Targeting vascular endothelial growth factor in advanced carcinoid tumor: a random assignment phase II study of depot octreotide with bevacizumab and pegylated interferon alpha-2b

Synchronous neuroendocine liver metastases in comparison to primary pancreatic neuroendocrine tumors on MRI and SSR-PET/CT

Background

The study aimed to compare and correlate morphological and functional parameters in pancreatic neuroendocrine tumors (pNET) and their synchronous liver metastases (NELM), while also assessing prognostic imaging parameters.

Methods

Patients with G1/G2 pNET and synchronous NELM underwent pretherapeutic abdominal MRI with DWI and 68Ga-DOTATATE/TOC PET/CT were included. ADC (mean, min), SNR_art and SNT_T2 (SNR on arterial phase and on T2) and SUV (max, mean) for three target NELM and pNET, as well as tumor-free liver and spleen (only in PET/CT) were measured. Morphological parameters including size, location, arterial enhancement, cystic components, T2-hyperintensity, ductal dilatation, pancreatic atrophy, and vessel involvement were noted. Response evaluation used progression-free survival (PFS) with responders (R;PFS>24 months) and non-responders (NR;PFS ≤ 24 months).

Results

33 patients with 33 pNETs and 95 target NELM were included. There were no significant differences in ADC and SUV values between NELM and pNET. 70% of NELM were categorized as hyperenhancing lesions, whereas the pNETs exhibited significantly lower rate (51%) of hyperenhancement (p<0.01) and significant lower SNR_art. NELM were qualitatively and quantitatively (SNR_T2) significantly more hyperintense on T2 compared to pNET (p=0.01 and p<0.001). NELM of R displayed significantly lower ADCmean value in comparison to the ADC mean value of pNET (0.898 versus 1.037x10-3mm²/s,p=0.036). In NR, T2-hyperintensity was notably higher in NELM compared to pNET (p=0.017). The hepatic tumor burden was significantly lower in the R compared to the NR (10% versus 30%).

Conclusions

Arterial hyperenhancement and T2-hyperintensity differ between synchronous NELM and pNET. These findings emphasize the importance of a multifaceted approach to imaging and treatment planning in patients with these tumors as well as in predicting treatment responses.

ETV6-NTRK2 Fusion in a Patient With Metastatic Pulmonary Atypical Carcinoid Successfully Treated With Entrectinib: A Case Report and Review of the Literature

Pulmonary atypical carcinoid (AC) is an extremely rare neuroendocrine tumor. The neurotrophic tropomyosin receptor kinase (NTRK) fusions are reported in only 0.5% of nonsmall cell lung cancer, and are more rare in AC with only one previously reported case. Currently, there is little established evidence on the optimal therapeutic strategies and prognosis for advanced cases. We present a female patient with metastatic AC after complete resection. Due to low expression of somatostatin receptor in this case, somatostatin analogs and peptide receptor radionuclide therapy were not available. After pursuing other alternative treatments, including chemotherapy (ie, carboplatin, etoposide, capecitabine, temozolomide, and paclitaxel), everolimus, and atezolizumab, she returned with significant progression, including innumerable subcutaneous nodules, left pleura metastasis, multiple bone metastases, and brain metastases. New biopsy analysis revealed an ETV6-NTRK2 fusion. She was immediately administered the first-generation tropomyosin receptor kinase inhibitor entrectinib at a dose of 600 mg q.d. A subsequent month of treatment resulted in a complete response in all of the metastatic lung lesions. To date, she has maintained sustained benefit for at least 1 year from initiation of entrectinib. Here, we present the first case of a female patient with metastatic AC harboring the ETV6-NTRK2 fusion, and successfully treated with entrectinib, providing evidence for the application of entrectinib in patients with NTRK-positive AC, and underscoring the critical role of molecular profiling for such cases.

Status of alternative angiogenic pathways in glioblastoma resected under and after bevacizumab treatment

Glioblastoma multiforme (GBM) acquires resistance to bevacizumab (Bev) treatment. Bev affects angiogenic factors other than vascular endothelial growth factor (VEGF), which are poorly understood. We investigated changes in angiogenic factors under and after Bev therapy, including angiopoietin-1 (ANGPT1), angiopoietin-2 (ANGPT2), placental growth factor (PLGF), fibroblast growth factor 2, and ephrin A2 (EphA2). Fifty-four GBM tissues, including 28 specimens from 14 cases as paired specimens from the same patient obtained in three settings: initial tumor resection (naïve Bev), tumors resected following Bev therapy (effective Bev), and recurrent tumors after Bev therapy (refractory Bev). Immunohistochemistry assessed their expressions in tumor vessels and its correlation with recurrent MRI patterns. PLGF expression was higher in the effective Bev group than in the naïve Bev group (p = 0.024) and remained high in the refractory Bev group. ANGPT2 and EphA2 expressions were higher in the refractory Bev group than in the naïve Bev group (p = 0.047 and 0.028, respectively). PLGF expression was higher in the refractory Bev group compared with the naïve Bev group for paired specimens (p = 0.036). PLGF was more abundant in T2 diffuse/circumscribe patterns (p = 0.046). This is the first study to evaluate angiogenic factors other than VEGF during effective and refractory Bev therapy in patient-derived specimens.

Combination Systemic Therapies in Advanced Well-Differentiated Gastroenteropancreatic Neuroendocrine Tumors (GEP-NETs): A Comprehensive Review of Clinical Trials and Prospective Studies

There is an evolving landscape of systemic combination regimens for patients with advanced well-differentiated gastroenteropancreatic neuroendocrine tumors (GEP-NETs). In this review, we provide a comprehensive outline of the existing clinical trials/prospective studies investigating these combinations. PubMed was searched using key relevant terms to identify articles referring to GEP-NETs and combination treatments. No systematic search of the literature or metanalysis of the data was performed, and we focused on the most recent literature results. Primarily, phase 1 and 2 clinical trials were available, with a smaller number of phase 3 trials, reporting results from combination treatments across a wide range of antiproliferative agents. We identified significant variability in the anti-tumor activity of the reported combinations, with occasional promising results, but only a very small number of practice-changing phase 3 clinical trials. Overall, the peptide receptor radionuclide therapy (PRRT)-based combinations (with chemotherapy, dual PPRT, and targeted agents) and anti-vascular endothelial growth factor (VEGF) agent combinations with standard chemotherapy were found to have favorable results and may be worth investigating in future, larger-scale trials. In contrast, the immune-checkpoint inhibitor-based combinations were found to have limited applicability in advanced, well-differentiated GEP-NETs.

Therapeutic response to pazopanib: case report and literature review on molecular abnormalities of aggressive prolactinomas

Introduction

Aggressive prolactinomas (APRLs) pose a significant clinical challenge due to their high rate of regrowth and potentially life-threatening complications. In this study, we present a case of a patient with an APRL who had a trial of multiple therapeutic modalities with the aim to provide a review of molecular abnormalities and management of APRLs by corroborating our experience with previous literature.

Methods

A total of 268 articles were reviewed and 46 were included. Case reports and series, and studies that investigated the molecular and/or genetic analysis of APRLs were included. Special care was taken to include studies describing prolactinomas that would fall under the APRL subtype according to the European Society of Endocrinology guidelines; however, the author did not label the tumor as "aggressive" or "atypical". Addiontionally, we present a case report of a 56-year-old man presented with an invasive APRL that was resistant to multiple treatment modalities.

Results

Literature review revealed multiple molecular abnormalities of APRLs including mutations in and/or deregulation of ADAMTS6, MMP-9, PITX1, VEGF, POU6F2, CDKN2A, and Rb genes. Mismatch repair genes, downregulation of microRNAs, and hypermethylation of specific genes including RASSF1A, p27, and MGMT were found to be directly associated with the aggressiveness of prolactinomas. APRL receptor analysis showed that low levels of estrogen receptor (ER) and an increase in somatostatin receptors (SSTR5) and epidermal growth factor receptors (EGFR) were associated with increased invasiveness and higher proliferation activity. Our patient had positive immunohistochemistry staining for PD-L1, MSH2, and MSH6, while microarray analysis revealed mutations in the CDKN2A and POU6F2 genes. Despite undergoing two surgical resections, radiotherapy, and taking dopamine agonists, the tumor continued to progress. The patient was administered pazopanib, which resulted in a positive response and the patient remained progression-free for six months. However, subsequent observations revealed tumor progression. The patient was started on PD-L1 inhibitor pembrolizumab, yet the tumor continued to progress.

Conclusion

APRLs are complex tumors that require a multidisciplinary management approach. Knowledge of the molecular underpinnings of these tumors is critical for understanding their pathogenesis and identifying potential targets for precision medical therapy.

Advanced gastric neuroendocrine tumor with hepatic metastasis - A case report

INTRODUCTION AND IMPORTANCE

Gastric neuroendocrine tumors (NETs) are rare neoplasms that originate from enterochromaffin cells in the gastric mucosa and pose a diagnostic dilemma due to their non-specific presentation.

