Everolimus plus octreotide long-acting repeatable for the treatment of advanced neuroendocrine tumours associated with carcinoid syndrome (RADIANT-2): a randomised, placebo-controlled, phase 3 study

Activity and Safety of Immune Checkpoint Inhibitors in Neuroendocrine Neoplasms: A Systematic Review and Meta-Analysis

Immune-checkpoint inhibitors (ICIs) have widened the therapeutic scenario of different cancer types. Phase I/II trials have been designed to evaluate the role of ICIs both as single agents and in combination in neuroendocrine neoplasms (NENs), but as yet no randomized controlled phase III trials have been carried out. A systematic review and meta-analysis of studies published could help to reduce the biases of single-phase II trials. Efficacy data were obtained on 636 patients. Pooled percentages of the overall response rate (ORR) and disease control rate (DCR) were 10% (95% CI: 6-15%, I2 = 67%, p < 0.1) and 42% (95% CI: 28-56%, I2 = 93%, p < 0.1), respectively. Median progression-free survival (mPFS) was 4.1 months (95% CI 2.6-5.4; I2 = 96%, p < 0.1) and median overall survival (mOS) was 11 months (95% CI 4.8-21.1; I2 = 98%, p < 0.1). Among the ICIs used as single agents, the anti-PD1 toripalimab achieved the highest ORR. Combination regimens were superior to monotherapy, e.g., the ICI combination nivolumab + ipilimumab, and the ICI + anti-angiogenetic combination atezolizumab + bevacizumab, both of which warrant further investigation. Promising efficacy and a good safety profile of ICIs represent a valid opportunity for expanding the therapeutic landscape of NENs. Predictive biomarkers are needed to identify the most suitable candidates for these regimens.

Spontaneous intra-abdominal hemorrhage of a well-differentiated, grade 3 gastric neuroendocrine tumor during drug-based treatment

Grade 3, well-differentiated, gastric neuroendocrine tumors (NET G3) are extremely rare. Herein, we report the case of a 64-year-old man with a grade 3 neuroendocrine tumor of the stomach who experienced intra-abdominal bleeding during the course of drug treatment. The patient was referred to our hospital for examination of a gastric tumor that was initially diagnosed by a local medical doctor. Esophagogastroduodenoscopy revealed an elevated lesion with a central ulcer in the upper body of the stomach, and biopsy specimens confirmed the pathological diagnosis of NET G3. Abdominal contrast-enhanced computed tomography (CT) showed a 25-cm, well-defined mass lesion showing heterogeneous enhancement in the liver. A clinical diagnosis of NET G3 with multiple liver metastases was given, after which everolimus was administered in combination with a somatostatin analogue. However, the patient developed sudden-onset epigastric abdominal pain and general fatigue 2 months later, and emergency abdominal contrast-enhanced CT confirmed the presence of intra-abdominal hemorrhage. Following blood transfusion, the patient's symptoms and general condition improved. Although the patient was treated with streptozocin, abdominal CT indicated progression of the liver metastases. Unfortunately, despite receiving best supportive care, the patient died 8 months after the initial of the treatment. To the best of our knowledge, this is the first case of a patient who developed spontaneous hemoperitoneum during drug treatment for a NET G3 to be reported in the English literature. It is essential that additional data be obtained to determine the optimal treatment for this disease.

Prognostic Implications of the Immune Tumor Microenvironment in Patients With Pancreatic and Gastrointestinal Neuroendocrine Tumors

OBJECTIVES

The aim of this study was to characterize the tumor microenvironment of patients with gastroenteropancreatic neuroendocrine tumors relative to progression-free survival (PFS).

METHODS

Immune profiling for CD3, CD8, programmed death-1/programmed death-ligand 1, and indoleamine 2,3-dioxygenase expression in 2 cohorts of gastroenteropancreatic neuroendocrine tumors: patients with short PFS (<4 years, n = 12) versus long PFS (≥4 years, n = 14) after surgery. Immune infiltrates in the tumor and interface were quantified. Programmed death-ligand 1 expression was determined within the tumor, stroma, and interface.

RESULTS

Patients with shorter PFS had larger tumors (P = 0.02), mostly in the pancreas (P = 0.04). We observed a higher mean expression of CD3+, CD8+, programmed death-1+ cells, and indoleamine 2,3-dioxygenase at the interface compared with the tumor: log 10 mean differences 0.56 (95% confidence interval [CI], 0.43-0.68; P < 0.0001), 0.45 (95% CI, 0.32-0.59; P = 0.0002), 0.50 (95% CI, 0.40-0.61; P < 0.0001), and 0.24 (95% CI, 0.03-0.46; P = 0.046), respectively. Patients with longer PFS had higher intratumoral CD3+ T cells, log 10 mean difference 0.38 (95% CI, 0.19-0.57; P = 0.004). Programmed death-ligand 1 expression tended to be higher among patients with shortened PFS (odds ratio, 2.00; 95% CI, 0.68-5.91).

CONCLUSIONS

Higher intratumoral CD3+ T-cell infiltrate was associated with longer PFS after resection.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Drug-Related Pneumonitis in Cancer Treatment during the COVID-19 Era

Interstitial lung disease is recognized as a group of diseases with a different etiopathogenesis characterized by chronic lung inflammation with the accumulation of inflammatory cells, lymphocytes and macrophages, and the consequent release of proinflammatory cytokines. Various degrees of pulmonary fibrosis can be associated with this inflammatory condition. Interstitial lung disease related to oncological drugs is a relevant problem in clinical practice. The etiopathogenetic mechanisms underlying this adverse event are not completely known but can be partly explained by the mechanism of action of the drug involved. Therefore, knowledge of the relevance of this potentially fatal adverse event supported by the reported safety data of pivotal studies becomes fundamental in the management of patients. The prompt diagnosis of drug-related pneumonia and the consequent differential diagnosis with other forms of pneumonia allow a rapid suspension of treatment and the establishment of an immunosuppressive treatment if necessary. In the context of the health emergency related to SARS CoV2 infection and COVID-19-related interstitial lung disease, such knowledge holds decisive relevance in the conscious choice of cancer treatments. Our intent was to describe the oncological drugs most correlated with this adverse event by reporting, where possible, the percentages of insurgency in pivotal studies to provide an overview and therefore promote greater awareness of this important toxicity related to oncological treatment.

