Hepatic-directed Therapies in Patients with Neuroendocrine Tumors

A case of frequent hypoglycemic attacks successfully controlled with capecitabine plus temozolomide and 177Lu-DOTATATE peptide receptor radionuclide therapy in a patient with recurrent pancreatic insulinoma

A 59-year-old woman with metastatic pancreatic insulinoma, having undergone several treatment regimens including sunitinib, everolimus, lanreotide and streptozocin plus 5-fluorouracil, was admitted to our hospital because of frequent hypoglycemic attacks. These were refractory to medical treatment using diazoxide and required frequent daily intravenous glucose infusions. She was started on capecitabine and temozolomide (CAPTEM), followed by initiation of 177Lu-DOTATATE peptide receptor radionuclide therapy (PRRT). The frequency of hypoglycemic attacks decreased after treatment began and she was discharged on day 58 post-admission, without requiring daily glucose infusions. CAPTEM and PRRT were continued without any major adverse events. Computed tomography revealed shrinkage of primary and metastatic lesions, an anti-tumor effect that continued 8 months after treatment was initiated. Hypoglycemic attacks caused by insulinomas are often refractory to conventional therapy; however, combination treatment using CAPTEM and PRRT has demonstrated a positive and significant response, successfully restoring glycemic control.

Grade Progression and Intrapatient Tumor Heterogeneity as Potential Contributors to Resistance in Gastroenteropancreatic Neuroendocrine Tumors

Gastroenteropancreatic neuroendocrine neoplasms (NENs) are a heterogenous group of tumors that are incurable when metastatic, regardless of grade. The aim of this article is to understand tumor heterogeneity and grade progression as possible contributors to drug resistance in gastroentropancreatic neuroendocrine tumors (GEP-NETs). Heterogeneity has been observed in the genetic, pathological, and imaging features of these tumors at baseline. Diagnostic challenges related to tumor sampling and the potential for changes in grade over time further confound our ability to optimize therapy for patients. A better understanding of NEN biology and tumor heterogeneity at baseline and over time could lead to the development of new therapeutic avenues.

Necrolytic migratory erythema is an important visual cutaneous clue of glucagonoma

Glucagonoma is an extremely rare neuroendocrine tumor that arises from pancreatic islet alpha cells. Although glucagonoma is usually accompanied by a variety of characteristic clinical symptoms, early diagnosis is still difficult due to the scarcity of the disease. In this study, we present the cumulative experiences, clinical characteristics and treatments of seven patients diagnosed with glucagonoma during the past 10 years at the First Affiliated Hospital of Xi'an Jiaotong University. The seven patients in our cohort consisted of six females and one male with an average diagnosis age of 40.1 years (range 23-51). The average time from onset of symptoms to diagnosis of glucagonoma was 14 months (range 2-36 months). All the patients visited dermatology first for necrolytic migratory erythema (NME) 7/7 (100%), and other presenting symptoms included diabetes mellitus (DM) 4/7 (57%), stomatitis 2/7 (28%), weight loss 4/7 (57%), anemia 4/7 (57%), diarrhea 1/7 (14%), and DVT1/7 (14%). Plasma glucagon levels were increased in all patients (range 216.92-3155 pg/mL) and declined after surgery. Imaging studies revealed that four of seven patients had liver metastasis. Six of seven patients received surgical resection, and all of them received somatostatin analog therapy. Symptoms improved significantly in 6 out of 7 patients. Three of seven patients died of this disease by the time of follow-up. Our data suggest that if persistent NME is associated with DM and high glucagon levels, timely abdominal imaging should be performed to confirm glucagonoma. Once diagnosed, surgery and somatostatin analogs are effective for symptom relief and tumor control.

Management of Small Bowel Neuroendocrine Tumors

Small bowel neuroendocrine tumors (SBNETS) are slow-growing neoplasms with a noted propensity toward metastasis and comparatively favorable prognosis. The presentation of SBNETs is varied, although abdominal pain and obstructive symptoms are the most common presenting symptoms. In patients with metastases, hypersecretion of serotonin and other bioactive amines results in diarrhea, flushing, valvular heart disease, and bronchospasm, termed carcinoid syndrome. The treatment of SBNETs is multimodal and includes surgery, liver-directed therapy, somatostatin analogues, targeted therapy, and peptide receptor radionuclide therapy.

