Results of long-term continuous subcutaneous octreotide administration in 14 patients with medullary thyroid carcinoma.

Abstract

Treatment by octreotide has been suggested in medullary thyroid carcinoma patients with post-surgery metastases. The purpose of this study was to evaluate if the tumoral regression could be improved by a high dose and by prolonged octreotide treatment. Fourteen thyroidectomized patients were studied. All patients had persistently elevated plasma calcitonin levels with normal or elevated carcino-embryonic antigen levels. Five hundred micrograms/day of octreotide were administered by continuous subcutaneous infusion for 90 days. Plasma calcitonin and carcino-embryonic antigen levels were determined at days -30, -20, -2, -1, 0, +30, +60, +90, +120; morphological extension was evaluated every month. Continuous infusion of octreotide did not induce any significant decrease of calcitonin levels, or any morphological improvement, and had no major undesirable effect. However, in 4/14 patients calcitonin levels fell during treatment (-43, -50, -15, -20%), and in 9 patients calcitonin increased (+22 to +130%) after cessation of therapy. Biological or morphological parameters of medullary thyroid carcinoma are not significantly improved in a large series of patients treated by octreotide.