Current Management of Appendiceal Neoplasms

Appendiceal neoplasms include a heterogeneous group of epithelial and nonepithelial tumors that exhibit varying malignant potential. This review article summarizes current diagnostic criteria, classification systems, and optimal therapeutic strategies for the five main histopathologic subtypes of appendiceal neoplasms. In particular, the management of epithelial appendiceal neoplasms has evolved. Although their treatment has historically been extrapolated from colon cancer, improved understanding of their unique histopathologic and molecular characteristics and a growing body of published clinical data support a more nuanced approach to their management.

mTOR Inhibitors as Radiosensitizers in Neuroendocrine Neoplasms

Peptide receptor radioligand therapy (PRRT) has evolved as an important second-line treatment option in the management of inoperable and metastatic neuroendocrine neoplasms (NEN). Though high radiation doses can be delivered to the tumors, complete remission is still rare. Radiosensitization prior to PRRT is therefore considered to be a promising strategy to improve the treatment effect. In this study, effect and mechanism of mTOR inhibitors were investigated in a comprehensive panel of five NEN cell lines (BON, QGP-1, LCC-18, H727, UMC-11), employing assays for cellular proliferation, clonogenic survival, cell cycle modification and signaling. mTOR inhibition lead to growth arrest with a biphasic concentration-response pattern: a partial response at approximately 1 nM and full response at micromolar concentrations (8-48 µM). All cell lines demonstrated elevated p70S6K phosphorylation yet also increased phosphorylation of counterregulatory Akt. The pulmonary NEN cell line UMC-11 showed the lowest induction of phospho-Akt and strongest growth arrest by mTOR inhibitors. Radiation sensitivity of the cells (50% reduction versus control) was found to range between 4 and 8 Gy. Further, mTOR inhibition was employed together with irradiation to evaluate radiosensitizing effects of this combination treatment. mTOR inhibition was found to radiosensitize all five NEN cells in an additive manner with a moderate overall effect. The radiation-induced G2/M arrest was diminished under combination treatment, leading to an increased G1 arrest. Further investigation involving a suitable animal model as well as radioligand application such as ¹⁷⁷Lu-DOTATATE or ¹⁷⁷Lu-DOTATOC will have to demonstrate the full potential of this strategy for radiosensitization in NEN.

Treatment of Advanced Gastro-Entero-Pancreatic Neuro-Endocrine Tumors: A Systematic Review and Network Meta-Analysis of Phase III Randomized Controlled Trials

Simple Summary

The most effective and safest approach for the treatment of advanced gastro-entero-pancreatic neuroendocrine neoplasms (GEP–NENs) remains unknown. A systematic review was done to clarify this point. A network meta-analysis was used to overcome the multiarm problem. Our study confirmed that somatostatin analogs (SSAs) alone remain the best choice for well-differentiated GEP–NENs. ¹⁷⁷Lu-Dotatate plus SSA is a valid alternative for midgut NENs since it has been shown to be slightly more efficacious but yielding a higher risk for toxicity than SSAs.

Abstract

Several new therapies have been approved to treat advanced gastro-entero-pancreatic neuroendocrine neoplasms (GEP–NENs) in the last twenty years. In this systematic review and meta-analysis, we searched MEDLINE, ISI Web of Science, and Scopus phase III randomized controlled trials (RCTs) comparing two or more therapies for unresectable GEP–NENs. Network metanalysis was used to overcome the multiarm problem. For each arm, we described the surface under the cumulative ranking (SUCRA) curves. The primary endpoints were progression-free survival and grade 3–4 of toxicity. We included nine studies involving a total of 2362 patients and 5 intervention arms: SSA alone, two IFN-α plus SSA, two Everolimus alone, one Everolimus plus SSA, one Sunitinib alone, one ¹⁷⁷Lu-Dotatate plus SSA, and one Bevacizumab plus SSA. ¹⁷⁷Lu-Dotatate plus SSA had the highest probability (99.6%) of being associated with the longest PFS. This approach was followed by Sunitinib use (64.5%), IFN-α plus SSA one (53.0%), SSA alone (46.6%), Bevacizumab plus SSA one (45.0%), and Everolimus ± SSA one (33.6%). The placebo administration had the lowest probability of being associated with the longest PFS (7.6%). Placebo or Bevacizumab use had the highest probability of being the safest (73.7% and 76.7%), followed by SSA alone (65.0%), IFN-α plus SSA (52.4%), ¹⁷⁷Lu-Dotatate plus SSA (49.4%), and Sunitinib alone (28.8%). The Everolimus-based approach had the lowest probability of being the safest (3.9%). The best approaches were SSA alone or combined with ¹⁷⁷Lu-Dotatate.

The Landmark Series: Management of Small Bowel Neuroendocrine Tumors

Surgical resection is the foundation for treatment of small bowel neuroendocrine tumors (SBNETs). Guidelines for surgical management of SBNETs rely on retrospective data, which suggest that primary tumor resection and cytoreduction improve symptoms, prevent future complications, and lengthen survival. In advanced NETs, improvement in progression-free survival has been reported in large, randomized, controlled trials of various medical treatments, including somatostatin analogues, targeted therapy, and peptide receptor radionuclide therapy. This review discusses important studies influencing the management of SBNETs and the limitations of current evidence regarding surgical interventions for SBNETs.

The State of Peptide Receptor Radionuclide Therapy and Its Sequencing among Current Therapeutic Options for Gastroenteropancreatic Neuroendocrine Tumors

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are the most common form of neuroendocrine neoplasia, but there is no current consensus for the sequencing of approved therapies, particularly with respect to peptide receptor radionuclide therapy (PRRT). This comprehensive review evaluates the data supporting approved therapies for GEP-NETs and recommendations for therapeutic sequencing with a focus on how PRRT currently fits within sequencing algorithms. The current recommendations for PRRT sequencing restrict its use to metastatic, inoperable, progressive midgut NETs; however, this may change with emerging data to suggest that PRRT might be beneficial as neoadjuvant therapy for inoperable tumors, is more tolerable than other treatment modalities following first-line standard dose somatostatin analogs, and can be used as salvage therapy after disease relapse following prior successful cycles of PRRT. PRRT has also been shown to reduce tumor burden, improve quality of life, and prolong the time to disease progression in a broad spectrum of patients with GEP-NETs. As the various potential benefits of PRRT in GEP-NET therapy continues to expand, it is necessary to review and critically evaluate our treatment algorithms for GEP-NETs.

Opportunistic and Serious Infections in Patients with Neuroendocrine Tumors Treated with Everolimus: A Multicenter Study of Real-World Patients

INTRODUCTION

The incidence of infections is poorly studied in patients with neuroendocrine tumors (NET) treated with everolimus outside of clinical trials. We aimed to evaluate the frequency of and risk factors for opportunistic infections (Opl) or any serious infection in eligible patients.

