk factor panel (R-panel), which predicted early recurrence (P < 0.001, HR = 15.02, 95% CI 5.76-39.19). Predictive accuracy of this R-panel was favorable, with a C-index of 0.853, higher than AJCC TNM staging (0.713). We further built an integrated staging system combining R-panel scoring and TNM staging, which improved predictive probability of TNM staging. Finally, we showed that adjuvant therapy with long-acting somatostatin analogs (SSAs) significantly reduced postoperative recurrence (P < 0.001) and prolonged long-term survival (P = 0.021) in patients with the above risk factors.

CONCLUSION

We identified a novel risk factor panel, which includes PanNET G3, pancreatic duct dilatation, and perineural invasion; this panel predicted early recurrence of PanNETs after curative resection. Patients with these risk factors can benefit from adjuvant therapy with SSAs.

CXCR4-Directed PET/CT in Patients with Newly Diagnosed Neuroendocrine Carcinomas

We aimed to elucidate the diagnostic potential of the C-X-C motif chemokine receptor 4 (CXCR4)-directed positron emission tomography (PET) tracer ⁶⁸Ga-Pentixafor in patients with poorly differentiated neuroendocrine carcinomas (NEC), relative to the established reference standard ¹⁸F-FDG PET/computed tomography (CT). In our database, we retrospectively identified 11 treatment-naïve patients with histologically proven NEC, who underwent ¹⁸F-FDG and CXCR4-directed PET/CT for staging and therapy planning. The images were analyzed on a per-patient and per-lesion basis and compared to immunohistochemical staining (IHC) of CXCR4 from PET-guided biopsies. ⁶⁸Ga-Pentixafor visualized tumor lesions in 10/11 subjects, while¹⁸F-FDG revealed sites of disease in all 11 patients. Although weak to moderate CXCR4 expression could be corroborated by IHC in 10/11 cases, ¹⁸F-FDG PET/CT detected significantly more tumor lesions (102 vs. 42; total lesions, n = 107; p < 0.001). Semi-quantitative analysis revealed markedly higher ¹⁸F-FDG uptake as compared to ⁶⁸Ga-Pentixafor (maximum and mean standardized uptake values (SUV) and tumor-to-background ratios (TBR) of cancerous lesions, SUV_max: 12.8 ± 9.8 vs. 5.2 ± 3.7; SUV_mean: 7.4 ± 5.4 vs. 3.1 ± 3.2, p < 0.001; and, TBR 7.2 ± 7.9 vs. 3.4 ± 3.0, p < 0.001). Non-invasive imaging of CXCR4 expression in NEC is inferior to the reference standard ¹⁸F-FDG PET/CT.

Recent advances and conceptual changes in the classification of neuroendocrine tumors of the thymus

Neuroendocrine tumors of the thymus (TNET) are exceedingly rare neoplasms. Their histomorphology is identical to neuroendocrine tumors elsewhere in the body (in particular the lungs) and bears no similarity with thymomas and thymic carcinomas. Recent molecular findings have profoundly changed our perception of these tumors and may impact future histological classification systems.

CT-derived radiomic features to discriminate histologic characteristics of pancreatic neuroendocrine tumors

PURPOSE

To assess the ability of radiomic features (RF) extracted from contrast-enhanced CT images (ceCT) and non-contrast-enhanced (non-ceCT) in discriminating histopathologic characteristics of pancreatic neuroendocrine tumors (panNET).

METHODS

panNET contours were delineated on pre-surgical ceCT and non-ceCT. First- second- and higher-order RF (adjusted to eliminate redundancy) were extracted and correlated with histological panNET grade (G1 vs G2/G3), metastasis, lymph node invasion, microscopic vascular infiltration. Mann-Whitney with Bonferroni corrected p values assessed differences. Discriminative power of significant RF was calculated for each of the end-points. The performance of conventional-imaged-based-parameters was also compared to RF.

