The use of a long-acting somatostatin analogue in the treatment of advanced endocrine malignancies with gastrointestinal symptoms

Abstract

Four patients with advanced endocrine malignancies were treated with a somatostatin analogue (SMS 201-995) for palliation of hormone-induced symptoms during 3-6 months. Two had the carcinoid syndrome (one midgut and one foregut), one had medullary thyroid carcinoma and an ectopic ACTH syndrome, and one patient had a metastatic gastrinoma. The carcinoid patients had excellent symptomatic relief with a low dose of the drug, 50 micrograms subcutaneously twice daily, in one case despite progression of tumour disease and biochemical tumour markers. These findings indicate an action of the drug not only on hormonal release but also at peripheral sites. The patient with medullary thyroid carcinoma had relief of gastrointestinal symptoms when the drug dose was increased (100 micrograms twice daily). The levels of ACTH in peripheral blood were reduced, but not the calcitonin levels. The gastrinoma patient had undergone a major pancreatic resection (Whipple procedure) and was treated with omeprazole. SMS 201-995 reduced the peripheral gastrin levels acutely, but during the treatment fasting gastrin values increased, and the tumour growth progressed. Treatment was stopped owing to elevated fasting glucose level, increased steatorrhoea, and clinical attacks of cholangitis. Special attention is advocated for patients with major pancreatic resection and biliary reconstruction, who may be susceptible to physiological effects of somatostatin (or its analogues)--that is, impaired insulin release and decreased motility.