METHODS

This was a retrospective multicenter study of a Latin American cohort of consecutive patients with advanced NET treated with everolimus. Duration of everolimus, comorbidities, Charlson comorbidity score, type of prior treatment, institution, and concurrent immunosuppressive conditions were tested for possible associations with serious (grade 3-5) infections in univariate and multivariable logistic regression models.

RESULTS

One hundred eleven patients from 5 centers were included. The median duration of everolimus was 8.9 months. After a median follow-up of 32.9 months, 34 patients (30.6%; 95% CI 22.2-40.1) experienced infections of any grade, with 24 (21.6%; 95% CI 14.8-30.4) having a serious infection and 7 (6.3%; 95% CI 2.6-12.6) having at least 1 OpI (Candida sp., Toxoplasma gondi, Pneumocystis sp., Herpes sp., and Cryptococcus sp.). Four patients (3.6%) died from infections, but only 2 deaths (1.8%) were deemed to be related to everolimus. The multivariable analysis identified everolimus duration (every 6-month increase; OR = 1.28; 95% CI 1.02-1.60; p = 0.03) as an independent risk factor for serious infection.

CONCLUSION

Infections are more frequent in NET patients using everolimus than previously reported in clinical trials. Patients on everolimus should be closely monitored for infections, especially those receiving it for several months.

Models of Gastroenteropancreatic Neuroendocrine Neoplasms: Current Status and Future Directions

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are a rare, heterogeneous group of tumors that originate from the endocrine system of the gastrointestinal tract and pancreas. GEP-NENs are subdivided according to their differentiation into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). Since GEP-NENs represent rare diseases, only limited data from large prospective, randomized clinical trials are available, and recommendations for treatment of GEP-NEN are in part based on data from retrospective analyses or case series. In this context, tractable disease models that reflect the situation in humans and that allow to recapitulate the different clinical aspects and disease stages of GEP-NET or GEP-NEC are urgently needed. In this review, we highlight available data on mouse models for GEP-NEN. We discuss how these models reflect tumor biology of human disease and whether these models could serve as a tool for understanding the pathogenesis of GEP-NEN and for disease modeling and pharmacosensitivity assays, facilitating prediction of treatment response in patients. In addition, open issues applicable for future developments will be discussed.

Everolimus Related Fulminant Hepatitis in Pancreatic Neuroendocrine Tumor With Liver Metastases: A Case Report and Literature Review

BACKGROUND

Everolimus, an immunosuppressant, is approved for the treatment of advanced renal cell carcinoma, metastatic hormone receptor-positive breast cancer, and pancreatic neuroendocrine tumors (P-NETs) but has been reported to be related to hepatitis B reactivation. Here, we present the first case of fatal fulminant hepatitis B reactivation in a man with P-NET accompanied by multiple liver metastases who received everolimus and octreotide long-acting repeatable (LAR).

CASE PRESENTATION

A 45-year-old male had a history of chronic hepatitis B infection. He was found to have a complicated liver cyst incidentally, and then he underwent biopsy, which disclosed a grade 2 neuroendocrine tumor (NET). Subsequent MRI of the abdomen and PET revealed a solid mass at the pancreatic tail with numerous liver tumors favoring metastases and peripancreatic lymph node metastases. Transarterial chemoembolization (TACE) of the right lobe of the liver was performed, and he started to take 5 mg everolimus twice a day and 20 mg octreotide LAR every month 8 days after the 1^st TACE. No hepatitis B virus (HBV) prophylaxis treatment was administered. He then underwent laparoscopic distal pancreatectomy and splenectomy three and half months after the initial treatment of everolimus. He continued everolimus 5 mg twice a day and octreotide 20 mg every month after the operation. Three months later, hepatic failure occurred due to acute hepatitis B flare-up-related fulminant hepatic failure since other possible causes of hepatic failure were excluded. Five days after hepatic failure presented, hepatic failure was apparent, and pulseless ventricular tachycardia occurred. The patient expired after failed resuscitation.

CONCLUSION

A literature review of everolimus-related hepatitis B reactivation was conducted. In P-NET patients with chronic hepatitis B who will undergo everolimus treatment, HBV prophylaxis should be considered since fatal hepatitis B reactivation might occur under rare conditions.

MYC Upregulation Confers Resistance to Everolimus and Establishes Vulnerability to Cyclin-Dependent Kinase Inhibitors in Pancreatic Neuroendocrine Neoplasm Cells

INTRODUCTION

Dysregulation of the mechanistic target of rapamycin complex 1 (mTORC1)-dependent pathways in pancreatic neuroendocrine neoplasms (PanNENs) underlies the introduction of the mTORC1 inhibitor everolimus as treatment of advanced progressive PanNENs. Although everolimus significantly increases progression-free survival, most patients acquire secondary resistance to the drug. This study aimed at identifying mechanisms involved in acquisition of resistance to everolimus.

METHODS

BON-1 and everolimus-resistant (ER) BON-1 cells were used as in vitro system of sensitivity and acquired resistance. Transcriptome changes occurring in BON-1 and ER-BON-1 were investigated by RNA sequencing and validated by quantitative PCR analysis. RNA extracted from patients' biopsies was used to validate MYC upregulation. Drug screening and functional assays were performed using ER-BON-1 cells. Cell cycle progression was evaluated by FACS analysis.

RESULTS

Our results show that MYC overexpression is a key event in the development of secondary resistance to everolimus in PanNEN cell lines and in metastatic lesions from neuroendocrine neoplasm patients. MYC knockdown restored ER-BON-1 sensitivity to everolimus. Pharmacological inhibition of MYC mediated by the cyclin-dependent kinase inhibitor dinaciclib strongly reduced viability of ER-BON-1. Dinaciclib synergized with everolimus and inhibited ER-BON-1 cell cycle progression.

DISCUSSION

Our findings suggest that MYC upregulation drives the development of secondary resistance to everolimus in PanNENs and that its inhibition is an exploitable vulnerability. Indeed, our results indicate that combined treatments with cyclin-dependent kinase and mTOR inhibitors may counteract secondary resistance to everolimus in PanNENs and may pave the ground for new therapeutic regimens for these tumors.

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.