CASE PRESENTATION

We present a 79-year-old woman, who came with complaints of abdominal pain associated with loss of pain and appetite. Although on the first look multiple differentials could be listed, upon complete evaluation she was diagnosed to have type III Gastric NET. Histopathology and immunohistochemistry allowed diagnostic confirmation of the disease along with strong clinical suspicion. The patient however succumbed to the illness due to advanced disease and lack of established protocol for its management.

CLINICAL DISCUSSION

The treatment of Gastric NETs primarily involves surgical resection of the tumor and is especially helpful in type I and II cases. For advanced metastatic type III NETs, lines of therapy have not been established although surgical resection can be done if the majority (∼90 %) of the tumor is resectable. Patients should be given a choice in decision making and newer drug therapies should always be considered.

CONCLUSION

Since gastric NETs are a rarer cause of abdominal pain, it can often be overlooked in favor of other, more common differentials. One should be aware of this disease and the newer diagnostic methods to have any sort of clinical suspicion when presented with such a scenario. The management of the condition although not been established, novel therapies should be considered if the tumor is not resectable.

Neuroendocrine neoplasms in the context of inherited tumor syndromes: a reappraisal focused on targeted therapies

PURPOSE

Neuroendocrine neoplasms can occur as part of inherited disorders, usually in the form of well-differentiated, slow-growing tumors (NET). The main predisposing syndromes include: multiple endocrine neoplasias type 1 (MEN1), associated with a large spectrum of gastroenteropancreatic and thoracic NETs, and type 4 (MEN4), associated with a wide tumour spectrum similar to that of MEN1; von Hippel-Lindau syndrome (VHL), tuberous sclerosis (TSC), and neurofibromatosis 1 (NF-1), associated with pancreatic NETs. In the present review, we propose a reappraisal of the genetic basis and clinical features of gastroenteropancreatic and thoracic NETs in the setting of inherited syndromes with a special focus on molecularly targeted therapies for these lesions.

METHODS

Literature search was systematically performed through online databases, including MEDLINE (via PubMed), and Scopus using multiple keywords' combinations up to June 2022.

RESULTS

Somatostatin analogues (SSAs) remain the mainstay of systemic treatment for NETs, and radiolabelled SSAs can be used for peptide-receptor radionuclide therapy for somatostatin receptor (SSTR)-positive NETs. Apart of these SSTR-targeted therapies, other targeted agents have been approved for NETs: the mTOR inhibitor everolimus for lung, gastroenteropatic and unknown origin NET, and sunitinib, an antiangiogenic tyrosine kinase inhibitor, for pancreatic NET. Novel targeted therapies with other antiangiogenic agents and immunotherapies have been also under evaluation.

CONCLUSIONS

Major advances in the understanding of genetic and epigenetic mechanisms of NET development in the context of inherited endocrine disorders have led to the recognition of molecular targetable alterations, providing a rationale for the implementation of treatments and development of novel targeted therapies.

Personalized functional profiling using ex-vivo patient-derived spheroids points out the potential of an antiangiogenic treatment in a patient with a metastatic lung atypical carcinoid

Lung carcinoids are neuroendocrine tumors representing 1 to 2% of lung cancers. This study outlines the case of a patient with a metastatic lung atypical carcinoid who presented with a pleural effusion and progression of liver metastases after developing resistance to conventional treatments. Personalized functional profiling (PFP), i.e. drug screening, was performed in ex-vivo spheroids obtained from the patient's liver metastasis to identify potential therapeutic options. The drug screening results revealed cediranib, an antiangiogenic drug, as a hit drug for this patient, from a library of 66 Food and Drug Administration (FDA)-approved and investigational drugs. Based on the PFP results and the reported evidence of clinical efficacy of bevacizumab and capecitabine combination in gastro-intestinal neuroendocrine tumors, this combination was given to the patient. Four months later, the pleural effusion and pleura carcinosis regressed and the liver metastasis did not progress. The patient experienced 2 years of a stable disease under the PFP-guided personalized treatment.

Metronomic chemotherapy in patients with advanced neuroendocrine tumors: A single-center retrospective analysis

Neuroendocrine tumors (NETs) are more commonly slow-growing, therefore patients often receive chronic systemic therapies for tumor growth control and preservation of quality of life. Metronomic chemotherapy (mCT) is in line with this goal as it leads to stabilization of tumor growth over time without severe systemic toxicity. This is a retrospective analysis of patients with metastatic NETs receiving metronomic capecitabine (mCAP) or temozolomide (mTEM), at a NET-referral center. The aims of the study were to explore activity and safety of mCT and relationships between some characteristics of the patient population and clinical outcomes. Among a total of 67 patients with metastatic well or moderately differentiated (W/M-D) NETs, mostly gastroenteropancreatic (GEP) and nonfunctioning, 1.2 years (95% CI: 0.8-1.8) median progression-free survival (mPFS), and 3.0 years (95% CI: 2.3-4.9) median overall survival (mOS) were observed. Disease control rate was 85%. Grade 3 adverse events occurred in 15% of patients in mCAP and 13% in mTEM, and were mostly hematological and gastrointestinal. At univariate and multivariate analysis none of the variables analyzed (treatment regimen, sex, age at diagnosis, site of primary tumor and metastases, number of previous mCT lines, baseline tumor status before mCT, Ki67 value) were significantly correlated to OS and PFS. Our retrospective study suggested that mCAP and mTEM can be active and well tolerated in patients with metastatic W/M-D NETs, irrespective of the primary site, site of metastases, line of treatment and baseline tumor status.

Angiogenesis in NENs, with a focus on gastroenteropancreatic NENs: from biology to current and future therapeutic implications

Neuroendocrine neoplasms (NENs) are highly vascularized malignancies arising from cells of the diffuse neuroendocrine system. An intricated cross-talk exists between NEN cells and the tumor microenvironment, and three main molecular circuits (VEGF/VEGFR pathway, FGF-dependent signaling and PDGF/PDGFR axis) have been shown to regulate angiogenesis in these neoplasms. Multiple randomized trials have investigated antiangiogenic agents over the past two decades, and sunitinib is currently approved for the treatment of advanced, progressive, G1/G2 pancreatic NENs. In recent years, two phase III clinical trials have demonstrated the efficacy and safety of surufatinib, a multi-tyrosine kinase angioimmune inhibitor, in patients with well-differentiated pancreatic and extrapancreatic NENs, and two studies of this agent are currently underway in Europe and US. The HIF-2α inhibitor belzutifan has recently received regulatory approval for the treatment of tumors arising in the context of Von-Hippel Lindau syndrome including pancreatic NENs, and a study of this drug in patients with sporadic tumors is presently ongoing. Combinations of antiangiogenic agents with chemotherapeutics and targeted drugs have been tested, with accumulating toxicities being a matter of concern. The potential of antiangiogenic agents in fine-tuning the immune microenvironment of NENs to enhance the activity of immune checkpoint inhibitors has been only partially elucidated, and further research should be carried out at this regard. Here, we review the current understanding of the biology of angiogenesis in NENs and provide a summary of the latest clinical investigations on antiangiogenic drugs in this malignancy.

Predicting Novel Drug Candidates for Pancreatic Neuroendocrine Tumors via Gene Signature Comparison and Connectivity Mapping

INTRODUCTION

There is a paucity of effective treatment options for advanced pancreatic neuroendocrine tumors (pNETs). Genome-wide analyses may allow for potential drugs to be identified based on differentially expressed genes (DEGs).

METHODS

Oligo microarray data of RNA expression profiling of pNETs and normal pancreas tissues were downloaded from the Gene Expression Omnibus. Functional and pathway enrichment information of the DEGs was obtained using the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases. Corresponding homologous proteins were analyzed and potential therapeutic drugs for pNETs were identified using the Connectivity Map and Drug-Gene Interaction Database.

RESULTS

Assessment of raw data from 12,610 pNET genes demonstrated that 1082 and 380 genes were upregulated and downregulated, respectively, compared with normal pancreas tissue. Upregulated pathways were associated with nitrogen metabolism (i.e., GABAergic synapse, and graft-versus-host disease), whereas downregulated pathways included C-type leptin receptor signaling pathway, pertussis and AMPK signaling pathway. In particular, the protein-protein interaction analysis revealed 10 upregulated hub genes (DYNLL1, GNB5, GNB2, GNG4, GNAI2, GNAI1, HIST2H2BE, NUP107, NUP133, and SNAP25) and 10 downregulated hub genes (CXCL8, F2, CXCL2, GCG, SST, INS, GALR3, CCL20, ADRA2B, and CXCL6). Using the Drug-Gene Interaction Database, candidate drugs for pNETs treatment included 3 EGFR inhibitors (canertinib, erlotinib, WZ-4-145), as well as other cell-signaling pathway inhibitors such as AG-592, acarbose, lonidamine, azacytidine, rottlerin, and HU-211.

CONCLUSION

Using available genetic atlas data, potential drug candidates for treatment of pNETs were identified based on differentially expressed genes. These results may help focus efforts on identifying targeted agents with therapeutic efficacy to treat patients with pNETs.

