Metachronous hormonal syndromes in patients with pancreatic neuroendocrine tumors: a case-series study

Approach to the Patient: Insulinoma

Insulinomas are hormone-producing pancreatic neuroendocrine neoplasms with an estimated incidence of 1 to 4 cases per million per year. Extrapancreatic insulinomas are extremely rare. Most insulinomas present with the Whipple triad: (1) symptoms, signs, or both consistent with hypoglycemia; (2) a low plasma glucose measured at the time of the symptoms and signs; and (3) relief of symptoms and signs when the glucose is raised to normal. Nonmetastatic insulinomas are nowadays referred to as "indolent" and metastatic insulinomas as "aggressive." The 5-year survival of patients with an indolent insulinoma has been reported to be 94% to 100%; for patients with an aggressive insulinoma, this amounts to 24% to 67%. Five percent to 10% of insulinomas are associated with the multiple endocrine neoplasia type 1 syndrome. Localization of the insulinoma and exclusion or confirmation of metastatic disease by computed tomography is followed by endoscopic ultrasound or magnetic resonance imaging for indolent, localized insulinomas. Glucagon-like peptide 1 receptor positron emission tomography/computed tomography or positron emission tomography/magnetic resonance imaging is a highly sensitive localization technique for seemingly occult, indolent, localized insulinomas. Supportive measures and somatostatin receptor ligands can be used for to control hypoglycemia. For single solitary insulinomas, curative surgical excision remains the treatment of choice. In aggressive malignant cases, debulking procedures, somatostatin receptor ligands, peptide receptor radionuclide therapy, everolimus, sunitinib, and cytotoxic chemotherapy can be valuable options.

Hereditary Renal Cancer Syndromes

Familial kidney tumors represent a rare variety of hereditary cancer syndromes, although systematic gene sequencing studies revealed that as many as 5% of renal cell carcinomas (RCCs) are associated with germline pathogenic variants (PVs). Most instances of RCC predisposition are attributed to the loss-of-function mutations in tumor suppressor genes, which drive the malignant progression via somatic inactivation of the remaining allele. These syndromes almost always have extrarenal manifestations, for example, von Hippel-Lindau (VHL) disease, fumarate hydratase tumor predisposition syndrome (FHTPS), Birt-Hogg-Dubé (BHD) syndrome, tuberous sclerosis (TS), etc. In contrast to the above conditions, hereditary papillary renal cell carcinoma syndrome (HPRCC) is caused by activating mutations in the MET oncogene and affects only the kidneys. Recent years have been characterized by remarkable progress in the development of targeted therapies for hereditary RCCs. The HIF2aplha inhibitor belzutifan demonstrated high clinical efficacy towards VHL-associated RCCs. mTOR downregulation provides significant benefits to patients with tuberous sclerosis. MET inhibitors hold promise for the treatment of HPRCC. Systematic gene sequencing studies have the potential to identify novel RCC-predisposing genes, especially when applied to yet unstudied populations.

The Evolutionary History of Metastatic Pancreatic Neuroendocrine Tumours Reveals a Therapy Driven Route to High-Grade Transformation

Tumour evolution with acquisition of more aggressive disease characteristics is a hallmark of disseminated cancer. Metastatic pancreatic neuroendocrine tumours (PanNETs) in particular, show frequent progression from a low/intermediate to a high-grade disease. To understand the molecular mechanisms underlying this phenomenon, we performed multi-omics analysis of 32 longitudinal samples from six metastatic PanNET patients. Following MEN1 inactivation, PanNETs exhibit genetic heterogeneity on both spatial and temporal dimensions with parallel and convergent tumuor evolution involving the ATRX/DAXX and mTOR pathways. Following alkylating chemotherapy treatment, some PanNETs develop mismatch repair deficiency and acquire a hypermutator phenotype. This DNA hypermutation phenotype was only found in cases that also showed transformation into a high-grade PanNET. Overall, our findings contribute to broaden the understanding of metastatic PanNET, and suggests that therapy driven disease evolution is an important hallmark of this disease.

