Clinical and Biomarker Evaluations of Sunitinib in Patients with Grade 3 Digestive Neuroendocrine Neoplasms

[Clinical significance of neuroendocrine tumors : Incidence, symptoms, diagnosis, stage, and prognostic factors and their influence on disease management]

BACKGROUND

Neuroendocrine neoplasms (NEN) are heterogenous with an increasing incidence in recent years.

OBJECTIVES

Overview on incidence, symptoms, diagnostics, grading, imaging and prognostic determinants, including factors having an impact on therapeutic management.

METHODS

Review on current literature, including original articles, reviews, guidelines and expert opinions.

RESULTS

NEN are mainly located in the gastrointestinal tract and their incidence has increased in recent years, mainly due to improved diagnostics, e.g., cross-sectional imaging. Clinical characteristics include hormone excess syndromes (carcinoid syndrome). Laboratory markers such as chromogranin A are commonly used as part of routine diagnostics, followed by endoscopic and endosonographic procedures, which also allow biopsies to be obtained. Tumor spread can be determined by contrast-enhanced computed tomography/magnetic resonance imaging (CT/MRI) or somatostatin receptor (SSRT)-PET/CT (positron emission tomography). Prognostic factors include Ki67 index, type, and grading. Resection with curative intent is the therapy of choice. In a metastasized setting, SSRT-directed treatment approaches are favored, while in dedifferentiated NEN, conventional chemotherapy is needed.

CONCLUSION

A broad diagnostic armamentarium can be offered to NEN patients and the improved diagnostic procedures have most likely caused a raising incidence in recent years. Among others, prognostic factors are Ki67 and NEN subtypes; these clinical determinants also have an impact on patient management.

Surufatinib plus toripalimab in patients with advanced neuroendocrine tumours and neuroendocrine carcinomas: An open-label, single-arm, multi-cohort phase II trial

BACKGROUND

The programmed death 1 inhibitor toripalimab plus the angio-immuno kinase inhibitor surufatinib revealed a tolerable safety profile and preliminary efficacy in patients with advanced solid tumours in a phase I study.

PATIENTS AND METHODS

This was an open-label, single-arm, multi-cohort phase II study in China. Patients with advanced neuroendocrine tumours (NETs) or neuroendocrine carcinomas (NECs) or mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) who had failed or were intolerable of standard treatment were given surufatinib (250 mg orally, once daily) plus toripalimab (240 mg intravenously, once every 3 weeks). Primary end-point was investigator-assessed objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1. Secondary end-points included duration of response (DoR), disease control rate, progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Forty patients were enrolled into two cohorts by tumour types (NET, n = 19; NEC-MiNEN, n = 21). ORRs (95% CIs) were 21.1% (6.1-45.6) and 23.8% (8.2-47.2) in the NET and NEC-MiNEN cohorts, respectively. Median DoR was 7.1 months (6.9-not evaluable [NE]) and 4.1 months (3.0-NE), respectively. Median PFS was 9.6 months (4.1-NE) and 4.1 months (1.5-5.5); median OS was 27.3 (15.3-NE) and 10.9 months (9.1-14.6), respectively. Overall, grade ≥ 3 treatment-related adverse events occurred in 18 (45.0%) patients.

CONCLUSIONS

Surufatinib plus toripalimab showed antitumour activity and a tolerable safety profile in patients with previously treated NETs/NECs/MiNENs. Further study of this combination regimen is ongoing for advanced NECs, for which current therapeutic options remain limited.

CLINICALTRIALS

gov: NCT04169672.

Treatment modalities favoring outcome in well-differentiated neuroendocrine tumors G3

Introduction

Neuroendocrine neoplasms (NEN) are a rare and heterogenous group of tumors arising from neuroendocrine cells in multiple organs. Neuroendocrine tumors (NET) G3 encompass a small subgroup accounting for less than 10% of all neuroendocrine neoplasms. In contrast to NET G1 and G2 as well as neuroendocrine carcinomas (NEC), in NET G3 data on treatment and patient outcomes are still limited. Especially in a metastasized tumor stage, the role of surgery, peptide receptor radionucleotide therapy (PRRT), and systemic chemotherapy is not clearly defined.

Methods

In this real-life cohort, we consecutively analyzed clinical outcome in NET G3 patients receiving different diagnostic and treatment.