RESULTS

Thirty-nine patients were included (mean age 55-years-old; 24 male). Mean diameters of the lesions were 24 × 27 mm. Sixty-nine RF were considered. Sphericity could discriminate high grade tumors (AUC = 0.79, p = 0.002). Tumor volume (AUC = 0.79, p = 0.003) and several non-ceCT and ceCT RF were able to identify microscopic vascular infiltration: voxel-alignment, neighborhood intensity-difference and intensity-size-zone families (AUC ≥ 0.75, p < 0.001); voxel-alignment, intensity-size-zone and co-occurrence families (AUC ≥ 0.78, p ≤ 0.002), respectively). Non-ceCT neighborhood-intensity-difference (AUC = 0.75, p = 0.009) and ceCT intensity-size-zone (AUC = 0.73, p = 0.014) identified lymph nodal invasion; several non-ceCT and ceCT voxel-alignment family features were discriminative for metastasis (p < 0.01, AUC = 0.80-0.85). Conventional CT 'necrosis' could discriminate for microscopic vascular invasion (AUC = 0.76, p = 0.004) and 'arterial vascular invasion' for microscopic metastasis (AUC = 0.86, p = 0.001). No conventional-imaged-based-parameter was significantly associated with grade and lymph node invasion.

CONCLUSIONS

Radiomic features can discriminate histopathology of panNET, suggesting a role of radiomics as a non-invasive tool for tumor characterization.

TRIAL REGISTRATION NUMBER

NCT03967951, 30/05/2019.

Epidemiology and Retrospective Analysis in Extrapulmonary Neuroendocrine Carcinoma

Objectives: We conducted a retrospective analysis of patients with extrapulmonary neuroendocrine carcinomas (EPNECs) to explore the distribution and overall outcomes by different regimens and their primary sites.

Setting: We reviewed the outcomes of one of the largest data sets of patients with extrapulmonary small cell carcinomas (EPSCCs) identified at Allegheny General Hospital located in Pittsburgh, Pennsylvania, USA.

Participants: Patients diagnosed with grade 3 EPNECs were retrospectively identified.

Primary endpoint and epidemiology: Overall survival (OS) with different treatment regimens was the primary endpoint. Also, epidemiological factors such as risk factors, race, family history of cancer, and associated comorbidities were recorded.

Results: OS was 16 months in seven patients who received cisplatin/etoposide chemotherapy and 8.5 months in seven patients with carboplatin/etoposide chemotherapy. The commonest primary site was the gastrointestinal tract (GIT). Smoking history association was observed to be 50%. Merkel cell carcinoma (MCC) patients had significantly better OS. Simultaneously, an extensive form of disease pattern was also noticed in 94.4% of the patients. Significantly, neutropenic sepsis was observed in 71.4% of the patients who were treated with cisplatin/etoposide combination.

Conclusion: EPNECs demonstrated a low response rate to chemotherapy and high rates of distant metastases. Conclusively, brain metastases were rare.

Analysis of miR-29 Serum Levels in Patients with Neuroendocrine Tumors-Results from an Exploratory Study

BACKGROUND AND AIMS

Due to its involvement in tumor biology as well as tumor-associated stroma cell responses, recent data suggested a potential role of miR-29 as a biomarker for different malignancies. However, its role in neuroendocrine tumors (NETs) is only poorly understood.

METHODS

We measured circulating levels of miR-29b in 45 patients with NET and compared them to 19 healthy controls. Results were correlated with clinical records.

RESULTS

In our cohort of NET patients treated between 2010 and 2019 at our department, miR-29b serum levels were significantly downregulated when compared to healthy control samples. Further, a significant correlation between chromogranin A (CgA) and relative miR-29b levels was noted. However, serum levels of miR-29b were independent of tumor-related factors such as proliferation activity according to Ki-67 index, tumor grading, the TMN stage of malignant tumors, somatostatin receptor expression or clinical features such as functional or non-functional disease and presence of tumor relapse. Finally, in contrast to previous results from other malignancies, miR-29b serum levels were not a significant predictor of overall survival in NET patients.

CONCLUSION

Our data suggest a role for miR-29b serum levels as a previously unrecognized biomarker for diagnosis of NET. However, miR-29 does not allow for predicting tumor stage or patients' outcome.