The Driver Role of Pathologists in Endocrine Oncology: What Clinicians Seek in Pathology Reports

Endocrine neoplasia represents an increasingly broad spectrum of disorders. Endocrine neoplasms range from incidental findings to potentially lethal malignancies. In this paper, we cover the impact of pathology in the interpretation of the clinic-pathological, genetic, and radiographic features underpinning these neoplasms. We highlight the critical role of multidisciplinary interactions in structuring a rational diagnostic and efficient therapeutic plan and emphasize the role of histopathological input in decision-making. In this context, standardized pathology reporting and second opinion endocrine pathology review represent relevant tools to improve the overall diagnostic workup of patients affected by endocrine tumors in every specific scenario. In fact, although a relevant proportion of cases may be correctly identified based on clinical presentation and biochemical/imaging investigations, a subset of cases presents with atypical findings that may lead to an inappropriate diagnosis and treatment plan based on a wrong pathological diagnosis if all pieces of the puzzle are not correctly considered. Pathologists have a responsibility to actively guide clinicians before and during surgical procedures to prevent unnecessary interventions. In all areas of endocrine pathology, pathologists must understand the complexity of tissue preservation and assay sensitivities and specificities to ensure the optimal quality and interpretation of diagnostic material. Finally, pathologists are central actors in tumor tissue biobanking, which is an expanding field in oncology that should be promoted while adhering to strict ethical and methodological standards.

Transformation of pancreatic nonfunctioning neuroendocrine tumor into metastatic insulinoma: A rare case report

Pancreatic neuroendocrine tumors can be classified as functional or nonfunctional based on hormone secretion. Management of each entity is different, with nonfunctional tumors being treated with traditional chemotherapy while functional tumors respond well to antihormonal therapy and immunologic agents. The conversion of one nonfunctional tumor into a functional tumor is an exceedingly rare event that complicates the overall management of these patients. In this report, we present the case of a 73-year-old woman who developed the conversion from a nonfunctional into a functional tumor and discuss the management options considered.

[Well-differentiated neuroendocrine tumors of the digestive tract: Focus on pancreatic neuroendocrine tumors]

Pancreatic neuroendocrine tumors are rare tumors showing a rising incidence. They are well-differentiated tumors, classified by grade according to their Ki67 index value (grade 1 to 3). Pancreatic neuroendocrine tumors are mainly sporadic tumors but about 10% arise within endocrine tumor syndromes such as multiple endocrine neoplasia type 1. They can be responsible for functional syndromes or non-specific clinical symptoms depending on tumor extension. However, there is also an increase of incidental diagnoses of nonfunctional pancreatic neuroendocrine tumors with the widespread use of high-quality imaging techniques. About 50 % of pancreatic neuroendocrine tumors are diagnosed at a metastatic stage, with metastases often located in the liver. Chromogranin A, CT-scan and often an abdominal MRI, and functional imaging should be performed for tumor staging and follow-up. Imaging with PET/CT with 68Ga-labeled somatostatin analogues has the highest sensitivity for the diagnosis of pancreatic neuroendocrine tumors, while 18fluorodeoxyglucose PET/CT can sometimes be useful. Overall, they are rather indolent tumors with prolonged survival. Surgery is the recommended treatment in the localized setting, with the exception of small<2cm nonfunctional tumors that can be monitored with imaging techniques. For advanced tumors, there are several available treatments such as somatostatine analogues, chemotherapy, targeted therapies (sunitinib, everolimus), locoregional ablative therapies and Peptide Receptor Radiolabelled Therapy. The treatment strategy will depend on the initial tumor staging, tumor grade, aggressiveness and patient's choice.

Effective strategies for adequate control of hormonal secretion in functioning neuroendocrine neoplasms

Neuroendocrine neoplasms are a unique form of malignancies as they can be accompanied by specific functioning hormonal syndromes that can impair survival and quality of life in patients. Functioning syndromes are defined by the combination of specific clinical signs and symptoms in combination with inappropriately elevated circulating levels of hormones. Clinicians should remain vigilant for the presence of functioning syndromes in neuroendocrine neoplasm patients at presentation as well as during follow-up. The correct diagnostic work-up should be initiated in cases of clinical suspicion of a neuroendocrine neoplasm-associated functioning syndrome. Management of a functional syndrome includes options from supportive, surgical, hormonal and antiproliferative treatment modalities. Here, we review the patient and tumour characteristics for each functioning syndrome that should be taken into account when deciding the optimum treatment strategy in neuroendocrine neoplasm patients.