Results and discussion

We found that even metastasized NET G3 patients undergoing surgery, or receiving radiation, somatostatin analogues (SSA), and PRRT showed a clear survival benefit. Interestingly, all treatment regimen were superior to classical chemotherapeutic agents. In addition, somatostatin receptor (SSTR) PET-CT, FDG PET-CT, and repetitive biopsies were shown to be useful diagnostic and prognostic tools in NET G3. Our study demonstrates that patients with highly proliferative NET G3 might benefit from less aggressive treatment modalities commonly used in low proliferative NEN.

Extrapulmonary Neuroendocrine Carcinomas: Current Management and Future Perspectives

Neuroendocrine carcinomas (NECs) are poorly differentiated and highly aggressive epithelial neuroendocrine neoplasms. The most common primary site is the lung, but they may arise in every organ. Approximately 37% of extrapulmonary NECs (EP-NECs) occur in the gastroenteropancreatic (GEP) tract, followed by the genitourinary (GU) system and gynecological tract. As a result of their rarity, there is scant evidence to guide treatment recommendations, and a multidisciplinary approach is essential for the management of such patients. Platinum-based chemotherapy currently represents the standard of care for EP-NECs of any site, mirroring the management of small-cell lung cancer (SCLC), but further approaches are still under investigation. Indeed, ongoing trials evaluating targeted therapies, immune checkpoint inhibitors (ICIs), and radionuclide therapy could provide potentially breakthrough therapeutic options. Given the relative dearth of evidence-based literature on these orphan diseases, the aim of this review is to provide an overview of the pathology and current treatment options, as well as to shed light on the most pressing unmet needs in the field.

European Neuroendocrine Tumour Society (ENETS) 2023 guidance paper for nonfunctioning pancreatic neuroendocrine tumours

This ENETS guidance paper for well-differentiated nonfunctioning pancreatic neuroendocrine tumours (NF-Pan-NET) has been developed by a multidisciplinary working group, and provides up-to-date and practical advice on the management of these tumours. Using the extensive experience of centres treating patients with NF-Pan-NEN, the authors of this guidance paper discuss 10 troublesome questions in everyday clinical practice. Our many years of experience in this field are still being verified in the light of the results of new clinical, which set new ways of proceeding in NEN. The treatment of NF-Pan-NEN still requires a decision of a multidisciplinary team of specialists in the field of neuroendocrine neoplasms.

Managing Metastatic Extrapulmonary Neuroendocrine Carcinoma After First-Line Treatment

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Tyrosine Kinase Inhibitors and Immunotherapy Updates in Neuroendocrine Neoplasms

Neuroendocrine tumors (NETs) represent a heterogeneous group of malignancies that arise from neuroendocrine cells dispersed throughout the organs/tissues of the body. Treatment of advanced/metastatic disease varies depending on tumor origin and grade. Somatostatin analogs (SSA) have been the mainstay first-line treatment in the advanced/metastatic setting for tumor control and managing hormonal syndromes. Treatments beyond SSAs have expanded to include everolimus (mTOR inhibitor), tyrosine kinase inhibitors (TKI) (e.g., sunitinib), and peptide receptor radionuclide therapy (PRRT) with the choice of therapy to some extent dictated by the anatomic origin of the NETs. This review will focus on emerging systemic treatments for advanced/metastatic NETs, particularly TKIs, and immunotherapy.

Potent molecular-targeted therapies for gastro-entero-pancreatic neuroendocrine carcinoma

Neuroendocrine neoplasms (NENs), which are characterized by neuroendocrine differentiation, can arise in various organs. NENs have been divided into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs) based on morphological differentiation, each of which has a distinct etiology, molecular profile, and clinicopathological features. While the majority of NECs originate in the pulmonary organs, extrapulmonary NECs occur most predominantly in the gastro-entero-pancreatic (GEP) system. Although platinum-based chemotherapy is the main therapeutic option for recurrent or metastatic GEP-NEC patients, the clinical benefits are limited and associated with a poor prognosis, indicating the clinically urgent need for effective therapeutic agents. The clinical development of molecular-targeted therapies has been hampered due to the rarity of GEP-NECs and the paucity of knowledge on their biology. In this review, we summarize the biology, current treatments, and molecular profiles of GEP-NECs based on the findings of pivotal comprehensive molecular analyses; we also highlight potent therapeutic targets for future precision medicine based on the most recent results of clinical trials.

Integrating Functional Imaging and Molecular Profiling for Optimal Treatment Selection in Neuroendocrine Neoplasms (NEN)

PURPOSE OF REVIEW

Gastroenteropancreatic NEN (GEP-NEN) are group of malignancies with significant clinical, anatomical and molecular heterogeneity. High-grade GEP-NEN in particular present unique management challenges.

