Marc J. Berna

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. Cancer 2008;113(7 suppl):1807–43. Published 2008 American Cancer Society.

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. Abbreviations: BAO = basal acid output, CT = computed tomography, FSG = fasting serum gastrin, GERD = gastroesophageal reflux disease, MAO = maximal acid output, MEN1 = multiple endocrine neoplasia type 1, MRI = magnetic resonance imaging, NIH = National Institutes of Health, PPI = proton pump inhibitor, PTH = parathormone, SPECT = single photon emission computed tomography imaging, SRS = somatostatin receptor scintigraphy, ZES = Zollinger-Ellison syndrome.

A Prospective Study of Gastric Carcinoids and Enterochromaffin-Like Cell Changes in Multiple Endocrine Neoplasia Type 1 and Zollinger-Ellison Syndrome: Identification of Risk Factors

CONTEXT Multiple endocrine neoplasia type 1 (MEN1) patients frequently develop Zollinger-Ellison syndrome (ZES). These patients can develop proliferative changes of gastric enterochromaffin-like (ECL) cells and gastric carcinoids (ECL-cell tumors). ECL-cell changes have been extensively studied in sporadic ZES patients and can be precursor lesions of gastric carcinoids, but little is known about factors influencing their severity or development of carcinoids in MEN1/ZES patients. OBJECTIVES Our objective was to prospectively analyze ECL-cell changes and gastric carcinoids (ECL-cell tumors) in a large series of MEN1/ZES patients to detect risk factors and deduct clinical guidelines. SETTING AND PATIENTS Fifty-seven consecutive MEN1/ZES patients participated in this prospective study at two tertiary-care research centers. INTERVENTIONS AND OUTCOME MEASURES Assessment of MEN1, gastric hypersecretion, and gastroscopy with multiple biopsies was done according to a fixed protocol and tumor status. ECL-cell changes and alpha-human chorionic gonadotropin staining were assessed in each biopsy and correlated with clinical, laboratory, and MEN1 features. RESULTS ECL-cell proliferative changes were universally present, advanced changes in 53% and carcinoids in 23%. Gastric nodules are common and are frequently associated with carcinoids. Patients with high fasting serum gastrin levels, long disease duration, or a strong alpha-human chorionic gonadotropin staining in a biopsy are at higher risk for an advanced ECL-cell lesion and/or gastric carcinoid. CONCLUSIONS Gastric carcinoids and/or advanced ECL-cell changes are frequent in MEN1/ZES patients, and therefore, regular surveillance gastroscopy with multiple routine biopsies and biopsies of all mucosal lesions are essential. Clinical/laboratory data and biopsy results can be used to identify a subgroup of MEN1/ZES patients with a significantly increased risk for developing gastric carcinoids, allowing development of better surveillance strategies.

Prospective study of surgery for primary hyperparathyroidism (HPT) in multiple endocrine neoplasia-type 1 and Zollinger-Ellison syndrome: long-term outcome of a more virulent form of HPT.

Background:Primary hyperparathyroidism (HPT) in multiple endocrine neoplasia type 1 (MEN1) patients with Zollinger-Ellison syndrome (ZES) is caused by parathyroid hyperplasia. Surgery for parathyroid hyperplasia is tricky and difficult. Long-term outcome in ZES/MEN1/HPT is not well known. Methods:Eighty-four consecutive patients (49 F/35 M) with ZES/MEN1/HPT underwent initial parathyroidectomy (PTX) and were followed at 1- to 3-year intervals. Results:Age at PTX was 36 ± 2 years. Mean follow-up was 17 ± 1 years. Before PTX, mean Ca = 2.8 mmol/L (normal level (nl <2.5), PTH i = 243 pg/mL (nl <65), and gastrin = 6950 pg/mL (nl < 100). Sixty-one percent had nephrolithiasis. Each patient had parathyroid hyperplasia. Fifty-eight percent of patients had 4 parathyroid glands identified. Nine of 84 (11%) had 4 glands removed with immediate autograft, 40/84 (47%) 3 to 3.5 glands, whereas 35/84 (42%) <3 glands removed. Persistent/recurrent HPT occurred in 42%/48% of patients with <3 glands, 12%/44% with 3 to 3.5 glands, and 0%/55% with 4 glands removed. Hypoparathyroidism occurred in 3%, 10%, and 22%, respectively. The disease-free interval after surgery was significantly longer if >3 glands were removed. After surgery to correct the HPT, each biochemical parameter of ZES was improved and 20% of patients no longer had laboratory evidence of ZES. Conclusions:HPT/MEN1/ZES is a severe form of parathyroid hyperplasia with a high rate of nephrolithiasis, persistent and recurrent HPT. Surgery to correct the hypercalcemia significantly ameliorates the ZES. Removal of less than 3.5 glands has an unacceptably high incidence of persistent HPT (42%), whereas 4-gland resection and transplant has a high rate of permanent hypoparathyroidism (22%). More than 3-gland resection has a longer disease-free interval. The surgical procedure of choice for patients with HPT/MEN1/ZES is 3.5-gland parathyroidectomy. Careful long-term follow-up is necessary as a significant proportion will develop recurrent HPT.