Managing carcinoid heart disease in patients with neuroendocrine tumors

Carcinoid heart disease is a complex clinical entity frequently complicating the course of neuroendocrine tumors and carcinoid syndrome and is associated with significant morbidity and mortality. Although the pathogenesis of carcinoid heart disease remains poorly understood, it appears that the exposure to excessive circulating levels of serotonin contribute a key role, triggering a cascade of events that ultimately results in the development of plaque-like material on the endocardial surfaces of the valve leaflets. The occurrence of carcinoid heart disease may initially run an asymptomatic period, followed by the development of symptoms of congestive cardiac failure. The diagnosis of carcinoid heart disease is suspected by raised biomarkers, such as serum NT-pro-BNP and confirmed by imaging modalities, with echocardiogram being the gold standard to date. Carcinoid heart disease treatment remains challenging as in addition to cardiac dysfunction, tumor burden needs to be tackled with, hence requiring a multidisciplinary approach. Therapy comprises watchful waiting during the first initial stages of the disease; medications for heart failure; optimal control of serotonin secretion from the NET with pharmacotherapy, interventional means or even surgical techniques; and, in selected patients, cardiac valve replacement. The current review summarizes the literature on the diagnosis and management of carcinoid heart disease.

The Challenge of Evaluating Response to Peptide Receptor Radionuclide Therapy in Gastroenteropancreatic Neuroendocrine Tumors: The Present and the Future

The NETTER-1 study has proven peptide receptor radionuclide therapy (PRRT) to be one of the most effective therapeutic options for metastatic neuroendocrine tumors (NETs), improving progression-free survival and overall survival. However, PRRT response assessment is challenging and no consensus on methods and timing has yet been reached among experts in the field. This issue is owed to the suboptimal sensitivity and specificity of clinical biomarkers, limitations of morphological response criteria in slowly growing tumors and necrotic changes after therapy, a lack of standardized parameters and timing of functional imaging and the heterogeneity of PRRT protocols in the literature. The aim of this article is to review the most relevant current approaches for PRRT efficacy prediction and response assessment criteria in order to provide an overview of suitable tools for safe and efficacious PRRT.

Cost-effectiveness of Lutetium [177Lu] oxodotreotide versus best supportive care with octreotide in patients with midgut neuroendocrine tumors in France

BACKGROUND AND AIMS

In France, there are approximately 2,400 new cases of neuroendocrine tumors (NETs) annually. Peptide receptor radionuclide therapy with ¹⁷⁷Lu-Dotatate plus long-acting repeatable [LAR] octreotide 30 mg has been shown to significantly improve progression-free survival and overall survival relative to high-dose octreotide LAR 60 mg in patients with unresectable or metastatic progressive midgut NETs. A long-term cost-effectiveness analysis was performed to assess whether ¹⁷⁷Lu-Dotatate is a cost-effective option versus octreotide 60 mg for patients with unresectable/metastatic progressive midgut NETs from the perspective of French healthcare payer.

METHODS

The analysis was performed using a three-state partitioned survival model. In the base case analysis ¹⁷⁷Lu-Dotatate plus octreotide LAR 30 mg was compared with high-dose octreotide LAR 60 mg in patients with midgut NETs. Survival data were obtained from the phase III NETTER-1 trial in patients with metastatic midgut NETs. Future costs and clinical outcomes were discounted at 4% per annum. One-way deterministic and probabilistic sensitivity analyses were performed.

RESULTS

In the base case analysis, for patients with midgut NETs, ¹⁷⁷Lu-Dotatate treatment improved quality-adjusted life expectancy by 1.21 quality-adjusted life years (QALYs) relative to octreotide LAR 60 mg and the lifetime treatment costs were EUR 50,784 higher with ¹⁷⁷Lu-Dotatate resulting in an incremental cost-effectiveness ratio (ICER) of EUR 42,106 per QALY gained versus octreotide LAR 60 mg. When compared with everolimus, ¹⁷⁷Lu-Dotatate was associated with an ICER of EUR 59,769 per QALY gained. Sensitivity analyses showed that the results were sensitive to methods used to extrapolate survival data.

CONCLUSIONS

For patients with advanced progressive midgut NETs ¹⁷⁷Lu-Dotatate is likely to be considered a cost-effective option versus octreotide 60 mg from the perspective of the French healthcare payer.

Metformin and everolimus in neuroendocrine tumours: A synergic effect?

OBJECTIVE

To explore potential synergy in effectiveness between metformin and everolimus, 2 inhibitors of the mTOR pathway, for neuroendocrine tumours (NET).

DESIGN AND METHODS

A cohort of patients with advanced gastroenteropancreatic or lung NETs treated by everolimus were stratified in to those without diabetes, those with diabetes and without metformin, and those with diabetes with metformin. The primary endpoint was the median progression-free survival (PFS).

RESULTS

A total of 213 patients were included, 165 of which were non-diabetic; among diabetic patients, 19 were treated with metformin and 29 with others anti-diabetic drugs. No significant difference in median PFS [95%CI] was found between the three groups: 10.05 months [8.27;11.83] for non-diabetic patients, 15.24 [19.88;49.43] for diabetic w/metformin, and 9.03 months [4.01;14.06] for diabetic w/o metformin group. In univariate analysis, factors significantly associated with longer PFS was a functioning NET, a number of metastatic sites<3, the absence of lung metastasis, and an uptake on Octreoscan®, but not the absence of metformin use; only uptake on Octreoscan® remained significant in multivariate analysis.

CONCLUSIONS

In contrast with the literature, we did not find a synergy between everolimus and metformin in NET. Prospective studies are underway to improve the comprehension of the potential synergy regarding population and tumour type.

Results of Surgical Resection of Locally Advanced Pulmonary Neuroendocrine Tumors

BACKGROUND

Pulmonary neuroendocrine tumors include well-differentiated and poorly differentiated histology for which cell type has proved to be a determinant of survival in many studies. In patients diagnosed with bronchial carcinoid and large cell neuroendocrine carcinoma (LCNEC), surgery is the treatment of choice even in the case of locally advanced disease with lymph node involvement.

METHODS

We retrospectively analyzed patients undergoing anatomic lung resection for bronchial carcinoid or LCNEC with lymph node involvement (N1/N2) at the final pathologic examination (pN+). Characteristics of patients and differences in overall survival and disease-free survival are presented according to tumor type. Overall survival of distinct histologic groups was compared with survival in our institutional experience in stage I patients, without nodal involvement (pN0).