Efficacy and toxicity of surufatinib in neuroendocrine tumors: A systematic review and meta-analysis

The incidence and prevalence of neuroendocrine neoplasms (NENs) has increased in the US in recent decades. These are well-vascularized tumors, but no antiangiogenic drug has been approved for treatment of extra-pancreatic NENs. The aim is to assess efficacy and safety of surufatinib in pancreatic and extra-pancreatic NETs. We searched PubMed, Embase, Cochrane Library, Web of Science and Clinicaltrials.gov. Clinical trials and observational studies that provided safety and efficacy data in clinical terms were included. Characteristics of the study, baseline characteristics of participants, treatment drugs, measures of efficacy, and toxicity (≥grade 3 adverse effects) were extracted. The meta-analysis was performed using the "R" programming language. Risk ratio (RR) of objective response (OR)/partial response (PR) was 8.55 (95% CI: 1.68-43.66, I²  = 0) in favor of surufatinib. The hazard ratio (HR) of progression-free survival (PFS) was 0.48 (95% CI: 0.25-0.92, I²  = 77%) in favor of surufatinib. The risk of ≥grade 3 adverse effects: diarrhea, hypertension, hypertriglyceridemia, proteinuria, and vomiting were high with the use of surufatinib. Quality of life (QoL) was similar in surufatinib and placebo groups except for the diarrhea that was high with surufatinib. Lack of randomized clinical trials in non-Chinese population. Surufatinib is well tolerated and is more effective than placebo in both pancreatic and extra-pancreatic NETs. More multicenter randomized, double-blinded clinical trials are needed to confirm these results.

Angiogenic factors as prognostic markers in neuroendocrine neoplasms

PURPOSE

Angiogenic markers in neuroendocrine neoplasms (NENs) have recently received increasing attention, but their clinical role remains unclear. The aim of this study was to evaluate the role of angiogenic markers in NEN aggressiveness and prognosis.

METHODS

We performed a prospective observational study including 46 consecutive patients with proven NENs of pulmonary (45.65%) and gastro-entero-pancreatic (GEP) (54.35%) origin and 29 healthy controls. Circulating pro-angiogenic factors were measured by ELISA assay. ANG2 tissue expression was evaluated in a subgroup of ten patients by immunohistochemistry.

RESULTS

The study demonstrated a significantly higher level of ANG2, ANG1, sTIE2, and PROK2 in patients affected by NENs compared to controls. In the NENs' group we measured that: (i) ANG2 levels were higher in poorly vs well-differentiated NENs: 4.85 (2.75-7.42) vs 3.16 (1.66-6.36) ng/ml, p = 0.046 and in tumor stage 3-4 compared to stage 1-2: 4.24 (2.66-8.72) vs 2.73 (1.53-5.70), p = 0.044; (ii) ANG2 and PROK2 were significantly higher in patents with progressive disease compared to stable disease: ANG2 = 6.26 (3.98-10.99) vs 2.73 (1.65-4.36) pg/ml, p = 0.001; PROK2 = 29.19 (28.42-32.25) vs 28.37 (28.14-28.91) pg/ml, p = 0.035. Immunohistochemistry confirmed ANG2 expression in tumor specimens.

CONCLUSIONS

We documented higher levels of angiogenic markers in NENs, with an association between ANG2 serum levels and NENs morphology and staging. In both GEP and lung NENs, ANG2 and PROK2 are higher in case of tumor progression, suggesting a potential role as prognostic markers in NENs patients.

Medical management of gastrointestinal neuroendocrine tumors

PURPOSE OF REVIEW

To summarize the recent developments in the medical treatment of gastrointestinal neuroendocrine neoplasms.

RECENT FINDINGS

The medical management of gastrointestinal neuroendocrine tumors (GI-NETs) continues to evolve with advances in the management of symptoms related to hormone hypersecretion and therapeutic control of disease progression. Systemic therapy options include somatostatin analogs (SSAs), radiolabeled SSAs, molecularly targeted agents, and cytotoxic therapy. Recent progress has focused on new targeted therapies, the sequencing of therapy and the role of immunotherapy.

SUMMARY

This review will focus on treatment of GI-NETs and highlight new developments published over the last year.

Neuroendocrine Tumors: a Relevant Clinical Update

PURPOSE OF REVIEW

The field of neuroendocrine oncology has changed much since the time of Oberndorfer first described and coined the term carcinoid. The purpose of this review is to summarize recent findings and highlight clinically relevant updates in the management of NENs, particularly those that are practice changing.

RECENT FINDINGS

Neuroendocrine tumors (NETs) have replaced carcinoid tumor, for the most part. The classification of neuroendocrine neoplasms (NENs) improved, and the epidemiological understanding of this disease group also expanded with global collaborations and maturation of large tumor registries. Clarity in the utility of some NET biomarkers continues to be evolving. Knowledge of molecular drivers of tumorigenesis increases, and scientific/technological advancements lead the way to multiple drug approvals for the treatment of advanced NETs. The incidence and prevalence of NENs continue to increase, and patients are living longer. Better understanding of molecular drivers and further understanding of the role of immunotherapy in NENs will further elevate the level of care and transform care for all patients with NENs.

Bronchial Carcinoids: From Molecular Background to Treatment Approach

Simple Summary

Bronchial carcinoids (BCs) are uncommon and usually slow growing neuroendocrine epithelial malignancies that represent less than 2% of all lung cancers. Differences in the extent of molecular alterations between neuroendocrine carcinomas and BCs may underline the differences in the aggressiveness of these lesions. Moreover, although atypical BCs and typical BCs have similar set of mutations, some differential molecular and genetic alterations have been described between these two entities. A better understanding of the genetic and molecular background of BCs would allow a better selection of medical treatments in these patients. Regarding treatment, most BCs can be cured by surgery; however, inoperable tumors are mostly insensitive to chemotherapy and radiotherapy. In advanced BCs, the only drug that has a positive phase III clinical trial in BCs is everolimus. Somatostatin analogues constitute the gold standard for symptomatic relief. Peptide receptor radionuclide therapy has been associated with longer progression free. The efficacy of other treatments such as antiangiogenic agents and immunotherapy is still not established.

Abstract

A better understanding of the genetic and molecular background of bronchial carcinoids (BCs) would allow a better estimation of the risk of disease progression and the personalization of treatment in cases of advanced disease. Molecular studies confirmed that lungs neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs) are different entities; thus, no progression of NET to NEC is expected. In BCs, MEN1 gene mutations and deletions and decreased gene expression have been associated with a poor prognosis. ATRX mutation has also been linked to a shorter disease-specific survival. In terms of therapeutic targets, PI3K/AKT/mTOR pathway mutations have been described in 13% of typical carcinoids (TCs) and 39% of atypical carcinoids (ACs), representing a targetable mutation with kinase inhibitors. Regarding treatment, surgical resection is usually curative in localized BCs and adjuvant treatment is not routinely recommended. Multiple options for systemic therapy exist for patients with advanced BCs, although limited by a heterogeneity in the scientific evidence behind their use recommendation. These options include somatostatin analogues, everolimus, peptide receptor radionuclide therapy, chemotherapy, radiotherapy, antiangiogenic agents, and immunotherapy. In this article, we provide a comprehensive review about the molecular and genetic background of BCs, and about the treatment of local and metastatic disease, as well as the main paraneoplastic syndromes that have been associated with this tumor.

Treatment for gastrointestinal and pancreatic neuroendocrine tumours: a network meta-analysis

BACKGROUND

Several available therapies for neuroendocrine tumours (NETs) have demonstrated efficacy in randomised controlled trials. However, translation of these results into improved care faces several challenges, as a direct comparison of the most pertinent therapies is incomplete.

OBJECTIVES

To evaluate the safety and efficacy of therapies for NETs, to guide clinical decision-making, and to provide estimates of relative efficiency of the different treatment options (including placebo) and rank the treatments according to their efficiency based on a network meta-analysis.

SEARCH METHODS

We identified studies through systematic searches of the following bibliographic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library; MEDLINE (Ovid); and Embase from January 1947 to December 2020. In addition, we checked trial registries for ongoing or unpublished eligible trials and manually searched for abstracts from scientific and clinical meetings.

SELECTION CRITERIA

We evaluated randomised controlled trials (RCTs) comparing two or more therapies in people with NETs (primarily gastrointestinal and pancreatic).

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data to a pre-designed data extraction form. Multi-arm studies were included in the network meta-analysis using the R-package netmeta. We separately analysed two different outcomes (disease control and progression-free survival) and two types of NET (gastrointestinal and pancreatic NET) in four network meta-analyses. A frequentist approach was used to compare the efficacy of therapies.

