Cushing's syndrome in patients with the Zollinger-Ellison syndrome

Long-Term Proton Pump Inhibitor-Acid Suppressive Treatment Can Cause Vitamin B12 Deficiency in Zollinger-Ellison Syndrome (ZES) Patients

Whether the long-term treatment of patients with proton pump inhibitors (PPIs) with different diseases [GERD, Zollinger-Ellison syndrome (ZES), etc.] can result in vitamin B12 (VB12) deficiency is controversial. In this study, in 175 patients undergoing long-term ZES treatment with anti-acid therapies, drug-induced control acid secretory rates were correlated with the presence/absence of VB12 deficiency, determined by assessing serum VB12 levels, measurements of VB12 body stores (blood methylmalonic acid (MMA) and total homocysteine[tHYC]), and other features of ZES. After a mean of 10.2 yrs. of any acid treatment (5.6 yrs. with PPIs), 21% had VB12 deficiency with significantly lower serum and body VB12 levels (p < 0.0001). The presence of VB12 deficiency did not correlate with any feature of ZES but was associated with a 12-fold lower acid control rate, a 2-fold higher acid control pH (6.4 vs. 3.7), and acid control secretory rates below those required for the activation of pepsin (pH > 3.5). Over a 5-yr period, the patients with VB12 deficiency had a higher rate of achlorhydria (73% vs. 24%) and a lower rate of normal acid secretion (0% vs. 49%). In conclusion, in ZES patients, chronic long-term PPI treatment results in marked acid hyposecretion, resulting in decreased serum VB12 levels and decreased VB12-body stores, which can result in VB12 deficiency.

Ectopic Adrenocorticotropic Hormone-Producing Metastatic Gastrinoma: A Case Report

Pancreatic neuroendocrine tumors secreting gastrin and adrenocorticotropic hormone (ACTH) are rare. The presentation of the cases can be varied, making the diagnosis challenging and often delayed. Here, we present a patient who presented with severe hypokalemia and was found to have ectopic Cushing's syndrome. An abdominal CT scan showed a pancreatic lesion with metastatic liver disease. A biopsy of the liver lesion confirmed a metastatic neuroendocrine tumor. The final diagnosis was ectopic ACTH-producing metastatic gastrinoma. Twenty-four-hour urinary cortisol was significantly elevated at 9,790 mcg/24 hours. The excess hormonal secretion was successfully treated with ketoconazole and somatostatin analogs. She was further started on chemotherapy with capecitabine plus temozolomide, which has become the preferred chemotherapy treatment after the results of the recently completed trial. She also received Y90 therapy for metastatic liver disease. The prognosis of metastatic pancreatic neuroendocrine tumors is poor. Multidisciplinary combined therapies can help control disease and improve prognosis. We present an 18-month-long patient follow-up and a literature review of ectopic ACTH-producing metastatic gastrinomas.

Successful Lifetime/Long-Term Medical Treatment of Acid Hypersecretion in Zollinger-Ellison Syndrome (ZES): Myth or Fact? Insights from an Analysis of Results of NIH Long-Term Prospective Studies of ZES

Analysis of the efficacy/pharmacology of long-term/lifetime medical treatment of acid hypersecretion in a large cohort of ZES patients in a prospective study. This study includes the results from all 303 patients with established ZES who were prospectively followed and received acid antisecretory treatment with either H2Rs or PPIs, with antisecretory doses individually titrated by the results of regular gastric acid testing. The study includes patients treated for short-term periods (<5 yrs), patients treated long-term (>5 yrs), and patients with lifetime treatment (30%) followed for up to 48 years (mean 14 yrs). Long-term/lifelong acid antisecretory treatment with H2Rs/PPIs can be successfully carried out in all patients with both uncomplicated and complicated ZES (i.e., with MEN1/ZES, previous Billroth 2, severe GERD). This is only possible if drug doses are individually set by assessing acid secretory control to establish proven criteria, with regular reassessments and readjustments. Frequent dose changes both upward and downward are needed, as well as regulation of the dosing frequency, and there is a primary reliance on the use of PPIs. Prognostic factors predicting patients with PPI dose changes are identified, which need to be studied prospectively to develop a useful predictive algorithm that could be clinically useful for tailored long-term/lifetime therapy in these patients.

Severe ectopic Cushing syndrome in a transgender man with a metastatic gastrinoma and an adrenal tumor-A case report and review of the literature

A 38-year-old transgender man with advanced metastatic functional pancreatic neuroendocrine neoplasm (PanNEN) gastrinoma was admitted to the Department of Endocrinology due to severe ACTH-dependent hypercortisolemia. An ectopic production of ACTH by PanNEN was suspected. The patient qualified for bilateral adrenalectomy after preoperative treatment with metyrapone. Finally, the patient underwent resection of the left adrenal gland with the tumor only, which surprisingly resulted in a significant decrease in ACTH and cortisol levels, leading to clinical improvement. Pathology report revealed an adenoma of the adrenal cortex with positive ACTH staining. The result of the simultaneous liver lesion biopsy confirmed a metastatic NEN G2 with positive ACTH immunostaining as well. We looked for a correlation between gender-affirming hormone treatment and the onset of the disease and its rapid progression. This may be the first case describing the coexistence of gastrinoma and ectopic Cushing disease in a transsexual patient.

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.

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.

Multiple Endocrine Neoplasia Type 1 (MEN1): An Update and the Significance of Early Genetic and Clinical Diagnosis

Multiple endocrine neoplasia type 1 (MEN1) is a rare hereditary tumor syndrome inherited in an autosomal dominant manner and characterized by a predisposition to a multitude of endocrine neoplasms primarily of parathyroid, enteropancreatic, and anterior pituitary origin, as well as nonendocrine neoplasms. Other endocrine tumors in MEN1 include foregut carcinoid tumors, adrenocortical tumors, and rarely pheochromocytoma. Nonendocrine manifestations include meningiomas and ependymomas, lipomas, angiofibromas, collagenomas, and leiomyomas. MEN1 is caused by inactivating mutations of the tumor suppressor gene MEN1 which encodes the protein menin. This syndrome can affect all age groups, with 17% of patients developing MEN1-associated tumors before 21 years of age. Despite advances in the diagnosis and treatment of MEN1-associated tumors, patients with MEN1 continue to have decreased life expectancy primarily due to malignant neuroendocrine tumors. The most recent clinical practice guidelines for MEN1, published in 2012, highlight the need for early genetic and clinical diagnosis of MEN1 and recommend an intensive surveillance approach for both patients with this syndrome and asymptomatic carriers starting at the age of 5 years with the goal of timely detection and management of MEN1-associated neoplasms and ultimately decreased disease-specific morbidity and mortality. Unfortunately, there is no clear genotype-phenotype correlation and individual mutation-dependent surveillance is not possible currently.