RECENT FINDINGS

In the current era, multidisciplinary management with access to a combination of functional imaging and targeted molecular profiling can provide important disease characterisation, guide individualised management and improve patient outcome. Multiple treatment options are now available, and combination and novel therapies are being explored in clinical trials. Precision medicine is highly relevant for a heterogenous disease like NEN. The integration of dual-tracer functional PET/CT imaging, molecular histopathology and genomic data has the potential to be used to gain a more comprehensive understanding of an individual patient's disease biology for precision diagnosis, prognostication and optimal treatment allocation.

The Glasgow Prognostic Score Predicts Survival Outcomes in Neuroendocrine Neoplasms of the Gastro-Entero-Pancreatic (GEP-NEN) System

Background: Across a variety of solid tumors, prognostic implications of nutritional and inflammation-based risk scores have been identified as a complementary resource of risk stratification. Methods: In this retrospective study, we performed a comparative analysis of several established risk scores and ratios, such as the Glasgow Prognostic Score (GPS), in neuroendocrine neoplasms of the gastro−entero−pancreatic (GEP-NEN) system with respect to their prognostic capabilities. Clinicopathological and treatment-related data for 102 GEP-NEN patients administered to the participating institutions between 2011 and 2021 were collected. Scores/ratios significantly associated with overall or progression-free survival (OS, PFS) upon univariate analysis were subsequently included in a Cox-proportional hazard model for the multivariate analysis. Results: The median age was 62 years (range 18−95 years) and the median follow-up period spanned 51 months. Pancreatic or intestinal localization at the initial diagnosis were present in 41 (40.2%) and 44 (43.1%) cases, respectively. In 17 patients (16.7%), the primary manifestation could not be ascertained (NNUP; neuroendocrine neoplasms of unknown primary). Histological grading (HG) revealed 24/102 (23.5%) NET/NEC (poorly differentiated; high grade G3) and 78/102 (76.5%) NET (highly or moderately differentiated; low−high grade G1−G2). In total, 53/102 (51.9%) patients presented with metastatic disease (UICC IV), 11/102 (10.7%) patients presented with multifocal disease, and 56/102 (54.9%) patients underwent a primary surgical or endoscopic approach, whereas 28 (27.5%) patients received systemic cytoreductive treatment. The univariate analysis revealed the GPS and PI (prognostic index), as well as UICC-stage IV, HG, and the Charlson comorbidity index (CCI) to predict both the PFS and OS in GEP-NEN patients. However, the calculation of the survival did not separate GPS subgroups at lower risk (GPS 0 versus GPS 1). Upon the subsequent multivariate analysis, GPS was the only independent predictor of both OS (p < 0.0001; HR = 3.459, 95% CI = 1.263−6.322) and PFS (p < 0.003; HR = 2.119, 95% CI = 0.944−4.265). Conclusion: In line with previous results for other entities, the present study revealed the GPS at baseline to be the only independent predictor of survival across all stages of GEP-NEN, and thus supports its clinical utility for risk stratification in this group of patients.

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.

Therapeutic strategies for patients with neuroendocrine neoplasms: current perspectives

INTRODUCTION

Neuroendocrine neoplasms (NENs) are a heterogeneous group of malignancies mainly arising in the gastroenteropancreatic (GEP) and bronchopulmonary systems, with steadily increasing incidence. The therapeutic landscape has widened and the therapeutic strategy should be based on new sequences and combinations, still debated.

AREAS COVERED

Herein, we provide an overview of current approved pharmacological treatments in patients with NENs, with the aim to summarize evidence of efficacy of the main different options in GEP and pulmonary NENs, principally focusing on somatostatin analogs (SSAs), targeted therapy with everolimus and sunitinib, peptide receptor radionuclide therapy (PRRT) and chemotherapy. We discuss biological rationale and toxicities, including current indications according to differentiation and placement in the therapeutic algorithm, clinical trials, and combinations. Furthermore, we recommend areas for further research.

EXPERT OPINION

Therapeutic management of patients with NENs represents a challenge for clinicians and the identification of effective sequences and combinations is of utmost importance. Major efforts should be directed to early identify and overcome resistance and to limit toxicity. The progress in the therapeutic management of NENs grows faster and the choice of the best approach should be based on randomized clinical trials, as well as on long-term, real-world data.

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.

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.