RESULTS

In all, 325 patients underwent surgical resection for neuroendocrine tumors; 89 patients had nodal involvement. Five-year survival was 89% in pN+ bronchial carcinoid both for typical carcinoid and atypical carcinoid but worse for pN+ LCNEC (47%). Cell type did not influence the prognosis in N0 disease, and no differences in survival were evident between N0 and N+ in the bronchial carcinoid group. In the group of LCNEC, 5-year overall survival was much worse for pN+ LCNEC (47%) compared with pN0 LCNEC (91%).

CONCLUSIONS

Bronchial carcinoids have the best prognosis, and surgery remains the treatment of choice for both early and locally advanced disease. On the contrary, aggressive forms (LCNEC) with lymph nodal metastasis have a poor prognosis, and they need to be treated with an aggressive multidisciplinary approach.

Carcinoid Heart Disease: How to Diagnose and Treat in 2020?

Neuroendocrine tumors (NETs, originally termed “carcinoids”) create a relatively rare group of neoplasms with an approximate incidence rate of 2.5 to 5 cases per 100 000 persons. Roughly 30% to 40% of subjects with NETs develop carcinoid syndrome (CS), and 20% to 50% of subjects with CS are diagnosed with carcinoid heart disease (CaHD). The long-standing exposure to high serum serotonin concentration is one of the crucial factors in CaHD development. White plaque-like deposits on the endocardial surface of heart structures with valve leaflets and subvalvular apparatus thickening (fused and shortened chordae; thickened papillary muscles) are characteristic for CaHD. NT pro-BNP and 5-hydroxyindoleacetic acid are the 2 most useful screening markers. Long-acting somatostatin analogs are the standard of care in symptoms control. They are also the first-line treatment for tumor control in subjects with a metastatic somatostatin receptor avid disease. In cases refractory to somatostatin analogs, several options are available. We can increase a somatostatin analog to off-label doses, add telotristat ethyl or administer peptide receptor radionuclide therapy. Cardiac surgery, which mainly involves valve replacement, is presently the most efficient strategy in subjects with advanced CaHD and can relieve unmanageable symptoms or be partly responsible for better prognosis.

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.

Use of octreotide long acting repeatable (LAR) as second-line therapy in advanced neuroendocrine tumors in different clinical settings: an Italian Delphi survey

BACKGROUND

Somatostatin receptor ligands including octreotide LAR are first-line therapy in locally advanced or metastatic NETs that are nonresectable and well differentiated and are recommended as first-line therapy in functioning and in G1/low G2 nonfunctioning NETs. However, several questions remain that are not adequately addressed in current guidelines regarding its use in clinical scenarios in which the tumor progresses. These include use of nonconventional doses or schedules of octreotide LAR in tumors with hormonal symptoms or showing clinical-radiological progression, administration in combination with everolimus, peptide receptor radionuclide therapy, and chemotherapy, following first-line treatment with octreotide LAR.

METHODS

An expert panel was gathered to obtain consensus using Delphi methodology on a series of statements regarding further administration of octreotide LAR after its use in first-line therapy in these settings in patients who experience disease progression.

RESULTS

Consensus was reached for 8 of the 10 statements proposed in the above clinical scenarios; consensus was not achieved for two statements.

CONCLUSIONS

The present statements aim to fill current gaps in treatment guidelines by providing recommendations based on expert consensus in clinical settings in which patients progress following first-line therapy with octreotide LAR.

Asphericity of Somatostatin Receptor Expression in Neuroendocrine Tumors: An Innovative Predictor of Outcome in Everolimus Treatment?

Background: in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NET), the mTOR inhibitor everolimus is associated with significant improvement in progression-free survival (PFS). This study evaluated the lesional asphericity (ASP) in pretherapeutic somatostatin receptor (SSR) imaging as the first imaging-based prognostic marker for PFS. Methods: this retrospective bicentric cohort study included 30 patients (f = 13, median age, 66.5 (48–81) years) with pretherapeutic [¹¹¹In-DTPA⁰]octreotide scintigraphy (Octreoscan^®). ASP of functional volumes of up to three leading lesions per patient (n = 74) was calculated after semiautomatic, background-adapted segmentation. Uni- and multivariable Cox regression regarding PFS for clinical factors and the maximum ASP per patient was obtained. Results: all 30 patients showed metachronous or progressive liver metastases. ASP, primary tumor site, metastases pattern, and prior peptide receptor radionuclide therapy (PRRT) were significantly associated with PFS in univariable Cox regression. Only ASP > 12.9% (hazard ratio (HR), 3.33; p = 0.024) and prior PRRT (HR, 0.35; p = 0.043) remained significant in multivariable Cox. Median PFS was 6.7 months for ASP > 12.9% (95% confidence interval (CI), 2.1–11.4 months) versus 14.4 (12.5–16.3) months for ASP ≤ 12.9% (log-rank, p = 0.028). Conclusion: pretherapeutic ASP of SSR positive lesions independently predicted PFS for treatment with everolimus in GEP-NET. ASP may supplement risk-benefit assessment before patient inclusion to treatment.

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.

Positivity for SATB2 distinguishes Islet1 positive rectal neuroendocrine tumours from pancreaticoduodenal neuroendocrine tumours

AIMS

Determining the site of origin of a metastatic neuroendocrine tumour (NET) can be challenging and has important prognostic and therapeutic implications. An immunohistochemical (IHC) panel consisting of TTF1, CDX2, PAX8/PAX6 and Islet1 is often employed. However, there can be a significant IHC overlap among different primary sites. Herein, we sought to determine the utility of including Special AT-rich sequence binding protein-2 (SATB2) in the IHC panel that is used for determining the site of origin of a metastatic NET.

METHODS

Paraffin tissue microarrays consisting of 137 primary NETs (26 lung, 22 jejunoileal, 8 appendix, 5 stomach, 4 duodenum, 17 rectum and 55 pancreas) were stained for SATB2, in addition to the well-described lineage-associated markers, such as TTF1, CDX2, PAX6 and Islet1. Additionally, a tissue microarray consisting of 21 metastatic NETs (1 lung, 1 stomach, 8 jejunoileal and 11 pancreas) was stained for TTF1, CDX2, SATB2 and Islet1. The results were recorded as no staining, weak staining and moderate to strong staining.