European Neuroendocrine Tumor Society 2023 guidance paper for functioning pancreatic neuroendocrine tumour syndromes

This ENETS guidance paper aims to provide practical advice to clinicians for the diagnosis, treatment and follow-up of functioning syndromes in pancreatic neuroendocrine tumours (NET). A NET-associated functioning syndrome is defined by the presence of a clinical syndrome combined with biochemical evidence of inappropriately elevated hormonal levels. Different hormonal syndromes can be encountered in pancreatic NET patients, including insulinoma, gastrinoma as well as the rare glucagonoma, VIPoma, ACTHoma, PTHrPoma, carcinoid syndrome, calcitoninoma, GHRHoma and somatostatinoma. The recommendations provided in this paper focus on the biochemical, genetic and imaging work-up as well as therapeutic management of the individual hormonal syndromes in well-differentiated, grade 1-3, functioning NET with the primary tumour originating in the pancreas, and for specific subtypes also in the duodenum.

Spatial and temporal heterogeneity of digestive neuroendocrine neoplasms

Neuroendocrine neoplasms (NENs) are initially monoclonal neoplasms that progressively become polyclonal, with very different genotypic and phenotypic characteristics leading to biological differences, including the Ki-67 proliferation index, morphology, or sensitivity to treatments. Whereas inter-patient heterogeneity has been well described, intra-tumor heterogeneity has been little studied. However, NENs present a high degree of heterogeneity, both spatially within the same location or between different lesions, and through time. This can be explained by the emergence of tumor subclones with different behaviors. These subpopulations can be distinguished by the Ki-67 index, but also by the expression of hormonal markers or by differences in the intensity of uptake on metabolic imaging, such as ⁶⁸Ga-somatostatin receptor and Fluorine-18 fluorodeoxyglucose positron emission tomography. As these features are directly related to prognosis, it seems mandatory to move toward a standardized, improved selection of the tumor areas to be studied to be as predictive as possible. The temporal evolution of NENs frequently leads to changes in tumor grade over time, with impact on prognosis and therapeutic decision-making. However, there is no recommendation regarding systematic biopsy of NEN recurrence or progression, and which lesion to sample. This review aims to summarize the current state of knowledge, the main hypotheses, and the main implications regarding intra-tumor spatial and temporal heterogeneity in digestive NENs.

Malignant Insulinoma Arising From Nonfunctioning Pancreatic Neuroendocrine Tumor

Pancreatic neuroendocrine tumors are rare neoplasms characterized into nonfunctioning (NF-PNET) and functioning (F-PNET) subtypes. F-PNETs typically involve overt symptoms related to excessive hormone secretion but may rarely present first as NF-PNETs with delayed transformation. We present a patient with known NF-PNET with liver metastases who developed hypoglycemia 2 years after initial diagnosis due to malignant insulinoma. Hypoglycemia was refractory to continuous dextrose but improved temporarily after diazoxide and hepatic artery embolization. Malignant insulinomas are usually metastatic at presentation and portend poor prognosis. Hypoglycemia may be medically managed with steroids, somatostatin analogues, and diazoxide, along with therapies to reduce tumor burden.

Medullary Thyroid Cancer with Ectopic Cushing's Syndrome: A Case Report and Systematic Review of Detailed Cases from the Literature

Background: Medullary thyroid cancer (MTC) is a neuroendocrine tumor arising from parafollicular C-cells of the thyroid gland that, in rare cases, can cause a paraneoplastic ectopic Cushing's syndrome (ECS). The development of Cushing's syndrome (CS) in MTC patients is generally associated with advanced disease and poor prognosis. Summary: We described a case of severe CS due to MTC in a young male. We performed a systematic review to identify cases of ECS due to MTC. We searched PubMed, Scopus, and Web of Science for publications between database inception and February 2022 and we collected the patient characteristics, disease presentation, employed treatment strategies, and disease outcomes. In addition to our patient, we identified 96 cases of ECS due to MTC reported in literature. Mean age at diagnosis was 44.4 years (range 10-84), and there was a male predominance (male:female [M:F] = 1.8:1). Most patients (51%) presented with metastatic disease at diagnosis and showed severe hypercortisolism. Seventeen patients developed distant metastasis and hypercortisolism during follow-up. Interestingly, in 48% of patients, the diagnosis of CS followed the diagnosis of MTC with a median time of 48 months but, among patients in whom the diagnosis was concomitant (38%), symptoms due to hypercortisolism were frequently the reason for seeking medical advice. Pathology results showed evidence of adrenocorticotropic hormone (ACTH) or corticotropin releasing hormone (CRH) positive cells in 76% of patients in whom they were tested. The management of hypercortisolism was challenging in most patients with 48% requiring, eventually, definitive treatment with bilateral adrenalectomy (BLA). Recently, some limited evidence has emerged regarding tyrosine kinase inhibitors (TKIs) treatment for hypercortisolism in patients with ECS due to MTC. Despite limited information on survival, prognosis was generally poor and the main causes of death were either complications of CS or disease progression. Conclusions: Despite its rarity, MTC should be considered in the differential diagnosis of ECS. Management of hypercortisolism is a key factor to improve the patient's symptoms but it is often challenging and BLA is frequently required. Further studies are needed for investigating the role of TKIs in patients with MTC with ECS.

