Management of the Zollinger-Ellison syndrome in patients with multiple endocrine neoplasia type 1

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.

Towards Understanding of Gastric Cancer Based upon Physiological Role of Gastrin and ECL Cells

Simple Summary

Generally, we know that cancers represent genetic changes in tumour cells, but we most often do not know the causes of cancers or how they develop. Our knowledge of the regulation of gastric acid secretion is well known, with the gastric hormone gastrin maintaining gastric acidity by stimulation of the enterochromaffin-like (ECL) cell to release histamine, which subsequently augments acid secretion. Furthermore, it seems to be a general principle that stimulation of function (which, for the ECL cell, is release of histamine) in a parallel way stimulates the proliferation of the same cell. Long-term hyperstimulation of cell division predisposes to genetic changes and, thus, development of tumours. All conditions with reduced gastric acidity result in an increased risk of gastric tumours due to elevated gastrin in order to restore gastric acidity. It is probable that Helicobacter pylori infection (the most important cause of gastric cancer), as well as drugs inhibiting gastric acid secretion induce gastric cancer in the long-term, due to an elevation of gastrin caused by reduced gastric acidity. Gastric carcinomas have been shown to express ECL cell markers, further strengthening this relationship.

Abstract

The stomach is an ideal organ to study because the gastric juice kills most of the swallowed microbes and, thus, creates rather similar milieu among individuals. Combined with a rather easy access to gastric juice, gastric physiology was among the first areas to be studied. During the last century, a rather complete understanding of the regulation of gastric acidity was obtained, establishing the central role of gastrin and the histamine producing enterochromaffin-like (ECL) cell. Similarly, the close connection between regulation of function and proliferation became evident, and, furthermore, that chronic overstimulation of a cell with the ability to proliferate, results in tumour formation. The ECL cell has long been acknowledged to give rise to neuroendocrine tumours (NETs), but not to play any role in carcinogenesis of gastric adenocarcinomas. However, when examining human gastric adenocarcinomas with the best methods presently available (immunohistochemistry with increased sensitivity and in-situ hybridization), it became clear that many of these cancers expressed neuroendocrine markers, suggesting that some of these tumours were of neuroendocrine, and more specifically, ECL cell origin. Thus, the ECL cell and its main regulator, gastrin, are central in human gastric carcinogenesis, which make new possibilities in prevention, prophylaxis, and treatment of this cancer.

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

This article is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The guidelines panel consisted of medical oncologists, pathologists, gastroenterologists, endocrinologists, and radiologists. The panel reviewed a series of questions regarding the medical management of patients with pancreatic neuroendocrine tumors as well as questions regarding surveillance after resection. The available literature was reviewed for each of the question and panel members voted on controversial topics, and the recommendations were included in a document circulated to all panel members for a final approval.

Surgical management of pancreatic neuroendocrine tumors: an introduction

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

Insights into Effects/Risks of Chronic Hypergastrinemia and Lifelong PPI Treatment in Man Based on Studies of Patients with Zollinger-Ellison Syndrome

The use of proton pump inhibitors (PPIs) over the last 30 years has rapidly increased both in the United States and worldwide. PPIs are not only very widely used both for approved indications (peptic ulcer disease, gastroesophageal reflux disease (GERD), Helicobacter pylori eradication regimens, stress ulcer prevention), but are also one of the most frequently off-label used drugs (25–70% of total). An increasing number of patients with moderate to advanced gastroesophageal reflux disease are remaining on PPI indefinitely. Whereas numerous studies show PPIs remain effective and safe, most of these studies are <5 years of duration and little data exist for >10 years of treatment. Recently, based primarily on observational/epidemiological studies, there have been an increasing number of reports raising issues about safety and side-effects with very long-term chronic treatment. Some of these safety issues are related to the possible long-term effects of chronic hypergastrinemia, which occurs in all patients taking chronic PPIs, others are related to the hypo-/achlorhydria that frequently occurs with chronic PPI treatment, and in others the mechanisms are unclear. These issues have raised considerable controversy in large part because of lack of long-term PPI treatment data (>10–20 years). Zollinger–Ellison syndrome (ZES) is caused by ectopic secretion of gastrin from a neuroendocrine tumor resulting in severe acid hypersecretion requiring life-long antisecretory treatment with PPIs, which are the drugs of choice. Because in <30% of patients with ZES, a long-term cure is not possible, these patients have life-long hypergastrinemia and require life-long treatment with PPIs. Therefore, ZES patients have been proposed as a good model of the long-term effects of hypergastrinemia in man as well as the effects/side-effects of very long-term PPI treatment. In this article, the insights from studies on ZES into these controversial issues with pertinence to chronic PPI use in non-ZES patients is reviewed, primarily concentrating on data from the prospective long-term studies of ZES patients at NIH.

