Assessment of the secretin provocation test in the diagnosis of gastrinoma.

The effect of intravenous secretin on plasma immunoreactive gastrin is presumed to improve diagnostic accuracy in patients with a gastrinoma. To investigate this further, the secretin provocation test was performed in control patients (n = 10), patients with a primary duodenal ulcer (n = 10), patients who had previously had surgery for a duodenal ulcer (n = 20), patients with symptomatic recurrent peptic ulceration (n = 50) and 2 patients with a histologically proved gastrinoma. It was found that the secretin test gave a false positive result in 3 out of 10 symptomatic duodenal ulcer patients, 2 out of 20 patients who had had previous duodenal ulcer surgery and were now asymptomatic and 15 out of 50 patients with recurrent peptic ulceration. Both gastrinoma patients had positive secretin tests but there were no obvious criteria that separated the gastrin response of a gastrinoma patient from those with primary or recurrent peptic ulceration. It is concluded that the secretin test is probably of little value in both the screening and the diagnosis of a gastrinoma.