Management of malignant insulinoma

Carcinoid Syndrome and Hyperinsulinemic Hypoglycemia Associated with Neuroendocrine Neoplasms: A Critical Review on Clinical and Pharmacological Management

The carcinoid syndrome (CS) and hyperinsulinemic hypoglycemia (HH) represent two of the most common clinical syndromes associated with neuroendocrine neoplasms (NENs). The former is mainly related to the serotonin secretion by a small bowel NEN, whereas the latter depends on an insulin hypersecretion by a pancreatic insulinoma. Both syndromes/conditions can affect prognosis and quality of life of patients with NENs. They are often diagnosed late when patients become strongly symptomatic. Therefore, their early detection and management are a critical step in the clinical management of NEN patients. A dedicated and experienced multidisciplinary team with appropriate therapeutic strategies is needed and should be encouraged to optimize clinical outcomes. This review aims to critically analyze clinical features, evidence and treatment options of CS and HH and therefore to improve their management.

Surgical Management of Neuroendocrine Tumours of the Pancreas

Neuroendocrine tumours of the pancreas (pNET) are rare, accounting for 1-2% of all pancreatic neoplasms. They develop from pancreatic islet cells and cover a wide range of heterogeneous neoplasms. While most pNETs are sporadic, some are associated with genetic syndromes. Furthermore, some pNETs are 'functioning' when there is clinical hypersecretion of metabolically active peptides, whereas others are 'non-functioning'. pNET can be diagnosed at a localised stage or a more advanced stage, including regional or distant metastasis (in 50% of cases) mainly located in the liver. While surgical resection is the cornerstone of the curative treatment of those patients, pNET management requires a multidisciplinary discussion between the oncologist, radiologist, pathologist, and surgeon. However, the scarcity of pNET patients constrains centralised management in high-volume centres to provide the best patient-tailored approach. Nonetheless, no treatment should be initiated without precise diagnosis and staging. In this review, the steps from the essential comprehensive preoperative evaluation of the best surgical approach (open versus laparoscopic, standard versus sparing parenchymal pancreatectomy, lymphadenectomy) according to pNET staging are analysed. Strategies to enhance the short- and long-term benefit/risk ratio in these particular patients are discussed.

Modified linear regression predicts drug-target interactions accurately

State-of-the-art approaches for the prediction of drug-target interactions (DTI) are based on various techniques, such as matrix factorisation, restricted Boltzmann machines, network-based inference and bipartite local models (BLM). In this paper, we propose the framework of Asymmetric Loss Models (ALM) which is more consistent with the underlying chemical reality compared with conventional regression techniques. Furthermore, we propose to use an asymmetric loss model with BLM to predict drug-target interactions accurately. We evaluate our approach on publicly available real-world drug-target interaction datasets. The results show that our approach outperforms state-of-the-art DTI techniques, including recent versions of BLM.

Surgical management of pancreatic neuroendocrine tumors: an introduction

Introduction: Neuroendocrine tumors of the pancreas (pNETs) represent only 1% to 2% of all pancreatic neoplasms. These tumors can be classified as functional or nonfunctional tumors; as sporadic or from a genetic origin; as neuroendocrine neoplasms or carcinoma. Over the last decade, diagnosis of pNETs has increased significantly mainly due to the widespread use of cross-sectional imaging. Those tumors are usually associated with a good prognosis. Surgery, the only curative option for those patients, should always be discussed, ideally in a multidisciplinary team setting.Areas covered: We discuss i), the preoperative management of pNETs and the importance of accurate diagnosis, localization, grading and staging with computed tomography, magnetic resonance imaging, endoscopic ultrasound, and nuclear medicine imaging; ii), surgical indications and iii), the surgical approach (standard pancreatectomy vs pancreatic-sparing surgery).Expert opinion: The treatment option of all patients presenting with pNETs should be discussed in a multidisciplinary team setting with surgeon's experienced in both pancreatic surgery and neuroendocrine tumor management. A complete preoperative imaging assessment - morphological and functional - must be performed. Surgery is usually recommended for functional pNETs, nonfunctional pNETs >2 cm (nf-pNETs) or for symptomatic nf-pNETs.

Targeted Systemic Treatment of Neuroendocrine Tumors: Current Options and Future Perspectives

Neuroendocrine tumors (NETs) originate from the neuroendocrine cell system in the bronchial and gastrointestinal tract and can produce hormones leading to distinct clinical syndromes. Systemic treatment of patients with unresectable NETs aims to control symptoms related to hormonal overproduction and tumor growth. In the last decades prognosis has improved as a result of increased detection of early stage disease and the introduction of somatostatin analogs (SSAs) as well as several new therapeutic options. SSAs are the first-line medical treatment of NETs and can control hormonal production and tumor growth. The development of next-generation multireceptor targeted and radiolabelled somatostatin analogs, as well as target-directed therapies (as second-line treatment options) further improve progression-free survival in NET patients. To date, however, a significant prolongation of overall survival with systemic treatment in NET has not been convincingly demonstrated. Several new medical options and treatment combinations will become available in the upcoming years, and although preliminary results of preclinical and clinical trials are encouraging, large, preferrably randomized clinical studies are required to provide definitive evidence of their effect on survival and symptom control.