Therapeutic strategies for gastroenteropancreatic neuroendocrine neoplasms: State-of-the-art and future perspectives

Although gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have always been considered rare tumors, their incidence has risen over the past few decades. They represent a highly heterogeneous group of neoplasms with several prognostic factors, including disease stage, proliferative index (Ki67), and tumor differentiation. Most of these neoplasms express somatostatin receptors on the cell surface, a feature that has important implications in terms of prognosis, diagnosis, and therapy. Although International Guidelines propose algorithms aimed at guiding therapeutic strategies, GEP-NEN patients are still very different from one another, and the need for personalized treatment continues to increase. Radical surgery is always the best option when feasible; however, up to 80% of cases are metastatic upon diagnosis. Regarding medical treatments, as GEP-NENs are characterized by relatively long overall survival, multiple therapy lines are adopted during the lifetime of these patients, but the optimum sequence to be followed has never been clearly defined. Furthermore, although new molecular markers aimed at predicting the response to therapy, as well as prognostic scores, are currently being studied, their application is still far from being part of daily clinical practice. As they represent a complex disease, with therapeutic protocols that are not completely standardized, GEP-NENs require a multidisciplinary approach. This review will provide an overview of the available therapeutic options for GEP-NENs and attempts to clarify the possible approaches for the management of these patients and to discuss future perspectives in this field.

Well-differentiated gastroenteropancreatic G3 NET: findings from a large single centre cohort

Neuroendocrine neoplasms are known to have heterogeneous biological behavior. G3 neuroendocrine tumours (NET G3) are characterized by well-differentiated morphology and Ki67 > 20%. The prognosis of this disease is understood to be intermediate between NET G2 and neuroendocrine carcinoma (NEC). Clinical management of NET G3 is challenging due to limited data to inform treatment strategies. We describe clinical characteristics, treatment, and outcomes in a large single centre cohort of patients with gastroenteropancreatic NET G3. Data was reviewed from 26 cases managed at Queen Elizabeth Hospital, Birmingham, UK, from 2012 to 2019. Most commonly the site of the primary tumour was unknown and majority of cases with identifiable primaries originated in the GI tract. Majority of cases demonstrated somatostatin receptor avidity. Median Ki67 was 30%, and most cases had stage IV disease at diagnosis. Treatment options included surgery, somatostatin analogs (SSA), and chemotherapy with either platinum-based or temozolomide-based regimens. Estimated progression free survival was 4 months following initiation of SSA and 3 months following initiation of chemotherapy. Disease control was observed following treatment in 5/11 patients treated with chemotherapy. Estimated median survival was 19 months; estimated 1 year survival was 60% and estimated 2 year survival was 13%. NET G3 is a heterogeneous group of tumours and patients which commonly have advanced disease at presentation. Prognosis is typically poor, though select cases may respond to treatment with SSA and/or chemotherapy. Further study is needed to compare efficacy of different treatment strategies for this disease.

Diagnosis and Management of Gastrointestinal Neuroendocrine Neoplasms

The latest WHO classification cleanly divides gastrointestinal neuroendocrine neoplasms into neuroendocrine tumor (NET; well-differentiated, any grade) and neuroendocrine carcinoma (NEC; poorly differentiated, high-grade by definition), along with mixed neuroendocrine-non-neuroendocrine neoplasms. NECs are always aggressive, with multiple mutations; they are treated with chemotherapy. NETs have widely different presentations, behavior, and management depending on site of origin. Esophageal examples are vanishingly rare. Most gastric and appendiceal tumors are indolent, as are many colonic and rectal tumors. The duodenum is home to some unusual variants of NET, and jejunal/ileal NETs frequently metastasize, which impacts their staging and clinical management.

State of the art and future directions in the systemic treatment of neuroendocrine neoplasms

PURPOSE OF REVIEW

Neuroendocrine neoplasms (NENs) are rare and heterogeneous malignancies whose natural evolution may be defined according to various prognostic factors, including localization of the primitive tumour, hormone secretory status, histological grade, tumour burden, tumour growth rate, expression of somatostatin receptors and fluorodeoxyglucose-avidity. The treatment of these tumours in an advanced setting is based on relatively little robust data.

RECENT FINDINGS

A recent pathological classification introduced a new category of high-grade but well differentiated neuroendocrine tumours (NET G3), with markedly different behaviour from neuroendocrine carcinomas (NECs). Yet, the optimal treatment of those tumours is still uncertain. Advances are needed in molecular subtyping of NENs to understand better their heterogeneity and inform personalized therapies.

SUMMARY

The current review summarizes the current knowledge, indicates some exciting future directions and outlines the most interesting ongoing clinical trials likely to impact current practice.