Clinical Features of Multiple Endocrine Neoplasia Type 4: Novel Pathogenic Variant and Review of Published Cases

CONTEXT

The clinical phenotype of multiple endocrine neoplasia type 4 (MEN4) is undefined due to a limited number of published cases. Knowledge on disease manifestation in MEN4 is essential for developing prevention programs and treatment.

OBJECTIVE

To expand current knowledge of the MEN4 phenotype including assessment of penetrance.

DESIGN

This is a case report and a brief review of previously published MEN4 cases.

PATIENTS

We report a large Danish family with multiple cases of endocrine tumors that segregated with a pathogenic variant in the CDKN1B gene.

MAIN OUTCOME/RESULT

The medical history of the proband included primary hyperparathyroidism and Cushing disease. Genetic analysis identified a pathogenic variant in CDKN1B (c.121_122delTT, p.Leu41Asnfs*83). Among the family members, another 12 individuals were identified as carriers of the same variant, which segregated with development of endocrine tumors. Hypercalcemia due to primary hyperparathyroidism occurred in all 13 of the available carriers of the genetic variant, and 4 patients also had functioning or nonfunctioning pituitary adenomas, whereas 1 patient had a metastatic neuroendocrine tumor (carcinoid). Loss-of-heterozygosity was detected in two of five parathyroid adenomas, supporting that CDKN1B acts as a tumor suppressor gene. Thirty cases representing 16 different CDKN1B variants have previously been reported, and these cases presented primarily with primary hyperparathyroidism and functioning and nonfunctioning pituitary tumors.

CONCLUSION

Hypercalcemia due to primary hyperparathyroidism and pituitary tumors are common in MEN4. Gastrointestinal neuroendocrine tumors appear to be less prevalent in MEN4 than in MEN1.

Duodenal neuroendocrine neoplasms: a still poorly recognized clinical entity

BACKGROUND

Duodenal neuroendocrine neoplasms (dNENs) are rare tumors, which usually show good prognosis. The optimal management of these tumors is still far from being clearly understood because of their rarity and the poor level of knowledge about their natural history. Herein, we have reviewed the literature on dNENs to collect and analyze the current data on epidemiology, diagnosis and management of these rare tumors.

METHODS

Bibliographical searches were performed in PubMed, using the following keywords: duodenal neuroendocrine neoplasm; duodenum; gastrinoma; diagnosis; therapy; guidelines. We searched for all relevant articles published over the last 15 years. Non-English language papers were excluded.

RESULTS

We reviewed the pertinent articles about dNENs. Upper gastrointestinal endoscopy with biopsy is the cornerstone of the dNENs diagnostic process. Endoscopic ultrasound with fine-needle aspiration/biopsy should be performed in order to locally stage the disease and in all cases of non-diagnostic endoscopy. Endoscopic or complete surgical removal of the primary lesion is the recommended treatment and is generally achievable for the majority of the patients. A less aggressive approach may be suggested for well-differentiated low-stage tumors. After NEN removal, patients should be closely followed-up especially during the first 3 years by endoscopic examination, imaging tests and CgA measurements.

CONCLUSIONS

The multi-disciplinary approach and the preservation of the quality of life of the patients play a key role in the therapeutic process for dNENs. Further studies are needed to better define standardized guidelines specific to dNENs, including optimal management approaches and follow-up intervals.

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.

Current and emerging therapies for PNETs in patients with or without MEN1

Pancreatic neuroendocrine tumours (PNETs) might occur as a non-familial isolated endocrinopathy or as part of a complex hereditary syndrome, such as multiple endocrine neoplasia type 1 (MEN1). MEN1 is an autosomal dominant disorder characterized by the combined occurrence of PNETs with tumours of the parathyroids and anterior pituitary. Treatments for primary PNETs include surgery. Treatments for non-resectable PNETs and metastases include biotherapy (for example, somatostatin analogues, inhibitors of receptors and monoclonal antibodies), chemotherapy and radiological therapy. All these treatments are effective for PNETs in patients without MEN1; however, there is a scarcity of clinical trials reporting the efficacy of the same treatments of PNETs in patients with MEN1. Treatment of PNETs in patients with MEN1 is challenging owing to the concomitant development of other tumours, which might have metastasized. In recent years, preclinical studies have identified potential new therapeutic targets for treating MEN1-associated neuroendocrine tumours (including PNETs), and these include epigenetic modification, the β-catenin-wingless (WNT) pathway, Hedgehog signalling, somatostatin receptors and MEN1 gene replacement therapy. This Review discusses these advances.