Malignant insulinoma: Can we predict the long-term outcomes?

Insulinomas are the most frequent type of functional pancreatic neuroendocrine tumors with a variety of neuroglycopenic and autonomic symptoms and well-defined diagnostic criteria; however, prediction of their clinical behavior and early differentiation between benign and malignant lesions remain a challenge. The comparative studies between benign and malignant cases are limited, suggesting that short clinical history, early hypoglycemia during fasting, high proinsulin, insulin, and C-peptide concentrations raise suspicion of malignancy. Indeed, malignant tumors are larger with higher mitotic count and Ki-67 proliferative activity, but there are no accurate histological criteria to distinguish benign from malignant forms. Several signaling pathways have been suggested to affect the pathophysiology and behavior of insulinomas; however, our knowledge is limited, urging a further understanding of molecular genetics. Therefore, there is a need for the identification of reliable markers of metastatic disease that could also serve as therapeutic targets in patients with malignant insulinoma. This opinion review reflects on current gaps in diagnostic and clinical aspects related to the malignant behavior of insulinoma.

Canine insulinoma as a model for human malignant insulinoma research: Novel perspectives for translational clinical studies

Insulinomas are considered rare indolent neuroendocrine neoplasms in human medicine, however when metastases occur no curative treatment is available thus, novel therapies are needed. Recently advances have been made in unraveling the pathophysiology of malignant insulinoma still major challenges hinder the development of a functional model to study them. Canine malignant insulinoma have similar recurrence and a poor prognosis as human malignant insulinoma. Additionally, both human and canine patients share extensively the same environment, tend to develop insulinoma seemingly spontaneously with an etiological role for hormones, at a similar incidence and stage of lifespan, with metastasis commonly to liver and regional lymph nodes, which are unresponsive to current therapies. However, the occurrence of metastases in dogs is as high as 95% compared with only 5-16% in human studies. From a comparative oncology perspective, the shared features with human insulinoma but higher incidence of metastasis in canine insulinoma suggests the latter as a model for human malignant insulinomas. With the common purpose of increasing survival rates of human and veterinary patients, in this review we are going to compare and analyze clinical, pathological and molecular aspects of canine and human insulinomas to evaluate the suitability of the canine model for future translational clinical studies.

Pancreatic neuroendocrine tumor producing vasopressin: A case report

RATIONALE

Functional pancreatic neuroendocrine tumors (pNETs) rarely produce vasopressin. Here, we reported a case of pNET producing vasopressin in a 78-year-old man with hyponatremia.

PATIENT CONCERNS

The patient presented with anorexia approximately 4 years ago, and the laboratory test results indicated hyponatremia. He was hospitalized 3 times subsequently due to anorexia in the past 4 years, during which laboratory tests consistently indicated severe hyponatremia.

DIAGNOSIS

Upon admission, his serum osmolarity, urine osmolarity, urine sodium level, and 24-hour urine sodium level was 277 mOsm/kg H2O, 465 mOsm/kg H2O, 82.5 mmol/L, and 140.25 mmol, respectively. Gallium-68-labeled tetraazacyclododecanetetraacetic acid-Dphel-Tyr3-octreotate positron emission tomography-computed tomography showed a high uptake lesion measuring approximately 1 cm in diameter in the pancreatic body, and the possibility of pNET was considered. Besides, laboratory tests showed that adrenocorticotropic hormone, follicle-stimulating hormone, and luteinizing hormone released by the pituitary was insufficient in the case of low levels of cortisol, estradiol, progesterone, and testosterone. Thus, the diagnosis of the syndrome of inappropriate antidiuresis (SIAD) was considered along with hypopituitarism.

INTERVENTIONS

The patient underwent surgery, and pNET was confirmed by pathology examination. The immunohistochemical study showed that the tumor cells were positive for somatostatin receptors 2 and vasopressin.