MAIN RESULTS

We identified 55 studies in 90 records in the qualitative analysis, reporting 39 primary RCTs and 16 subgroup analyses. We included 22 RCTs, with 4299 participants, that reported disease control and/or progression-free survival in the network meta-analysis. Precision-of-treatment estimates and estimated heterogeneity were limited, although the risk of bias was predominantly low. The network meta-analysis of progression-free survival found nine therapies for pancreatic NETs: everolimus (hazard ratio [HR], 0.36 [95% CI, 0.28 to 0.46]), interferon plus somatostatin analogue (HR, 0.34 [95% CI, 0.14 to 0.80]), everolimus plus somatostatin analogue (HR, 0.38 [95% CI, 0.26 to 0.57]), bevacizumab plus somatostatin analogue (HR, 0.36 [95% CI, 0.15 to 0.89]), interferon (HR, 0.41 [95% CI, 0.18 to 0.94]), sunitinib (HR, 0.42 [95% CI, 0.26 to 0.67]), everolimus plus bevacizumab plus somatostatin analogue (HR, 0.48 [95% CI, 0.28 to 0.83]), surufatinib (HR, 0.49 [95% CI, 0.32 to 0.76]), and somatostatin analogue (HR, 0.51 [95% CI, 0.34 to 0.77]); and six therapies for gastrointestinal NETs: 177-Lu-DOTATATE plus somatostatin analogue (HR, 0.07 [95% CI, 0.02 to 0.26]), everolimus plus somatostatin analogue (HR, 0.12 [95%CI, 0.03 to 0.54]), bevacizumab plus somatostatin analogue (HR, 0.18 [95% CI, 0.04 to 0.94]), interferon plus somatostatin analogue (HR, 0.23 [95% CI, 0.06 to 0.93]), surufatinib (HR, 0.33 [95%CI, 0.12 to 0.88]), and somatostatin analogue (HR, 0.34 [95% CI, 0.16 to 0.76]), with higher efficacy than placebo. Besides everolimus for pancreatic NETs, the results suggested an overall superiority of combination therapies, including somatostatin analogues. The results indicate that NET therapies have a broad range of risk for adverse events and effects on quality of life, but these were reported inconsistently. Evidence from this network meta-analysis (and underlying RCTs) does not support any particular therapy (or combinations of therapies) with respect to patient-centred outcomes (e.g. overall survival and quality of life).

AUTHORS' CONCLUSIONS

The findings from this study suggest that a range of efficient therapies with different safety profiles is available for people with NETs.

Targeted Cancer Therapy: What's New in the Field of Neuroendocrine Neoplasms?

Neuroendocrine tumors (NETs) are a heterogeneous family of neoplasms of increasing incidence and high prevalence due to their relatively indolent nature. Their wide anatomic distribution and their characteristic ability to secrete hormonally active substances pose unique challenges for clinical management. They are also characterized by the common expression of somatostatin receptors, a target that has been extremely useful for diagnosis and treatment (i.e., somatostatin analogues (SSAs) and peptide-receptor radionuclide therapy (PRRT)). Chemotherapy is of limited use for NETs of non-pancreatic origin, and the only approved targeted agents for advanced progressive NETs are sunitinib for those of pancreatic origin, and everolimus for lung, gastrointestinal and pancreatic primaries. Despite recent therapeutic achievements, thus, systemic treatment options remain limited. In this review we will discuss the state-of-the-art targeted therapies in the field of NETs, and also future perspectives of novel therapeutic drugs or strategies in clinical development, including recently presented results from randomized trials of yet unapproved antiangiogenic agents (i.e., pazopanib, surufatinib and axitinib), PRRT including both approved radiopharmaceuticals (177Lu-Oxodotreotide) and others in development (177Lu-Edotreotide, 177Lu-Satoreotide Tetraxetan), immunotherapy and other innovative targeted strategies (antibody-drug conjugates, bites,…) that shall soon improve the landscape of personalized treatment options in NET patients.

Systemic Treatment of Advanced Gastroenteropancreatic Neuroendocrine Tumors in Korea: Literature Review and Expert Opinion

Neuroendocrine tumors (NETs) are a group of malignancies arising from neuroendocrine cells and frequently originate in the gastrointestinal tract and pancreas. Although curative resection is the main treatment for localized disease, systemic therapy is needed for relapsed or metastatic/unresectable gastroenteropancreatic NETs (GEP-NETs). Although there are several NET treatment guidelines from various countries, the geographical discrepancies between patient clinical characteristics, the regulatory approval status for therapeutic agents, and medical practices necessitate specific guidelines for Korean patients. We here provide a consensus review of the diagnosis, staging and systemic treatment of Korean GEP-NET patients. Systemic therapy options and the current Korean expert consensus on these treatments, including somatostatin analogs, targeted therapies such as everolimus and sunitinib, peptide receptor radionuclide treatments, and cytotoxic chemotherapies are addressed.

Vorolanib (X-82), an oral anti-VEGFR/PDGFR/CSF1R tyrosine kinase inhibitor, with everolimus in solid tumors: results of a phase I study

Background Anti-vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKI) combined with mTOR inhibitors, like everolimus, result in significant responses and prolonged progression-free survival (PFS) among patients with renal cell carcinoma (RCC) [1]. However, everolimus doses >5 mg are often not tolerated when combined with other TKIs^2,3. Vorolanib (X-82), an oral anti-VEGFR/platelet derived growth factor receptor (PDGFR)/colony stimulating factor 1 receptor (CSF1R) multitarget TKI, has a short half-life and limited tissue accumulation. We conducted a Phase 1 study of vorolanib with everolimus (10 mg daily) in patients with solid tumors. Methods A 3 + 3 dose escalation design was utilized to determine dose limiting toxicities (DLT) and recommended Phase 2 dose (RP2D) of vorolanib/everolimus. Oral vorolanib at 100, 150, 200, 300, or 400 mg was combined with 10 mg oral everolimus daily. The phase 2 portion was terminated after enrolling two patients due to funding. Results Eighteen patients were evaluable for DLT among 22 treated subjects. Observed DLTs were grade 3 fatigue, hypophosphatemia, and mucositis. The RP2D is vorolanib 300 mg with everolimus 10 mg daily. In 15 patients evaluable for response, three had partial response (PR; 2 RCC, 1 neuroendocrine tumor [NET]) and eight had stable disease (SD; 2 RCC, 6 NET). Conclusions Vorolanib can safely be combined with everolimus. Encouraging activity is seen in RCC and NET. Further studies are warranted. Trial Registration Number: NCT01784861.

Intravitreal Bevacizumab (Avastin) as an Adjuvant Therapy for Choroidal Carcinoid Metastasis

Purpose:

To report a case of choroidal carcinoid metastasis with neovascularization of the optic disc and macular edema that was treated with three sessions of intravitreal anti-vascular endothelial growth factor (anti-VEGF) as an adjuvant therapy with photodynamic therapy (PDT).

Methods:

A 16-year-old patient with a diagnosis of lung carcinoid tumor presented to an ophthalmology clinic with a complaint of decreased vision in his right eye. Fundus examination revealed choroidal carcinoid metastasis in addition to neovascularization of the optic disc. Macular optical coherence tomography revealed cystoid macular edema and subretinal fluid. The patient was treated with PDT in addition to three sessions of intravitreal anti-VEGF injections.

Results:

Following the treatment, the new vessels regressed, and visual acuity improved. Furthermore, central retinal thickness reduced significantly. The tumor size reduced significantly over a follow-up period of 6 weeks.

Conclusion:

Choroidal carcinoid metastasis may be complicated by neovascularization of optic disc, which responds favorably to intravitreal injections of bevacizumab.

Neuroendocrine liver metastases: The role of liver transplantation

PURPOSE OF REVIEW

Neuroendocrine tumor (NET) metastasis localized to the liver is an accepted indication for liver transplantation as such tumors have a low biological aggressiveness in terms of malignancy and are slow growing.

RECENT FINDINGS

The long-term results are comparable with and in some cases even better than those of transplantations performed for primary liver cancer. However, compared with nonmalignant conditions, neuroendocrine liver metastasis (NELM) may result in an inferior outcome of transplantation. In the face of the scarcity of donated organs and recent improved results of non-surgical treatment for NELM, controversy over patient selection and timing for liver transplantation continues.

SUMMARY

In this review, we provide an overview of the diagnostic work-up and selection criteria of patients with NELM being considered for liver transplantation. Thereafter, we provide a critical analysis of the reported outcomes of OLT.

A Comparison of Liver-Directed Therapy and Systemic Therapy for the Treatment of Liver Metastases in Patients with Gastrointestinal Neuroendocrine Tumors: Analysis of the California Cancer Registry

PURPOSE

To compare the outcomes of patients with gastrointestinal neuroendocrine tumor liver metastases treated with liver-directed therapy (LDT) to those treated with systemic therapy (ST) in a statewide cancer database.

MATERIALS AND METHODS

A retrospective study was performed of patients with metastatic gastrointestinal tract neuroendocrine tumors treated with either LDT or ST alone between the years 2000-2012 in the California Cancer Registry. Overall survival and disease-specific survival were assessed using multivariable Cox proportional hazards analysis and propensity score matching.

RESULTS

A total of 154 patients (ST, n = 87 and LDT, n = 67) were studied. The median overall survival and disease-specific survival for patients that received ST was 29 and 35 months versus 51 and >60 months for patients that received LDT. On multivariate analysis, LDT and the resection of the primary tumor were associated with improved survival (hazard ratio [HR] 0.52, P = .002; HR 0.43, P = .001). Non-white race, Medicaid/uninsured status, and the presence of lung metastases were associated with poor survival (HR 1.76, P = .014; HR 2.29, P = .009; and HR 1.79, P = .031). Propensity score matching demonstrated an improvement in disease-specific survival for LDT compared to ST (HR 0.53, P = .036). The improvement in overall survival on propensity score matching did not achieve statistical significance (HR 0.70, P = .199).

