Clinical and hormonal effects of a long‐acting somatostatin analogue in pancreatic endocrine tumors and in carcinoid syndrome

Nine patients with pancreatic apudomas (seven gastrinomas, one glucagonoma, one tumor secreting a substance P‐like component) and nine with metastasized carcinoid tumors were treated with a somatostatin analogue (SMS 201–995), administered subcutaneously twice daily for 3 days. Treatment was pursued for 2 to 12 months in nine patients in whom SMS was clinically and/or biologically beneficial. In gastrinomas, SMS decreased plasma gastrin in all but one patient, inhibited the residual gastric acid secretion under H2‐blockers and improved diarrhea; in the glucagonoma patient, glucagonemia decreased and skin lesions disappeared. In carcinoid syndrome, clinical efficacy was partial and inconstant; daily 5‐hydroxyindole acetic acid (5‐HIAA) output was slightly decreased. Plasma substance P levels decreased in six patients with initially high concentrations. No antitumoral activity or side effects have been so far evidenced. SMS 201–995 is a useful, well‐tolerated agent in secreting pancreatic apudomas and to a lesser extent in carcinoid syndrome, where high‐dosage regimens may be required.