Severe chronic diarrhoea secondary to primary lymph node gastrinoma

The existence of primary lymph node (LN) gastrinoma is questionable and controversial. In fact, the presence of gastrinoma in such uncommon site raises the possibility of metastasis from another occult primary site. An extensive evaluation and careful follow-up is always warranted. A female aged 48 years presented with chronic abdominal pain and watery diarrhoea. Her serum gastrin and chromogranin were elevated, and an underlying gastrinoma was suspected. Further evaluation with an octreotide scan, an endoscopic ultrasound and a secretin stimulation test confirmed the diagnosis. Further evaluation for multiple endocrine neoplasia-1 syndrome was negative. She underwent a surgical enucleation near the head of the pancreas. No other lesions were found after careful exploration of the gastrinoma triangle. Histology showed a LN with a neuroendocrine tumour that tested positively with gastrin and chromogranin stains. Her symptoms resolved postoperatively, her serum gastrin normalised and a repeated octreotide scan was negative.

Complicated Case Presentation: Management of Pancreatic Neuroendocrine Tumors in Multiple Endocrine Neoplasia Type 1

Multiple endocrine neoplasia type 1 (MEN1) is an inherited predisposition to tumors of the parathyroid glands, anterior pituitary, and pancreatic islet cells. In this review, we discuss the clinical case of a 45-year-old woman with MEN1 that was presented at the 2015 North American Neuroendocrine Tumor Society Symposium. In our review of this patient's complicated clinical course and subsequent operative management, we highlight controversies in the diagnosis and management of pancreatic neuroendocrine tumors in MEN1. In particular, this case illustrates the lack of consensus regarding the optimal biochemical and radiologic screening for pancreatic neuroendocrine tumors and absence of guidelines about the appropriate surgical approach for treatment. We review these controversies and discuss possible approaches to management.

Pancreatic neuroendocrine tumors: contemporary diagnosis and management

Pancreatic neuroendocrine tumors (PNETs) are neoplasms that arise from the hormone producing cells of the islets of Langerhans, also known as pancreatic islet cells. PNETs are considered a subgroup of neuroendocrine tumors, and have unique biology, natural history and clinical management. These tumors are classified as 'functional' or 'non-functional' depending on whether they release peptide hormones that produce specific hormone- related symptoms, usually in established patterns based on tumor subtype. This manuscript will review pancreatic neuroendocrine tumor subtypes, syndromes, diagnosis, and clinical management.

Weight Gain in Zollinger-Ellison Syndrome After Acid Suppression

OBJECTIVES

Zollinger-Ellison syndrome (ZES) is characterized by hypergastrinemia and gastric acid hypersecretion resulting in peptic ulcer disease, diarrhea, and weight loss. Acid secretion can be controlled with medication, and biochemical cure is possible with surgery. Data on how these interventions affect patients' weight are lacking. We aimed to determine how medical and surgical acid control affects weight over time.

METHODS

We performed a retrospective cohort study on 60 ZES patients. Acid control was achieved with appropriate-dose proton pump inhibitor (PPI) therapy. Surgery was performed for curative intent when appropriate. Weight change was assessed versus pre-acid control or immediate preoperative weights and expressed as absolute and percent change from baseline at 6, 12, 18, and 24 months.

RESULTS

A total of 30 PPI-controlled patients and 20 surgery-controlled patients were analyzed. Weight gain was noted at all time points while on appropriate-dose PPI therapy (P < 0.005). Of patients who had surgery with curative intent, weight gain was noted at 12 months (7.9%, P = 0.013) and 18 months (7.1%, P = 0.007). There was a trend toward weight gain seen at all time points in the patients who were surgically cured.

CONCLUSIONS

These data represent a novel description of weight gain after acid suppression in ZES.

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.

Multiple Endocrine Neoplasia: Genetics and Clinical Management

Early diagnosis of multiple endocrine neoplasia (MEN) syndromes is critical for optimal clinical outcomes; before the MEN syndromes can be diagnosed, they must be suspected. Genetic testing for germline alterations in both the MEN type 1 (MEN1) gene and RET proto-oncogene is crucial to identifying those at risk in affected kindreds and directing timely surveillance and surgical therapy to those at greatest risk of potentially life-threatening neoplasia. Pancreatic, thymic, and bronchial neuroendocrine tumors are the leading cause of death in patients with MEN1 and should be aggressively considered by at least biannual computed tomography imaging.

Hypergastrinemia

Gastrin is an important hormone of the digestive system, which assists gastric acid secretion. It may be pathologically elevated in conditions such as Zollinger-Ellison syndrome, or due to common medications such as proton pump inhibitors. In this review we provide an overview of the pathophysiology and medical causes of hypergastrinemia, diagnostic testing and clinical consequences of chronic hypergastrinemia.