CONCLUSIONS

LDT is associated with improved overall and disease-specific survival as compared to ST in patients with gastrointestinal neuroendocrine tumor liver metastases. Further investigation is needed to determine whether combination or sequential treatment can improve outcomes in this population.

Are Markers of Systemic Inflammatory Response Useful in the Management of Patients With Neuroendocrine Neoplasms?

Given the increasing incidence of neuroendocrine neoplasms (NENs) over the past few decades, a more comprehensive knowledge of their pathophysiological bases and the identification of innovative NEN biomarkers represents an urgent unmet need. There is still little advance in the early diagnosis and management of these tumors, due to the lack of sensible and specific markers with prognostic value and ability to early detect the response to treatment. Chronic systemic inflammation is a predisposing factor for multiple cancer hallmarks, as cancer proliferation, progression and immune-evading. Therefore, the relevance of inflammatory biomarkers has been identified as critical in several types of tumours, including NENs. A bidirectional relationship between chronic inflammation and development of NENs has been reported. Neuroendocrine cells can be over-stimulated by chronic inflammation, leading to hyperplasia and neoplastic transformation. As the modulation of inflammatory response represents a therapeutic target, inflammatory markers could represent a promising new key tool to be applied in the diagnosis, the prediction of response to treatment and also as prognostic biomarkers in NENs field. The present review provides an overview of the pre-clinical and clinical data relating the potentially usefulness of circulating inflammatory markers: neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), cytokines and tissue inflammatory markers (PD-1/PD-L1), in the management of NENs. (1) NLR and PLR have both demonstrated to be promising and simple to acquire biomarkers in patients with advanced cancer, including NEN. To date, in the context of NENs, the prognostic role of NLR and PLR has been confirmed in 15 and 4 studies, respectively. However, the threshold value, both for NLR and PLR, still remains not defined. (2) Cytokines seem to play a central role in NENs tumorigenesis. In particular, IL-8 levels seems to be a good predictive marker of response to anti-angiogenic treatments. (3) PD-1 and PD-L1 expression on tumour cells and on TILs, have demonstrated to be promising predictive and prognostic biomarkers in NENs. Unfortunately, these two markers have not been validated so far and further studies are needed to establish their indications and utility.

Comparative safety review of the current therapies for gastroenteropancreatic neuroendocrine tumors

Introduction: Neuroendocrine neoplasms (NENs) comprise a heterogeneous group of neoplasms, whose management requires complex and individualized clinical decisions. Over the last decades the advent of novel medications and advanced diagnostic and therapeutic modalities, alongside our deeper understanding of the disease, revolutionized the landscape of their management, significantly improving both prognosis and quality of life of patients.Area covered: Treatment-related adverse events and safety concerns as demonstrated in clinical trials, as well as in real-world clinical practice.Expert opinion: The only true curative option for NENs remains surgery, whereas high-grade advanced neuroendocrine carcinomas should be primarily managed with platinum-based chemotherapy. For the remaining cases, that comprise the vast majority, the current armamentarium includes somatostatin analogs, interferon, telotristat ethyl, molecular targeted therapies, chemotherapy, peptide receptor radionuclide therapy, and locoregional treatment. The use of the aforementioned therapeutic options is associated with several and not uncommonly severe treatment-related adverse events. However, the benefits offered inclusive of improved prognosis, amelioration of symptoms, and better quality of life amidst others, by far outweighs any adverse event.

Recent Advances in the Management of Typical and Atypical Lung Carcinoids

Neuroendocrine neoplasms of the lung represent about 20% to 30% of all neuroendocrine tumors. On the basis of clinical and pathologic characteristics, 2 different categories of tumors may be defined: poorly differentiated neuroendocrine neoplasms, characterized by a high rate of recurrences and poor prognosis, and well-differentiated neuroendocrine neoplasms (typical carcinoids and atypical carcinoids), which generally display an indolent course. Lung carcinoids represent only 1% to 5% of all lung malignancies, but their incidence has significantly increased over the past 30 years. Surgery is the reference standard of treatment for lung carcinoids with locoregional disease. For advanced or unresectable lung carcinoids, several therapeutic options are available, but the choice should be shared within a multidisciplinary team to ensure optimal therapeutic outcomes. We describe the current management of these rare neoplasms.

Targeted Therapies in the Management of Well-Differentiated Digestive and Lung Neuroendocrine Neoplasms

OPINION STATEMENT

Ongoing advances in our understanding of neuroendocrine tumor (NET) biology, genetics, and immunology, will continue to expand the availability of targeted therapies, thus improving the outcomes of patients. Well-differentiated neuroendocrine tumors (NETs) are grouped into pancreatic and non-pancreatic NETs (includes GI and thoracic NETs) for treatment considerations (Fig. 1). For panNETs, initial therapy is driven by the need of radiographic response, and targeted agents are typically reserved for second and third line based on the toxicity profile. Treatment options for non-pancreatic NETs are also expanding and while SSAs are the typical first-line option, everolimus and PRRT both remain approved therapies for future lines, and VEGF TKIs are showing promising results in research settings. Sequencing these agents and best time to incorporate peptide receptor radio therapy into the management algorithm remains an unmet need.

Therapeutic options in lung neuroendocrine tumors: between established concepts and new hopes

Typical (TC) and atypical (AC) carcinoids are low-grade neuroendocrine tumors (NETs) of the lung and, are neglected diseases in respect of both high-grade NETs of the lung (i.e. small-cell lung cancer and large-cell neuroendocrine carcinoma) and gastroenteropancreatic (GEP)-NETs. AC and TC account for 2 and 0.2% of all thoracic malignancies, respectively, and have a 12.9% chance of metastatic spread at diagnosis, reaching up to 20% during disease history. There are very few trials specifically designed for lung NETs, and therapeutic options are mainly derived by studies carried out in patients with GEP-NETs. We report a case of a patient affected by AC progressed to available standard treatments who received off-label treatment with sunitinib, a well-known multitarget tyrosine-kinase inhibitor with marked antiangiogenic activity, used routinely for the treatment of GEP-NETs. During treatment, the patient required the administration of an alternative schedule to improve tolerability, with benefit, and achieved a partial response according to the RECIST criteria, which is unusual in NETs. We critically reviewed available data supporting the use of somatostatin analogs, chemotherapy, and target therapies (everolimus and sunitinib) in advanced lung NETs. In the review, ongoing trials in lung NETs and future developments in this research field are also discussed.

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.

Oncological management of advanced neuroendocrine tumours (Review)

The oncological principles of managing patients with gastroenteropancreatic neuroendocrine tumours (GEP-NETs) depends on a number of factors and requires a multidisciplinary approach. Recent data have provided additional therapeutic options, including biotherapy, traditional chemotherapy and novel targeted agents. Somatostatin analogues (SSAs) inhibit multiple cellular functions, including secretion, motility and proliferation. Interferon appears to act through several mechanisms, with antisecretory effects, immunomodulatory effects and antiproliferative functions, the latter inhibiting direct growth or attenuating angiogenesis. Opinions on when to commence chemotherapy for well differentiated GEP-NETs varies among experts. In previous years, reserving chemotherapy for patients with progressive disease (well differentiated, inoperable and/or metastatic GEP-NETs) was reasonably well argued for. Most well differentiated endocrine tumours are richly vascular and many express vascular endothelial growth factor (VEGF) receptors. In a xenograft model of a human carcinoid, treatment with an anti-VEGF monoclonal antibody was revealed to inhibit tumour growth and metastasis. As the role of angiogenesis and hypoxic-associated factors appears to be associated with tumour aggressiveness, strategies using agents which target angiogenesis have been developed. Mammalian target of rapamycin (mTOR) is a conserved serine-threonine kinase that regulates the cell cycle and metabolism in response to environmental factors. In addition, mTOR inhibition suppression was demonstrated to suppress NET growth. Each patient requires an individual approach to the choice of therapy, which should be selected depending on the severity of disease.