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

AbstractMultiple 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.

Role of CCK/gastrin receptors in gastrointestinal/metabolic diseases and results of human studies using gastrin/CCK receptor agonists/antagonists in these diseases

In this paper, the established and possible roles of CCK1 and CCK2 receptors in gastrointestinal (GI) and metabolic diseases are reviewed and available results from human agonist/antagonist studies are discussed. While there is evidence for the involvement of CCK1R in numerous diseases including pancreatic disorders, motility disorders, tumor growth, regulation of satiety and a number of CCK-deficient states, the role of CCK1R in these conditions is not clearly defined. There are encouraging data from several clinical studies of CCK1R antagonists in some of these conditions, but their role as therapeutic agents remains unclear. The role of CCK2R in physiological (atrophic gastritis, pernicious anemia) and pathological (Zollinger-Ellison syndrome) hypergastrinemic states, its effects on the gastric mucosa (ECL cell hyperplasia, carcinoids, parietal cell mass) and its role in acid-peptic disorders are clearly defined. Furthermore, recent studies point to a possible role for CCK2R in a number of GI malignancies. Current data from human studies of CCK2R antagonists are presented and their potential role in the treatment of these conditions reviewed. Furthermore, the role of CCK2 receptors as targets for medical imaging is discussed.

CCK1 and CCK2 Receptors Are Expressed on Pancreatic Stellate Cells and Induce Collagen Production

The gastrointestinal hormone cholecystokinin (CCK) can induce acute pancreatitis in rodents through its action on acinar cells. Treatment with CCK, in combination with other agents, represents the most commonly used model to induce experimental chronic pancreatitis. Pancreatic stellate cells (PSC) are responsible for pancreatic fibrosis and therefore play a predominant role in the genesis of chronic pancreatitis. However, it is not known whether PSC express CCK receptors. Using real time PCR techniques, we demonstrate that CCK1 and CCK2 receptors are expressed on rat PSC. Interestingly both CCK and gastrin significantly induced type I collagen synthesis. Moreover, both inhibit proliferation. These effects are comparable with TGF-β-stimulated PSC. Furthermore, the natural agonists CCK and gastrin induce activation of pro-fibrogenic pathways Akt, ERK, and Src. Using specific CCK1 and CCK2 receptor (CCK2R) inhibitors, we found that Akt activation is mainly mediated by CCK2R. Akt activation by CCK and gastrin could be inhibited by the PI3K inhibitor wortmannin. Activation of ERK and the downstream target Elk-1 could be inhibited by the MEK inhibitor U0126. These data suggest that CCK and gastrin have direct activating effects on PSC, are able to induce collagen synthesis in these cells, and therefore appear to be important regulators of pancreatic fibrogenesis. Furthermore, similar to TGF-β, both CCK and gastrin inhibit proliferation in PSC.

Neuromedin B receptors regulate EGF receptor tyrosine phosphorylation in lung cancer cells