Thoracic and duodenopancreatic neuroendocrine tumors in multiple endocrine neoplasia type 1: natural history and function of menin in tumorigenesis

Mutations of the multiple endocrine neoplasia type 1 (MEN1) gene lead to loss of function of its protein product menin. In keeping with its tumor suppressor function in endocrine tissues, the majority of the MEN1-related neuroendocrine tumors (NETs) show loss of heterozygosity (LOH) on chromosome 11q13. In sporadic NETs, MEN1 mutations and LOH are also reported, indicating common pathways in tumor development. Prevalence of thymic NETs (thNETs) and pulmonary carcinoids in MEN1 patients is 2-8%. Pulmonary carcinoids may be underreported and research on natural history is limited, but disease-related mortality is low. thNETs have a high mortality rate. Duodenopancreatic NETs (dpNETs) are multiple, almost universally found at pathology, and associated with precursor lesions. Gastrinomas are usually located in the duodenal submucosa while other dpNETs are predominantly pancreatic. dpNETs are an important determinant of MEN1-related survival, with an estimated 10-year survival of 75%. Survival differs between subtypes and apart from tumor size there are no known prognostic factors. Natural history of nonfunctioning pancreatic NETs needs to be redefined because of increased detection of small tumors. MEN1-related gastrinomas seem to behave similar to their sporadic counterparts, while insulinomas seem to be more aggressive. Investigations into the molecular functions of menin have led to new insights into MEN1-related tumorigenesis. Menin is involved in gene transcription, both as an activator and repressor. It is part of chromatin-modifying protein complexes, indicating involvement of epigenetic pathways in MEN1-related NET development. Future basic and translational research aimed at NETs in large unbiased cohorts will clarify the role of menin in NET tumorigenesis and might lead to new therapeutic options.

Zollinger-Ellison syndrome: classical considerations and current controversies

Zollinger-Ellison syndrome (ZES) is an endocrinopathy characterized by gastrin-secreting tumors, responsible for causing the formation of multiple, refractory, and recurrent peptic ulcers in the distal duodenum and proximal jejunum. Two main variants have been described, sporadic and those found in association with parathyroid and pituitary tumors, a genetic disorder known as multiple endocrine neoplasia-1 (MEN-1). Biochemical serum evaluation for elevated gastrin, followed by radiological or nuclear localization of the primary lesion, is mandated for establishing diagnosis. The mainstays of treatment include management of hypersecretory state with medical suppression of gastric acid production and surgical resection of primary tumor for the prevention of malignant transformation and metastatic complications. Medical therapy with proton pump inhibitors has virtually eliminated the need for acid-reducing surgical procedures. Surgical approach to sporadic and MEN-1-associated ZES varies based on our understanding of the natural history of the condition and the probability of cure; however, resection to a negative microscopic margin is indicated in both cases. Postoperative surveillance involves measurement of gastrin level, followed by imaging if elevation is detected. Re-excision of recurrent or resection of metastatic disease is a subject of controversy; however, at the present time aggressive cytoreductive approach is favored.

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.

[New considerations in the surgical treatment of pancreatic neuroendocrine tumours]

Except insulinomas, pancreatic neuroendocrine tumours are malignant in more than 50% of cases. Treatment of these tumours should be directed against the tumours and the excess of hormones produced by the tumours. Surgical treatment may reduce the mortality and morbidity of patients and, in case of localized lesions, may result in a definitive cure. The aim of this review is to summarize novel developments in the surgical treatment of pancreatic neuroendocrine tumours, including those related to metastatic diseases and MEN1 syndrome.

Gastric carcinoids (neuroendocrine neoplasms)

Gastric neuroendocrine neoplasms of the stomach can be divided into the usually well-differentiated, hypergastrinemia-dependent type I and II lesions and the more aggressively behaving gastrin-independent type III lesions. Studying menin and its complex interrelationship with gastrin may provide insight into tumor biology at the clinical level and in terms of basic cell biology (eg, the role of the epigenome in neuroendocrine cell proliferation), and lead to potential consideration of other targets that are known candidates for molecular-based therapies in other adenocarcinomas.

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.