Phase-II Trials of Pazopanib in Metastatic Neuroendocrine Neoplasia (mNEN): A Systematic Review and Meta-Analysis

Background: Several phase-II trials have been designed to evaluate tyrosine kinase inhibitors (TKIs), in particular, pazopanib in neuroendocrine neoplasia (NEN), but its efficacy has not yet been demonstrated in a randomised-controlled Phase III trial. A systematic review of the published clinical trials of metastatic NEN patients could reduce the possible bias of single phase II studies. The present systematic review focuses on the efficacy and safety of pazopanib in patients with metastatic and locally advanced NEN. Methods: A systematic search in the major databases Medline/PubMed, Cochrane and Embase and in supplementary material from important international Meetings was performed to identify publications on pazopanib for the treatment of neuroendocrine neoplasia. English language was defined as a restriction. Four authors of the present review independently performed the study selection, assessed the risk of bias and extracted study data. Four published clinical trials and 2 abstracts were identified. One trial was excluded because the topic was Von-Hippel Landau disease and one abstract was eliminated because of the lack of information on meeting proceedings. Results: In all of the trials pazopanib was orally administered at a dose of 800 mg daily continuously with a 28-day cycle. The intention-to-treat population for efficacy was composed of 230 patients with a median age of 62 years. The partial response rate was 10.7% (95% confidence interval 2.6-20.5). The rate for stable disease was 79.6% (range: 61.7-92.1%) with a disease control rate (DCR) of 90.3%. Progressive disease was reported in 9.7% (range 5.2-17.6) of patients. No complete responses were observed. Median progression-free survival was 11.6 months (95% CI: 9.2-13.9). Overall survival from all the trials was 24.6 (95% CI: 18.7-40.8) months. Severe adverse events (grade III-IV) included hypertension 31%, 16% increase in AST/ALT, diarrhoea 10% and fatigue 10%. Conclusions: Pazopanib monotherapy achieved a DCR of 90.3% in patients with locally advanced and/or metastatic neuroendocrine neoplasia, with an overall response rate comparable to other TKIs and mTOR inhibitors and a safety profile similar to that of drugs of the same class.

Medical Management of Gastroenteropancreatic Neuroendocrine Tumors

The increased incidence and prevalence of neuroendocrine tumors (NETs) over the past few decades has been accompanied by an improvement in overall survival. There are differences in the management of small bowel NETs versus pNETs. The management of all patients with NETs must be individualized based on patient characteristics as well tumor-related factors. This article reviews the role of somatostatin analogues, historical results with chemotherapy in gastroenteropancreatic NETs (GEPNETs), and more recent evidence for the use of cytotoxic chemotherapy in GEPNETs. The article also discusses molecular targeted therapies approved for use in GEPNETs and some ongoing clinical trials.

A Phase II Study of Ibrutinib in Advanced Neuroendocrine Neoplasms

BACKGROUND

Ibrutinib is an orally administered inhibitor of Bruton's tyrosine kinase (Btk). Preclinical data suggest that mast cells are recruited within neuroendocrine neoplasms (NENs) where they stimulate angiogenesis and tumor growth. Ibrutinib inhibits mast cell degranulation and has been associated with regression of tumors in a mouse insulinoma model.

METHODS

A prospective, phase II trial evaluated patients with advanced gastrointestinal (GI)/lung NENs and pancreatic NENs (pNENs) who had evidence of progression within 12 months of study entry on at least one prior therapy. Patients received ibrutinib 560 mg daily until unacceptable toxicity, progression of disease, or withdrawal of consent. The primary endpoint was objective response rate.

RESULTS

Twenty patients were enrolled on protocol from November 2015 to December 2017 (15 advanced GI/lung NENs and 5 pNENs). No patient reached an objective response. Median PFS was 3.0 months. A total of 44 drug-related adverse events (AEs) were captured as probably or definitely associated with ibrutinib. Five patients experienced probably or definitely related grade 3 AEs, and 1 patient experienced a probably related grade 4 AE. Five patients discontinued treatment prior to radiographic assessment.

CONCLUSIONS

Ibrutinib does not show significant evidence of activity in well-differentiated gastroenteropancreatic and lung NENs.

Strong Antitumor Activity of Bevacizumab and Aflibercept in Neuroendocrine Carcinomas: In-Depth Preclinical Study

BACKGROUND

Neuroendocrine carcinoma (NEC) is a rare and very aggressive tumor. It has been greatly understudied, and very little is known about optimal treatment strategy for patients with this disease. The purpose of this study was to evaluate in vivo whether anti-vascular endothelial growth factor (VEGF) drugs could be a therapeutic alternative for these tumors with a poor prognosis.

METHODS

We have developed 2 xenograft models using either human cell line derived from lung (H460) or from colon (COLO320) NEC to assess the effect of 2 antiangiogenic drugs, aflibercept and bevacizumab, on tumor growth and their pathological characteristics. Additionally, tumors were subjected to immunohistochemistry staining and proteins were measured with Western blot and ELISA.

RESULTS

Both aflibercept and bevacizumab showed significant antitumor activity (p < 0.001). In the H460 model, aflibercept resulted in 94% tumor growth inhibition (TGI) and bevacizumab treatment resulted in 72.2% TGI. Similarly, in the COLO320 model, aflibercept and bevacizumab resulted in 89.3 and 84% TGI, respectively. Moreover, antitumor activity occurs early after treatment initiation. Using Tumor Control Index score, which address the kinetics of tumor growth in a way comparable to the methods used in human clinical studies, we confirmed that both drugs inhibit significantly tumor growth. When tumor stabilization was evaluated, aflibercept shows higher ability to stabilize NEC tumors than bevacizumab.

CONCLUSION

Results derived from this study strongly support anti-VEGF therapies, especially aflibercept, as a novel therapeutic option in NECs. Further studies are necessary, but our observations encourage the evaluation of antiangiogenics in clinical trials combined with standard chemotherapy.

Treatment of Gastroenteropancreatic Neuroendocrine Tumors

Neuroendocrine tumors (NETs) represent a group of biologically and clinically heterogeneous neoplasms arising from the diffuse neuroendocrine system. Although NETs may develop in almost any organ, they commonly arise in the gastrointestinal tract and pancreas and are referred to as gastroenteropancreatic (GEP)-NETs when they arise from these sites. In recent years, advances in understanding of the biology of NETs have resulted in an expansion in treatment options and improved survival for patients. This review focuses on treatment of GEP-NETS and highlights factors that govern the therapeutic approach.

An update on the management of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are a rare and heterogeneous group of neoplasia and differ in their clinical presentation, behavior, and prognosis based on both histological features and cancer stage at the time of diagnosis. Although small-sized tumors can be surgically resected, locally advanced and metastatic tumors confer a poor prognosis. In addition, only limited treatment options are available to the latter group of patients with PNETs, such as hormonal analogs, cytotoxic agents, and targeted therapy. In selected patients, liver-directed therapies are also used. As expected, clinicians taking care of these patients are challenged to develop an effective and comprehensive treatment strategy for their patients amid a wide variety of treatment modalities. Targeted therapy for PNETs is limited to sunitinib and everolimus. Presently, a number of clinical studies are ongoing to assess the efficacy of newer targeted agents alone and in combination with previous agents for the treatment of advanced PNETs. The authors reviewed the current treatment and also discussed the emerging agents and emphasized the need to identify biomarkers.

Systemic treatment for lung carcinoids: from bench to bedside

In the huge spectrum of lung neuroendocrine neoplasms, typical and atypical carcinoids should be considered as a separate biological entity from poorly differentiated forms, harboring peculiar molecular alterations. Despite their indolent behavior, lung carcinoids correlate with a worse survival. To date, only limited therapeutic options are available and novel drugs are strongly needed. In this work, we extensively reviewed scientific literature exploring available therapeutic options, new molecular targets and future perspectives in the management of well differentiated neoplasms of bronchopulmonary tree. Systemic therapy represents the main option in advanced and unresectable disease; accepted choices are somatostatin analogs, peptide receptor radionuclide therapy, everolimus and chemotherapy. To date, an univocal treatment strategy has not been identified yet, thus tailored therapeutic algorithms should consider treatment efficacy as well as safety profiles. Several molecular alterations found in carcinoid tumors might act as molecular targets leading to development of new therapeutic options. Further studies are necessary to identify new potential “druggable” molecular targets in the selected subset of low-grade lung carcinoids. Furthermore, evaluating the available therapies in more homogeneous population might improve their efficacy through a perfect tailoring of treatment options.

Treatments for patients with advanced neuroendocrine tumors: a network meta-analysis

Background

It remains unknown which is the most effective regimen among the available therapies for advanced well-differentiated neuroendocrine tumors (NETs). We performed a network meta-analysis to address this important issue.

Methods

PubMed, Embase, Web of Science, Cochrane Library, and major international scientific meetings were searched for relevant randomized controlled trials (RCTs). Progression-free survival (PFS) data was the primary outcome of interest, and overall survival (OS) and serious adverse events (SAEs) were the secondary outcomes of interests, reported as hazard ratio (HR), or odds ratio (OR) and 95% confidence intervals (CIs).

Results

Included in the meta-analysis were 21 eligible articles reporting 15 RCTs with a total of 2922 patients randomized to receive 11 treatments. Peptide receptor radionuclide therapy (PRRT) showed significant PFS advantage over somatostatin analogs (SSA) (HR = 0.21, 95% CI: 0.11-0.41), everolimus (HR = 0.25, 95% CI: 0.11-0.53), sunitinib (HR = 0.29, 95% CI: 0.10-0.82), everolimus+SSA (HR = 0.26, 95% CI: 0.12-0.54), and everolimus+bevacizumab (HR = 0.31, 95% CI: 0.11-0.82). OS findings were not significantly different between treatments. In terms of treatment rankings of PFS, PRRT had the highest probability (96%) of being the most effective treatment, followed by SSA+bevacizumab (86%) and SSA+interferon-α (IFN-α) (78%). As for toxicity, risk of SAEs was similar between the three treatments. Based on the benefit-risk ratio, PRRT, SSA+bevacizumab, and SSA+IFN-α seemed to be the best, second-, and third-best treatment, respectively.