Clinical outcomes of 20 Japanese patients with insulinoma treated with diazoxide

Diazoxide is recognized as an effective medical treatment for insulinoma. However, due to its adverse effects, such as fluid retention, it is sometimes difficult to employ diazoxide at an effective dose in clinical practice. This study aimed to clarify the clinical factors, which may affect efficacy and safety of the diazoxide treatment. We retrospectively evaluated the medical records of 20 patients with insulinoma including 4 malignant cases. The patients were divided into two groups according to the presence or absence of favorable outcomes or adverse effects, and the clinical features of both groups were compared. Diazoxide was effective and ineffective in each 9 patients, respectively. In other 2 cases, the efficacy could not be determined. In the effective group, all patients had benign insulinoma. Additionally, the tumor size determined by imaging test was tended to smaller than the ineffective group but not statistically significant when malignant cases were excluded (p = 0.065). Fluid retention was observed more frequently in females than in males (p = 0.025). Five patients displayed unacceptable thrombocytopenia within a few weeks after the administration of diazoxide. In these patients, the diazoxide dose was significantly higher than that in the other patients [400 mg/day (250-500 mg/day) vs. 225 mg/day (50-425 mg/day), p = 0.027]. These findings may be informative in determining the indication and dose of diazoxide against insulinoma. In addition, a careful evaluation of platelet count would be required for a few weeks after the initiation of diazoxide treatment.

Insulinoma: A retrospective study analyzing the differences between benign and malignant tumors

BACKGROUND/OBJECTIVES

Insulinoma is a rare pancreatic tumor and, usually, a benign disease but can be a malignant one and, sometimes, a highly aggressive disease. The aim of this study was to determine differences between benign and malignant tumors.

METHODS

Retrospective study of 103 patients with insulinoma treated in a tertiary center. It was analyzed demographic, clinical, laboratory, localization and histologic analysis of tumor and follow up data of subjects in order to identify differences between individuals benign and malignant disease.

RESULTS

Almost all patients (87%) had a benign tumor and survival rates of 100% following pancreatic tumor surgery. Those with malignant tumors (13%) have a poor prognosis, 77% insulinoma-related deaths over a period of 1-300 months after the diagnosis with a survival rate of 24% in five years. The following factors are associated with an increased risk of malignant disease: duration of symptoms < 24 months, fasting time for the occurrence of hypoglycemia < 8 h, blood plasma insulin concentration ≥ 28 μU/mL and C-peptide ≥ 4.0 ng/mL at the glycemic nadir and tumor size ≥ 2.5 cm.

CONCLUSIONS

Our data help to base the literature about these tumors, reinforcing that although insulinoma is usually a single benign and surgically treated neoplasia, the malignant one is difficult to treat. We highlight the data that help predict a malignancy behavior of tumor and suggest a long follow up after diagnosis in these cases.

Everolimus as first line therapy for pancreatic neuroendocrine tumours: current knowledge and future perspectives

PURPOSE

Everolimus has been shown to be effective for advanced pancreatic neuroendocrine tumours (pNETs), but its positioning in the therapeutic algorithm for pNETs is matter of debate.

METHODS

With the aim to shed light on this point, we performed an up-to-date critical review taking into account the results of both retrospective and prospective published studies, and the recommendations of international guidelines. In addition, we performed an extensive search on the Clinical Trial Registries databases worldwide, to gather information on the ongoing clinical trials related to this specific topic.

RESULTS

We identified eight retrospective published studies, two prospective published studies, and five registered clinical trials. Moreover, we analyzed the content of four widespread international guidelines.

CONCLUSIONS

Our critical review confirms the lack of high-quality data to recommend everolimus as the first line therapy for pNETs. The ongoing clinical trials reported in this review will hopefully help clinicians, in the near future, to better evaluate the role of everolimus as the first line therapy for pNETs. However, at the moment, there is already enough evidence to recommend everolimus as the first line therapy for patients with symptomatic malignant unresectable insulin-secreting pNETs, to control the endocrine syndrome regardless of tumour growth.