Gastrinomas: Medical or Surgical Treatment

This article reviews the role of surgical and medical management in patients with Zollinger-Ellison syndrome (ZES) due to a gastrin-secreting neuroendocrine tumor (gastrinoma). It concentrates on the status at present but also briefly reviews the changes over time in treatment approaches. Generally, surgical and medical therapy are complementary today; however, in some cases, such as patients with ZES and multiple endocrine neoplasia type 1, the treatment approach remains controversial.

Imaging of pancreatic neuroendocrine tumors: recent advances, current status, and controversies

INTRODUCTION

Recently, there have been a number of advances in imaging pancreatic neuroendocrine tumors (panNETs), as well as other neuroendocrine tumors (NETs), which have had a profound effect on the management and treatment of these patients, but in some cases are also associated with controversies. Areas covered: These advances are the result of numerous studies attempting to better define the roles of both cross-sectional imaging, endoscopic ultrasound, with or without fine-needle aspiration, and molecular imaging in both sporadic and inherited panNET syndromes; the increased attempt to develop imaging parameters that correlate with tumor classification or have prognostic value; the rapidly increasing use of molecular imaging in these tumors and the attempt to develop imaging parameters that correlate with treatment/outcome results. Each of these areas and the associated controversies are reviewed. Expert commentary: There have been numerous advances in all aspects of the imaging of panNETs, as well as other NETs, in the last few years. The advances are leading to expanded roles of imaging in the management of these patients and the results being seen in panNETs/GI-NETs with these newer techniques are already being used in more common tumors.

Black swans - neuroendocrine tumors of rare locations

Neuroendocrine neoplasms (NEN) are rare and heterogeneous. Therefore, they often remain unrecognized for many years, causing significant disease burden. We here report on four unusual NEN presentations including a metastatic NEN of the kidney, hypoglycemia caused by an insulin-like growth factor-2-oma (previously called non-islet-cell tumor hypoglycemia), multifocal pheochromocytoma in von Hippel Lindau syndrome, and ileal NEN metastatic to the heart. One could say that each one of these tumors were "black swans" and learning about them will increase further awareness of the spectrum of NEN.

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.

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.

Clinical Presentation and Diagnosis of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors are a rare group of neoplasms that arise from multipotent stem cells in the pancreatic ductal epithelium. Although they comprise only 1% to 2% of pancreatic neoplasms, their incidence is increasing. Most pancreatic neuroendocrine tumors are nonfunctioning, but they can secrete various hormones resulting in unique clinical syndromes. Clinicians must be aware of the diverse manifestations of this disease, as the key step to management of these rare tumors is to first suspect the diagnosis.

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.

Imaging in multiple endocrine neoplasia type 1: recent studies show enhanced sensitivities but increased controversies

In multiple endocrine neoplasia type 1 (MEN1) patients, a number of recent studies compare the ability of different, new imaging modalities to existing modalities to localize the important neuroendocrine tumors (NETs) that contribute to their decreased life expectancy (pancreatic NETs [pNETs] and thymic carcinoids). These included the use of ⁶⁸Ga-DOTATOC-PET/CT, endoscopic ultrasound and MRI. The current paper analyzes these results in light of current guidelines and controversies involved in the treatment/management of MEN1 patients. Particular attention is paid to results in these studies with thymic carcinoids and nonfunctional pNETs/gastrinomas, which recent studies show are particularly important in determining long-term survival. These studies show a number of promising imaging results but also raise a number of controversies, which will need to be addressed both in their use initially and for serial studies in these patients.

Zollinger-Ellison syndrome: recent advances and controversies

PURPOSE OF REVIEW

To review the recent advances and current controversies in patients with Zollinger-Ellison syndrome (ZES).

RECENT FINDINGS

Recent advances in the management of ZES include: improved understanding of the pathogenesis of gastrinoma and pancreatic neuroendocrine tumors, new prognostic classification systems, new diagnostic algorithms, more sensitive localization studies, new treatment strategies including improved control of gastric acid secretion and role for surgery, and new approaches to patients with advanced disease. Controversies include: the best approach to a patient with hypergastrinemia suspected of possibly having ZES, the appropriate gastrin assay to use, the role of surgery in patients with ZES, especially those with multiple endocrine neoplasia type 1, and the precise order of therapeutic modalities in the treatment of patients with advanced disease.

SUMMARY

This review updates clinicians regarding important advances and controversies required to optimally diagnose and manage patients with ZES.

Causes of death and prognostic factors in multiple endocrine neoplasia type 1: a prospective study: comparison of 106 MEN1/Zollinger-Ellison syndrome patients with 1613 literature MEN1 patients with or without pancreatic endocrine tumors