Digestive Well-Differentiated Grade 3 Neuroendocrine Tumors: Current Management and Future Directions

Digestive well-differentiated grade 3 neuroendocrine tumors (NET G-3) have been clearly defined since the 2017 World Health Organization classification. They are still a rare category lacking specific data and standardized management. Their distinction from other types of neuroendocrine neoplasms (NEN) not only lies in morphology but also in genotype, aggressiveness, functional imaging uptake, and treatment response. Most of the available data comes from pancreatic series, which is the most frequent tumor site for this entity. In the non-metastatic setting, surgical resection is recommended, irrespective of grade and tumor site. For metastatic NET G-3, chemotherapy is the main first-line treatment with temozolomide-based regimen showing more efficacy than platinum-based regimen, especially when Ki-67 index <55%. Targeted therapies, such as sunitinib and everolimus, have also shown some positive therapeutic efficacy in small samples of patients. Functional imaging plays a key role for detection but also treatment selection. In the second or further-line setting, peptide receptor radionuclide therapy has shown promising response rates in high-grade NEN. Finally, immunotherapy is currently investigated as a new therapeutic approach with trials still ongoing. More data will come with future work now focusing on this specific subgroup. The aim of this review is to summarize the current data on digestive NET G-3 and explore future directions for their management.

Advanced Pancreatic Neuroendocrine Neoplasms: Which Systemic Treatment Should I Start With?

PURPOSE OF REVIEW

Pancreatic neuroendocrine neoplasms (panNENs) often present as advanced disease and there is little data to guide treatment sequencing in the advance disease setting. Therefore, we aim to provide a comprehensive summary of the current evidence supporting the use of systemic treatment for patients with diagnosis of advanced and metastatic panNENs, as well as to provide strategies for treatment selection and address challenges for treatment selection and sequencing of therapy.

RECENT FINDINGS

Substantial advances have been made and many clinical trials have been performed over the past two decades expanding therapeutic options available for patients with advanced panNETs. Available systemic treatments for patients with well-differentiated pancreatic neuroendocrine tumors include somatostatin receptors ligands (SRLs), traditional cytotoxic chemotherapy regimens, peptide receptor radiotherapy (PRRT), and biologically targeted therapies, whereas patients with poorly differentiated neurodocrine carcinomas have more limited treatment options. Despite these advances, no clear guidelines exist to support the best sequence of treatments, not only the first-line, but also subsequent lines of therapy in patients with panNENs. Advances in molecular research and discovery of biomarkers for response allowing a more personalized approach to the multimodality therapy of panNENs are still limited. Understanding the impact of previous therapies on subsequent treatment efficacy and toxicity is also an ongoing research question. In the absence of definite predictive markers and paucity of comparative randomized trials, along with the heterogeneity of this patient population, systemic therapy selection in advanced non-resectable disease should be patient centered and often require evaluation within a multidisciplinary setting. The specific clinical context of the patient, with assessment of individual patient clinical and pathological features, somatostatin receptors imaging, and goals of treatment must all be considered when deciding on systemic therapy in the patient. Additional research is needed to address the gap in knowledge regarding optimal sequencing and timing of therapies and to provide individual care.

Multicenter Analysis of Treatment Outcomes for Systemic Therapy in Well Differentiated Grade 3 Neuroendocrine Tumors (NET G3)

Well-differentiated grade 3 neuroendocrine tumors (NET G3) have been distinguished from poorly differentiated neuroendocrine carcinomas (NEC) in the most current WHO classifications. Commonly applied first-line chemotherapy protocols with cisplatin or carboplatin in combination with etoposide (PE) are less effective in NET G3 than NEC. Suggested alternative treatment protocols have not been studied in first-line therapy of NET G3 so far. We performed a retrospective analysis of patients with NET G3 in the databases of 3 German cancer centers. Out of 142 patients, 136 patients received palliative first-line therapy: overall response rate (ORR) was 35.1% for PE (n = 37), 56.4% for FOLFOX (n = 39), 27.3% for temozolomide/capecitabine (TEM/CAP) (n = 22), 45.0% for streptozotocin/5-fluorouracil (STZ/5-FU) (n = 20), and 16.7% for other (n = 18). Median progression-free survival (PFS) for PE was 6.9 months. Compared to PE, PFS in the other treatment groups was 6.9 months for FOLFOX (p = 0.333), 12.0 months for TEM/CAP (p = 0.093), 4.8 months for STZ/5-FU (p = 0.919), and 14.1 months for other (p = 0.014). In a univariate setting, all non-PE patients combined showed a significantly prolonged PFS vs. PE (9.0 months; p = 0.049) which could not be confirmed in a multivariate analysis. In conclusion, NET G3 with FOLFOX showed the highest ORR, and with TEM/CAP showed the longest PFS. Further prospective evaluation of the optimal therapeutic strategy for this tumor entity is needed.