Conclusions

PRRT is likely to be the most preferable treatment for patients with advanced well-differentiated NETs. SSA+bevacizumab and SSA+IFN-α also seem to be more effective regimens with limited risk of SAEs.

Everolimus, lutetium-177 DOTATATE and sunitinib for advanced, unresectable or metastatic neuroendocrine tumours with disease progression: a systematic review and cost-effectiveness analysis

BACKGROUND

Neuroendocrine tumours (NETs) are a group of heterogeneous cancers that develop in cells in the diffuse neuroendocrine system.

OBJECTIVES

To estimate the clinical effectiveness of three interventions [everolimus (Afinitor^®; Novartis International AG, Basel, Switzerland), lutetium-177 DOTATATE (177Lu-DOTATATE) (Lutathera^®; Imaging Equipment Ltd, Radstock, UK) and sunitinib (Sutent^®; Pfizer Inc., New York, NY, USA)] for treating unresectable or metastatic NETs with disease progression and establish the cost-effectiveness of these interventions.

DATA SOURCES

The following databases were searched from inception to May 2016: MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE Daily, Epub Ahead of Print, EMBASE, Cochrane Central Register of Controlled Trials and Web of Science.

REVIEW METHODS

We systematically reviewed the clinical effectiveness and cost-effectiveness literature on everolimus, 177Lu-DOTATATE and sunitinib for treating advanced, unresectable or metastatic progressive NETs. The following NET locations were considered separately: pancreas, gastrointestinal (GI) tract and lung, and GI tract (midgut only). We wrote a survival partition cohort-based economic evaluation in Microsoft Excel^® 2013 (Microsoft Corporation, Redmond, WA, USA) from the UK NHS and Personal Social Services perspective. This comprised three health states: (1) progression-free survival (PFS), (2) progressed disease and (3) death.

RESULTS

Three randomised controlled trials (RCTs), RADIANT-3 [RAD001 in Advanced Neuroendocrine Tumors, Third Trial; pancreatic NETs (pNETs): everolimus vs. best supportive care (BSC)], A6181111 (pNETs: sunitinib vs. BSC) and RADIANT-4 (RAD001 in Advanced Neuroendocrine Tumors, Fourth Trial; GI and lung NETs: everolimus vs. BSC), met the inclusion criteria for the clinical effectiveness systematic review. The risk of bias was low. Although the NETTER-1 (Neuroendocrine Tumors Therapy) RCT, of 177Lu-DOTATATE plus 30 mg of octreotide (Sandostatin^®, Novartis) compared with 60 mg of octreotide, was excluded from the review, we nonetheless present the results of this trial, as it informs our estimate of the cost-effectiveness of 177Lu-DOTATATE. The pNETs trials consistently found that the interventions improved PFS and overall survival (OS) compared with BSC. Our indirect comparison found no significant difference in PFS between everolimus and sunitinib. Estimates of OS gain were confounded because of high rates of treatment switching. After adjustment, our indirect comparison suggested a lower, but non-significant, hazard of death for sunitinib compared with everolimus. In GI and lung NETs, everolimus significantly improved PFS compared with BSC and showed a non-significant trend towards improved OS compared with BSC. Adverse events were more commonly reported following treatment with targeted interventions than after treatment with BSC. In the base case for pNETs, assuming list prices, we estimated incremental cost-effectiveness ratios (ICERs) for everolimus compared with BSC of £45,493 per quality-adjusted life-year (QALY) and for sunitinib compared with BSC of £20,717 per QALY. These ICERs increased substantially without the adjustment for treatment switching. For GI and lung NETs, we estimated an ICER for everolimus compared with BSC of £44,557 per QALY. For GI (midgut) NETs, the ICERs were £199,233 per QALY for everolimus compared with BSC and £62,158 per QALY for a scenario analysis comparing 177Lu-DOTATATE with BSC. We judge that no treatment meets the National Institute for Health and Care Excellence's (NICE) end-of-life criteria, although we cannot rule out that sunitinib in the A6181111 trial does.

LIMITATIONS

A RCT with included comparators was not identified for 177Lu-DOTATATE. The indirect treatment comparison that our economic analysis was based on was of a simple Bucher type, unadjusted for any differences in the baseline characteristics across the two trials.

CONCLUSIONS

Given NICE's current stated range of £20,000-30,000 per QALY for the cost-effectiveness threshold, based on list prices, only sunitinib might be considered good value for money in England and Wales.

FUTURE WORK

Further analysis of individual patient data from RADIANT-3 would allow assessment of the robustness of our findings. The data were not made available to us by the company sponsoring the trial.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016041303.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Therapeutic Options for Neuroendocrine Tumors: A Systematic Review and Network Meta-analysis

IMPORTANCE

Multiple therapies are currently available for patients with neuroendocrine tumors (NETs), yet many therapies have not been compared head-to-head within randomized clinical trials (RCTs).

OBJECTIVE

To assess the relative safety and efficacy of therapies for NETs.

DATA SOURCES

PubMed, Embase, the Cochrane Central Register of Controlled Trials, trial registries, meeting abstracts, and reference lists from January 1, 1947, to March 2, 2018, were searched. Key search terms included neuroendocrine tumors, gastrointestinal neoplasms, therapy, and randomized controlled trial.

STUDY SELECTION

Randomized clinical trials comparing 2 or more therapies in patients with NETs (primarily gastrointestinal and pancreatic) were evaluated. Thirty RCTs met the selection criteria.

DATA EXTRACTION AND SYNTHESIS

Pairs of independent reviewers screened studies, extracted data, and assessed the risk of bias. A network meta-analysis with a frequentist approach was used to compare the efficacy of therapies; the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was used.

MAIN OUTCOMES AND MEASURES

Disease control, progression-free survival, overall survival, adverse events, and quality of life.

RESULTS

The systematic review identified 30 relevant RCTs comprising 3895 patients (48.4% women) assigned to 22 different therapies for NETs. These therapies showed a broad range of risk for serious and nonserious adverse events. The network meta-analyses included 16 RCTs with predominantly a low risk of bias; nevertheless, precision-of-treatment estimates and estimated heterogeneity were limited. The network meta-analysis found 7 therapies for pancreatic NETs: everolimus (hazard ratio [HR], 0.35 [95% CI, 0.28-0.45]), everolimus plus somatostatin analogue (HR, 0.35 [95% CI, 0.25-0.51]), everolimus plus bevacizumab plus somatostatin analogue (HR, 0.44 [95% CI, 0.26-0.75]), interferon (HR, 0.37 [95% CI, 0.16-0.83]), interferon plus somatostatin analogue (HR, 0.31 [95% CI, 0.13-0.71]), somatostatin analogue (HR, 0.46 [95% CI, 0.33-0.66]), and sunitinib (HR, 0.42 [95% CI, 0.26-0.67]), and 5 therapies for gastrointestinal NETs: bevacizumab plus somatostatin analogue (HR, 0.22 [95% CI, 0.05-0.99]), everolimus plus somatostatin analogue (HR, 0.31 [95% CI, 0.11-0.90]), interferon plus somatostatin analogue (HR, 0.27 [95% CI, 0.07-0.96]), Lu 177-dotatate plus somatostatin analogue (HR, 0.08 [95% CI, 0.03-0.26], and somatostatin analogues (HR, 0.40 [95% CI, 0.21-0.78]) with higher efficacy than placebo and suggests an overall superiority of combination therapies.

CONCLUSIONS AND RELEVANCE

The findings from this study suggest that a range of efficient therapies with different safety profiles is available for patients with NETs.

A Phase II Trial of Ziv-Aflibercept in Patients With Advanced Pancreatic Neuroendocrine Tumors

OBJECTIVES

Therapies for patients with advanced well-differentiated pancreatic neuroendocrine tumors (pNETs) are insufficient, with patients succumbing to disease despite recent treatment advances. Ziv-aflibercept is a fusion protein of portions of the vascular endothelial growth factor (VEGF) receptors 1 and 2, fused to the Fc portion of immunoglobulin G1, forming a VEGF trap. Perfusion computed tomography (CT) has previously defined hyperperfused neuroendocrine tumors, potentially predicting antiangiogenic benefit.

METHODS

We performed a single-arm open-label study, using the Simon optimal 2-stage design, of 6 mg/kg ziv-aflibercept in patients with advanced pNETs. The primary end point was objective radiographic response, with a hierarchically tested co-primary end point of response prediction by baseline hyperperfusion, defined as blood volume greater than 5.25 mL/100 g and permeability surface area product greater than 25 mL/min per 100 g.

RESULTS

Between July 3, 2014, and September 28, 2016, 21 patients were treated. Two patients (9.5%; 95% confidence interval, 1.1%-30.4%) demonstrated objective response, satisfying criteria to open the second stage, but the study was terminated for accrual. Perfusion CT could not be confirmed to predict radiographic response. Toxicities include 1 grade 5 gastrointestinal hemorrhage and 5 incidents of proteinuria requiring treatment discontinuation.