Multiple endocrine neoplasia type 1 (MEN1) is classically characterized by the development of functional or nonfunctional hyperplasia or tumors in endocrine tissues (parathyroid, pancreas, pituitary, adrenal). Because effective treatments have been developed for the hormone excess state, which was a major cause of death in these patients in the past, coupled with the recognition that nonendocrine tumors increasingly develop late in the disease course, the natural history of the disease has changed. An understanding of the current causes of death is important to tailor treatment for these patients and to help identify prognostic factors; however, it is generally lacking.To add to our understanding, we conducted a detailed analysis of the causes of death and prognostic factors from a prospective long-term National Institutes of Health (NIH) study of 106 MEN1 patients with pancreatic endocrine tumors with Zollinger-Ellison syndrome (MEN1/ZES patients) and compared our results to those from the pooled literature data of 227 patients with MEN1 with pancreatic endocrine tumors (MEN1/PET patients) reported in case reports or small series, and to 1386 patients reported in large MEN1 literature series. In the NIH series over a mean follow-up of 24.5 years, 24 (23%) patients died (14 MEN1-related and 10 non-MEN1-related deaths). Comparing the causes of death with the results from the 227 patients in the pooled literature series, we found that no patients died of acute complications due to acid hypersecretion, and 8%-14% died of other hormone excess causes, which is similar to the results in 10 large MEN1 literature series published since 1995. In the 2 series (the NIH and pooled literature series), two-thirds of patients died from an MEN1-related cause and one-third from a non-MEN1-related cause, which agrees with the mean values reported in 10 large MEN1 series in the literature, although in the literature the causes of death varied widely. In the NIH and pooled literature series, the main causes of MEN1-related deaths were due to the malignant nature of the PETs, followed by the malignant nature of thymic carcinoid tumors. These results differ from the results of a number of the literature series, especially those reported before the 1990s. The causes of non-MEN1-related death for the 2 series, in decreasing frequency, were cardiovascular disease, other nonendocrine tumors > lung diseases, cerebrovascular diseases. The most frequent non-MEN1-related tumor deaths were colorectal, renal > lung > breast, oropharyngeal. Although both overall and disease-related survival are better than in the past (30-yr survival of NIH series: 82% overall, 88% disease-related), the mean age at death was 55 years, which is younger than expected for the general population.Detailed analysis of causes of death correlated with clinical, laboratory, and tumor characteristics of patients in the 2 series allowed identification of a number of prognostic factors. Poor prognostic factors included higher fasting gastrin levels, presence of other functional hormonal syndromes, need for >3 parathyroidectomies, presence of liver metastases or distant metastases, aggressive PET growth, large PETs, or the development of new lesions.The results of this study have helped define the causes of death of MEN1 patients at present, and have enabled us to identify a number of prognostic factors that should be helpful in tailoring treatment for these patients for both short- and long-term management, as well as in directing research efforts to better define the natural history of the disease and the most important factors determining long-term survival at present.

Pharmacotherapy of Zollinger-Ellison syndrome

INTRODUCTION

The role of pharmacotherapy in the management of patients with Zollinger-Ellison syndrome (ZES) is often equated with the medical management of acid hypersecretion. However, pharmacotherapy is also increasingly involved in the other management areas of these patients.

AREAS COVERED

This paper reviews the role of pharmacotherapy in all aspects of the management of patients with ZES. Newer aspects are emphasized. This includes the difficulty of diagnosing ZES in patients taking proton pump inhibitors. Also covered is the role of pharmacotherapy in controlling acid hypersecretion and other hormonal hypersecretory states these patients may develop, including hyperparathyroidism in patients with multiple endocrine neoplasia type 1 and ZES; tumor localization; and the treatment of advanced metastatic disease. The last includes chemotherapy, liver-directed therapies, biotherapy (somatostatin/interferon), peptide radio-receptor therapy and molecular-targeted therapies including the use of mTor inhibitors (everolimus) and tyrosine kinase inhibitors (sunitinib).

EXPERT OPINION

Pharmacotherapy is now involved in all aspects of the management of patients with ZES, with the result that ZES has progressed from being considered an entirely surgical disease initially to the present where medical treatment plays a major role in almost all aspects of the management of these patients.

Pancreatic neuroendocrine tumors: clinical features, diagnosis and medical treatment: advances

Pancreatic neuroendocrine tumors (pNETs) comprise with gastrointestinal carcinoids, the main groups of gastrointestinal neuroendocrine tumors (GI-NETs). Although these two groups of GI-NETs share many features including histological aspects; over-/ectopic expression of somatostatin receptors; the ability to ectopically secrete hormones/peptides/amines which can result in distinct functional syndromes; similar approaches used for tumor localization and some aspects of treatment, it is now generally agreed they should be considered separate. They differ in their pathogenesis, hormonal syndromes produced, many aspects of biological behaviour and most important, in their response to certain anti-tumour treatment (chemotherapy, molecular targeted therapies). In this chapter the clinical features of the different types of pNETs will be considered as well as aspects of their diagnosis and medical treatment of the hormone-excess state. Emphasis will be on controversial areas or recent advances. The other aspects of the management of these tumors (surgery, treatment of advanced disease, tumor localization) are not dealt with here, because they are covered in other chapters in this volume.

Therapy of metastatic pancreatic neuroendocrine tumors (pNETs): recent insights and advances

Neuroendocrine tumors (NETs) [carcinoids, pancreatic neuroendocrine tumors (pNETs)] are becoming an increasing clinical problem because not only are they increasing in frequency, but they can frequently present with advanced disease that requires diagnostic and treatment approaches different from those used in the neoplasms that most physicians are used to seeing and treating. In the past few years there have been numerous advances in all aspects of NETs including: an understanding of their unique pathogenesis; specific classification systems developed which have prognostic value; novel methods of tumor localization developed; and novel treatment approaches described. In patients with advanced metastatic disease these include the use of newer chemotherapeutic approaches, an increased understanding of the role of surgery and cytoreductive methods, the development of methods for targeted delivery of cytotoxic agents, and the development of targeted medical therapies (everolimus, sunitinib) based on an increased understanding of the disease biology. Although pNETs and gastrointestinal NETs share many features, recent studies show they differ in pathogenesis and in many aspects of diagnosis and treatment, including their responsiveness to different therapies. Because of limited space, this review will be limited to the advances made in the management and treatment of patients with advanced metastatic pNETs over the past 5 years.

Cushing's syndrome in multiple endocrine neoplasia type 1

OBJECTIVE

  In patients with multiple endocrine neoplasia type 1 (MEN1), Cushing's syndrome (CS) from endogenous hypercortisolism can result from pituitary, adrenal or other endocrine tumours. The purpose of this study was to characterize the range of presentations of CS in a large series of MEN1 patients.