Perspectives on the current pharmacotherapeutic strategies for management of functional neuroendocrine tumor syndromes

Introduction: In the past, controlling the hormone-excess-state was the main determinant of survival in Functional-Neuroendocrine-Neoplasm-syndromes (F-NENs). This was difficult because the pharmacological-armamentarium available was limited. Recently, new therapeutic strategies have increased but it also generated controversies/uncertainties.Areas covered: The authors briefly review: established/proposed F-NENs; the rationale for treatments; the recommended initial-pharmacotherapeutic-approach to controlling F-NENs hormone-excess-state; the secondary-approaches if the initial approach fails or resistance develops; and the approach to deal with the malignant nature of the NEN. Also discussed are controversies/uncertainties related to new treatments.Expert opinion: Unfortunately, except for patients with insulinomas (>90-95%), gastrinomas (<20-40%), a minority with the other F-panNENs and 0-<1% with Carcinoid-syndrome is curative-surgery possible. Except for insulinomas, gastrinomas, and ACTHomas, long-acting somatostatin-analogs are the initial-pharmacological-treatments for hormone-excess-state. For insulinomas prior to surgery/malignancy, diazoxide is the initial drug-treatment; for gastrinomas, oral PPIs; and for ACTHomas, steroidogenesis inhibitors. There are now several secondary pharmacotherapeutic treatments. Surgery and liver-directed therapies also have a role in selected patients. Particularly promising is the recent results with PRRT for the hormone-excess-state, independent of its anti-growth effect. The sequence to use various agents and the approach to syndrome diagnosis while taking various agents remains unclear/controversial in many cases.

The Landmark Series: Neuroendocrine Tumor Liver Metastases

BACKGROUND

Neuroendocrine tumors are becoming increasingly prevalent, with many patients presenting with or developing metastatic disease to the liver.

METHODS

In this landmark series paper, we highlight the critical studies that have defined the surgical management of neuroendocrine tumor liver metastases, as well as several randomized control trials which have investigated strategies for systemic control of metastatic disease.

RESULTS

Liver-directed surgical approaches and locally ablative procedures are recommended for patients with limited, resectable, and in some cases, nonresectable tumor burden. Angiographic liver-directed techniques, such as transarterial embolization, chemoembolization, and radioembolization, offer another approach for management in patients with liver-predominant disease. Peptide receptor radionuclide therapy is a promising therapy for patients with hepatic and/or extrahepatic metastases. Various systemic medical therapies are also available as adjunct or definitive therapy for patients with metastatic disease.

CONCLUSIONS

This article reviews current data regarding management of neuroendocrine liver metastases and highlights areas for future study.

[Indications for the Surgical Management of Pancreatic Neuroendocrine Neoplasms]

Neuroendocrine neoplasms of the pancreas (pNEN) have an increasing incidence and prevalence. Thus, this entity is of increasing clinical significance. Patients with pNEN become clinically apparent due to different and unspecific symptoms. Some tumours secrete hormones and peptides and become clinically symptomatic. In general, these tumours can metastasise early and even small tumours lead to distant metastases. Nonetheless, primary tumour size and grading are important prognostic factors. On the basis of a systematic literature research and the formulation of key issues according to the PICO system, therapeutic concepts were established. These concepts were evaluated with a Delphi process among the members of the pancreas research group and the indications for surgery group of the German Society of General and Visceral Surgery. Thus this article gives an overview of the surgical treatment modalities and indications for the treatment of pNEN. Surgery is still the gold standard in treatment and the only potential chance of cure. Surgery is indicated for sporadic as well as hereditary pNEN > 2 cm independent of the functional activity. A so called "wait and see" strategy might be indicated in smaller pNEN; however, there is little evidence for this approach. In this respect, pNEN of 1 - 2 cm represent a surgical indication. The treatment of hereditary pNEN is challenging and should be interdisciplinary. Even in the case of distant metastases, a curative approach might be feasible and multimodal treatment is indicated.

Evaluation and Management of Neuroendocrine Tumors of the Pancreas

Pancreatic neuroendocrine tumors are a diverse group of neoplasms with a generally favorable prognosis. Although they exhibit indolent growth, metastases are seen in roughly 60% of patients. Pancreatic neuroendocrine tumors may produce a wide variety of hormones, which are associated with dramatic symptoms, but the majority are nonfunctional. The diagnosis and treatment of these tumors is a multidisciplinary effort, and management guidelines continue to evolve. This review provides a concise summary of the presentation, diagnosis, surgical management, and systemic treatment of pancreatic neuroendocrine tumors.

Clinical analysis of 547 patients with neuroendocrine tumors in a Chinese population: A single-center study

BACKGROUND

Neuroendocrine tumors (NETs) are rare, which has resulted in a lack of published data on their epidemiology and clinical features. We therefore aimed to investigate the epidemiology, clinical features, treatments, and prognosis of patients with NETs.

