Endocrine Abstracts

Prospective non-comparable randomized clinical investigation of GH/IGH-1 control and tumor growth reduction in active acromegalic patients on Octreotide-LAR is presented. Fifty patients (pts) with newly diagnosed acromegaly (primary teratment, group 1; mean age 47.8±13.9 years old) and 39 pts after previous surgical and/or radiological treatment (secondary treatment, group 2; mean age 48.1±12.2 years old) were treated with Ocrteotide LAR 20–40 mg every 4 weeks, duration of treatment was 24 months.

Initial hormonal levels were [median (25%÷75%)]: group 1- GH 25 (12.9÷55) ng/ml; IGF-1 685 ng/ml (578÷843); group 2: GH 14 (6.6÷39.5) ng/ml; IGF-1 574 (443÷755) ng/ml. Clinical improvement and hormonal response (more then 30% decrease of the GH and/or IGF-1 levels) were observed in 44 (88%) pts from group 1 and 35 (95%) pts from group 2. Significant IGF-1 levels decrease without any changes of GH levels were observed in 3 (6%) pts from group 1 and 3 (7.7%) pts from group 2; markable GH levels decrease without changes of IGF-1 levels – in 7 (14%) pts from group 1 and 2 (5%) pts from group 2. Tachyphylaxis phenomenon was noted in 4 (8%) pts from group 1: both [GH+IGF-1] after 6–12 months of treatment in 3 pts, only IGF-1 after 3 months of treatment in 1 patient.

In group 1 GH/IGF-1 levels after 12 months of treatment were 4.3 (1.9÷13.9) ng/ml and 453 (215÷568) ng/ml; after 24 months – 7.1 (1.3÷10.8) ng/ml and 469 (395÷670) ng/ml respectively. In group 2 GH/IGF-1 levels after 12 months of treatment were 3.7 (1.2÷5.1) and 220 (174÷330) ng/ml and after 24 months 5.8 (1.5÷10.2) and 328 (180÷476) ng/ml respectively.

Shrinkage of the pituitary tumor were observed in 58.4% of pts from group 1; degree of shrinkage was 13–99% from the initial tumor volume.

Thus, Octreotide LAR is an effective treatment of 88% of de novo patients with active acromegaly, and 95% of patients with previous surgical and/or radiological treatment. In our hogort of patients hormonal control was more effective in group with secondary medical therapy compared with newly diagnosed acromegalic patients. However, tumor shrinkage was more obvious in patients with primary medical treatment.