How I treat neuroendocrine tumours

Neuroendocrine tumours (NETs) constitute a heterogeneous group of neoplasms characterised by variable endocrine activity and somatostatin receptor expression, with the latter allowing the use of targeted therapeutic concepts. Currently accepted treatment strategies for advanced well-differentiated NET include somatostatin analogues octreotide and lanreotide, peptide receptor radionuclide therapy using radiolabelled somatostatin analogues, mammalian target of Rapamycin inhibitor everolimus, tyrosine kinase inhibitor sunitinib, interferon alpha and classical cytostatic, such as streptozotocin-based and temozolomide-based treatment. Indication, use and approval of these treatments differ based on primary tumour origin, grading and symptomatic burden and require an optimised multidisciplinary cooperation of medical oncologists, endocrinologists and nuclear medicine specialists. Interestingly, hot topics in oncology including immunotherapy and use of next-generation-sequencing techniques currently play a minor role for the treatment of NETs. The recent revision of the WHO classification including the recognition of the novel NET G3 category allows for potentially more tailored treatment strategies in the near future. However, this new entity also poses a therapeutic challenge as only limited data are currently available. The present article aims to provide an overview on our personal treatment concepts for advanced NETs with a focus on tumours of gastroenteropancreatic origin.

Pancreatic neuroendocrine tumors G3 and pancreatic neuroendocrine carcinomas: Differences in basic biology and treatment

In 2017 the World Health Organization revised the criteria for classification of pancreatic neuroendocrine neoplasms (pNENs) after a consensus conference at the International Agency for Research on Cancer. The major change in the new classification was to subclassify the original G3 group into well-differentiated pancreatic neuroendocrine tumors G3 (pNETs G3) and poorly differentiated pancreatic neuroendocrine carcinomas (pNECs), which have been gradually proven to be completely different in biological behavior and clinical manifestations in recent years. In 2019 this major change subsequently extended to NENs involving the entire digestive tract. The updated version of the pNENs grading system marks a growing awareness of these heterogeneous tumors. This review discusses the clinicopathological, genetic and therapeutic features of poorly differentiated pNECs and compare them to those of well-differentiated pNETs G3. For pNETs G3 and pNECs (due to their lower incidence), there are still many problems to be investigated. Previous studies under the new grading classification also need to be reinterpreted. This review summarizes the relevant literature from the perspective of the differences between pNETs G3 and pNECs in order to deepen understanding of these diseases and discuss future research directions.

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.

S-1 plus apatinib followed by salvage esophagectomy for irinotecan-refractory small cell carcinoma of the esophagus: A case report and review of the literature

RATIONALE

Small cell carcinoma of the esophagus (SCCE) is an uncommon but lethal disease characterized by dismal prognosis. Only 10% of advanced SCCE patients survive longer than 1 year. Resection is a choice for limited-stage cases, whereas the optimal treatment regimen for primary SCCE is yet to be elucidated. To the best of our knowledge, the efficacy of S-1 plus apatinib for irinotecan-refractory SCCE has not been reported before.

PATIENT CONCERNS

A 61-year old, previously healthy male was admitted for dysphagia and fatigue. Endoscopic biopsy revealed a tumor in the middle third of the esophagus. Further exams including abdomen computed tomography excluded distant metastasis.

DIAGNOSES

Primary SCCE (pT1bN1M0, IIB) was established after salvage operation.

INTERVENTIONS

The tumor was enlarged after 1 cycle of first-line chemotherapy using irinotecan plus cisplatin, which indicated drug resistance. Second-line oral apatinib (425 mg daily) plus S-1 (60 mg, twice daily for 4 weeks with a 2-week drug-free interval) for a month showed efficacy, as shown by decreased serum neuron-specific enolase and stable of the esophageal lesion. Thereafter, salvage minimally invasive Ivor-Lewis esophagectomy and 2-field lymph node dissection was performed, followed by oral apatinib plus S-1 at the prior dosage for 6 months. In addition, maintenance therapy using low-dose apatinib (250 mg daily) plus S-1 (40 mg, twice daily for 4 weeks with a 2-week interval) were administered for another 6 months. Then the patient was followed up irregularly at the outpatient clinic.

OUTCOMES

The adverse events including hand-foot syndrome, hypertension, vomiting, leukopenia, impaired hepatic function, and fatigue were mainly tolerable. Forty months after the operation, he was readmitted for back pain and disseminated bone metastases appeared in magnetic resonance images. His progression-free survival could not be obtained precisely, and his overall survival was longer than 40 months up to September 2019.