Surgical Management of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) are a rare, heterogeneous group of neoplasms infamous for their endocrinopathies. Up to 90% of PNETs, however, are nonfunctional and are frequently detected incidentally on axial imaging during the evaluation of vague abdominal symptoms. Surgery remains the mainstay of therapy for patients diagnosed with both functional and nonfunctional PNETs. However, the multifaceted nature of PNETs challenges treatment decision making. In general, resection is recommended for patients with acceptable perioperative risk and amenable lesions.

Giant insulinoma: report of a case and review of published reports

Background

Larger insulinomas are reportedly more likely to be malignant; however, their biological behavior has not been clearly elucidated. We here report the characteristics and treatment of a giant insulinoma with local invasion and lymph node metastasis. We also review published reports concerning the clinical features of giant insulinomas and comparing their grading with that of pancreatic neuroendocrine tumors.

Case presentation

A 71-year-old man was referred to our hospital for investigation of persistent hypoglycemia. On the current presentation, laboratory tests showed serum glucose, immunoreactive insulin, and C peptide concentrations of 45 mg/dL, 17.2 μIU/mL and 4.1 ng/mL, respectively. Dynamic magnetic resonance imaging showed a hypervascular tumor measuring 13.5 cm in the head of the pancreas. Computed tomography scanning demonstrated local invasion and lymph node involvement. He thus had Whipple’s triad, which is associated with malignant insulinoma. No distant metastases having been identified, pancreaticoduodenectomy was performed. Intraoperatively, three separate tumors were identified in the pancreatic head. Pathological examination showed all three tumors were pancreatic neuroendocrine tumors; the tumor cells in the largest mass were strongly immunoreactive for insulin. The Ki-67 index was 2–5% in most parts of the largest tumor and over 20% in the poorly differentiated areas. This tumor was classified as neuroendocrine carcinoma in accordance with the 2010 World Health Organization classification of pancreatic endocrine neoplasms. He remains free of evidence of recurrence 2 years postsurgery.

A review of published reports indicated that giant insulinomas are more malignant than smaller ones, and metastatic disease is found on presentation in 56% of patients with giant insulinomas; however, we were unable to identify any correlation between grade of pancreatic neuroendocrine tumor and biological behavior of giant insulinomas.

Conclusions

Giant insulinomas more frequently exhibit malignant behavior, such as local invasion, lymph node involvement, and liver metastasis, than smaller ones. However, there was no relationship between grade and rate of metastases or survival in this small case series. Identification of useful biological markers is necessary.

Single-cell approaches for molecular classification of endocrine tumors

PURPOSE OF REVIEW

In this review, we summarize recent developments in single-cell technologies that can be employed for the functional and molecular classification of endocrine cells in normal and neoplastic tissue.

RECENT FINDINGS

The emergence of new platforms for the isolation, analysis, and dynamic assessment of individual cell identity and reactive behavior enables experimental deconstruction of intratumoral heterogeneity and other contexts where variability in cell signaling and biochemical responsiveness inform biological function and clinical presentation. These tools are particularly appropriate for examining and classifying endocrine neoplasias, as the clinical sequelae of these tumors are often driven by disrupted hormonal responsiveness secondary to compromised cell signaling. Single-cell methods allow for multidimensional experimental designs incorporating both spatial and temporal parameters with the capacity to probe dynamic cell signaling behaviors and kinetic response patterns dependent upon sequential agonist challenge.

SUMMARY

Intratumoral heterogeneity in the provenance, composition, and biological activity of different forms of endocrine neoplasia presents a significant challenge for prognostic assessment. Single-cell technologies provide an array of powerful new approaches uniquely well suited for dissecting complex endocrine tumors. Studies examining the relationship between clinical behavior and tumor compositional variations in cellular activity are now possible, providing new opportunities to deconstruct the underlying mechanisms of endocrine neoplasia.

Diagnostic Difficulties in a Pediatric Insulinoma: A Case Report

Insulinomas are functional neuroendocrine pancreatic tumors rarely encountered in pediatric pathology. Insulinomas are usually solitary and sporadic, but may occur in association with multiple endocrine neoplasia type 1. Whipple's triad-hypoglycemia, simultaneous compatible adrenergic and/or neurological signs, and relief of symptoms upon the administration of glucose-remains the fundamental diagnostic tool. We report a case of insulinoma in an 11-year-old boy with malnutrition and mild psychic retardation. History revealed neuroglycopenic symptoms associated with hypoglycemia that returned to normal values after glucose intravenous infusion; before admission in our unit, the levels of circulating insulin, as well as the abdominal ultrasound and abdominal computed tomography scan, were reported within normal range. During hospitalization in our service, the glycemic curves showed recurring low values associated with low glycated hemoglobin, positive fasting test, and elevated C-peptide. The pancreatic ultrasound was inconclusive, but the magnetic resonance imaging revealed a high signal focal area with a diameter of 1 cm, located in the tail of pancreas. Conventional enucleation of the lesion prompted a spectacular normalization of glucose metabolism and the alleviation of the main clinical symptoms. The child had a favorable evolution in the clinical follow-up, presenting with weight gain and progressive remission to complete disappearance of most symptoms-except for the mental impairments. Although in our case Whipple's triad was apparent from the beginning, the diagnosis was delayed due to the failure of conventional imaging methods in locating the tumor. Weight loss and mental impairment contributed to the diagnosis pitfalls. Pediatricians should be aware of confusing and nonspecific symptoms, especially when children with insulinoma present mental or neurological retardation. Despite the existence of medical regimens, surgery remains the gold standard for the therapeutic approach to this condition.