OUTCOMES

In the last follow-up 17 months after surgery, the patient was in good condition, taking methylprednisolone 4 mg every other day, and had been free of anorexia or hyponatremia episodes.

LESSONS

This case illustrated the potential ectopic production of vasopressin resulting in SIAD in pNETs, highlighting the adoption of gallium-68-labeled tetraazacyclododecanetetraacetic acid-Dphel-Tyr3-octreotate positron emission tomography-computed tomography and vasopressin immunohistochemical staining in the evaluation of the etiology of SIAD.

Hormonal tumor mapping for liver metastases of gastroenteropancreatic neuroendocrine neoplasms: a novel therapeutic strategy

PURPOSE

In patients with metastatic functional gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs), it is unknown what degree of tumor reduction is required to eliminate hormonal symptoms. We aimed to reduce hormonal symptoms derived from advanced GEP-NENs by efficient minimal intervention, constructing a hormonal tumor map of liver metastases.

METHODS

Between 2013 and 2019, we treated 12 insulinoma or gastrinoma patients with liver metastases. Liver segments containing hormone-producing tumors were identified by injecting calcium gluconate via the hepatic arteries and monitoring the change in serum hormone concentration in the three hepatic veins. A greater-than-twofold increase in hormone concentration indicated a tumor-feeding vessel.

RESULTS

Cases included eight insulinomas and four gastrinomas. Primary lesions were functional in three patients and nonfunctional in 9. Nine patients showed hormonal step-up indicating the presence of functional lesions; eight showed step-up in tumor-bearing liver segments, while one with synchronous liver metastases showed step-up only in the pancreatic region. Five patients underwent surgery. Serum hormone concentration decreased markedly after removing the culprit lesions in 3; immediate improvement in hormonal symptoms was achieved in all patients. Three patients with previous surgical treatment who showed step-up underwent transcatheter arterial embolization, achieving temporary improvement of hormonal symptoms. Four patients showed unclear localization of the hormone-producing tumors; treatment options were limited, resulting in poor outcomes.

CONCLUSION

Hormonal tumor mapping demonstrated heterogeneity in hormone production among primary and metastatic tumors of GEP-NENs. Minimally invasive treatment based on hormonal mapping may be a viable alternative to conventional cytoreduction.

Gastroenteropancreatic neuroendocrine neoplasms: A clinical snapshot

Our understanding about the epidemiological aspects, pathogenesis, molecular diagnosis, and targeted therapies of neuroendocrine neoplasms (NENs) have drastically advanced in the past decade. Gastroenteropancreatic (GEP) NENs originate from the enteroendocrine cells of the embryonic gut which share common endocrine and neural differentiation factors. Most NENs are well-differentiated, and slow growing. Specific neuroendocrine biomarkers that are used in the diagnosis of functional NENs include insulin, glucagon, vasoactive intestinal polypeptide, gastrin, somatostatin, adrenocorticotropin, growth hormone releasing hormone, parathyroid hormone-related peptide, serotonin, histamine, and 5-hydroxy indole acetic acid (5-HIAA). Biomarkers such as pancreatic polypeptide, human chorionic gonadotrophin subunits, neurotensin, ghrelin, and calcitonin are used in the diagnosis of non-functional NENs. 5-HIAA levels correlate with tumour burden, prognosis and development of carcinoid heart disease and mesenteric fibrosis, however several diseases, medications and edible products can falsely elevate the 5-HIAA levels. Organ-specific transcription factors are useful in the differential diagnosis of metastasis from an unknown primary of well-differentiated NENs. Emerging novel biomarkers include circulating tumour cells, circulating tumour DNA, circulating micro-RNAs, and neuroendocrine neoplasms test (NETest) (simultaneous measurement of 51 neuroendocrine-specific marker genes in the peripheral blood). NETest has high sensitivity (85%-98%) and specificity (93%-97%) for the detection of gastrointestinal NENs, and is useful for monitoring treatment response, recurrence, and prognosis. In terms of management, surgery, radiofrequency ablation, symptom control with medications, chemotherapy and molecular targeted therapies are all considered as options. Surgery is the mainstay of treatment, but depends on factors including age of the individual, location, stage, grade, functional status, and the heredity of the tumour (sporadic vs inherited). Medical management is helpful to alleviate the symptoms, manage inoperable lesions, suppress postoperative tumour growth, and manage recurrences. Several molecular-targeted therapies are considered second line to somatostatin analogues. This review is a clinical update on the pathophysiological aspects, diagnostic algorithm, and management of GEP NENs.