LESSONS

S-1 plus apatinib followed by a timely esophagectomy with curative intent might be an alternative option for chemotherapy-refractory SCCE in selected patients. Better evidence is warranted.

Recent Survival Trends in High-Grade Neuroendocrine Neoplasms and Lung Cancer

BACKGROUND

Poorly differentiated neuroendocrine neoplasms (pdNEN) are a rare cancer entity, treatment of which is to a great part informed by studies on the much more common small-cell lung cancer (SCLC).

OBJECTIVE

To reveal and compare recent survival trends for pdNEN and SCLC in an authorative, population-based database.

METHODS

Using the Surveillance, Epidemiology, and End Results 18 database, 3,482 digestive tract pdNEN and 30,383 SCLC diagnosed from 2000 through 2015 were analyzed in detail.

RESULTS

Whereas changes in one- and 2-year relative survival in pdNEN were small, improvements in median survival appeared consistent and relevant. For example, median survival (95% CI) for distant disease pdNEN diagnosed in 2000-2004, 2005-2009, and 2010-2015 was 4.6 (3.8-5.4), 5.6 (4.5-6.7), and 6.4 (5.4-7.5) months. Changes in SCLC survival during the study period overall were even more limited, which - in the case of distant disease - meant that survival disadvantages of patients with pdNEN as compared to SCLC disappeared during the study period. Unfortunately, relevant improvements in year-wise conditional survival after the first year since diagnosis essentially were restricted to localized pdNEN and localized SCLC.

CONCLUSIONS

Our results should stipulate further research, in particular, of the pdNEN-SCLC relationship. They will also be helpful in patient care and communication, providing the first conditional survival details in this context, a highly patient-relevant outcome.

Therapy of Patients with Neuroendocrine Neoplasia-Evidence-Based Approaches and New Horizons

Neuroendocrine tumors (NETs) show low but increasing incidence and originate in multiple organs, including the pancreas, midgut, caecum, rectum, appendix, colon, and lungs. Due to their stunning genetic, histological, and clinical variability, diagnosis and treatment of NETs are challenging. In addition, low incidence and high variability hamper the implementation of high evidence trials. Therefore, guidelines do not cover the complexity of NETs and, frequently, treatment decisions are taken by interdisciplinary tumor conferences at comprehensive cancer centers. Treatment aims are (i) control of tumor growth, (ii) symptom control, as well as (iii) the improvement of progression-free survival (PFS) and overall survival (OS). Here, we discuss high evidence trials facilitating the achievement of these treatment aims. The majority of the evidence exists for treatment with somatostatin analogue, everolimus, peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE, sunitinib, and telotristat. Among those, PRRT is the only treatment option that has the potential to control symptoms, stop tumor growth, and to improve PFS and OS. In contrast, only a low level of evidence exists for treatment with cytotoxic drugs such as streptozotocin and doxorubicine. Finally, we discuss novel treatment options by a combination of cytotoxic drugs, 177Lu-DOTATATE, and tyrosine kinase inhibitors to be tested in randomized prospective trials in the future. In addition, the application of innovative isotopes, such as 225Ac, for PRRT is discussed.

Analysis of B-ultrasound and contrast-enhanced ultrasound characteristics of different hepatic neuroendocrine neoplasm

BACKGROUND

Hepatic neuroendocrine neoplasm (hNEN) is a highly heterogeneous tumor. The exact identification of the source and malignant degree of hNEN is important. However, there is a lack of information regarding diagnosis of hNEN with imaging. In addition, no studies have compared the imaging between hNEN and hepatocellular carcinoma (HCC) and among different sources and malignant degrees of hNEN.

AIM

To compare the ultrasound characteristics between hNEN and HCC and among different sources and malignant degrees of hNEN.

METHODS

A total of 55 patients with hNEN were recruited and defined as the hNEN group. Among them, 35 cases of hNET were defined as the hNET group. Twenty cases of hepatic neuroendocrine carcinoma (hNEC) were defined as the hNEC group. Among the 55 lesions, 29 were transferred from the pancreas, 20 were from the gastrointestinal tract, and six were from other sites. In total, 55 patients with HCC were recruited and defined as the HCC group. The characteristic differences of B-mode ultrasound and contrast-enhanced ultrasound (CEUS) between hNEN and HCC and among different sources and malignant degrees of hNEN were compared.

