Related Experiment Videos
Somatostatin analogue (SMS 201-995) in patients with gastrinomas
A I Vinik1, S Tsai, A R Moattari
1Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109-0331.
Abstract:
We have examined the effects of the somatostatin analogue (SMS 201-995) in 10 patients with gastrinoma syndrome. Four had hepatic metastases, one had a tumor in a peripancreatic lymph node, two had resectable intrahepatic and intraduodenal gastrinomas, and in three the primary tumor was not found. Acutely, SMS 201-995 decreased acid secretion and restored the BAO/MAO ratio to normal in eight of eight patients. Basal and secretin-stimulated gastrin responses were suppressed but not normalized in eight of eight patients. Suppression of endogenous gastrin restored responsiveness to exogenous gastrin. Treatment for up to 12 months with SMS 201-995 controlled symptoms in six of eight patients, suppressed serum gastrin in three of five, and suppressed acid secretion in three of three patients. Treatment with SMS 201-995 in three patients for 5 months decreased tumor secretion of gastrin and diminished basal acid secretion, an effect that persisted in two of three patients 48 hours after withdrawal of SMS. In patients with metastatic disease who had high levels of gastrin, SMS treatment for 5 to 12 months did not inhibit tumor growth or decrease gastrin levels. SMS treatment arrested progression of tumor growth only in patients who had a reduction in gastrin and gastric acid secretion. We conclude that SMS may be useful in the management of gastrinoma patients by decreasing hypersecretion of gastrin and gastric acid and, over a longer term, may even change tumor capacity to release gastrin and gastric acid secretion. SMS may thus be useful as a palliative agent and as an adjunct to conventional treatment of the gastrinoma syndrome. SMS does not appear to shrink tumor mass in patients with very high basal gastrin levels.
Insights
The somatostatin analogue SMS 201-995 effectively reduced gastric acid and gastrin secretion in gastrinoma patients. While not shrinking tumors, it controlled symptoms and potentially altered tumor secretion capacity.
Area of Science:
- Endocrinology
- Gastroenterology
- Oncology
Background:
- Gastrinoma syndrome is characterized by hypersecretion of gastrin, leading to gastric acid hypersecretion and peptic ulcers.
- The somatostatin analogue SMS 201-995 is a potential therapeutic agent for managing gastrinoma.
Purpose of the Study:
- To evaluate the efficacy of SMS 201-995 in patients with gastrinoma syndrome.
- To assess the effects of SMS 201-995 on gastric acid secretion, gastrin levels, and tumor progression.
Main Methods:
- A study involving 10 patients with gastrinoma syndrome.
- Administration of SMS 201-995 and monitoring of acid secretion, gastrin levels, symptoms, and tumor growth.
- Acute and long-term treatment protocols were employed.
Main Results:
- SMS 201-995 acutely decreased acid secretion and normalized the BAO/MAO ratio in most patients.
- Basal and stimulated gastrin levels were suppressed, and symptom control was achieved in a majority of patients.
- SMS 201-995 did not inhibit tumor growth in patients with metastatic disease and high gastrin levels, but arrested progression in those with reduced gastrin and acid secretion.
Conclusions:
- SMS 201-995 is a potentially useful palliative agent for gastrinoma syndrome, managing hypersecretion and symptoms.
- Long-term treatment may alter the tumor's capacity for gastrin and acid secretion.
- SMS 201-995 may serve as an adjunct to conventional therapies but does not appear to shrink tumor mass.