Practical guide to supportive care of patients with functional neuroendocrine tumors

Supportive care of patients with functional neuroendocrine tumors (NETs) has evolved to include the use of multiple targeted agents to control paraneoplastic states and newer surgical and interventional radiologic techniques to reduce tumor bulk. Challenges encountered by the clinician are the recognition of specific symptom complexes, selecting the relevant laboratory tests and radiologic/scintigraphic scans, and the timing of intervention(s). Individual variables such as the severity of symptoms in the context of primary and metastatic disease sites, tumor bulk, comorbidities, and previous treatment are factors determining the prioritization of specific treatment regimens for patients with functional NETs. Symptoms such as flushing, secretory diarrhea, hypercalcemia, hyper /hypoglycemia, hypercortisolism, and peptic ulcers should improve with decreasing the elevated amino acid and/or peptide levels produced by NETs. These paraneoplastic symptoms may be accompanied by complaints related to tumor burden such as fatigue, pain, early satiety, anorexia, weight loss, night sweats, and/or symptoms secondary to adverse drug effects such as mucositis, dysgeusia, diarrhea, rash, hypertension, and myelosuppression. Developing a comprehensive continuum of care plan early in disease management assists in controlling the presenting signs and symptoms, and in minimizing disease- and/or treatment-related side effects. This guide serves as a framework to manage the signs and symptoms of metastatic functional neuroendocrine tumors.

Lymph nodes metastasis and recurrences justify an aggressive treatment of gastrinoma

In the current study, short- and long-term outcomes after aggressive surgical treatment for gastrinoma were evaluated. From August 1990 to August 2009, 20 patients diagnosed with Zollinger Ellison syndrome were reviewed. Eleven pancreaticoduodenectomies, three total pancreatectomies, four lymph node dissections, four enucleations and two palliative procedures were performed. Four (27.8 %) patients had disease associated with MEN1 syndrome, 13 (72.2 %) had sporadic gastrinomas (SG) and 3 had disease of unknown primary origin. No in-hospital mortality was observed. After radical resection, lymph node metastasis was present in 82 % of the cases. Eight percent of patients who underwent radical resection developed recurrence compared with 100 % of those who underwent enucleoresection (p = 0.03). Average time to recurrence in patients with sporadic gastrinoma was 66.7 months (confidence interval (CI) 62.9-70.5) in those treated with enucloeresection compared to 181.1 months (CI 124.3-237.8) in the radical resection group (p = 0.007). One recurrence was observed in the MEN1 group. Based on post-operative mortality, recurrence and lymph node metastasis, our data suggest that patients with gastrinoma should undergo abdominal exploration with aggressive resection of the primary tumour and regional lymph nodes in place of conservative treatment.

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.

Management of gastric carcinoids (neuroendocrine neoplasms)

Gastric neuroendocrine neoplasms of the stomach can be divided into the usually well-differentiated, hypergastrinemia-dependent type I and II lesions and the more aggressively behaving gastrin-independent type III lesions. Mainly due to better diagnostics and awareness of this tumor, the observed incidence has increased more than tenfold over the last 30 years. Small (<15-20 mm) localized type I and II lesions that are slowly proliferating (Ki67<2%) can usually be managed conservatively with endoscopic surveillance. Reducing hypergastrinemia by surgical removal of an underlying gastrinoma is important in inhibiting growth and induce reduction of type II lesions, while the specific gastrin receptor antagonist YF476 or gastrin antibodies may become useful for both type I and II lesions. Infiltrating and metastasized tumors and type III lesions require a more aggressive approach with surgical resection and consideration of modalities such as somatostatin analogs, cytotoxics, and peptide receptor targeted treatment.

Gastric and duodenal neuroendocrine tumours

Gastric neuroendocrine neoplasms (NENs) are increasing in frequency and have a varied spectrum with regard to histology, clinicopathologic background, stage, and prognosis. They are usually discovered incidentally, are for the most part benign and are associated with hypergastrinaemia (secondary either to chronic atrophic gastritis or rarely Zollinger-Ellison syndrome; types 1 and 2, respectively) or more rarely sporadic type 3. Applications of recent staging and grading systems - namely using Ki-67 proliferative indices - (from ENETS and WHO 2010) can be particularly helpful in further categorising these tumours. The natural history of Type 1 gastric carcinoids is generally (>95%) favourable and simple surveillance is usually recommended for small (<1 cm) T1 tumours, with local (endoscopic or surgical) resection for larger lesions. Other potential therapies such as somatostatin analogues and gastrin receptor antagonists may offer newer therapeutic possibilities. Rarely, gastric NENs have a malignant course and this is usually confined to Type 2 and especially Type 3 tumours; the latter mimic the biological course of gastric adenocarcinoma and require radical oncological therapies. Most duodenal NENs, apart from gastrinomas (that are not dealt with here) are sporadic and non functional. They are also increasing in frequency probably due to incidental discovery at endoscopy or imaging for other reasons and this may account for their overall good prognosis. Peri-ampullary and ampullary NENs may have a more aggressive outcome and should be carefully appraised and treated (often with surgical resection).

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.