DESIGN

  Retrospective review of NIH Clinical Center inpatient records over an approximately 40-year period.

PATIENTS

  Nineteen patients (eight males, 11 females) with CS and MEN1.

MEASUREMENTS

  Biochemical, imaging, surgical and pathological findings.

RESULTS

  An aetiology was determined for 14 of the 19 patients with CS and MEN1: 11 (79%) had Cushing's disease (CD) and three (21%) had ACTH-independent CS owing to adrenal tumours, frequencies indistinguishable from sporadic CS. Three of 11 MEN1 patients with CD (27%) had additional non-ACTH-secreting pituitary microadenomas identified at surgery, an incidence 10-fold higher than in sporadic CD. Ninety-one per cent of MEN1 patients with CD were cured after surgery. Two of three MEN1 patients with ACTH-independent CS (67%) had adrenocortical carcinoma. One patient with adrenal cancer and another with adrenal adenoma were cured by unilateral adrenalectomy. No case of ectopic ACTH secretion was identified in our patient cohort. The aetiology of CS could not be defined in five patients; in three of these, hypercortisolism appeared to resolve spontaneously.

CONCLUSIONS

  The tumour multiplicity of MEN1 can be reflected in the anterior pituitary, MEN1-associated ACTH-independent CS may be associated with aggressive adrenocortical disease and an aetiology for CS in MEN1 may be elusive in a substantial minority of patients.

New and emerging syndromes due to neuroendocrine tumors

Neuroendocrine tumors (NETs) are rare, slow-growing neoplasms characterized by their ability to store and secrete different peptides and neuroamines. Some of these substances cause specific clinical syndromes whereas others are not associated with specific syndromes or symptom complexes. NETs usually have episodic expression that makes diagnosis difficult, erroneous, and often late. For these reasons a high index of suspicion is needed, and it is important to understand the pathophysiology of each tumor to decide which biochemical markers are more useful and when they should be used.

Pancreatic endocrine tumors

Pancreatic endocrine tumors have been steadily growing in incidence and prevalence during the last two decades, showing an incidence of 4-5/1,000,000 population. They represent a heterogeneous group with very varying tumor biology and prognosis. About half of the patients present clinical symptoms and syndromes related to substances released from the tumors (Zollinger-Ellison syndrome, insulinoma, glucagonoma, etc) and the other half are so-called nonfunctioning tumors mainly presenting with symptoms such as obstruction, jaundice, bleeding, and abdominal mass. Ten percent to 15% of the pancreatic endocrine tumors are part of an inherited syndrome such as multiple endocrine neoplasia type 1 (MEN-1), von Hippel-Lindau (VHL), neurofibromatosis, or tuberousclerosis. The diagnosis is based on histopathology demonstrating neuroendocrine features such as positive staining for chromogranin A and specific hormones such as gastrin, proinsulin, and glucagon. Moreover, the biochemical diagnosis includes measurement of chromogranins A and B or specific hormones such as gastrin, insulin, glucagon, and vasoactive intestinal polypeptide (VIP) in the circulation. In addition to standard localization procedures, radiology (computed tomography [CT] scan, magnetic resonance imaging [MRI], ultrasound [US]), somatostatin receptor scintigraphy, and most recently positron emission tomography with specific isotopes such as (11)C-5 hydroxytryptamin ((11)C-5-HTP), fluorodopa and (68)Ga-1,4,7,10-tetra-azacyclododecane-N,N',N″,N‴-tetra-acetic acid (DOTA)-octreotate are performed. Surgery is still one of the cornerstones in the management of pancreatic endocrine tumors, but curative surgery is rarely obtained in most cases because of metastatic disease. Debulking and other cytoreductive procedures might facilitate systemic treatment. Cytotoxic drugs, biological agents, such as somatostatin analogs, alpha interferons, mammalian target of rapamycin (mTOR) inhibitors and tyrosine kinase inhibitors are routinely used. Tumor-targeted radioactive treatment is available in many centres in Europe and is effective in patients with tumors that express high content of somatostatin receptors type 2 and 5. In the future, treatment will be based on tumor biology and molecular genetics with the aim of so-called personalized medicine.

NANETS treatment guidelines: well-differentiated neuroendocrine tumors of the stomach and pancreas

Well-differentiated neuroendocrine tumors (NETs) of the stomach and pancreas represent 2 major subtypes of gastrointestinal NETs. Historically, there has been little consensus on the classification and management of patients with these tumor subtypes. We provide an overview of well-differentiated NETs of the stomach and pancreas and describe consensus guidelines for the treatment of patients with these malignancies.

Pancreatic islet cell carcinoma presenting with concurrent Cushing's and Zollinger-Ellison syndromes: case series and literature review

Cushing's syndrome and Zollinger-Ellison syndrome occur occasionally as a result of neuroendocrine cancers. The concurrence of the two syndromes has been considered to confer a poor clinical and therapeutic outcome. In this study, we are reviewing two patients with pancreatic islet cell carcinomas and with both Zollinger-Ellison and Cushing's syndromes, one followed up for more than 5 years, and the other still receiving therapy, 5 years since diagnosis. A literature review showed that surgery has limited utility as the majority of these patients had metastases at the time of diagnosis. Proton-pump inhibitors, ketoconazole, and somatostatin antagonists have a major role in controlling symptoms. Interferon and systemic chemotherapeutic agents play a role in the management of metastatic and fast-growing cases. Chemoembolization and bland embolization show encouraging results in controlling liver metastases. The latter was used effectively and more than once in the two patients presented herein. On the basis of recent molecular genetics studies, target therapy may be helpful, however, ongoing trials will define it's utility. As the data confers a worse prognosis versus other pancreatic neuroendocrine tumors, the relatively favorable outcome of the two patients reported herein may reflect the impact of multiple therapeutic modalities.

Treatment of endocrine pancreatic tumors

Endocrine pancreatic tumors are rare with an incidence of 4 per million inhabitants. Most tumors are malignant except for insulinomas that usually are benign. They are slowly growing in the majority of cases but there are exceptions with rapidly progressing malignant carcinomas. Because of the rarity of these tumors large randomized trials are difficult to accomplish. However, most physicians treating these patients agree that surgery should be considered in all cases and that medical treatment with chemotherapy and biotherapy is well established for this group of patients.

