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).

Prospective study of the ability of serial measurements of serum chromogranin A and gastrin to detect changes in tumor burden in patients with gastrinomas.

Background: Assessment of tumor burden changes is essential for the management of patients with neuroendocrine gastrointestinal (GI) tumors. Chromogranin A (CgA) is a tumor marker for such tumors; however, to the authors' knowledge, there is little information on whether serial assessments can assess changes in tumor burden. In this prospective study of patients with gastrinomas, serial changes in serum CgA levels were compared with changes in levels of the specific tumor marker gastrin to determine whether they reflected changes in tumor burden.

Prospective study of the ability of histamine, serotonin or serum chromogranin A levels to identify gastric carcinoids in patients with gastrinomas.

Background: Chronic hypergastrinaemia causes gastric enterochromaffin cell proliferation and carcinoid tumours. The only reliable means to diagnose enterochromaffin cell changes/carcinoids is by biopsy.

Aim: To assess whether serum histamine, chromogranin A or serotonin and urinary N-methylimidazoleacetic acid or 5-hydroxyindoleacetic acid correlate with advanced enterochromaffin cell changes or gastric carcinoids in patients with gastrinomas.

Prospective study of the antitumor efficacy of long-term octreotide treatment in patients with progressive metastatic gastrinoma.

Background: Malignant pancreatic endocrine tumors (PETs) have a poor prognosis and existing antitumor treatments are unsatisfactory. Recent studies have shown somatostatin analogues to have antitumor growth effects in patients with malignant PETs; however, to the authors' knowledge, little information exists regarding their efficacy or effect on survival in patients with progressive malignant gastrinoma, the most common symptomatic malignant PET. The purpose of the current study was to study prospectively the efficacy, safety, and effect on survival of long-term treatment with octreotide in consecutive patients with progressive malignant gastrinoma.

Prospective study of the natural history of gastrinoma in patients with MEN1: definition of an aggressive and a nonaggressive form.

The natural history of pancreatic endocrine tumors (PETs) in patients with MEN1 is largely unknown. Recent studies in patients with sporadic PETs show that in a subset, tumor growth is aggressive. To determine whether PETs in patients with MEN1 show similar growth behavior, we report results from a long-term prospective study of 57 patients with MEN1 and Zollinger-Ellison syndrome.