Pancreatic insulinomas: Laparoscopic management

Insulinomas are rare pancreatic neuroendocrine tumors that are most commonly benign, solitary, and intrapancreatic. Uncontrolled insulin overproduction from the tumor produces neurological and adrenergic symptoms of hypoglycemia. Biochemical diagnosis is confirmed by the presence of Whipple’s triad, along with corroborating measurements of blood glucose, insulin, proinsulin, C-peptide, β-hydroxybutyrate, and negative tests for hypoglycemic agents during a supervised fasting period. This is accompanied by accurate preoperative localization using both invasive and non-invasive imaging modalities. Following this, careful preoperative planning is required, with the ensuing procedure being preferably carried out laparoscopically. An integral part of the laparoscopic approach is the application of laparoscopic intraoperative ultrasound, which is indispensable for accurate intraoperative localization of the lesion in the pancreatic region. The extent of laparoscopic resection is dependent on preoperative and intraoperative findings, but most commonly involves tumor enucleation or distal pancreatectomy. When performed in an experienced surgical unit, laparoscopic resection is associated with minimal mortality and excellent long-term cure rates. Furthermore, this approach confers equivalent safety and efficacy rates to open resection, while improving cosmesis and reducing hospital stay. As such, laparoscopic resection should be considered in all cases of benign insulinoma where adequate surgical expertise is available.

Insulinoma: a multicenter, retrospective analysis of three decades of experience (1983-2014)

OBJECTIVE

To analyze the clinical features, diagnostic procedures, treatment, and clinical outcome of insulinomas diagnosed and treated in the period 1983-2014 in four Spanish hospitals.

METHODS

All patients with either biochemical and morphological criteria of insulinoma and/or histological demonstration of insulin-secreting tumor were included.

RESULTS

Twenty-nine patients [23 women (79.3%); mean age 48.7±17.4 years (range, 16-74)] were recruited. Twenty-six patients (89.7%) had sporadic tumors, and the rest (3 women, 10.3%) developed in the context of multiple endocrine neoplasia type 1. There were 3 (10.3%) multiple insulinomas, one associated with multiple endocrine neoplasia type 1, and two (6.9%) malignant insulinomas, both sporadic. Most patients (n=18, 62.1%) had fasting hypoglycemia, about a third (31%) both postprandial and fasting hypoglycemia, and 6.9% postprandial hypoglycemia only. Time to glucose nadir (37.3±6.5mg/dL) in the fasting test was 9.0±4.4h, with maximal insulin levels of 25.0±20.3μU/mL. Abdominal CT detected insulinoma in 75% of patients. Twenty-seven (93.1%) patients underwent surgery [enucleation, 18 (66.7%) and subtotal pancreatectomy, 9 (33.3%); tumor size, 1,7±0,7cm]. Surgery achieved cure in the majority (n=24, 88.9%) of patients.

CONCLUSION

In our setting, insulinoma is usually a benign, small, and solitary tumor, mainly affecting women aged 45-50 years, and usually localized with abdominal CT. The most commonly used surgical technique is enucleation, which achieves a high cure rate.

Management of a metastasized high grade insulinoma (G3) with refractory hypoglycemia: case report and review of the literature

Insulinomas represent the most common functional neuroendocrine tumor of the pancreas. They are usually solitary, benign, well differentiated (G1/G2) and curable by surgery. We describe the case of a 45 year old male Caucasian with a unique malignant, metastasized pancreatic insulinoma (Ki 67 of 70%, G3). To control excessive insulin production emanating in refractory hypoglycemia and growth of the highly proliferating tumor a multimodal therapeutic approach including the consecutive use of tumor debulking surgery, chemotherapy, TACE, SIRT, PRRT as well as a drug therapy with diazoxide, somatostatin analogs and everolimus was employed. Chemotherapy with carboplatin/etoposide plus everolimus provided the longest normoglycemic period. After progress chemotherapy with dacarbazine had the most positive effect, while debulking approaches such as surgery and liver directed therapies, as well as PRRT were less efficient with only transient success.