RESULTS

All appendiceal NETs and majority (88%) of the rectal NETs were positive for SATB2. All primary foregut NETs (stomach, pancreas, duodenum and lung) were negative for SATB2, except for one pulmonary NET with weak staining. However, among the metastatic tumours, 5 of 11 pancreatic NETs, 1 stomach NET, 1 lung NET and 2 of 8 jejunoileal NETs showed weak staining. Receiver operating characteristic analysis incorporating sensitivity and specificity data of IHC panel, considering moderate to strong staining as truly positive cases, showed that inclusion of SATB2 to the previously described NET IHC panel outperformed the panel without SATB2, raising the specificity for pancreaticoduodenal NETs from 81.2% to 100%, with a positive predictive value (PPV) of 100% and negative predictive value (NPV) of 82.22% (p<0.0001); for appendiceal NETs the specificity changed from 99.1% to 98.5% and sensitivity increased from 11.8% to 80%, with a PPV and NPV of 66.67% and 99.26%, respectively (p<0.0001); and for rectal NETs the specificity increased from 97.6% to 99.3% and sensitivity raised from 7.1% to 66.7%, with a PPV and NPV of 80% and 98.53%, respectively (p<0.0001).

CONCLUSIONS

SATB2 stain is useful in differentiatingIslet1/PAX6 positive pancreatic and rectal NETs, as rectal NETs are typically moderately to strongly positive for SATB2 and pancreatic NETs are usually negative or weakly positive for SATB2. Moderate to strong staining for SATB2 is suggestive of an appendiceal or a rectal primary. SATB2 may complement the panel of CDX2, TTF1 and Islet1 in determining the site of origin of an NET in a metastatic setting.

Should everolimus be stopped after radiological progression in metastatic insulinoma? A "cons" point of view

Insulinoma is a rare pancreatic neuroendocrine tumor (pNET) potentially associated with severe hypoglycaemic crisis. The great majority of these tumors are benign. In patients with metastatic malignant insulinoma, systemic therapies aim to control both the syndrome and tumor growth. Everolimus is a drug approved for the management of advanced pNETs that can achieve both these goals. According to international guidelines and regulatory authorities, everolimus in patients with pNET should be continued until the demonstration of disease progression with standard radiologic imaging techniques. The drug is neither recommended nor authorized beyond progression. This could not be the case of advanced insulinoma patients since the antineoplastic and the glycaemic effects of everolimus seem to follow independent mechanisms. The authors present here their point of view in favor of continuing everolimus beyond progression in symptomatic insulinoma patients on the basis of a robust rationale and describing a case.

THE ROLE OF CONVENTIONAL ECHOENDOSCOPY (EUS) IN THERAPEUTIC DECISIONS IN PATIENTS WITH NEUROENDOCRINE GASTROINTESTINAL TUMORS

Background:

Gastrointestinal neuroendocrine tumors are rare, usually presented as subepithelial or polypoid tumors. Accurate diagnosis and indication of the type of resection are still challenging.

Aim:

To determine the effectiveness of echoendoscopy in determining the depth of the lesions (T) identified by endoscopy in order to evaluate surgical and/or endoscopic indication, and to evaluate the results of endoscopic removal in the medium term.

Methods:

Twenty-seven patients were included, all of whom underwent echoendoscopy for TN tumor staging and the evaluation of possible endoscopic resection. The parameters were: lesion size, origin layer, depth of involvement and identified perilesional adenopathies. The inclusion criteria for endoscopic resection were: 1) high surgical risk; 2) those with NET <2 cm; 3) absence of impairment of the muscle itself; and 4) absence of perilesional adenopathies in echoendoscopy and in others without distant metastases. Exclusion criteria were TNE> 2 cm; those with infiltration of the muscle itself; with perilesional adenopathies and distant metastases. The techniques used were: resection with polypectomy loop; mucosectomy with saline injection; and mucosectomy after ligation with an elastic band. The anatomopathological study of the specimens included evaluation of the margins and immunohistochemistry (chromogranin, synaptophysin and Ki 67) to characterize the tumor. Follow-up was done at 1, 6 and 12 months.

Results:

Resections with polypectomy loop were performed in 15 patients; mucosectomy in five; mucosectomy and ligation with elastic band in three and the remaining four were referred for surgery. The anatomopathological specimens and immunohistochemical analyzes showed positive chromogranin and synaptophysin, while Ki 67 was less than 5% among all cases. The medium-term follow-up revealed three recurrences. The average size of tumors in the stomach was 7.6 mm and in the duodenum 7.2 mm. Well-demarcated, hypoechoic, homogeneous lesions occurred in 75%; mucous layer in 80%; and the deep and submucosal mucosa in 70%.

Conclusions:

Echoendoscopy proved to be a good method for the study of subepithelial lesions, being able to identify the layer affected by the neoplasm, degree of invasion, echogenicity, heterogeneity, size of the lesion and perilesional lymph node involvement and better indicate the treatment option.

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.

Risk Factors for Lymph Node Metastasis and Survival Outcomes in Colorectal Neuroendocrine Tumors

Objective

The aim of our study was to analyze the factors affecting lymph node metastasis (LNM) and the prognosis of colorectal neuroendocrine tumors (NETs).

Patients and Methods

A retrospective analysis was conducted to collect the clinical data of 135 patients with colorectal NETs from January 2000 to December 2018, including clinical manifestations, pathological results, treatment methods, etc. Follow-up was regularly performed to observe the recurrence and metastasis of tumors and to identify the clinical and pathological features of colorectal NETs, risk factors for LNM and survival outcomes.

Results

Among 135 patients, there were 57 (42.2) patients with LNM, and the independent risk factors for LNM in the multivariable analyses were tumor diameter ≥2 cm (P= 0.040) and tumor grade G3 (P=0.001). Patients were followed up for 1 to 190 months, and of the 133 patients who were successfully followed up, the 5-year OS was 71.7%, and the 5-year PFS was 69.0%. The multivariate analysis for survival outcomes showed that age ≥65 years (P=0.002/<0.001) and lymph node metastasis (P=0.018/0.025) were independent risk factors affecting 5-year PFS and OS in colorectal neuroendocrine tumors. Tumors in the colon (P=0.022), moderately positive (++) CgA (P=0.010) and strongly positive (+++) CgA (P=0.007) were independent risk factors for poor 5-year PFS in patients with colorectal NETs.

Conclusion

Rectal NETs have a better prognosis than colonic neuroendocrine tumors. Tumor diameter and tumor grade are independent risk factors for LNM in colorectal neuroendocrine tumors. Age, tumor location, lymph node status and a positive level of the neuroendocrine marker CgA are independent risk factors that affect the prognosis of colorectal NETs.

