Slow-release lanreotide treatment in endocrine gastrointestinal tumors.

OBJECTIVES: Lanreotide is a somatostatin analogue whose activity persists for 10-14 days. In this study, we treated a group of patients with gastrointestinal endocrine tumors with lanreotide to assess its therapeutic efficacy and tolerability.

METHODS: Eighteen patients, 12 male and six female, mean age 58 yr (range, 25-80 yr) were studied. Ten had carcinoid tumors, five had nonfunctioning endocrine tumors, two had glucagonomas, and the remaining one had a gastrinoma. All patients had somatostatin receptors, demonstrated by octreoscan scintigraphy. Lanreotide was administered intramuscularly at a dose of 30 mg every 10 days, for a mean of 12 months (range, 5-18 months). Fifteen of the 18 patients had been previously treated with octreotide.

RESULTS: In patients with carcinoid tumors, lanreotide markedly reduced daily bowel movements and flushing episodes. A reduction was also observed in urinary serotonin and urinary 5-hydroxyindoleacetic acid, although it was not statistically significant. A marked reduction in symptoms, and in plasma glucagon and serum gastrin levels, was also observed in patients with glucagonoma and gastrinoma. In the five patients with nonfunctioning endocrine tumors, as in all the other 13 patients, no significant effects were noted in the size of the tumor. The administration of lanreotide did not cause side effects, apart from transient abdominal pain and pain at the injection site in two patients. Only in the patient with gastrinoma was lanreotide suspended, because of the appearance of attacks of marked hypoglycemia. In the 15 patients previously treated with octreotide, no differences in the effects were noted with lanreotide.

CONCLUSIONS: Lanreotide has a satisfactory therapeutic efficacy and tolerability in the treatment of gastrointestinal endocrine tumors; its effects are similar to those of octreotide. However, unlike octreotide, it can be administered once every 10-14 days, instead of 2 or 3 times daily and for this reason, it is preferable in clinical practice.