CONCLUSIONS

Responses with ziv-aflibercept were consistent with other VEGF inhibitors in pNET, but perfusion CT could not be confirmed to predict outcome.

[Systemic Therapy for Low-grade Pulmonary Neuroendocrine Tumor]

肺部是神经内分泌肿瘤（neuroendocrine tumor, NET）的第二好发部位。肺类癌包括典型类癌和不典型类癌，属于低级别神经内分泌肿瘤。这一类肿瘤由于发病率较低，目前尚未得到广大医务工作者的重视。但有效的治疗不仅能提高患者的远期生存，还能控制患者症状，改善生活质量。本文分别阐述肺低级别神经内分泌肿瘤的流行病学和病理学特点、早期患者的治疗策略以及进展期患者的治疗策略。早期患者应当尽早进行手术治疗。进展期患者治疗方式包括化疗、SSAs、mTOR抑制剂、肽受体介导的放射性核素治疗、生物治疗以及靶向治疗。目前的研究结论大多来自其他部位的NETs研究外推而来，仍需针对肺低级别神经内分泌肿瘤患者进行特异性临床试验加以证实。

Unmet Medical Needs in Pulmonary Neuroendocrine (Carcinoid) Neoplasms

Pulmonary carcinoids (PCs) display the common features of all well-differentiated neuroendocrine neoplasms (NEN) and are classified as low- and intermediate-grade malignant tumours (i.e., typical and atypical carcinoid, respectively). There is a paucity of randomised studies dedicated to advanced PCs and management principles are drawn from the larger gastroenteropancreatic NEN experience. There is growing evidence that NEN anatomic subgroups have different biology and different responses to treatment and, therefore, should be investigated as separate entities in clinical trials. In this review, we discuss the existing evidence and limitations of tumour classification, diagnostics and staging, prognostication, and treatment in the setting of PC, with focus on unmet medical needs and directions for the future.

The Tumor Microenvironment in Neuroendocrine Tumors: Biology and Therapeutic Implications

Neuroendocrine tumors (NETs) include a heterogeneous group of malignancies arising in the diffuse neuroendocrine system and characterized by indolent growth. Complex interactions take place among the cellular components of the microenvironment of these tumors, and the recognition of the molecular mediators of their interplay and cross talk is crucial to discover novel therapeutic targets. NET cells overexpress a plethora of proangiogenic molecules including vascular endothelial growth factor, platelet-derived growth factor, fibroblast growth factor, semaphorins, and angiopoietins that promote both recruitment and proliferation of endothelial cell precursors, thus resulting among the most vascularized cancers with a microvessel density 10-fold higher than epithelial tumors. Also, NETs operate multifaceted interactions with stromal cells, both at local and distant sites, and whether their paracrine secretion of serotonin, connective tissue growth factor, and transforming growth factor β primarily drives the fibroblast activation to enhance the tumor proliferation, on the other side NET-derived profibrotic factors accelerate the extracellular matrix remodeling and contribute to heart valves and/or mesenteric fibrosis development, namely, major complications of functioning NETs. However, at present, little is known on the immune landscape of NETs, but accumulating evidence shows that tumor-infiltrating neutrophils, mast cells, and/or macrophages concur to promote the neoangiogenic switch of these tumors by either direct or indirect mechanisms. On the other hand, immune checkpoint molecules are heterogeneously expressed in NETs' surrounding cells, and it is unclear whether or not tumor-infiltrating lymphocytes are antitumor armed within the microenvironment, given their low mutational load. Here, we review the current knowledge on both gastroenteropancreatic and pulmonary NETs' microenvironment as well as both established and innovative treatments aimed at targeting the tumor-host interplay.

Gastroenteropancreatic Neuroendocrine Tumors

Neuroendocrine tumors (NETs) are heterogeneous malignancies arising from the diffuse neuroendocrine system. They frequently originate in the gastroenteropancreatic (GEP) tract and the bronchopulmonary tree, and their incidence has steadily increased in the last 3 decades. Fundamental biologic and genomic differences underlie the clinical heterogeneity of NETs, and distinct molecular features characterize NETs of different grades and different primary sites. Although surgery remains the cornerstone of treatment for localized tumors, systemic treatment options for patients with metastatic NETs have expanded considerably. Somatostatin analogs have demonstrated both antisecretory and antitumor efficacy. Peptide receptor radionuclide therapy with lutetium-177 dotatate (¹⁷⁷ Lu-DOTATATE) has been approved for advanced GEP-NETs. The antitumor activity of everolimus has been demonstrated across a wide spectrum of NETs, and the antiangiogenic agent sunitinib has been approved for pancreatic NETs (pNETs). Chemotherapy with temozolomide and capecitabine has recently demonstrated an unprecedented prolongation of progression-free survival in a randomized trial of pNETs. Multiple retrospective series have reported the efficacy of liver-directed therapies both for palliating symptoms of hormone excess and for controlling tumor growth. Telotristat, an oral inhibitor of tryptophan hydroxylase, has been shown to reduce diarrhea in patients with carcinoid syndrome. Defining the therapeutic algorithm and identifying biomarkers predictive of response to treatments are among the main priorities for the next decade of research in the NET field.

New Treatments for the Carcinoid Syndrome

Neuroendocrine tumors, including carcinoids, are rare and insidiously growing tumors. Related to their site of origin, tumors can be functional, causing various forms of the carcinoid syndrome, owing to the overproduction of serotonin, histamine, or other bioactive substances. They often invade adjacent structures or metastasize to the liver and elsewhere. Treatment includes multimodal approaches, including cytoreductive surgery, locoregional embolization, cytotoxic therapy, peptide receptor radionuclide therapy, and various targeted therapies with goals of symptom relief and control of tumor growth. This article summarizes current and emerging approaches to management and reviews several promising future therapies.

E4206: AMG 706 and Octreotide in Patients with Low-Grade Neuroendocrine Tumors

LESSONS LEARNED

Rate of progression-free survival at a particular point in time, i.e., a landmark analysis, is a difficult endpoint for a heterogenous malignancy such as neuroendocrine cancer.Landmark analyses can also be complicated by evolution in the standard of care during the conduct of a clinical trial.Improvements in biomarker development would be useful in developing future clinical trials in NET to better tailor individualized therapies and assess for possible efficacy endpoints.

BACKGROUND

Neuroendocrine tumors (NETs) are rare malignancies of the gastrointestinal (GI) tract that are highly vascularized and overexpress vascular-endothelial growth factor (VEGF). Sunitinib has demonstrated efficacy in the pancreatic subset of NET. This study explored the activity of another oral VEGF inhibitor, AMG 706 or motesanib, a multikinase inhibitor that targets receptor tyrosine kinases, including VEGFR1, VEGFR2, VEGFR3, KIT, RET, and PDGFR (IC50s = 2, 3, 6, 8, 59, and 84 nM, respectively).

METHODS

This was a single-arm, first-line, phase II study run through the Eastern Cooperative Oncology Group. Patients with low-grade NET (as defined by central confirmation of Ki-67 of 0%-2%) were administered a flat dose of 125 mg per day orally combined with octreotide long acting-repeatable (LAR) for patients who had been on a stable dose. The primary objective was to determine the 4-month progression-free survival (PFS).

RESULTS

Forty-four patients were evaluated per protocol. The 4-month PFS was 78.5%. The partial response rate was 13.6% (6/44), stable disease was 54.5% (24/44), 9.1% (4/44) had progressive disease, and 10/44 were not evaluable for response. Common toxicities included fatigue, hypertension, nausea, and headache, and most were grade 1-2. Median PFS was 8.7 months, and overall survival was 27.5 months.

CONCLUSION

Motesanib (AMG 706) demonstrated a 4-month PFS that met the per-protocol definition of efficacy. Fatigue and hypertension were the most common toxicities, and few grade 3-4 toxicities were encountered. The progression-free survival of 8.7 months in all NETs merits further study.

Emerging multitarget tyrosine kinase inhibitors in the treatment of neuroendocrine neoplasms

In the last few years, the therapeutic approach for neuroendocrine neoplasms (NENs) has changed dramatically following the approval of several novel targeted treatments. The multitarget tyrosine kinase inhibitor (MTKI), sunitinib malate, has been approved by Regulatory Agencies in pancreatic NENs. The MTKI class, however, includes several other molecules (approved for other conditions), which are currently being studied in NENs. An in-depth review on the studies published on the MTKIs in neuroendocrine tumors such as axitinib, cabozantinib, famitinib, lenvatinib, nintedanib, pazopanib, sorafenib and sulfatinib was performed. Furthermore, we extensively searched on the Clinical Trial Registries databases worldwide, in order to collect information on the ongoing clinical trials related to this topic. Our systematic analysis on emerging MTKIs in the treatment of gastroenteropancreatic and lung NENs identifies in vitro and in vivo studies, which demonstrate anti-tumor activity of diverse MTKIs on neuroendocrine cells and tumors. Moreover, for the first time in the literature, we report an updated view concerning the upcoming clinical trials in this field: presently, phase I, II and III clinical trials are ongoing and will include, overall, a staggering 1667 patients. This fervid activity underlines the increasing interest of the scientific community in the use of emerging MTKIs in NEN treatment.