Medical Treatment of Gastrointestinal Neuroendocrine Neoplasms

Neuroendocrine neoplasms (NENs) are rare tumours that arise mainly in the gastrointestinal or pulmonary system. Most NENs are well-differentiated and may obtain prolonged survival besides the presence of metastatic disease; however, a subset (poorly differentiated NENs) may display a truly aggressive behaviour exhibiting a poor prognosis. The recently developed classification systems along with advances in functional imaging have helped stratify patients to the administration of appropriate therapeutic options. Surgery is the mainstay of treatment of NENs, but in recent decades there has been a considerable evolution of medical treatments that are used for locally advanced or metastatic disease not amenable to surgical resection. Long acting somatostatin analogues are the main therapeutic modality for patients with functioning and well-differentiated low grade NENs exhibiting symptomatic control and mainly stabilisation of tumour growth. Other systemic treatments include chemotherapy, molecular targeted agents, interferon-α, peptide receptor radionuclide therapy (PRRT), and immunotherapy. In addition, new agents such as telotristat may be used for the control of symptoms of carcinoid syndrome. The choice and/or sequence of therapeutic agents should be individualized according to tumour origin and differentiation, disease burden, presence of clinical symptoms and patients' performance status in the context of a multidisciplinary approach. Recent advances in the molecular pathogenesis of NENs set the field for a more personalised treatment approach.

Differential Diagnosis and Management of Diarrhea in Patients with Neuroendocrine Tumors

Diarrhea is a recurrent symptom in patients with neuroendocrine tumors (NETs) and can represent different etiologies; thus, differential diagnosis is challenging. This paper distinguishes the different causes of chronic diarrhea in patients with gastroenteropancreatic NETs, with the aim to identify the most appropriate therapeutic approach. Underlying causes of diarrhea can be multifactorial, including not only diarrhea that is related to specific hormonal hypersecretory syndromes, but also diarrhea that is secondary to the following: extensive surgery which can cause pancreatic exocrine insufficiency or short bowel syndrome, treatment with somatostatin analogs or other antineoplastic agents, and bile acid malabsorption. After initial management of diarrhea with general treatments (dietary modification, use of antidiarrheals), a proper differential diagnosis is necessary to treat patients with specific etiology-driven therapeutic approaches, such as somatostatin analogs, pancreatic enzyme replacement therapy, and tryptophan hydroxylase inhibitors. In conclusion, NETs should be considered in the differential diagnosis of patients suffering from chronic diarrhea, after the exclusion of more common etiologies. Furthermore, physicians should keep in mind that several different etiologies might be responsible for diarrhea occurrence in NET patients. A prompt diagnosis of the actual cause of diarrhea is necessary to guide the treatment and a multidisciplinary approach is mandatory.

How I treat neuroendocrine tumours

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

Phase 1 safety and pharmacodynamic study of lenalidomide combined with everolimus in patients with advanced solid malignancies with efficacy signal in adenoid cystic carcinoma

Background

Purpose: The combination of a mammalian target of rapamycin inhibitor and lenalidomide showed enhanced preclinical cytotoxicity. We conducted a phase 1 study in advanced solid tumour patients to assess safety, efficacy and pharmacodynamic (PD) outcomes.

Methods

We employed a 3+3 dose escalation design to establish the safety and recommended phase 2 doses (RP2D) of daily everolimus and lenalidomide in patients with advanced solid tumours. The starting doses were 5 and 10 mg, respectively, with planned escalation to maximum single-agent doses of 10 and 25 mg in the absence of dose-limiting toxicity. PD endpoints of lymphocyte subsets and immune cytokines were assessed in peripheral blood using multiparameter flow cytometry and LUMINEX assay. Efficacy was evaluated by cross-sectional imaging after every two cycles of treatment.

Results

The study enrolled 44 patients, median age of 58 years and 28 males (63.6%). The RP2D was established as 10 and 25 mg daily continuously for everolimus and lenalidomide. Common (>5%) grade ≥3 adverse events included rash (19%), neutropenia (19%), hypokalaemia (11%) and fatigue (9%). Best efficacy outcomes in 36 evaluable patients were partial response in 5 (13.8%), stable disease in 24 (55.8%) and progressive disease in 7 (19.4%) patients. PD assessment revealed significant association of cytokine levels (interleukin-2 (IL2), IL21 and IL17), baseline activated and total CD8+ lymphocytes and change in B cell lymphocytes and activated NK cells with clinical benefit.

Conclusions

The study demonstrated the safety of everolimus and lenalidomide with promising efficacy signal in thyroid and adenoid cystic cancers.

Clinical Trial Registration

NCT01218555

It Is Time to Rethink Biomarkers for Surveillance of Small Bowel Neuroendocrine Tumors

BACKGROUND

Tumor biomarkers (TBMs) reflect disease burden and correlate with survival for small bowel neuroendocrine tumors (SBNETs). This study sought to determine the performance of chromogranin A (CgA), pancreastatin (PST), neurokinin A (NKA), and serotonin (5HT) during follow-up assessment of resected SBNETs.

METHODS

An institutional database identified patients undergoing surgery for SBNETs. Tumor biomarker levels were assessed as categorical (normal vs elevated) and continuous variables for association with progression-free survival (PFS) and overall survival (OS) via the Kaplan-Meier method with Cox multivariable models adjusted for confounders. Sensitivity, specificity, and predictive values of TBM levels in identifying imaging-confirmed progression were calculated.

RESULTS

In 218 patients (44% female, 92% node + , 73% metastatic, 97% G1 or G2), higher levels of CgA, PST, NKA, and 5HT correlated with higher-grade and metastatic disease at presentation (p < 0.05). Elevated pre- and postoperative CgA, PST, and NKA correlated with lower PFS and OS (p < 0.05; median follow-up period, 49.6 months). Normal CgA, PST, and NKA were present in respectively 20.3%, 16.9%, and 72.6% of the patients with progression, whereas elevated levels were present in respectively 69.5%, 24.8%, and 1.3% of the patients without progression. Using TBMs to determine progression showed superiority of PST (78.9% accuracy) over CgA (63.3% accuracy) or CgA and PST together (60.3% accuracy).

CONCLUSION

Although specific for progression, NKA was rarely elevated, limiting its usefulness. Pre- and postoperative PST and CgA correlated with disease burden and survival, with PST providing better discrimination of outcomes. During the follow-up period, use of PST most accurately detected progression. These results suggest that PST should replace CgA for SBNET surveillance.