Inherited pancreatic endocrine tumor syndromes: advances in molecular pathogenesis, diagnosis, management, and controversies

Pancreatic endocrine tumors (PETs) can occur as part of 4 inherited disorders, including Multiple Endocrine Neoplasia type 1 (MEN1), von Hippel-Lindau disease (VHL), neurofibromatosis 1 (NF-1) (von Recklinghausen disease), and the tuberous sclerosis complex (TSC). The relative frequency with which patients who have these disorders develop PETs is MEN1>VHL>NF-1>TSC. Over the last few years, there have been major advances in the understanding of the genetics and molecular pathogenesis of these disorders as well in the localization and the medical and surgical treatment of PETs in such patients. The study of PETs in these disorders not only has provided insights into the possible pathogenesis of sporadic PETs but also has presented several unique management and treatment issues, some of which are applicable to patients with sporadic PETs. Therefore, the study of PETs in these uncommon disorders has provided valuable insights that, in many cases, are applicable to the general group of patients with sporadic PETs. In this article, these areas are reviewed briefly along with the current state of knowledge of the PETs in these disorders, and the controversies that exist in their management are summarized briefly and discussed.

Gastrointestinal neuroendocrine tumors: pancreatic endocrine tumors

Pancreatic endocrine tumors (PETs) have long fascinated clinicians and investigators despite their relative rarity. Their clinical presentation varies depending on whether the tumor is functional or not, and also according to the specific hormonal syndrome produced. Tumors may be sporadic or inherited, but little is known about their molecular pathology, especially the sporadic forms. Chromogranin A appears to be the most useful serum marker for diagnosis, staging, and monitoring. Initially, therapy should be directed at the hormonal syndrome because this has the major initial impact on the patient's health. Most PETs are relatively indolent but ultimately malignant, except for insulinomas, which predominantly are benign. Surgery is the only modality that offers the possibility of cure, although it generally is noncurative in patients with Zollinger-Ellison syndrome or nonfunctional PETs with multiple endocrine neoplasia-type 1. Preoperative staging of disease extent is necessary to determine the likelihood of complete resection although debulking surgery often is believed to be useful in patients with unresectable tumors. Once metastatic, biotherapy is usually the first modality used because it generally is well tolerated. Systemic or regional therapies generally are reserved until symptoms occur or tumor growth is rapid. Recently, a number of newer agents, as well as receptor-directed radiotherapy, are being evaluated for patients with advanced disease. This review addresses a number of recent advances regarding the molecular pathology, diagnosis, localization, and management of PETs including discussion of peptide-receptor radionuclide therapy and other novel antitumor approaches. We conclude with a discussion of future directions and unsettled problems in the field.

Multidisciplinary approach including receptor radionuclide therapy with 90Y-DOTATOC ([90Y-DOTA0, Tyr3]-octreotide) and 177Lu-DOTATATE ([177Lu-DOTA0, Tyr3]-octreotate) in ectopic cushing syndrome from a metastatic gastrinoma: a promising proposal

OBJECTIVE

To present a case of a young woman with Cushing syndrome caused by ectopic production of adrenocorticotropic hormone from a metastatic pancreatic gastrin-secreting endocrine carcinoma, who had a good response to combination peptide receptor radionuclide therapy.

METHODS

We review the history, physical examination, laboratory investigations, and radiographic findings in this unusual patient. Moreover, the multimodal interventions are described and discussed.

RESULTS

In a 38-year-old woman with typical signs of cortisol excess, laboratory studies revealed diabetes mellitus, hypokalemia, and high levels of adrenocorticotropic hormone, plasma cortisol, and urinary cortisol. Abdominal computed tomography showed a 4-cm pancreatic mass and multiple metastatic lesions in the liver, and ectopic Cushing syndrome was diagnosed. Treatment consisted of surgical debulking of the tumor, ketoconazole, somatostatin analogues, chemoembolization of the liver metastatic lesions, and peptide receptor radionuclide therapy with the radiolabeled somatostatin analogues 90Y-DOTATOC ([90Y-DOTA0, Tyr3]-octreotide) and 177Lu-DOTATATE ([177Lu-DOTA0, Tyr3]-octreotate). The 5 1/2-year follow-up showed positive results, which included complete regression of all clinical and hormonal evidence of the tumor and substantial decrease in the size and number of hepatic metastatic lesions. The patient achieved and still maintains an optimal quality of life.

CONCLUSION

To the best of our knowledge, this is the first report of a multidisciplinary approach including peptide receptor radionuclide therapy with 90Y-DOTATOC and 177Lu-DOTATATE, which proved to be effective in improving clinical outcome in a case of metastatic endocrine carcinoma of the pancreas in conjunction with ectopic Cushing syndrome. In this unusual case, the patient has one of the longest durations of survival in this setting described in the literature.

Pancreatic endocrine neoplasms: epidemiology and prognosis of pancreatic endocrine tumors

Pancreatic endocrine tumors (PETs) are uncommon tumors with an annual incidence <1 per 100 000 person-years in the general population. The PETs that produce hormones resulting in symptoms are designated as functional. The majority of PETs are non-functional. Of the functional tumors, insulinomas are the most common, followed by gastrinomas. The clinical course of patients with PETs is variable and depends on the extent of the disease and the treatment rendered. Patients with completely resected tumors generally have a good prognosis, and aggressive surgical therapy in patients with advanced disease may also prolong survival. The epidemiology, prognosis, and established and novel prognostic markers of PETs are reviewed.

Mifepristone for ectopic ACTH secretion in metastatic endocrine carcinomas: report of two cases

Ectopic adrenocorticotropin secretion (EAS) remains a therapeutic challenge whenever the tumor responsible for the syndrome is not amenable to curative resection. Two cases of EAS related to metastatic foregut-derived endocrine carcinomas led us to use mifepristone, an antagonist of both progesterone and glucocorticoids. Mifepristone clearly improved skin lesions and diabetes associated with hypercorticism. The beneficial effect lasted for about 10 months. In both cases, recurrent hypertension and hypokalemia eventually required adrenalectomy.