METHODS

The clinicopathologic characteristics of 547 patients who were pathologically diagnosed with NETs were retrospectively analyzed, including age, sex, primary and metastatic sites, symptoms, pathology, treatment, and prognosis.

RESULTS

The 547 patients had a wide age range (9-87 years), with a male to female ratio of 1:1.1. The primary tumor sites included 413 in the digestive system, 74 in the lung, 15 in the mediastinum, 8 in unknown sites, and 37 in other sites. Of the 413 patients with digestive system NETs, the pancreas, rectum, and stomach were the most common primary sites. Blood metastases were found in 84 patients at initial diagnosis, and the liver, bone, and lung were the most frequent sites of metastasis. Lymph node metastases were found in 82 patients at initial diagnosis. Surgery and chemotherapy were the most widely applied treatments. Statistical analysis showed that age <50 years, female sex, lower-grade tumor, no distant metastasis, intestinal NET and surgery indicated a favorable prognosis.

CONCLUSIONS

A difference between China and other countries is that small intestinal NETs are quite common in other countries but are rare in China. In China, the most common primary sites are the pancreas, rectum, and stomach. Furthermore, no unified treatments exist, though prognoses could be improved by using methods such as surgery, targeted therapies, and somatostatin analogs.

CLINICAL TRIAL REGISTRATION

This study was not a clinical trial.

Management of Small Bowel Neuroendocrine Tumors

Small bowel neuroendocrine tumors (NETs) are increasing in incidence and are now the most common primary malignancies of the small intestine. Despite this increase, the vague presentation and slow growth of these tumors lead to long delays in diagnosis, and many patients present with metastases. Patients with metastatic small bowel NETs have a favorable disease prognosis, particularly when contrasted with other GI malignancies, and benefit from aggressive, multimodal therapy. During the past decade, the options for the diagnosis and treatment of small bowel NETs have increased considerably. This review provides a practical framework for the physician who seek to understand the epidemiology, presentation, diagnosis, and management of small bowel NETs.

Management of functional neuroendocrine tumors of the pancreas

Pancreatic neuroendocrine tumors (pNETs) constitute a heterogenous group of malignancies with varying clinical presentation, tumor biology and prognosis. The incidence of pNETs has steadily increased during the last decades with an estimated incidence 2012 of 4.8/100,000. Recent whole genome sequencing of pNETs has demonstrated mutations in the DNA repair genes MUTYH and point mutations and gene fusions in four main pathways from chromatin remodeling, DNA damage repair, activation of mechanistic target of rapamycin (mTOR) signaling and the telomere maintenance. This new information will be the foundation for new therapies in the near future for malignant pNETs. The functioning pNETs constitute about 30-40% of all pNETs displaying nine different clinical syndromes: insulinoma, Zollinger-Ellison, Verner-Morrison, glucagonoma, somatostatinomas, ectopic adrenocorticotropic hormone (ACTH) and parathyroid hormone related peptide (PTH-rP) syndromes. Single patients might also present carcinoid syndrome. The diagnostic work-up include histopathology with the new WHO 2017 Classification, biomarkers (CgA, NSE), radiology and molecular imaging including CT-scan, magnetic resonance imaging (MRI), ultrasound and PET-scan. A cornerstone in the treatment of pNETs is surgery which is rarely curative but can reduce the clinical symptoms by debulking which also include radiofrequency ablation, embolization of liver metastases. Medical treatment includes chemotherapy and the targeted agents such as everolimus, sunitinib and peptide receptor radiotherapy (PRRT). Somatostatin analogs has for the last decades been the main stay for management for clinical symptoms related to functioning pNETs and is often combined with new targeted agents as well as chemotherapy. Long-term management of functioning pNETs need a combination of different procedures, surgery, local ablation, targeted agents and somatostatin analogs. Future therapies might be based on the recent advances in molecular genetics and tumor biology.

Retrospective analysis of interventional treatment of hepatic metastasis from gastroenteropancreatic neuroendocrine tumors

Objective

To analyze the angiography appearance of liver metastases from gastroenteropancreatic neuroendocrine tumors (GEP-NETs), and evaluate the clinical efficacy and prognostic factors of interventional treatment for hepatic metastases.

Methods

Fifty GEP-NETs patients with hepatic metastases were treated from January 2012 to December 2016, and received transarterial embolization (TAE) in the hepatic tumor or hepatic arterial infusion chemotherapy (HAIC). All patients received 179 times of the intervention therapy in total.

