Analysis of Clinical Characteristics and Survival in Patients With Functional Neuroendocrine Tumors of Gastrointestinal Origin

OBJECTIVES

Functional neuroendocrine tumors (FNETs) are characterized by excess secretion of disease-specific hormones. In this study, we attempted to define survival trends in patients with some of these uncommon tumors.

METHODS

Using the Surveillance, Epidemiology, and End Results database, 529 patients with FNETs (gastrinoma, insulinoma, glucagonoma, VIPoma, and somatostatinoma) were identified. We analyzed patient and tumor characteristics, overall survival, and cancer-specific survival.

RESULTS

Functional neuroendocrine tumors were found to be more predominant in White patients older than 50 years. Most common FNETs were gastrinoma (56.3%) and insulinoma (23.8%). Most FNETs were found in the pancreas, with the second most common location being the small bowel. Surgery was the primary modality of treatment, used in 55.8% of the cases. Median overall survival was 9.8 years (95% confidence interval [CI], 7.9-11.8) with a median cancer-specific survival of 18.5 years (95% CI, 12.8-24.2). In multivariate analysis, age >50 years (hazard ratio [HR], 2.7; 95% CI, 2.02-3.64), no surgical resection (HR, 1.88; 95% CI, 1.43-2.46), metastasis (HR, 3.0; 95% CI, 2.0-4.5), and poor differentiation were associated with poor survival. Site and histology did not have a significant impact on survival (P = 0.82 and 0.57 respectively).

CONCLUSIONS

Our study highlights the most important prognostic factors for gastrointestinal FNETs.

Primary peripancreatic lymph node gastrinoma in a woman with MEN1

A 39-year-old woman was admitted to hospital due to perforated relapsing duodenal ulcer. Clinical, laboratory, and surgical examinations revealed a peripancreatic lymph node gastrinoma as the cause of Zollinger-Ellison syndrome. Further examinations established multiple endocrine neoplasia type 1 (MEN1) with a germline mutation at codon 1153 (T->A) in exon 7, causing an amino-acid change, from isoleucine to asparagine (Ile348Asn), in the MEN1 gene. The following findings strongly supported a diagnosis of primary lymph node gastrinoma: a rapid fall of the serum gastrin level after operation, the continuous normalization of the serum gastrin level before and after secretin stimulation, the lack of any symptoms, and the absence of another tumor for 13 years after surgical resection of the tumor-bearing lymph node. A review of similar cases in the world literature reveals that not all gastrinomas in lymph nodes are the result of metastastic spread. A long-term symptom-free follow-up after the excision of a lymphnode gastrinoma is the only reliable criterion for the diagnosis of a primary lymph node tumor. To our knowledge, this is the only well-documented case of a primary lymph node gastrinoma in a patient with MEN1. Our case supports the idea that any gastrinoma in patients with MEN1 should be surgically resected for cure if possible.

Intramucosal cysts in the gastric body of patients with Zollinger-Ellison syndrome

To ascertain the frequency and the clinico-functional correlations of intramucosal cysts in the gastric body of patients with the Zollinger-Ellison syndrome (ZES) and to clarify the relevant mechanism of development, a total of 106 consecutive ZES patients (58 M, 48 F; mean age: 53 yrs, range 19-93 yrs) were investigated with a mean of 7.2 biopsy specimens of the body mucosa per patient proved to be suitable for the study. Biopsies of endoscopically detectable polypoid lesions were not considered. Cystic changes were evaluated with respect to their severity by assessing the cyst grade (0, absent, 1; <30%, 2; 30-60%; 3 >60% of the mucosal area of the biopsy specimen of individual patients showing the most pronounced finding, respectively) and to their intragastric distribution by assessing the ratio of biopsy specimens showing cystic changes over the total number of biopsies examined in each patient. Intramucosal cysts were found in biopsies of non-polypoid gastric body mucosa in 71.7% of 106 patients with Zollinger-Ellison syndrome (ZES) and showed grade 2 and 3 severity in 22 and 8 cases, respectively. The severity of cystic changes correlated with the gastrin levels (p = 0.0005) and was more advanced in patients with active than in those with cured disease (p = 0.037). In the former group, furthermore, advanced cystic changes correlated with age (p = 0.03), male gender (p = 0.014), years of disease from onset (p < 0.02), years of omeprazole treatment (p = 0.033), basal acid output (p < 0.02), severity of ECL cell proliferative changes (p = 0.028), and absence of previous gastrinoma resection (p = 0.039) whereas they did not correlate with MEN-1 status, gastritis, maximal acid output, total duration of any antisecretory drug treatment, daily doses of omeprazole (> 20 mg vs 20 mg), years from surgery, duodenal localization of gastrinoma(s), presence of gastric carcinoid tumor(s) and of liver metastases. In groups of patients subdivided according to three levels of serum gastrin, the duration of omeprazole treatment was not related to the severity of cystic changes. It is concluded that intramucosal cysts in non polypoid gastric body mucosa of ZES patients are by far more common than the already reported fundic gland polyps, to which they likely give raise. Circulating levels of gastrin have an important independent role in their development.