Multiple hormone secretion may indicate worse prognosis in patients with ectopic Cushing's syndrome

PURPOSE

Ectopic Cushing's syndrome (ECS) caused by an ACTH secreting neuroendocrine neoplasm (NEN) is a rare and challenging condition. We aimed to detect predictive and prognostic parameters for ECS patients identified from a retrospective, comprehensive cohort of NENs treated at a tertiary referral center.

METHODS

Medical records of 886 patients with NENs were reviewed. We identified 51 patients with ECS (33 females/18 men); mean age 52 ± 15 years (SD). Clinical parameters including symptoms, biochemical markers, and survival were extracted and further analyzed.

RESULTS

The primary tumor was located in the thorax (n = 28) or pancreas (n = 15) or was of unknown primary origin (n = 8). In 30 patients, tumor and ECS were diagnosed simultaneously. In 12 patients, the NEN diagnosis preceded ECS development, with a median time of 43.5 months (range: 9-96), and 10 of these showed radiological tumor progression at ECS diagnosis. Twenty-one patients had multiple hormone secretion, which correlated with shorter overall survival (OS), p = 0.012 (HR 2.4 (95% CI 1.2-4.9)), as did high morning cortisol, p = 0.037 (HR 2.3 (1.0-5.2)), higher tumor grade, p = 0.044 (HR 2.3 (1.0-5.1)), and diabetes, p = 0.050 (HR 2.4 (1.0-6.0)).

CONCLUSIONS

Multiple hormone secretion, high morning cortisol, higher tumor grade, and diabetes were correlated with shorter OS. Development of ECS in patients with a non-functioning NEN may indicate tumor progression. Multiple hormone secretion should be considered as a bad prognostic sign in ECS patients and should lead to intensified clinical management.

Digestive Neuroendocrine Neoplasms (NEN): French Intergroup clinical practice guidelines for diagnosis, treatment and follow-up (SNFGE, GTE, RENATEN, TENPATH, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, SFR)

INTRODUCTION

This document is a summary of the French Intergroup guidelines regarding the management of digestive neuroendocrine neoplasms (NEN) published in February 2020 (www.tncd.org).

METHODS

All French medical societies involved in the management of NEN took part in this work. Recommendations were graded into four categories (A, B, C or D), according to the level of evidence found in the literature until May 2019.

RESULTS

The management of NEN is challenging because of their heterogeneity and the increasing complexity of diagnostic and therapeutic procedures. Pathological analysis is required for their diagnostic and prognostic characterization, which mainly relies on differentiation, grade and stage. The two main emergency situations are functioning syndromes and poorly-differentiated carcinoma. Chromogranin A is the main biochemical marker of NET, although of limited clinical interest. Initial characterization relies on morphological and isotopic imaging. The treatment of localized NET relies on watchful follow-up and local or surgical resection depending on its supposed aggressiveness. Treatment options for metastatic disease include surgery, somatostatin analogues, chemotherapy, targeted therapies, organ-driven locoregional therapies and peptide-receptor radionuclide therapy. As specific predictive factors of treatment efficacy are yet to be identified and head-to-head comparisons have not or only rarely been performed, the therapeutic strategy currently depends on prognostic factors. Cumulative toxicity and the impact of treatment on quality of life must be considered since survival is relatively long in most patients with NET.

CONCLUSION

These guidelines are proposed to achieve the most beneficial therapeutic strategy in clinical practice as the therapeutic landscape of NEN is becoming ever more complex. These recommendations are permanently being reviewed.

Advances in the Diagnosis and Management of Well-Differentiated Neuroendocrine Neoplasms

Neuroendocrine neoplasms constitute a diverse group of tumors that derive from the sensory and secretory neuroendocrine cells and predominantly arise within the pulmonary and gastrointestinal tracts. The majority of these neoplasms have a well-differentiated grade and are termed neuroendocrine tumors (NETs). This subgroup is characterized by limited proliferation and patients affected by these tumors carry a good to moderate prognosis. A substantial subset of patients presenting with a NET suffer from the consequences of endocrine syndromes as a result of the excessive secretion of amines or peptide hormones, which can impair their quality of life and prognosis. Over the past 15 years, critical developments in tumor grading, diagnostic biomarkers, radionuclide imaging, randomized controlled drug trials, evidence-based guidelines, and superior prognostic outcomes have substantially altered the field of NET care. Here, we review the relevant advances to clinical practice that have significantly upgraded our approach to NET patients, both in diagnostic and in therapeutic options.