RESULTS

In the hNEN group, the proportions of multiple liver lesions, unclear borders, and high echo lesions were higher than those in the HCC group. The proportions of non-uniform echo and peripheral acoustic halo were lower than those in the HCC group (P < 0.05). The washout to iso-enhancement time and washout to hypo-enhancement time were lower than those in the HCC group (P < 0.05). The characteristics of B-ultrasound and CEUS among different sources of hNEN were similar, and the differences were not statistically significant (P > 0.05). B-mode ultrasound characteristics of hNET and hNEC were similar. The proportions of low enhancement at portal venous phase, non-uniform enhancement forms, and combined tumor vasculature in the hNEC group were larger than those in the hNEN group (P < 0.05).

CONCLUSION

Compared with HCC, hNEN showed multiple intrahepatic lesions, uniform high echo, uniform high enhancement at arterial phase, and rapid washout. Low enhancement at portal venous phase, overall non-uniform enhancement form, and the proportion of combined tumor vasculature in hNEC were larger than those in hNET.

Long-term control with chemoradiation of initially metastatic mixed adenoneuroendocrine carcinoma of the rectum: a case report

BACKGROUND

Mixed adenoneuroendocrine carcinomas are highly malignant tumors with both adenocarcinomatous and neuroendocrine components. They can originate in any organ but are more common in the rectum. Due to their rarity, current treatment recommendations for mixed adenoneuroendocrine carcinoma are based on limited data and follow general guidelines for the management of adenocarcinomas and neuroendocrine neoplasms. Uncertainty regarding the efficacy of the available local and systemic treatment strategies is a compounding issue. Even those patients with locally limited disease have a relatively short life expectancy. In this report, we describe a case of deep rectal mixed adenoneuroendocrine carcinoma with long survival after chemoradiation.

CASE PRESENTATION

A 48-year-old Caucasian woman was diagnosed with a grade 3 rectal adenocarcinoma combined with a poorly differentiated large cell neuroendocrine carcinoma component and synchronous metastases (cT3cN1cM1) in both lobes of the liver in 2012. She received concomitant chemoradiotherapy followed by four additional cycles of cisplatin plus irinotecan. Initial treatment induced complete remission of the rectal tumor and liver metastases. Consequently, it was not necessary to surgically resect the primary tumor or any of the metastases. Three months after the end of treatment, one metastasis in the first segment of the liver showed regrowth, and stereotactic body radiotherapy of the metastasis and chemotherapy resulted in a clinical complete response. The patient has been recurrence-free for more than 5 years.

CONCLUSIONS

Extended long-term control of a poorly differentiated metastatic (stage IV) mixed adenoneuroendocrine carcinoma is rare. The multimodal first- and second-line regimens of radiotherapy and chemotherapy described in this case report represent a new therapeutic approach. Encouraged by the results in this case, we compiled a review of the literature on mixed adenoneuroendocrine carcinoma.

Clinicopathological Profiling of Lung Carcinoids with a Ki67 Index > 20

The clinicopathological features of lung neuroendocrine neoplasms (NEN) with a high proliferative index at the border area between atypical carcinoid and neuroendocrine carcinoma have not been investigated so far. The aim of this study was, therefore, to search for lung NENs which are well differentiated but show Ki67 values that overlap with those of poorly differentiated (PD)-NENs. Resected lung NENs from 244 Japanese patients were reviewed, and Ki67 indices were assessed in all tumors. The data were then correlated to clinicopathological parameters and patient outcome. Among 59 (24%) well-differentiated (WD)-NENs and 185 (76%) lung PD-NENs, 7 were defined as WD-NENs with Ki67 indices > 20%. The Ki67 indices of these tumors (mean 29%, range 24-36) were significantly lower than those of PD-NENs (mean 74%, range 34-99). All WD-NENs with Ki67 > 20% lacked abnormal p53 and loss of retinoblastoma 1 (Rb1) expression. In contrast, many PD-NENs expressed p53 (48%) and showed loss of Rb1 (86%). The 2- and 5-year disease-free survival rates in WD-NEN patients with Ki67 > 20% were lower than those of WD-NEN patients with Ki67 ≤20% (p < 0.01 for disease-free and overall survival). No statistical differences were detected between outcome of WD-NEN patients with Ki67 > 20% and those of PD-NEN. It is concluded that WD-NEN patients with Ki67 > 20% share the morphological and immunohistochemical features of WD-NEN patients with Ki67 ≤20%, but they have a worse prognosis, suggesting that this tumor group requires particular attention in future classifications and probably new therapeutic regimes.