Diagnosis of Zollinger-Ellison syndrome: Increasingly difficult

In the present paper the increasing difficulty of diagnosis of Zollinger-Ellison syndrome (ZES) due to issues raised in two recent papers is discussed. These issues involve the difficulty and need to withdraw patients suspected of ZES from treatment with Proton Pump Inhibitors (omeprazole, esomeprazole, lansoprazole, rabeprazole, pantoprazole) and the unreliability of many gastrin radioimmunoassays. The clinical context of each of these important issues is reviewed and the conclusions in these articles commented from the perspective of clinical management.

MEN1 gene replacement therapy reduces proliferation rates in a mouse model of pituitary adenomas

Multiple endocrine neoplasia type 1 (MEN1) is characterized by the combined occurrence of pituitary, pancreatic, and parathyroid tumors showing loss of heterozygosity in the putative tumor suppressor gene MEN1. This gene encodes the protein menin, the overexpression of which inhibits cell proliferation in vitro. In this study, we conducted a preclinical evaluation of MEN1 gene therapy in pituitary tumors of Men1(+/-) mice, using a recombinant nonreplicating adenoviral serotype 5 vector that contained the murine Men1 cDNA under control of a cytomegalovirus promoter (Men1.rAd5). Pituitary tumors in 55 Men1(+/-) female mice received a transauricular intratumoral injection of Men1.rAd5 or control treatments, followed by 5-bromo-2-deoxyuridine (BrdUrd) in drinking water for four weeks before magnetic resonance imaging (MRI) and immunohistochemical analysis. Immediate procedure-related and 4-week mortalities were similar in all groups, indicating that the adenoviral gene therapy was not associated with a higher mortality. Menin expression was higher in the Men1.rAd5-treated mice when compared with other groups. Daily proliferation rates assessed by BrdUrd incorporation were reduced significantly in Men1.rAd5-injected tumors relative to control-treated tumors. In contrast, apoptotic rates, immune T-cell response, and tumor volumes remained similar in all groups. Our findings establish that MEN1 gene replacement therapy can generate menin expression in pituitary tumors, and significantly reduce tumor cell proliferation.

Gastroenteropancreatic neuroendocrine tumors in multiple endocrine neoplasia type 1

We reviewed the literature about entero-pancreatic neuroendocrine tumors in Multiple Endocrine Neoplasia type 1 syndrome (MEN1) to clarify their demographic features, localization imaging, practice, and appropriate therapeutical strategies, analyzing the current approach to entero-pancreatic neuroendocrine tumors in MEN1. Despite the fact that hyperparathyroidism is usually the first manifestation of MEN1, the penetrance of these tumors is similar. They are characterized by multiplicity of lesions, variable expression of the tumors, and propensity for malignant degeneration. Both the histological type and the size of MEN1 neuroendocrine tumors correlate with malignancy. Monitoring of pancreatic peptides and use of imaging exams allow early diagnosis and prompt surgical treatment, resulting in prevention of metastatic disease and improvement of long-term survival. Surgery is often the treatment of choice for MEN1-neuroendocrine tumors. The rationale for surgical approach is to curtail malignant progression of the disease, and to cure the associated biochemical syndrome, should it be present.

Pancreatic endocrine tumors in multiple endocrine neoplasia type 1 syndrome: review of literature

OBJECTIVE

To analyze the surgical approach to multiple endocrine neoplasia type 1 (MEN 1)-related pancreatic endocrine tumors (PETs).

METHODS

We reviewed selected publications and our personal experience with MEN 1-associated PETs to delineate their general characteristics, current practice and controversies, preoperative imaging and intraoperative assessment, and appropriate therapeutic strategies including radical surgical procedures.

RESULTS

The penetrance of PETs in the setting of MEN 1 is similar to that of parathyroid tumors, even though hyperparathyroidism is usually the first manifestation of MEN 1 syndrome. In contrast with the sporadic counterparts, MEN 1-related PETs are characterized by an early onset, multiplicity of lesions, variable expression of the tumors, and propensity for malignant degeneration. Both the histologic type and the size of these tumors correlate with malignant potential.

CONCLUSION

The rationale for surgical considerations for these tumors is to curtail the malignant progression of the disease and to cure or aid in management of the associated biochemical syndromes. A surgical procedure is often the treatment of choice for PETs in patients with MEN 1. Monitoring of pancreatic peptides and use of diagnostic imaging allow an early pancreatic resection, in conjunction with prevention of metastatic PETs and improvement of long-term survival. Hepatic metastatic lesions can be successfully treated by surgical resection.