Targeted therapy for upper gastrointestinal tract cancer: current and future prospects

Gastric and oesophageal carcinoma remain major causes of worldwide mortality and morbidity. Despite incredible progress in understanding tumour biology, few targeted treatment options have proved effective in prolonging survival, and adjuvant therapy is largely interchangeable in these carcinomas. Through large-scale sequencing by the Cancer Genome Atlas and the Asian Cancer Research Group, numerous potential molecular targets have been discovered. Of the approved targeted therapies for gastric and oesophageal cancer, pathologists play a role in patient selection for the majority of them. Trastuzumab has been approved as a first-line therapy in conjunction with standard treatment in adenocarcinomas with either 3+ HER2/neu expression by immunohistochemistry or ERBB2 amplification by FISH. PD-L1 immunohistochemistry showing a combined positive score of 1 or greater qualifies patients for third-line pembrolizumab therapy, and identification of microsatellite instability-high carcinomas may qualify patients for second-line pembrolizumab. Ramucirumab, targeting VEGFR2, has also been approved for second-line therapy in gastric carcinoma. Non-surgical therapy for gastrointestinal stromal tumours relies mainly upon tyrosine kinase inhibitors, while new targeted therapy options for neuroendocrine neoplasms have recently emerged. Potential future options for targeted therapy in all these malignancies are being investigated in clinical trials, as this review will discuss.

Molecular profile of pancreatic neuroendocrine neoplasms (PanNENs): Opportunities for personalized therapies

Pancreatic neuroendocrine neoplasms (panNENs) are the second most common epithelial tumors of the pancreas. Despite improvements in prognostic grading and staging systems, it remains a challenge to predict the clinical behavior of panNENs and the response to specific therapies given the high degree of heterogeneity of these tumors. Most panNENs are nonfunctional and present as advanced disease. However, systemic therapies provide modest benefits. Therefore, there is a need for predictive biomarkers to develop personalized treatment and to advance new drug development. The somatostatin receptors remain the only clinically established prognostic and predictive biomarkers in panNENs. Oncogenic drivers are at a very low frequency. Commonly mutated genes in panNENs include MEN1, chromatin remodeling genes (DAXX and ATRX), and mammalian target of rapamycin pathway genes. In contrast, poorly differentiated neuroendocrine carcinomas (panNECs), which carry a very poor prognosis, have distinctive mutations in certain genes (eg, RB1 and p53). Ongoing research to integrate epigenomics will provide tremendous opportunities to improve current understanding of the clinical heterogeneity of pancreatic neuroendocrine tumors and provide invaluable insight into the biology of these tumors, new drug development, and establishing personalized therapies.

Pancreatic neuroendocrine carcinoma G3 may be heterogeneous and could be classified into two distinct groups

BACKGROUND/OBJECTIVES

Pancreatic neuroendocrine carcinoma (PanNEC)-G3 often presents along with genetic abnormalities such as KRAS, RB1, and TP53 mutations. However, the association between these genetic findings and response to chemotherapy and prognosis has not been clarified. This study aimed to clarify the clinicopathological features of PanNEC-G3.

METHODS

We performed a subgroup analysis of the Japanese PanNEN-G3 study (multicenter, retrospective study), which revealed that Rb loss and KRAS mutation were predictors of the response to platinum-based regimen in PanNEN-G3. We re-classified WHO grades of PanNENs using the 2017 WHO classification and then analyzed the clinicopathological features and prognostic factors in 49 patients with PanNEC-G3.

RESULTS

The rates of Rb loss and KRAS mutation in PanNEC-G3 were 54.5% and 48.7%, respectively. Patients with Rb loss and/or KRAS mutation showed a higher response rate to first-line platinum-based regimen than those without Rb loss or KRAS mutation (object response rate 70.0% vs 33.3%, odds ratio 9.22; 95% CI 1.26-67.3, P = 0.029), but tended to have shorter overall survival rates than those without Rb loss or KRAS mutation (median 239 vs 473 days, hazard ratio 2.11; 95% CI 0.92-4.86, P = 0.077).

CONCLUSIONS

Patients with PanNEC-G3 have varied clinical outcomes for platinum-based regimen. When grouped based on Rb loss and KRAS mutation, there seemed to be two groups with distinct prognoses and responses to the platinum-based regimen. PanNEC-G3 could, therefore, be classified into two distinct groups based on immunohistochemical and genetic findings.