The theranostic promise for Neuroendocrine Tumors in the late 2010s - Where do we stand, where do we go?

More than 25 years after the first peptide receptor radionuclide therapy (PRRT), the concept of somatostatin receptor (SSTR)-directed imaging and therapy for neuroendocrine tumors (NET) is seeing rapidly increasing use. To maximize the full potential of its theranostic promise, efforts in recent years have expanded recommendations in current guidelines and included the evaluation of novel theranostic radiotracers for imaging and treatment of NET. Moreover, the introduction of standardized reporting framework systems may harmonize PET reading, address pitfalls in interpreting SSTR-PET/CT scans and guide the treating physician in selecting PRRT candidates. Notably, the concept of PRRT has also been applied beyond oncology, e.g. for treatment of inflammatory conditions like sarcoidosis. Future perspectives may include the efficacy evaluation of PRRT compared to other common treatment options for NET, novel strategies for closer monitoring of potential side effects, the introduction of novel radiotracers with beneficial pharmacodynamic and kinetic properties or the use of supervised machine learning approaches for outcome prediction. This article reviews how the SSTR-directed theranostic concept is currently applied and also reflects on recent developments that hold promise for the future of theranostics in this context.

My burning issues in neuroendocrine tumours (NET)

Several compounds have recently been approved for the systemic treatment of advanced well-differentiated neuroendocrine tumours (NET) of gastroenteropancreatic (GEP) or lung origin. Based on the PROMID and CLARINET trials, somatostatin analogues (SSA) are the preferred first-line approach for all GEP-NET and offer-in addition to antiproliferative effects-durable symptomatic relief for hormonally active tumours. The mTOR inhibitor everolimus has been approved for progressive GEP- and lung-NET and is a widely used drug in this setting. Furthermore, recent results have underlined the high efficacy of somatostatin-receptor targeting radionuclide therapy (PRRT) in somatostatin-receptor positive midgut tumours and PRRT is now considered standard treatment for midgut-NET progressing on SSA. The optimal application of PRRT in somatostatin receptor positive NET with non-midgut site is currently an issue of discussion and should be decided on an individually basis in multidisciplinary boards. Following new insights in the genetic landscape of NET, "hot topics" in recent months include optimal treatment of the recently defined NET G3 and preliminary data on immunotherapy.

Primary Gastric Small Cell Carcinoma: A Case Identified as a Large Subepithelial Tumor from Invisible State in 6 Months

Primary gastric small cell carcinoma (GSCC) is one of the gastroenteropancreatic neuroendocrine tumors. It is a rare cancer with a very aggressive behavior and a poor prognosis because of the high rate of metastases. It is usually found in far advanced stage. We experienced a case of GSCC which had developed into a large subepithelial tumor (SET) from invisible state in a short period. A 65-year-old man consulted our hospital because of early gastric cancer. He underwent endoscopic submucosal dissection for the early gastric cancer at high body posterior wall. After 6 months, the follow-up endoscopy showed a large newly developed SET-like lesion with central ulceration at the gastric cardia. Endoscopic biopsy revealed GSCC. Total gastrectomy was performed. One out of the 26 perigastric lymph nodes had a metastasis. He received 6 cycles of adjuvant chemotherapy with etoposide and cisplatin. He is still in good health 12 months after operation.

Open issues on G3 neuroendocrine neoplasms: back to the future

The recent recognition that grade 3 (G3) neuroendocrine neoplasms (NENs) can be divided into two different categories according to the histopathological differentiation, that is G3 neuroendocrine tumors (NETs) and G3 neuroendocrine carcinomas (NECs) has generated a lot of interest concerning not only the diagnosis, but also the differential management of such new group of NENs. However, several issues need to be fully clarified in order to put G3 NETs and G3 NECs in the right place. The aim of this review is to focus on those issues that are still undetermined starting from the current knowledge, evaluating the available evidence and the possible clinical implications.