Results

Blood supplies were identified in the 50 cases with angiography, which showed that 35 cases had abundant vessels, while 15 cases had poor blood supply. Twenty-two cases were found either collateral blood supply, or portal vein invasion or arterial-portal vein fistula. The best curative efficacy was complete remission (CR) in 4 cases, partial remission (PR) in 28 cases and stable disease (SD) in 18 cases during the process of treatment. The angiography (P=0.047) and the frequency of intervention (P=0.037) showed significantly statistical difference with Kaplan-Meier analysis. The Cox analysis showed that more than 3 times of interventional therapy was an independent prognostic factor.

Conclusions

Interventional treatment is safe and effective for GEP-NETs, and is beneficial to patients with main hepatic metastases after endocrine therapy.

Will clinical heterogeneity of neuroendocrine tumors impact their management in the future? Lessons from recent trials

PURPOSE OF REVIEW

Neuroendocrine tumors (NETs) are a group of biologically and clinically heterogeneous neoplasms arising from the diffuse neuroendocrine system. In the last few years, advances in our understanding of the biology of these tumors have translated into an expansion of treatment options for patients with NETs. Current treatment modalities include somatostatin analogs (SSAs), radiolabeled SSAs, targeted agents, cytotoxic drugs and liver-directed therapies for the management of metastatic disease.

RECENT FINDINGS

Recent studies have expanded the role of SSAs in gastroenteropancreatic (GEP)-NETs, and everolimus has shown robust antitumor activity across a broad range of NETs of the lung and GEP tract. The radiolobeled SSA Lu-DOTATATE has been investigated in a randomized phase III trial, and has demonstrated exceptional efficacy and tolerability in patients with progressive midgut NETs. The new serotonin inhibitor telotristat etiprate has shown significant activity in the palliation of symptoms of carcinoid syndrome, and its approval by regulatory authorities is expected soon.

SUMMARY

The field of NETs has been transformed from one dominated by limited treatment options to one characterized by an increasing number of therapeutic agents and active clinical trials. Navigating the current therapeutic algorithm may be challenging, and requires an understanding both of the heterogeneity of NETs and of characteristics that are shared by NETs across tumor subtypes.

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

There have been significant developments in diagnostic and therapeutic options for patients with neuroendocrine tumors (NETs). Key phase 3 studies include the CLARINET trial, which evaluated lanreotide in patients with nonfunctioning enteropancreatic NETs; the RADIANT-2 and RADIANT-4 studies, which evaluated everolimus in functioning and nonfunctioning NETs of the gastrointestinal tract and lungs; the TELESTAR study, which evaluated telotristat ethyl in patients with refractory carcinoid syndrome; and the NETTER-1 trial, which evaluated Lu-DOTATATE in NETs of the small intestine and proximal colon (midgut). Based on these and other advances, the North American Neuroendocrine Tumor Society convened a multidisciplinary panel of experts with the goal of updating consensus-based guidelines for evaluation and treatment of midgut NETs. The medical aspects of these guidelines (focusing on systemic treatment, nonsurgical liver-directed therapy, and postoperative surveillance) are summarized in this article. Surgical guidelines are described in a companion article.

Treatment of symptomatic neuroendocrine tumor syndromes: recent advances and controversies

INTRODUCTION

Neuroendocrine tumors(NETs), once thought rare, are increasing in frequency in most countries and receiving increasing-attention. NETs present two-treatment problems. A proportion is aggressive and a proportion has a functional, hormone-excess-state(F-NET), each of which must be treated. Recently, there have been many advances, well-covered in reviews/consensus papers on imaging-NETs; new, novel anti-tumor treatments and understanding their pathogenesis. However, little attention has been paid to advances in the treatment of the hormone-excess-state. These advances are usually reported in case-series, and case-reports with few large studies. In this paper these advances are reviewed. Areas covered: Advances in the last 5-years are concentrated on, but a review of literature from the last 10-years was performed. PubMed and other databases (Cochrane, etc.) were searched for F-NET-syndromes including carcinoid-syndrome, as well as meeting-abstracts on NETs. All advances that controlled hormone-excess-states or facilitated-control were covered. These include new medical-therapies [serotonin-synthesis inhibitors(telotristat), Pasireotide, new agents for treating ACTHomas], increased dosing with conventional therapies (octreotide-LAR, Lanreotide-Autogel), mTor inhibitors(everolimus), Tyrosine-kinase inhibitors(sunitinib),cytoreductive surgery, liver-directed therapies (embolization, chemoembolization, radioembolization, RFA), peptide radio-receptor-therapy(PRRT) and ¹³¹I-MIBG, ablation of primary F-NETs. Expert opinion: Although many of the newer therapies controlling the hormone-excess-states in F-NETs are reported in relatively few patients, all the approaches show promise. Their description also generates some controversies/unresolved areas,such as the order of these new treatments, their longterm-efficacy, and effectiveness of combinations which may require large,controlled studies.