Endocrine pancreatic tumors: diagnosis and treatment

Endocrine pancreatic tumors (EPTs) are uncommon, having an incidence of one per 100,000 people. They may appear as sporadic tumors or be associated with hereditary syndromes. EPTs are categorized as functioning or nonfunctioning tumors, based on the presence or absence of clinical syndromes. Among the former, insulinomas and gastrinomas are the most common. For the histopathological investigation of EPTs, chromogranin A and synaptophysin immunostainings are recommended. Measurement of circulating chromogranin A is also the cornerstone for the biochemical diagnosis of these tumors. Furthermore, specific hormones produced and released by the neoplastic cells can be identified by immunostaining and used for biochemical evaluation. To locate EPTs, both noninvasive (ultrasonography, computerized tomography, MRI and radionuclear imaging) and invasive techniques (arterial stimulation with venous sampling) can be used. Debulking procedures (surgery, radiofrequency ablation, embolization/chemoembolization and liver transplantation) and/or medical treatment (chemotherapy, biotherapy and peptide receptor radionuclide therapy) are the options available for the treatment of EPTs. Understanding the molecular events underlying the pathobiology of EPTs will aid the development of more accurate diagnostic/prognostic markers and give guidance for improved therapeutic modalities.

Serum gastrin in Zollinger-Ellison syndrome: II. Prospective study of gastrin provocative testing in 293 patients from the National Institutes of Health and comparison with 537 cases from the literature. evaluation of diagnostic criteria, proposal of new criteria, and correlations with clinical and tumoral features

In two-thirds of patients with Zollinger-Ellison syndrome (ZES), fasting serum gastrin (FSG) levels overlap with values seen in other conditions. In these patients, gastrin provocative tests are needed to establish the diagnosis of ZES. Whereas numerous gastrin provocative tests have been proposed, only the secretin, calcium, and meal tests are widely used today. Many studies have analyzed gastrin provocative test results in ZES, but they are limited by small patient numbers and methodologic differences. To address this issue, we report the results of a prospective National Institutes of Health (NIH) study of gastrin provocative tests in 293 patients with ZES and compare these data with those from 537 ZES and 462 non-ZES patients from the literature. In 97%-99% of gastrinoma patients, an increase in serum gastrin post secretin (Delta secretin) or post calcium (Delta calcium) occurred. In NIH ZES patients with <10-fold increase in FSG, the sensitivity/specificity of the widely used criteria were as follows: Delta secretin > or =200 pg/mL (83%/100%), Delta secretin >50% (86%/93%), Delta calcium > or =395 pg/mL (54%/100%), and Delta calcium >50% (78%/83%). A systematic analysis of the sensitivity and specificity of other possible criteria for a positive secretin or calcium test allowed us to identify a new criterion for secretin testing (Delta > or =120 pg/mL) with the highest sensitivity/specificity (94%/100%) and to confirm the commonly used criterion for calcium tests (Delta > or =395 pg/mL) (62%/100%). This analysis further showed that the secretin test was more sensitive than the calcium test (94% vs. 62%). Our results suggest that secretin stimulation should be used as the first-line provocative test because of its greater sensitivity and simplicity and lack of side effects. In ZES patients with a negative secretin test, 38%-50% have a positive calcium test. Therefore the calcium test should be considered in patients with a strong clinical suspicion of ZES but a negative secretin test. Furthermore, we found that some clinical (diarrhea, duration of medical treatment), laboratory (basal acid output), and tumoral (size, extent) characteristics correlate with the serum gastrin increase post secretin and post calcium. However, using the proposed criteria, the result of these provocative tests (that is, positive or negative) is minimally influenced by these factors, so secretin and calcium provocative tests are reliable in patients with different clinical, laboratory, and tumor characteristics. A systematic analysis of meal testing showed that 54%-77% of ZES patients have a <50% postprandial serum gastrin increase. However, 9%-20% of ZES patients had a >100% increase post meal, causing significant overlap with antral syndromes. Furthermore, we could not confirm the usefulness of meal tests for localization of duodenal gastrinomas. We conclude that the secretin test is a crucial element in the diagnosis of most ZES patients, the calcium test may be useful in selected patients, but the meal test is not helpful in the management of ZES. For secretin testing, the criterion with the highest sensitivity and specificity is an increase of > or =120 pg/mL, which should replace other criteria commonly used today.

Serum gastrin in Zollinger-Ellison syndrome: I. Prospective study of fasting serum gastrin in 309 patients from the National Institutes of Health and comparison with 2229 cases from the literature

The assessment of fasting serum gastrin (FSG) is essential for the diagnosis and management of patients with the Zollinger-Ellison syndrome (ZES). Although many studies have analyzed FSG levels in patients with gastrinoma, limited information has resulted from these studies because of their small size, different methodologies, and lack of correlations of FSG levels with clinical, laboratory, or tumor features in ZES patients. To address this issue, we report the results of a prospective National Institutes of Health (NIH) study of 309 patients with ZES and compare our results with those of 2229 ZES patients in 513 small series and case reports in the literature. In the NIH and literature ZES patients, normal FSG values were uncommon (0.3%-3%), as were very high FSG levels >100-fold normal (4.9%-9%). Two-thirds of gastrinoma patients had FSG values <10-fold normal that overlap with gastrin levels seen in more common conditions, like Helicobacter pylori infection or antral G-cell hyperplasia/hyperfunction. In these patients, FSG levels are not diagnostic of ZES, and gastrin provocative tests are needed to establish the diagnosis. Most clinical variables (multiple endocrine neoplasia type 1 status, presence or absence of the most common symptoms, prior medical treatment) are not correlated with FSG levels, while a good correlation of FSG values was found with other clinical features (prior gastric surgery, diarrhea, duration from onset to diagnosis). Increasing basal acid output, but not maximal acid output correlated closely with increasing FSG. Numerous tumoral features correlated with the magnitude of FSG in our study, including tumor location (pancreatic > duodenal), primary size (larger > smaller) and extent (liver metastases > local disease). In conclusion, this detailed analysis of FSG in a large number of patients with ZES allowed us to identify important clinical guidelines that should contribute to improved diagnosis and management of patients with ZES.