Extra-Pulmonary Neuroendocrine Carcinomas: A Population-Based Study in the Netherlands

BACKGROUND

Extra-pulmonary neuroendocrine carcinomas (EP-NEC) are rare tumours that require expertise for correct and timely diagnosis, which is essential for clinical decision making. The number of patients affected, treatment given, and the proportion surviving the disease is based on limited evidence. The aim of this study is to retrospectively analyse the incidence, treatment, and relative survival (RS) of EP-NEC patients in the Netherlands.

METHODS

Patients diagnosed between 2008-2012 with EP-NEC or NEC with unknown primary site (UP-NEC) were selected from the Netherlands Cancer Registry based on combinations of tumour localisation and morphology code. Incidence was studied using the European standardised (ESR) and world standardised rates, and RS was calculated using the Ederer II method.

RESULTS

In total, 1,544 cases were analysed, 1,045 EP-NEC and 499 UP-NEC. For EP-NEC, the incidence was 1.0 per 100,000 person-years (ESR), the mean age was 68 years, and the male to female ratio was 1: 0.6. Most frequent EP-NEC localisations were the bladder and the gastrointestinal tract, and the treatment most frequently given was surgery in combination with chemotherapy. The overall 5-year RS was 38% for patients with local/regional disease (n = 447), and 7% for patients with extensive disease (n = 582). For UP-NEC patients (n = 499), the 5-year RS was 6%.

CONCLUSIONS

This study is the first nationwide study presenting an increase in the incidence of EP-NEC patients from 196 to 260 cases annually in the Netherlands. The best 5-year RS was found for EP-NEC patients with local disease located in the bladder, where the worst 5-year RS was found for patients with disease located in the oesophagus.

Extremely Long Survival under Combined Immunotherapy in a Metastatic Functional Neuroendocrine Neoplasia Patient

Treatment and prognosis of neuroendocrine neoplasia depends on tumor size, stage, grade, resectability, and extent of distant metastasis. In most cases a multimodality approach including surgical, locally invasive procedures, peptide-guided radioreceptor therapy (PRRT), and medical therapies represent the mainstay of treatment in advanced disease. In the reported case, a 68-year-old man was diagnosed in 2010 with an initially functional (histamine) neuroendocrine tumor of gastric type III, G2, stage IVB, cT4cN1cM1 (hepatic, peritoneal, nodal, osseous), including a hepatic tumor load of 25%. Intensive multimodality approaches including combined immunotherapy (vaccination and PD-1/CTLA-4 blockade) led to a survival of 8 years until now with a high quality of life and minimal residual disease (only a single, small paragastric recurrence) despite the dedifferentiation of the tumor into a neuroendocrine carcinoma G3 (Ki-67 of 80%) including a nonfunctional stage.

[Classification of pancreatic neuroendocrine tumours: Changes made in the 2017 WHO classification of tumours of endocrine organs and perspectives for the future]

The WHO classification of the tumors of endocrine organs, published in July 2017, has introduced significant changes in the classification of pancreatic neuroendocrine tumors, the previous version of which has appeared in 2010, within the WHO classification of the tumors of the digestive system. The main change is the introduction of a new category of well-differentiated neoplasms, neuroendocrine tumors G3, in addition to the previous categories of neuroendocrine tumors G1 and G2. The differential diagnosis between neuroendocrine tumors G3 (well-differentiated) and neuroendocrine carcinomas (poorly-differentiated) might be difficult; the authors of the WHO classification therefore suggest the use of a number of immunohistochemical markers to facilitate the distinction between the two entities. The other changes are: (a) the modification of the threshold between neuroendocrine tumors G1 and G2, now set at 3%; (b) the terminology used for mixed tumors: the previous term mixed adeno-neuroendocrine carcinoma (MANEC) is substituted by the term mixed neuroendocrine-non neuroendocrine neoplasm (MiNEN). Finally, the recommendations for Ki-67 index evaluation are actualized. Even if these changes only concern, stricto sensu, the neuroendocrine tumors of pancreatic location, they will probably be applied, de facto, for all digestive neuroendocrine tumors. The revision of the histological classification of pancreatic neuroendocrine tumors coincides with the revision of their UICC TNM staging; significant changes have been made in the criteria for T3 and T4 stages. Our professional practices have to take into account all these modifications.