High-Grade Progression Confers Poor Survival in Pancreatic Neuroendocrine Tumors

INTRODUCTION

Little is known about how pancreatic neuroendocrine tumors (PanNETs) evolve over time and if changes toward a more aggressive biology correlate with prognosis. The purpose of this study was to characterize changes in PanNET differentiation and proliferation over time and to correlate findings to overall survival (OS).

PATIENTS AND METHODS

In this retrospective cohort study, we screened 475 PanNET patients treated at Uppsala University Hospital, Sweden. Sporadic patients with baseline and follow-up tumor samples were included. Pathology reports and available tissue sections were reevaluated with regard to tumor histopathology and Ki-67 index.

RESULTS

Forty-six patients with 106 tumor samples (56 available for pathology reevaluation) were included. Median Ki-67 index at diagnosis was 7% (range 1-38%), grade 1 n = 8, grade 2 n = 36, and grade 3 n = 2. The median change in Ki-67 index (absolute value; follow-up - baseline) was +14% (range -11 to +80%). Increase in tumor grade occurred in 28 patients (63.6%), the majority from grade 1/2 to grade 3 (n = 24, 54.5%). The patients with a high-grade progression had a median OS of 50.2 months compared to 115.1 months in patients without such progression (hazard ratio 3.89, 95% CI 1.91-7.94, p < 0.001).

CONCLUSIONS

A longitudinal increase in Ki-67 index and increase in tumor grade were observed in a majority of PanNETs included in this study. We propose that increase in Ki-67 index and high-grade progression should be investigated further as important biomarkers in PanNET.

hypercalcaemia due to a calcitriol-producing neuroendocrine tumour

In this case report, we describe a 40-year-old patient with a large grade 2 pancreatic neuroendocrine tumour (pNET) with spleen metastasis. Albeit radical resection, he developed liver metastasis after 2 years, for which he underwent radio frequency ablation and embolization, and was treated successfully with different subsequent lines of systemic therapy. Eight years after the initial diagnosis, he was admitted for symptomatic and refractory hypercalcaemia, due to calcitriol synthesis by the liver metastasis. After tumour load reduction by hemihepatectomy, there was an initial normalization of hypercalcaemia, until it recurred after 18 months. In this period, the liver metastasis had progressed despite chemo- and immunotherapy. Patient underwent an additional extend hemihepatectomy, from which he recovered well with normalization of calcium levels. This case illustrates the hormonal plasticity of pNETs and shows how prolonged survival can be achieved for metastatic pNET by multimodality approach.

Transformation of a non-secretory neuroendocrine tumor to insulinoma after treatment with Sunitinib: A case report and review of the literature

We report a case of a non-secretory neuroendocrine tumor which transformed into an insulin secreting tumor after treatment with Sunitinib. To our knowledge, this has only been described in three other cases worldwide. Previously reported case series find transformation of non-secretory neuroendocrine cancers into secretory lesions occurs in 3.4-6.8% of cases. Sunitinib is known to have the potential to lower blood glucose and induce epigenetic changes in cells of various types. We hypothesize that the mechanism for Sunitinib-induced transformation in cancer phenotype is through epigenetic changes in DNA expression within the tumor cells.

A Clinicopathological Study of Malignant Insulinoma in a Contemporary Series

OBJECTIVE

The aim of the study was to address the origin and natural history of malignant insulinoma.

METHODS

Retrospective review of medical records of patients diagnosed with insulinoma at Cedars-Sinai Medical Center between 2000 and 2015 was conducted. Hormonal expression in tumor specimens was examined by immunostaining.

RESULTS

All the 9 patients with malignant insulinoma (35% of 26 patients with insulinoma) already had liver metastasis at hypoglycemia presentation with bulky cumulative tumor burden. Six patients had de novo diagnosis, 2 had known metastatic nonfunctioning pancreatic neuroendocrine tumor, and 1 had a known pancreatic mass. Tumor grade at presentation was G1 in 4 patients, G2 in 4, and unknown in 1. Four patients died 2 to 32 months after presentation, all with extensive liver tumor involvement. Tumor expression of proinsulin and insulin was heterogeneous and overall infrequent. The proinsulin levels and proinsulin/insulin molar ratio in patients with malignant versus benign insulinoma were 334 versus 44 pmol/L and 2.1 versus 0.9, respectively.