Endocrine tumours of the pancreas

Endocrine pancreatic tumours (EPTs) are uncommon tumours occurring in approximately 1 in 100,000 of the population, representing 1-2% of all pancreatic neoplasms. Some of the tumours may be part of multiple endocrine neoplasia type one (MEN-1) syndrome or von Hippel-Lindau (vHL) disease. EPTs are classified as functioning or non-functioning tumours on the basis of their clinical manifestation. The biochemical diagnosis of EPT is based on hormones and amines released. Besides specific markers such as insulin, there are also general tumour markers such as chromogranin A, which is the most valuable marker and has been reported to be increased in plasma in 50-80% of patients with EPTs and correlates with tumour burden. The location of endocrine tumours of the pancreas includes different techniques, from endoscopic investigations to scintigraphy (e.g. somatostatin receptor scintigraphy) and positron emission tomography. The medical treatment of endocrine pancreatic tumours consists of chemotherapy, somatostatin analogues and alpha-interferon. None of these can cure a patient with malignant disease. In future, therapy will be custom-made and based on current knowledge of tumour biology and molecular genetics.

Rare endocrine tumours of the GI tract

Functional pancreatic endocrine tumors other than gastrinoma and insulinoma are quite rare. The principles of management include the diagnosis and management of the functional hormonal syndrome, and management of the potentially malignant tumor. Optimally, control of the hormonal syndrome is achieved preoperatively to stabilize the patient status for the operation, however, resection may be an important part of the control of the hormonal syndrome. Ultimately, the only curative treatment for these neoplasms is complete tumour resection, when feasible.

Pancreatic neuroendocrine tumor with ectopic adrenocorticotropin production upon second recurrence

We present a 54-yr-old woman with ectopic corticotropin syndrome caused by a neuroendocrine tumor of the pancreas. At initial presentation, the patient suffered from diarrhea, heartburn, and nonspecific abdominal pain. There was no evidence of Cushing's syndrome. A neuroendocrine tumor in the head of the pancreas with metastases into peripancreatic lymph nodes was diagnosed and completely resected. Fourteen months later, abdominal computed tomography and scintigraphy with (111)In-labeled octreotide suggested relapse of the tumor. The patient again had no evidence of Cushing's syndrome. A second in toto tumor resection was performed. Another 8 months later, the patient developed forgetfulness, depressive episodes, muscle weakness, new-onset hypertension, hypokalemia, plethora, diabetes mellitus, polyuria, and weight loss. Endocrine testing suggested a source of ectopic ACTH production. An octreotide scan showed an intense uptake ventromedial of the left kidney, an area that showed a mass lateral of the superior mesenteric artery on abdominal magnetic resonance imaging. A complete pancreatectomy with splenectomy and left-sided adrenalectomy were performed. At this second relapse, this neuroendocrine tumor clinically had changed its hormonal profile. Immunohistochemically, in contrast to primary tumor and first relapse, we found strong immunostaining for ACTH in tumor cells of the second relapse and a MIB-1 index greater than 20%. To our knowledge, this is the first report describing a pancreatic neuroendocrine tumor that started to secrete ACTH de novo at the time of the second relapse after two former complete tumor resections. This case underscores the pluripotency of neuroendocrine tumor cells and the importance of keeping in mind a possible shift in hormone production during tumor evolution and progression.

The diagnosis and medical management of advanced neuroendocrine tumors

Neuroendocrine tumors (NETs) constitute a heterogeneous group of neoplasms that originate from endocrine glands such as the pituitary, the parathyroids, and the (neuroendocrine) adrenal, as well as endocrine islets within glandular tissue (thyroid or pancreatic) and cells dispersed between exocrine cells, such as endocrine cells of the digestive (gastroenteropancreatic) and respiratory tracts. Conventionally, NETs may present with a wide variety of functional or nonfunctional endocrine syndromes and may be familial and have other associated tumors. Assessment of specific or general tumor markers offers high sensitivity in establishing the diagnosis and can also have prognostic significance. Imaging modalities include endoscopic ultrasonography, computed tomography and magnetic resonance imaging, and particularly, scintigraphy with somatostatin analogs and metaiodobenzylguanidine. Successful treatment of disseminated NETs requires a multimodal approach; radical tumor surgery may be curative but is rarely possible. Well-differentiated and slow-growing gastroenteropancreatic tumors should be treated with somatostatin analogs or alpha-interferon, with chemotherapy being reserved for poorly differentiated and progressive tumors. Therapy with radionuclides may be used for tumors exhibiting uptake to a diagnostic scan, either after surgery to eradicate microscopic residual disease or later if conventional treatment or biotherapy fails. Maintenance of the quality of life should be a priority, particularly because patients with disseminated disease may experience prolonged survival.

Multiple endocrine neoplasia type 1 and Zollinger-Ellison syndrome: a prospective study of 107 cases and comparison with 1009 cases from the literature