Neuromedin B (NMB), a member of the bombesin family of peptides, is an autocrine growth factor for many lung cancer cells. The present study investigated the ability of NMB to cause transactivation of the epidermal growth factor (EGF) receptor in lung cancer cells. By Western blot, addition of NMB or related peptides to NCI-H1299 human non-small cell lung cancer (NSCLC) cells, caused phosphorylation of Tyr(1068) of the EGF receptor. The signal was amplified using NCI-H1299 cells stably transected with NMB receptors. The transactivation of the EGF receptor or the tyrosine phosphorylation of ERK caused by NMB-like peptides was inhibited by AG1478 or gefitinib (tyrosine kinase inhibitors) and NMB receptor antagonist PD168368 but not the GRP receptor antagonist, BW2258U89. The transactivation of the EGF receptor caused by NMB-like peptides was inhibited by GM6001 (matrix metalloprotease inhibitor), PP2 (Src inhibitor), or transforming growth factor (TGF)alpha antibody. The transactivation of the EGF receptor and the increase in reactive oxygen species caused by NMB-like peptides was inhibited by N-acetylcysteine (NAC) or Tiron. Gefitinib inhibited the proliferation of NCI-H1299 cells and its sensitivity was increased by the addition of PD168368. The results indicate that the NMB receptor regulates EGF receptor transactivation by a mechanism dependent on Src as well as metalloprotease activation and generation of reactive oxygen species.

Late Outgrowth Endothelial Progenitor Cells in Patients with Age-Related Macular Degeneration

PURPOSE To evaluate the feasibility of isolating and expanding endothelial progenitor cells (EPCs), in the form of late outgrowth endothelial progenitor cells (OECs), from the peripheral blood of an aged population, particularly patients affected by different forms of AMD. METHODS Peripheral blood mononuclear cells were collected from young control subjects (n = 18) and from elderly subjects with non-AMD/low-risk dry AMD (n = 15), high-risk dry AMD (n = 6), or neovascular AMD (nvAMD; n = 32); cultured in established conditions; and observed for appearance of OEC clusters and growth characteristics on expansion. Expression of VEGF receptor-2 (KDR) in OECs after expansion was determined by Western blot. Plasma samples of study subjects were analyzed for CRP and VEGF levels. RESULTS OEC cultures were successfully generated from a similar number of subjects in each group. After adjustment for all other variables, subjects with high-risk dry AMD had a 5.6-fold higher number of OEC clusters per 20 mL blood, and subjects with nvAMD had a 5.1-fold high number than did subjects with non-AMD/low-risk dry AMD (P < 0.05). High-risk dry AMD generated 63 times more (NS) and nvAMD 32-times more (P < 0.05) OECs on expansion of clusters than did non-AMD/low-risk dry AMD. Population doubling occurred significantly faster in cultures from nvAMD eyes compared to non-AMD/low-risk dry AMD eyes. In addition, a significant correlation between the number of OEC clusters, expanded OECs and levels of KDR was demonstrated. CONCLUSIONS An OEC population was isolated and expanded from the blood of elderly control and AMD-affected patients and demonstrated significantly higher number of initial OEC clusters and expansion potential of OECs in patients at risk for or already affected by nvAMD. OECs may be used for further phenotypic, genetic, and functional analyses in patients with nvAMD.

Pancreas and Liver Injury Are Associated in Individuals With Increased Alcohol Consumption

BACKGROUND & AIMS Although chronic pancreatitis and liver cirrhosis are common sequelae of excess alcohol consumption, the 2 conditions are rarely associated. We studied the prevalence of simultaneous liver cirrhosis and chronic pancreatitis in alcoholics. METHODS Postmortem autopsy data from 620 individuals with a history of excess alcohol consumption and 100 nonalcoholics (controls) were analyzed. The individuals were classified into groups based on macroscopic observations of pancreas (no injury, acute pancreatitis, fibrosis, and chronic pancreatitis) and liver (no injury, moderate steatosis, severe steatosis, and cirrhosis). The same classification system was used for histological data, which was used to confirm and correlate macroscopic results. RESULTS Out of the 183 patients with liver cirrhosis, 33 (18%) had chronic pancreatitis and 93 (51%) had pancreatic fibrosis. Out of the 230 patients with severe steatosis, 37 (16%) had chronic pancreatitis and 97 (42%) were found to have a pancreatic fibrosis. Thirty-three (39%) with chronic pancreatitis also showed liver cirrhosis and 37 (44%) showed severe steatosis. Thirty-eight percent of the patients with a pancreatic fibrosis were found also to have liver cirrhosis and in another 40% severe steatosis. Thirty-five patients showed neither hepatic or pancreatic injury. We found no chronic pancreatitis or liver cirrhosis in the control group (n = 100). CONCLUSIONS Contrary to common belief there is a close association between pancreatic and hepatic injury in patients with increased alcohol consumption, and the degree of organ damage between the 2 organs correlate.