CONCLUSIONS

Malignant insulinoma seems to arise from and behave like nonfunctioning pancreatic neuroendocrine tumor oncologically but with metachronous hyperinsulinemic hypoglycemia. High proinsulin levels and proinsulin/insulin molar ratio may suggest malignant insulinoma.

Medical management of secretory syndromes related to gastroenteropancreatic neuroendocrine tumours

Although recent epidemiological evidence indicates that the prevalence of non-functioning gastroenteropancreatic (GEP) neuroendocrine tumours (NETs) is rising, a significant number of GEP-NETs still present with symptoms related to the secretion of biologically active substances leading to the development of distinct clinical syndromes. In the past, these syndromes were associated with substantial morbidity and mortality due to the lack of specific therapies; however, since the introduction of long-acting somatostatin analogues and medications such as proton pump inhibitors, their control has been greatly improved. As a result, nowadays, the main cause of morbidity and mortality in GEP-NETs is mostly directly related to tumour growth and the extent of metastatic disease. However, in some patients with functioning tumours and extensive disease, control of the secretory syndrome still remains problematic, necessitating the employment of several cytoreductive techniques, which may not always be sufficient. Recently, new agents directed against tumour growth, or exerting increased binding activity to receptors expressed in these tumours, or interfering with the synthetic pathway of some of the compounds secreted by these tumours, have been developed. Since there are no specific guidelines addressing the totality of the management of the secretory syndromes related to GEP-NETs, this review aims at critically analysing the medical management of previously recognised secretory syndromes; it also addresses areas of uncertainty, assesses the newer therapeutic developments and also addresses recently described but poorly characterised secretory syndromes related to GEP-NETs.

Gastroscopic features and serum gastrin in schizophrenics taking long-term medication

AIM: To investigate the gastroscopic features and serum gastrin in schizophrenics taking long-term medication.

METHODS: Sixty schizophrenics with digestive diseases treated at our hospital were divided randomly and equally into two groups according to medication course (group A: < 0.5 year; group C (> 1 year). Diabetes or high blood pressure patients taking long-term medication were included as controls (group B). All patients underwent painless gastroscopy and examination of fasting serum gastrin.

RESULTS: The rates of bile reflux gastritis and gastric stasis were significantly higher in group C (34.37% and 30.21%, respectively) than in groups A and B (P < 0.05). The level of serum gastrin was significantly lower in group C than in groups A and B (78.43 pg/mL ± 10.68 pg/mL vs 88.72 pg/mL ± 11.35 pg/mL, 90.14 pg/mL ± 9.57 pg/mL; P < 0.05).

CONCLUSION: Schizophrenics taking long-term medication tend to develop bile reflux gastritis, gastric stasis and lowered serum gastrin.

Multiple and Secondary Hormone Secretion in Patients With Metastatic Pancreatic Neuroendocrine Tumours

CONTEXT

As a group, neuroendocrine tumors (NETs) secrete many different peptide hormones, yet heretofore each NET patient is typically thought to produce at most one hormone that causes a distinct hormonal syndrome. A minority of patients have multiple hormones at diagnosis and may also develop secondary hormone secretion at a later stage.

OBJECTIVES

The objectives of the study were to determine the frequency and to describe the impact of multiple and secondary hormone secretion in sporadic gasteroenteropancreatic NET patients.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective analysis of patients (n = 972) with gasteroenteropancreatic NET treated at Uppsala University Hospital, Uppsala, Sweden. Patients with the secretion of multiple hormones at diagnosis and/or those developing secondary hormone secretion during the disease course were identified and studied in further detail.

RESULTS

In pancreatic NETs (PNETs), a total of 19 of 323 patients (6%) had secretion of multiple hormones at diagnosis, and 14 of 323 (4%) had secondary changes during the disease course. These phenomena occurred exclusively in patients with an advanced disease stage, and secondary hormones were detected in a close time span with progressive disease. Patients with secondary insulin hypersecretion had increased morbidity as well as reduced survival (P < .002). In contrast, multiple and secondary hormone secretion was rarely seen in NETs of the small intestine with 0 and 1 of 603 cases, respectively.

CONCLUSION

Diversity of PNET hormone secretion either at diagnosis or during the disease course occurred in a minority of patients (9.3%). These phenomena had a major impact on patient outcome both through increased morbidity and mortality. Our results support that patients with metastatic PNETs should be monitored for clinical symptoms of secondary hormone secretion during the disease course.