Current perspectives in the surgery of multiple endocrine neoplasias

Multiple endocrine neoplasia is an uncommon but fascinating condition. In this review we examine the multifaceted presentations, the diagnostic challenges and different management strategies for various syndromes. This is an attempt to share our knowledge and experience towards achieving better outcomes in the management of the diseases.

Progress in the field of pancreatic endocrine tumors in Japan

Since the first report of pancreatic endocrine tumors by Wilder et al. in 1927 and the development of radioimmunoassay of gut hormone by Berson and Yallow in 1961, Japanese clinicians and scientists have contributed significantly in the reporting, investigation, and management of patients with pancreatic endocrine tumors and other multiple endocrine neoplasia. This article summarizes our contribution in this field and contrasts our experiences with those reported in the English literature.

CD44 isoform expression in the diffuse neuroendocrine system. II. Benign and malignant tumors

The membrane glycoprotein CD44 may be associated with aggressive behavior, dissemination, and poor prognosis of a variety of human tumors. In order to extend our knowledge on the expression and significance of CD44 in cells of the dispersed neuroendocrine system we investigated a spectrum of 134 neuroendocrine tumors, including pituitary adenomas, medullary thyroid carcinomas, parathyroid adenomas, pheochromocytomas, neuroblastomas, small-cell lung carcinomas, and bronchopulmonary, pancreatic, and gastrointestinal neuroendocrine tumors immunohistochemically for CD44 standard and variant exon-encoded gene products (CD44v3, -v4, -v5, -v6, -v9). Furthermore, we compared protein expression with that of CD44 mRNA by reverse-transcriptase PCR and Southern blot hybridization in a subset of tumors. Our results show that CD44 expression is correlated with the "histogenetic origin" of the appropriate neuroendocrine neoplasm. Endoderm-derived tumors generally express 3'-end CD44 variant exon-containing isoforms, whereas neural crest-derived tumors rarely are positive for CD44. Furthermore, we provide evidence that CD44 expression is not correlated with metastatic disease or a particular hormonal phenotype but exhibits an association with the degree of cellular differentiation. Thus, CD44 is not useful as marker for malignancy or prognosis. The number of patients with clinical follow-up data in our study was too small to allow definite conclusions about a possible correlation between CD44 expression and prognosis. But CD44 may help to better classify neoplasms with an unclear neuroendocrine phenotype.

Gastrointestinal neuroendocrine tumors

It has been said that with the description of the Zollinger-Ellison syndrome in 1955, the clinical era of gastrointestinal endocrinology was inaugurated. Since that time, a virtual explosion of investigations, both basic and clinical, has occurred in which as many as 19 gastroenteropancreatic neuroendocrine cells have been identified and as many as 40 of their humoral products have been discovered. The pharmacologic and physiologic functions of some of these amines and peptides have been clearly identified and account for the clinical presentations of the various clinical syndromes so far described. However, the physiologic functions of many others remain to be elucidated. The interest in gastroenteropancreatic neuroendocrine tumors arising from these cells has markedly increased in recent years as a result of the creation of precise biochemical techniques to confirm the diagnosis and the refinement of localization techniques that allow for the identification of previously occult tumors. Therefore, the recognition and treatment of gastroenteropancreatic neuroendocrine tumors has improved so that an ever-increasing number of patients are diagnosed early and surgically treated before metastases occur. There are still more identified gastroenteropancreatic neuroendocrine cells and humoral products than there are recognized neoplasms and syndromes; continued investigation is essential. Undoubtedly, newer treatment modalities will continue to be created for chemotherapy and receptor modulation, but early surgical excision remains the cornerstone of successful treatment today.

Physiology of the APUD system

The characteristic biochemical pathway of the APUDoma cell, namely amine precursor uptake and decarboxylation, are illustrated by the examples of serotonin and catecholamine metabolism. Increasing understanding of the origins of APUDomas as well as the biochemistry and physiology of the hormones they produce, has led to improved methods of detection, imaging and treatment of afflicted patients.

Gastrinoma

The Zollinger-Ellison syndrome with its main symptom of massive gastric hypersecretion presents problems with both the medical and surgical approaches to treatment. Successful medical treatment depends on a life-long commitment to rigid medication schedules requiring careful ongoing supervision and is subject to pitfalls of compliance, drug side effects, drug resistance, and complications of persistent tumor growth. Surgical therapy carries risks of operative mortality and complications. If a low operative mortality can be maintained and the nutritional results after total gastrectomy are good, then it is the authors' opinion that the permanent relief from dangers of hypersecretion afforded by total gastrectomy makes surgery a worthwhile approach. Based on our operative experience in 34 patients and interpretation of the experience of others, we believe that resection of all tumor that can be resected, combined with total gastrectomy, is safe and dependable. The results compare well with those of long-term medical management.