Gastric neuroendocrine tumor: A practical literature review

Gastric neuroendocrine tumors are gastric neoplasms originating from enterochromaffin type cells and are inserted in a larger group, named gastroenteropancreatic neuroendocrine tumors. They are considered rare and variable in terms of their clinical, morphological and functional characteristics and may be indolent or aggressive. They are classified into types I, II and III, according to their pathophysiology, behavior and treatment. Their diagnosis occurs, in most cases, incidentally during upper digestive endoscopies, presenting as simple gastric polyps. Most cases (type I and type II) are related to hypergastrinemia, can be multiple and are treated by endoscopic resection, whenever possible. The use of somatostatin analogs for tumor control may be one of the options for therapy, in addition to total or subtotal gastrectomy for selected cases. Adjuvant chemotherapy is only reserved for poorly differentiated neuroendocrine carcinomas. Although rare, gastric neuroendocrine tumors have an increasing incidence over the years, therefore deserving more comprehensive studies on its adequate treatment. The present study reviews and updates management recommendations for gastric neuroendocrine tumors.

The North American Neuroendocrine Tumor Society Consensus Guidelines for Surveillance and Medical Management of Pancreatic Neuroendocrine Tumors

This article is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The guidelines panel consisted of medical oncologists, pathologists, gastroenterologists, endocrinologists, and radiologists. The panel reviewed a series of questions regarding the medical management of patients with pancreatic neuroendocrine tumors as well as questions regarding surveillance after resection. The available literature was reviewed for each of the question and panel members voted on controversial topics, and the recommendations were included in a document circulated to all panel members for a final approval.

Well Differentiated Grade 3 Neuroendocrine Tumors of the Digestive Tract: A Narrative Review

The 2017 World Health Organization (WHO) classification of neuroendocrine neoplasms (NEN) of the digestive tract introduced a new category of tumors named well-differentiated grade 3 neuroendocrine tumors (NET G-3). These lesions show a number of mitosis, or a Ki-67 index higher than 20% with a well-differentiated morphology, therefore separating them from neuroendocrine carcinomas (NEC) which are poorly differentiated. It has become clear that NET G-3 show differences not only in morphology but also in genotype, clinical presentation, and treatment response. The incidence of digestive NET G-3 represents about one third of NEN G-3 with main tumor sites being the pancreas, the stomach and the colon. Treatment for NET G-3 is not yet standardized because of lack of data. In a non-metastatic setting, international guidelines recommend surgical resection, regardless of tumor grading. For metastatic lesion, chemotherapy is the main treatment with similar regimen as NET G-2. Sunitinib has also shown some positive results in a small sample of patients but this needs confirmation. Peptide receptor radionuclide therapy (PRRT) and immunotherapy could be future available treatments after ongoing studies. The goal of this review was to sum up the latest data on the epidemiology and management of digestive NET G-3.

A Phase II Trial of Everolimus in Patients with Advanced Pancreatic Neuroendocrine Carcinoma Refractory or Intolerant to Platinum-Containing Chemotherapy (NECTOR Trial)

BACKGROUND

Platinum-containing regimens are widely used as first-line chemotherapy for unresectable pancreatic neuroendocrine carcinoma (NEC), but second-line chemotherapies have yet to be established.

OBJECTIVES

We evaluated the safety and efficacy of everolimus in patients with pancreatic NEC refractory or intolerant to platinum-containing chemotherapy.

METHODS

This study was a prospective, multicenter, phase II trial in patients with pancreatic NEC after platinum-containing chemotherapy. Everolimus treatment was continued until disease progression or intolerable toxicity was observed. The primary endpoint was progression-free survival (PFS).

RESULTS

Participants comprised 25 patients. Median age was 63 years, median PFS was 1.2 months (95% confidence interval [CI] 0.9-3.1 months), median overall survival was 7.5 months (95% CI 3.1-13.5 months), overall response rate was 0%, and disease control rate was 39.1%. Common grade 3/4 adverse events were hyperglycemia (20%), thrombocytopenia (16%), and anemia (16%).

CONCLUSION

The efficacy of everolimus was limited in patients with unresectable pancreatic NEC.

Management of Well-Differentiated High-Grade (G3) Neuroendocrine Tumors

OPINION STATEMENT

In 2017, the World Health Organization (WHO) classification for pancreatic NET was updated to include a new category of well-differentiated high-grade (Ki 67 > 20%) pancreatic tumors (NET G3), distinct from high-grade poorly differentiated neuroendocrine carcinoma (NEC). NET G3 are considered a molecularly, radiologically, and prognostically distinct entity compared to NEC and NET G1/G2. The optimal first-line management in NET G3 and sequencing therapies remains a challenge awaiting future trials taking into consideration the unique characteristics of this category. In this review, we aim to summarize the current evidence in the management of NET G3.