In patients with multiple endocrine neoplasia type 1 (MEN1), the most common functional pancreatic endocrine tumor (PET) syndrome is Zollinger-Ellison syndrome (ZES). ZES has been well studied in its sporadic form (that is, without MEN1); however, there are limited data on patients with MEN1 and ZES (MEN1/ZES), and the long-term natural history is largely unknown. To address this issue we report the results of a prospective long-term National Institutes of Health (NIH) study of 107 MEN1/ZES patients and compare our results with those of 1009 MEN1/ZES patients in 278 case reports and small series in the literature. Patients were clinically, radiologically, and biochemically evaluated yearly for all MEN1 manifestations (mean follow-up, 10 yr; range, 0.1-31 yr). Compared with patients from the literature, the NIH MEN1/ZES patients more frequently had pituitary (60%) and adrenal (45%) disease and carcinoid tumors (30%), but had equal frequency of hyperparathyroidism (94%), thyroid disease (6%), or lipomas (5%). Twenty-five percent of both the NIH and the literature patients lacked a family history of MEN1; ZES was the initial clinical manifestation of MEN1 in 40%. ZES onset preceded the diagnosis of hyperparathyroidism in 45%. However, ZES was rarely (8%) the only initial manifestation of MEN1 if careful testing was done. ZES occurred before age 40 years in 50%-60% of the current patients, in contrast to older studies. The diagnosis of ZES is delayed 3-5 years from its onset and is delayed as long as in sporadic ZES cases. Pituitary disease and carcinoid tumors (gastric > bronchial, thymic) are more frequent than generally reported, whereas a second functional PET is uncommon. In patients with MEN1/ZES without a family history of MEN1, the MEN1 manifestations are not as severe. This study shows that MEN1/ZES patients differ in many aspects from those commonly reported in older studies involving few MEN1/ZES patients. In this study we have identified a number of important clinical and laboratory features of MEN1/ZES that were not previously appreciated, which should contribute to earlier diagnosis and improve both short- and long-term management.

Gastric secretion in Zollinger-Ellison syndrome. Correlation with clinical expression, tumor extent and role in diagnosis--a prospective NIH study of 235 patients and a review of 984 cases in the literature

We prospectively studied 235 patients with Zollinger-Ellison syndrome (ZES) (205 without and 30 with prior acid-reducing surgery) and compared the results with 984 patients from 182 reports in the literature. The aims of the study were to evaluate the sensitivity of proposed acid secretory criteria for the diagnosis of ZES, propose new criteria, evaluate the variability and methodology of gastric secretory testing, and correlate the symptoms and signs of ZES, tumor extent, and primary tumor size and location with the degree of gastric acid hypersecretion. Multiple endocrine neoplasia-type 1 (MEN1) occurred in 22% of patients. The mean basal acid output (BAO) in patients without and with prior acid-reducing surgery was 41.2 +/- 1.7 mEq/hr (range, 1.6-118.3 mEq/hr) and 27.6 +/- 3.5 mEq/hr (range 5.9-102.9 mEq/hr), respectively. In patients with MEN1, those with female gender, Hispanic, or Asian race had lower BAOs. Diarrhea, esophageal stricture, and pyloric scarring were associated with a higher BAO. Neither other symptoms nor the tumor extent, primary tumor location, or size correlated with the magnitude of acid hypersecretion. ZES diagnosis was delayed a mean of 5.5 +/- 0.4 yr. Patients who were misdiagnosed as having either Crohn or celiac disease had higher BAOs. The sensitivities from our study and the literature review of the proposed BAO criteria for the diagnosis of ZES in patients without previous gastric acid-reducing surgery were 91% and 90% for BAO > or = 15 mEq/hr, 86% and 82% for BAO > or = 18 mEq/hr, 69% and 67% for BAO > 25 mEq/hr, and < 60% for BAO > 31 mEq/hr, respectively. The specificities of all the proposed BAO criteria were high. Both the criterion of BAO > or = 15 mEq/hr and BAO > or = 18 mEq/hr had good specificities and equal sensitivity. With prior acid-reducing surgery, the sensitivities in our study and from the literature review were 100% and 81% for BAO > or = 5 mEq/hr, 73% and 45% for BAO > 14.4 mEq/hr, and 37% and 31% for BAO > 19.2 mEq/hr, respectively. The reported mean specificity for the criterion of BAO > or = 5 mEq/hr was 85%, while it was 100% for the other 2 criteria. The maximal acid output (MAO) criterion of > 70 mEq/hr had sensitivities in the present National Institutes of Health (NIH) study and the literature review of 39% and 31%, respectively, and the criterion of MAO > 100 mEq/hr had a sensitivity of < 15% in patients with no prior acid-reducing surgery. The proposed criterion of BAO/MAO ratio > 0.6 had a low sensitivity. The proposed criterion of the ratio of basal and maximal acid H+ concentration (BAC/MAC ratio) > or = 0.6 had an excellent sensitivity-- > or = 89% in patients with or without previous acid-reducing surgery. The reported specificity for both the BAO/MAO criterion and the BAC/MAC criterion were similar, but BAC/MAC had a better sensitivity. Combination criteria of BAO generally did not improve sensitivity. The criterion of pH < or = 1 was met by only 27% of patients, and pH < or = 0.96 by 21% of patients with previous acid-reducing surgery. For patients with MEN1 with no prior acid-reducing surgery, the sensitivities were lower compared with patients with the sporadic form of ZES. The mean gastric volume in patients without prior acid-reducing surgery was 314 +/- 10 mL/hr and 247 +/- 25 mL/hr in patients with prior acid-reducing surgery. A basal volume criteria of > 160 mL/hr in patients without prior acid-reducing surgery occurred in > 86% of patients, and > 140 mL/hr in 87% of patients with prior acid-reducing surgery; these, thus, are neglected findings that have good sensitivities. Our analysis shows criteria based on MAO, pH, and BAO/MAO ratio do not have high sensitivities and thus are not useful. In patients without prior acid-reducing surgery, the criteria of BAO > or = 15 mEq/hr, BAC/MAC ratio > or = 0.6, and basal gastric volume > 160 mL/hr are useful for the diagnosis of ZES and have good specificities. In patients with prior acid-reducing surgery, the criteria of BAO > or = 5 mEq/hr, BAC/MAC ratio > or = 0.6, and basal gastric volume > 140 mL/hr have high sensitivities. In patients with sporadic ZES without acid-reducing surgery, the criterion of BAO > or = 18 mEq/hr is recommended as it has a similar sensitivity but higher specificity than the criterion of BAO > or = 15 mEq/hr. Only 1 patient in either data set (NIH or the literature) with or without previous acid-reducing surgery had a basal gastric pH > 2, therefore this finding essentially excludes the diagnosis of ZES. Gastric secretory measurements for 30 minutes, but not 15 minutes, give results comparable to those for a full hour. On the basis of these results, a number of gastric secretory criteria are proposed, including some for the first time, and alterations in methodology are proposed that should prove useful in the diagnosis of ZES.