Short-term pre-surgical treatment with somatostatin analogues, octreotide and lanreotide, in acromegaly.

Eighteen patients with symptoms of active acromegaly were treated with somatostatin analogues for 4 weeks before surgery. Both before and after the treatment, levels of growth hormone (GH), prolactin (PRL), insulin growth factor -I (IGF-I), luteotropin (LH), folliculostimulin (FSH) and subunit alpha of glycoprotein hormones were estimated. Glucose tolerance test, magnetic resonance imaging (MRI) examination, sight acuity and field of vision tests were also performed. The same tests were performed on ten control patients with clinically and biochemically active acromegaly, subjected to surgery but not treated with somatostatin analogues. In six patients treated with somatostatin analogues GH levels decreased significantly to less than 5 ng/ml and in two patients remained elevated while in 10 patients GH level decreased and ranged from 6.1 to 42.9 ng/ml. In 13 patients we observed a decrease in IGF-I to normal levels (<400 ng/dl) and in 3 patients we noted a decrease to levels slightly higher than normal. There was also a slight decrease in alpha subunit concentration. In the glucose inhibition test 4 patients demonstrated normalized GH levels. In patients with elevated PRL and TSH levels, treatment with somatostatin analogues induced their decrease. No changes were observed in levels of LH and FSH. After therapy MRI examination disclosed a decrease in tumor volume in two patients (by 20 and 25%, respectively) and no changes in tumor size in 16 patients. The two patients with a decreased tumor volume also showed normalized glucose tolerance tests. All patients manifested an improved clinical condition. Neurosurgeons disclosed a decreased tumor consistency which greatly facilitated surgical procedure. Our studies documented favourable effects of somatostatin analogues on the assayed hormone levels, and on the general condition of the patients as well as on the course of the surgical procedure itself.