An Update on Gastroenteropancreatic Neuroendocrine Neoplasms: From Mysteries to Paradigm Shifts

Although neuroendocrine neoplasms (NEN) were once thought to be rare and mostly "benign" diseases, they are now being redefined in light of recently discovered molecular information. NENs constitute a spectrum of variably differentiated neoplasms, ranging from well-differentiated tumors with a protracted course over many years to very aggressive neuroendocrine carcinomas. Although the majority of NEN are non-functional lesions, some of these tumors, do produce a hormonal hypersecretion syndrome. Their reappraisal has led scientist to unveil previously unknown oncogenic pathways and connections that resulted in a new category in the International Classification of Diseases (ICD-11) and a revised version of the World Health Organization Classification (WHO 2018). Complex diseases like NEN require a multidisciplinary approach that includes the perspectives of endocrinologists, medical and surgical oncologists, radiation oncologists, imaging specialists and pathologists. There are currently virtually thousands of ongoing trials evaluating the efficacy and safety of several molecular targeted therapies. The purpose of this review was to critically evaluate recent information regarding the pathogenesis, diagnosis and treatment of NEN.

Clinical Evaluation of Everolimus in the Treatment of Neuroendocrine Tumors of the Lung: Patient Selection and Special Considerations. A Systematic and Critical Review of the Literature

Neuroendocrine tumors (NETs) of the lung are well-differentiated neuroendocrine neoplasms (NENs) with a heterogeneous clinical behaviour. Unlike gastroenteropancreatic NENs where therapeutic armamentarium clearly increased over the last decade, everolimus represented the only clinical practical innovation for lung NET patients over the last years. Therefore, for lung NETs, a multidisciplinary discussion within a dedicated team remains critical for an adequate decision-making. Although the main regulatory authorities considered the everolimus-related evidence is enough to approve the drug in advanced lung NETs, several clinical features deserve to be discussed. In this review, we systemically and critically analysed the main clinical studies including patients with advanced lung NETs receiving everolimus. Furthermore, we reported the biological and clinical background of everolimus in lung NET setting. The purpose of this review is to help clinical community to contextualize evidence and experience for a personalised use of this drug in clinical practice in the context of advanced lung NET patients.

Chemogenomic profiling of breast cancer patient-derived xenografts reveals targetable vulnerabilities for difficult-to-treat tumors

Subsets of breast tumors present major clinical challenges, including triple-negative, metastatic/recurrent disease and rare histologies. Here, we developed 37 patient-derived xenografts (PDX) from these difficult-to-treat cancers to interrogate their molecular composition and functional biology. Whole-genome and transcriptome sequencing and reverse-phase protein arrays revealed that PDXs conserve the molecular landscape of their corresponding patient tumors. Metastatic potential varied between PDXs, where low-penetrance lung micrometastases were most common, though a subset of models displayed high rates of dissemination in organotropic or diffuse patterns consistent with what was observed clinically. Chemosensitivity profiling was performed in vivo with standard-of-care agents, where multi-drug chemoresistance was retained upon xenotransplantation. Consolidating chemogenomic data identified actionable features in the majority of PDXs, and marked regressions were observed in a subset that was evaluated in vivo. Together, this clinically-annotated PDX library with comprehensive molecular and phenotypic profiling serves as a resource for preclinical studies on difficult-to-treat breast tumors.

Immunotherapy of Ipilimumab and Nivolumab in Patients with Advanced Neuroendocrine Tumors: A Subgroup Analysis of the CA209-538 Clinical Trial for Rare Cancers

PURPOSE

Combination immunotherapy with anti-CTLA-4 and anti-PD-1 blockade has demonstrated significant clinical activity across several tumor types. Neuroendocrine tumors (NET) are a heterogeneous group of rare tumors with limited treatment options. CA209-538 is a clinical trial of combination immunotherapy with ipilimumab and nivolumab in rare cancers, including advanced NETs.

PATIENTS AND METHODS

CA209-538 is a prospective multicenter clinical trial in patients with advanced rare cancers. Patients received treatment with nivolumab at a dose of 3 mg/kg and ipilimumab at 1 mg/kg every three weeks for four doses, followed by nivolumab 3 mg/kg every two weeks and continued for up to 96 weeks, until disease progression or the development of unacceptable toxicity. Response was assessed every 12 weeks by RECIST 1.1. The primary endpoint was clinical benefit rate (CBR; complete remission + partial remission + stable disease).

RESULTS

Twenty-nine patients with advanced NETs received treatment. Three (10%) patients had low-, 13 (45%) had intermediate-, and 13 (45%) had high-grade tumors; lung was the most common primary site (39%). The objective response rate was 24% with a CBR of 72%; 43% of patients with pancreatic neuroendocrine neoplasms (NEN), and 33% of patients with atypical bronchial carcinoid achieved an objective response. The median progression-free survival was 4.8 months [95% confidence interval (CI): 2.7-10.5] and overall survival was 14.8 months (95% CI: 4.1-21.3). Immune-related toxicity was reported in 66% of patients with 34% experiencing grade 3/4 events.

CONCLUSIONS

Combination immunotherapy with ipilimumab and nivolumab demonstrated significant clinical activity in subgroups of patients with advanced NETs including patients with atypical bronchial carcinoid and high-grade pancreatic NENs.

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.

mTOR Pathway Expression as Potential Predictive Biomarker in Patients with Advanced Neuroendocrine Tumors Treated with Everolimus

Background. Everolimus (Eve), which is a mammalian target of Rapamicin (mTOR) inhibitor, is part of the therapeutic armamentarium of neuroendocrine tumors (NETs). Currently, there are no validated biomarkers predicting Eve efficacy in NETs. In this study, we explore whether the expression of phosphorilated (p)-mTOR and p70S6-kinase (S6K), a downstream effector of mTOR, correlates with the outcome of patients with NET that were treated with Eve. Methods. Tissue specimens that were derived from NETs treated with Eve at our Institution were examined for the expression levels of p-mTOR and p-S6K by immunohistochemistry. Response rate (RR), progression-free survival (PFS), and overall survival (OS) were analyzed in two groups: p-mTOR/p-S6K positive (group 1) and p-mTOR/p-S6K negative (group 2). Univariate and multivariate Cox regression analysis were performed. Results. Twenty-four patients with advanced NETs that were treated with Eve were included in the analysis. Eight out 24 (33.3%) patients were both p-mTOR and p-S6K positive. A better median PFS and OS in group 1 (18.2 and 39.9 months) as compared to group 2 (13 and 32.4 months) was depicted, with a toxicity profile that was comparable with data literature. Conclusions. Our study suggests that the activation of mTOR pathway can predict better outcomes in patients with NET treated with Eve. However, these results warrant further confirmation in a prospective setting.