Classification of pulmonary neuroendocrine tumors: new insights

Neuroendocrine tumors of the lung (Lu-NETs) embrace a heterogeneous family of neoplasms classified into four histological variants, namely typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC). Defining criteria on resection specimens include mitotic count in 2 mm2 and the presence or absence of necrosis, alongside a constellation of cytological and histological traits including cell size and shape, nuclear features and overall architecture. Clinically, TC are low-grade malignant tumors, AC intermediate-grade malignant tumors and SCLC/LCNEC high-grade malignant full-blown carcinomas with no significant differences in survival between them. Homologous tumors arise in the thymus that occasionally have some difficulties in differentiating from the lung counterparts when presented with large unresectable or metastatic lesions. Immunohistochemistry (IHC) helps refine NE diagnosis at various anatomical sites, particularly on small-sized tissue material, in which only TC and small cell carcinoma categories can be recognized easily on hematoxylin & eosin stain, while AC and LCNEC can only be suggested on such material. The Ki-67 labeling index effectively separates carcinoids from small cell carcinoma and may prove useful for the clinical management of a metastatic disease to help the therapeutic decision-making process. Although carcinoids and high-grade neuroendocrine carcinomas in the lung and elsewhere make up separate tumor categories on molecular grounds, emerging data supports the concept of secondary high-grade NETs arising in the preexisting carcinoids, whose clinical and biological relevance will have to be placed into the proper context for the optimal management of these patients. In this review, we will discuss the selected, recent literature with a focus on current issues regarding Lu-NET nosology, i.e., classification, derivation and tumor evolution.

Rb Loss and KRAS Mutation Are Predictors of the Response to Platinum-Based Chemotherapy in Pancreatic Neuroendocrine Neoplasm with Grade 3: A Japanese Multicenter Pancreatic NEN-G3 Study

Purpose: Patients with pancreatic neuroendocrine neoplasm grade-3 (PanNEN-G3) show variable responses to platinum-based chemotherapy. Recent studies indicated that PanNEN-G3 includes well-differentiated neuroendocrine tumor with G3 (NET-G3). Here, we examined the clinicopathologic and molecular features of PanNEN-G3 and assessed the responsiveness to chemotherapy and survival.Experimental Design: A total of 100 patients with PanNEN-G3 were collected from 31 institutions, and after central review characteristics of each histologic subtype [NET-G3 vs. pancreatic neuroendocrine carcinoma (NEC-G3)] were analyzed, including clinical, radiological, and molecular features. Factors that correlate with response to chemotherapy and survival were assessed.Results: Seventy patients analyzed included 21 NETs-G3 (30%) and 49 NECs-G3 (70%). NET-G3 showed lower Ki67-labeling index (LI; median 28.5%), no abnormal Rb expression (0%), and no mutated KRAS (0%), whereas NEC-G3 showed higher Ki67-LI (median 80.0%), Rb loss (54.5%), and KRAS mutations (48.7%). Chemotherapy response rate (RR), platinum-based chemotherapy RR, and prognosis differed significantly between NET-G3 and NEC-G3. Chemotherapeutic outcomes were worse in NET-G3 (P < 0.001). When we stratified PanNEN-G3 with Rb and KRAS, PanNENs-G3 with Rb loss and those with mutated KRAS showed significantly higher RRs to platinum-based chemotherapy than those without (Rb loss, 80% vs. normal Rb, 24%, P = 0.006; mutated KRAS, 77% versus wild type, 23%, P = 0.023). Rb was a predictive marker of response to platinum-based chemotherapy even in NEC-G3 (P = 0.035).Conclusions: NET-G3 and NEC-G3 showed distinct clinicopathologic characteristics. Notably, NET-G3 does not respond to platinum-based chemotherapy. Rb and KRAS are promising predictors of response to platinum-based chemotherapy for PanNEN-G3, and Rb for NEC-G3. Clin Cancer Res; 23(16); 4625-32. ©2017 AACR.