Diagnosis and Treatment of Gastrinomas in Multiple Endocrine Neoplasia Type 1 (MEN-1)

Multiple endocrine neoplasia type 1 (MEN-1) is a rare autosomal-dominant disease. It is associated with a broad range of endocrine tumours, most frequently arising in the parathyroid glands, the pituitary and the pancreas. Most neuroendocrine tumours will be diagnosed in the pancreas as non-functioning neuroendocrine tumours or insulinomas. Forty-two percent of the patients will develop a gastrin-secreting neuroendocrine tumour, a gastrinoma. Gastrinomas in MEN-1 tend to be small, multiple and preferentially located in the duodenum. This paper will focus on the specific characteristics of gastrinomas in the setting of MEN-1 compared to sporadic gastrinomas. The developments in understanding the tumorigenesis of these tumours and the consequences for diagnosis and therapy will be discussed.

The current strategy for managing pancreatic neuroendocrine tumors in multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) is an inherited autosomal dominant disease presenting with pancreatic neuroendocrine tumors (pNETs), parathyroid tumors, or pituitary tumors. Using the PubMed database, we reviewed the literature on information regarding the proper diagnosis and treatment of MEN1-associated pNET. Many cases of MEN1-associated pNET are functioning pNETs. Gastrinomas and insulinomas tend to occur frequently in the duodenum and pancreas, respectively. In addition to diagnostic imaging, the selective arterial secretagogue injection test (SASI test) is useful for localizing functioning pNET. The standard treatment is surgical resection. However, in the case of a functioning pNET, the tumor should first be accurately located using the SASI test before an appropriate surgical method is selected. In cases of a MEN1-associated non-functioning pNET that exceeds 2 cm in diameter, the incidence of distant metastasis is significantly increased, and surgery is recommended. In cases of unresectable pNET, a somatostatin analog has been shown to demonstrate antitumor effects and is considered to be a promising treatment. In addition, molecular-targeted drugs have recently been found to be effective in phase III clinical trials.

Surgical treatment of multiple spine metastases from gastrinoma

STUDY DESIGN

 Case report.

CLINICAL QUESTION

 To report successful surgical therapy for spinal cord compression in a patient with spinal metastases from a pancreatic gastrinoma.

METHODS

 A 43-year-old man presented three times within 4 years with cervical and upper thoracic spinal cord compression because of metastatic gastrinoma. He had two previous spine metastases to the lower thoracic and lumbar spine, a T11 compressive lesion which required a T9L1 fusion, and an L4 lesion that was treated with chemotherapy and stereotactic radiation. The compression was relieved each time by surgery.

RESULTS

 The patient underwent three surgeries in 4 years: (1) debulking and removal of the rib head on the left at T3, and debulking of the tumor at T3 with hemilaminectomy and spinal cord decompression with internal fixation from T1-T5 using posterolateral instrumented fusion and allograft; (2) anterior C7 corpectomy with placement of a cage from C7-T1 with both anterior and posterior fusion of C2C7; and (3) T1-T3 laminectomy, T1-T3 exploration of wound, revision of hardware, T1-T3 removal of spinal tumor, and T3 bilateral transpedicular circumferential decompression. The patient is alive and regained the ability to walk 8 years after initial diagnosis, despite the appearance of spinal metastases 1 year after the diagnosis of liver metastases.

CONCLUSION

 Surgery for spinal cord compression in patients with metastatic neuroendocrine tumors can be effective in relieving radicular pain, weakness and numbness, and while not curative can greatly improve quality of life.

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.

A clinical perspective on gastric neuroendocrine neoplasia

The incidence of gastric neuroendocrine tumors (NETs) has increased exponentially based on widespread use of endoscopy and a greater pathological awareness of the condition. A key concern is the potential association with hypergastrinemia induced by proton pump inhibitor administration. Previous confusion regarding diagnosis and therapy has been diminished by a series of international consensus statements defining the biology and management strategies for the disease. Overall, gastric NETs are categorized as well-differentiated or poorly differentiated neoplasms. Well-differentiated gastric NETs are enterochromaffin-like (ECL) cell tumors subclassified into three types based on their relationship to gastrin, a key regulator of ECL cell neoplastic transformation. The treatment of type 1 and type 2 tumors depends on the size and invasiveness of the tumor, whereas type 3 tumors and poorly differentiated neuroendocrine carcinomas warrant aggressive surgical resection. The disease-specific 5-year survival ranges from about 95% in type 1 gastric carcinoids to about 25% in poorly differentiated gastric NECs. Elucidation of the precise biology of a gastric NET is critical to diagnosis and delineation of a type-specific management strategy.

Mechanism of acid hypersecretion post curative gastrinoma resection

BACKGROUND

Some patients with Zollinger-Ellison syndrome post curative gastrinoma resection continue to show gastric acid hypersecretion; however, the mechanism is unknown.

