Laboratory diagnosis of gastrinoma. I. A prospective evaluation of gastric analysis and fasting serum gastrin levels.

In a small percentage of patients with ulcer disease, a gastrinoma may be ultimately discovered. In most institutions, a fasting serum gastrin determination and gastric analysis are as first-line tests to identify this subgroup of patients with ulcer disease. The blood test is relatively inexpensive and well accepted by patients. Gastric analysis is uncomfortable and required a well-equipped facility staffed by skilled personnel. A prospective study designed to assess the diagnostic usefulness of these tests and, particularly, whether combining both tests adds to the individual value of each, revealed that gastric analysis does not improve the diagnostic ability of the fasting serum gastrin test. Therefore, gastric analysis probably is not indicated for determining whether a patient with active ulcer disease has a gastrinoma. The fasting serum gastrin test will suffice, and abnormal values on this test should be verified by the use of other tests such as responses to gastrin provocative tests.