Efficacy and safety of sunitinib in Japanese patients with progressive, advanced/metastatic, well-differentiated, unresectable pancreatic neuroendocrine tumors: final analyses from a Phase II study

Background

In an interim analysis of a Phase II trial in Japanese patients with pancreatic neuroendocrine tumors (panNETs), sunitinib demonstrated antitumor activity with an objective response rate (ORR) of 50% (95% confidence interval [CI], 21–79) and a median progression-free survival (PFS) of 16.8 months (95% CI, 9.3–26.2). Here, we report the final analyses of efficacy and safety, as well as additional analyses, from this Phase II study.

Methods

This was a multicenter, open-label, Phase II trial (NCT01121562) of sunitinib in Japanese patients with panNETs. Patients received oral sunitinib 37.5 mg/day on a continuous daily dosing schedule. Dose modifications were permitted. The primary endpoint was clinical benefit rate (CBR). Secondary endpoints included ORR, PFS, overall survival (OS), safety and pharmacokinetics.

Results

Of 12 patients enrolled and treated, all discontinued treatment—the majority (n = 8) owing to disease progression. Most patients were male (n = 8), <65 years of age (n = 11) and had a non-functional tumor (n = 10). The median (range) number of days on drug was 323.5 (22–727). The CBR (95% CI) was 75.0% (42.8–94.5). ORR (95% CI) was 50.0% (21.1–78.9). Median (95% CI) PFS was 16.8 (9.3–26.2) months; however, median (95% CI) OS was not reached (22.0–not estimable). Most common adverse events (AEs; all-causality) were diarrhea (n = 10; 83.3%), hand-foot syndrome (n = 8; 66.7%) and hypertension (n = 8; 66.7%).

Conclusions

These results support the efficacy and safety of sunitinib in Japanese patients with panNETs. Appropriate AE management through dose reduction and interruption may prolong sunitinib treatment and maximize its efficacy.

Angiogenesis in Pancreatic Cancer: Pre-Clinical and Clinical Studies

Angiogenesis is a crucial event in tumor development and progression, occurring by different mechanisms and it is driven by pro- and anti-angiogenic molecules. Pancreatic cancer vascularization is characterized by a high microvascular density, impaired microvessel integrity and poor perfused vessels with heterogeneous distribution. In this review article, after a brief introduction on pancreatic cancer classification and on angiogenesis mechanisms involved in its progression, the pre-clinical and clinical trials conducted in pancreatic cancer treatment using anti-angiogenic inhibitors will be described. Finally, we will discuss the anti-angiogenic therapy paradox between the advantage to abolish vessel supply to block tumor growth and the disadvantage due to reduction of drug delivery at the same time. The purpose is to identify new anti-angiogenic molecules that may enhance treatment regimen.

Recurrent loss of heterozygosity correlates with clinical outcome in pancreatic neuroendocrine cancer

Pancreatic neuroendocrine tumors (pNETs) are uncommon cancers arising from pancreatic islet cells. Here we report the analysis of gene mutation, copy number, and RNA expression of 57 sporadic well-differentiated pNETs. pNET genomes are dominated by aneuploidy, leading to concordant changes in RNA expression at the level of whole chromosomes and chromosome segments. We observed two distinct patterns of somatic pNET aneuploidy that are associated with tumor pathology and patient prognosis. Approximately 26% of the patients in this series had pNETs with genomes characterized by recurrent loss of heterozygosity (LoH) of 10 specific chromosomes, accompanied by bi-allelic MEN1 inactivation and generally poor clinical outcome. Another ~40% of patients had pNETs that lacked this recurrent LoH pattern but had chromosome 11 LoH, bi-allelic MEN1 inactivation, and universally good clinical outcome. The somatic aneuploidy allowed pathogenic germline variants (e.g., ATM) to be expressed unopposed, with RNA expression patterns showing inactivation of downstream tumor suppressor pathways. No prognostic associations were found with tumor morphology, single gene mutation, or expression of RNAs reflecting the activity of immune, differentiation, proliferative or tumor suppressor pathways. In pNETs, single gene mutations appear to be less important than aneuploidy, with MEN1 the only statistically significant recurrently mutated driver gene. In addition, only one pNET in the series had clearly actionable single nucleotide variants (SNVs) (in PTEN and FLCN) confirmed by corroborating RNA expression changes. The two clinically relevant patterns of LoH described here define a novel oncogenic mechanism and a plausible route to genomic precision oncology for this tumor type.