AIM

The aim of this study was to prospectively study acid secretion following curative gastrinoma resection and analyze factors contributing in patients with Zollinger-Ellison syndrome.

METHODS

Fifty patients cured post gastrinoma resection were studied with serial assessments of acid secretory status, cure status and ECL-cell status/activity (with serial biopsies, CgA, urinary N-MIAA). Correlative analysis was performed to determine predictive factors.

RESULTS

Hypersecretion occurred in 31 patients (62%) and 14 had extreme-hypersecretion. There was an initial decline (3-6 months) in BAO/MAO, which then remained stable for eight years. Preoperative BAO correlated with the postoperative secretion, but not other clinical, tumoral, laboratory variables, the degree of postoperative acid suppression or type of antisecretory drug needed. Hypersecretors had greater postoperative ECL changes (P=0.005), serum CGA (P=0.009) and 24-h urinary N-MIAA (P=0.0038).

CONCLUSIONS

Post curative resection, gastric hypersecretion persists long term (mean 8 years) in 62% of patients and in 28% it is extreme, despite normogastrinemia. No preoperative variable except BAO correlates with postresection hypersecretion. The persistent increased ECL-cell extent post curative resection suggests prolonged hypergastrinemia can lead to changes in ECL-cells that are either irreversible in humans or sustained by unknown mechanisms not involving fasting hypergastrinemia and which can result in hypersecretion, in a proportion of which it can be extreme. Whether similar findings may occur in patients with idiopathic GERD treated for prolonged periods (>10 years) with PPIs, at present, is unknown.

Neuroendocrine tumors of the small bowels are on the rise: Early aspects and management

Neuroendocrine tumors of the small bowel are on the rise. In the US they have increased by 300%-500% in the last 35 years. At the same time their prognosis is much improved. Today, most neuroendocrine tumors (NETs) of the duodenum are detected "incidentally" and therefore recognized at an early stage. Duodenal NETs which are well differentiated, not larger than 10 mm and limited to the mucosa/submucosa can be endoscopically resected. The management of duodenal NETs ranging between 10 and 20 mm needs an interdisciplinary discussion. Endoscopic ultrasound is the method of choice to determine tumor size and depth of infiltration. Surgery is recommended for well-differentiated duodenal NET tumors greater than 20 mm, for localized sporadic gastrinomas (of any size) and for localized poorly differentiated NE cancers. Surgery is recommended for any ileal NET. Advanced ileal NETs with a carcinoid syndrome are treated with long-acting somatostatin analogs. This treatment significantly improves (progression-free) survival in patients with metastatic NETs of the ileum. For optimal NET management, tumor biology, type, localization and stage of the neoplasm, as well as the patient's individual circumstances have to be taken into account.

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.

Surgical management of liver metastases from gastrointestinal endocrine tumors

Liver metastases from endocrine tumors can reduce 5-year survival from 90% to 40% and, in cases of functional gastrointestinal endocrine tumors, lead to a carcinoid syndrome. Complete resection of cancerous disease should be considered in all cases. Indeed, after hepatectomy, prolonged survival (41-86% at five years) can be achieved, with low rates of surgery-related mortality (0-6.7%). Extended liver resection is required in most cases. Percutaneous portal embolization increases the volumetric feasibility of resection, and sequential hepatectomy techniques enable a two-stage resection of both bilobar metastases and the primary tumor. For carcinoid syndrome that does not respond to medical therapy, incomplete resection of liver metastases, by reducing tumor volume, may be indicated to reduce symptoms and halt the progression of carcinoid heart disease. In cases of non-resectable liver metastases in selected patients, liver transplantation can lead to 5-year survival rates as high as 77%.

Five-Year Long-Term Followup of a Primary Lymph node Gastrinoma: Is a Pancreaticoduodenectomy Justified?

Background. Gastrinoma-positive lymph nodes and failed localization of the primary tumor during surgical exploration are described. Specialists suppose that these lymph nodes are metastases rather than a primary gastrinoma. Methods. Case report with a five-year long-term followup. A 60-year-old patient with an confirmed gastrinoma was treated in our department. All preoperative evaluations including somatostatin-receptor-scintigraphy and F-Dopa PET failed to localize the gastrinoma. Explorative laparotomy revealed a gastrinoma in two peripancreatic lymph nodes. Despite extensive intraoperative exploration, no primary gastrinoma could be detected in typical localization. Results. Over a period of 5 years, the patient's gastrin level stayed in the normal range and the patient seems to be completely cured. Conclusion. A prophylactic partial pancreatoduodenectomy is not indicated to avoid recurrence, since complete biochemical cure by local resection of the lymph node gastrinoma is possible.