Endocrine Abstracts

In acromegaly, an excessive GH secretion by pituitary adenoma, minimal active disease may be defined as slow progression of characteristic signs and symptoms at presence of slightly elevated or normal IGF1 levels and lack of GH suppression after glucose load. Nadir post-glucose GH level defining active disease is under permanent discussion and depends on assessment methods. IGF1 reference range is wide, must be age-adjusted and often is sex-dependent. From mid-00’s excess over upper limit reference range (ULN) for IGF1 is used to define disease activity. Acromegaly contributes to decrease in life expectancy, coexisting disease progression and social disclosure. Somatostatin analogues (SA) are effective in normalization of GH and IGF1, reducing symptoms and tumor shrinkage. Sporadically published data shows prolonged effectiveness of octreotide LAR.

Aim: To assess prospectively if octreotide LAR is effective if given every 6 weeks in group of minimal active acromegaly. Group: 11 patients (9F/2M) mean age 62 S.D. 14.8 y, with acromegaly diagnosed mean 9 years earlier, treated with somatostatin analogues for mean 7 years (S.D. 2.9). Out of 11 patient 7 received octreotide after uncurative surgery. In 6 of 7 surgery was preceded by SA pretreatment. In all cases minimal active acromegaly was confirmed and therapy effectiveness during standard octreotide 10–20 mg every 4 weeks (GH 1.1 ng/ml S.D. 0.9; IGF1 155 ng/ml S.D. 176=0.6 ULN S.D. 0.7) proven. No patients underwent radiotherapy. Intervention: octreotide LAR 20 mg given every 6 weeks (stable dose, injections intervals titrated accordingly to IGF1 level, target – lower than ULN.

Results: After 6 months of octreotide LAR 20 mg titration patients received injection every 5 weeks (1); 6 weeks (7); 7 weeks (1); 8 (1); 9(1). Mean GH levels during stabilized treatment did not differ significantly (1.9 S.D. 1.9 NS v. previous therapy). IGF1 show trend to increase (mean 217 ng/ml S.D. 104 P=0.3; 0.9 ULN S.D. 0.4). No clinical worsening were observed. Clinical symptoms score did not differ in any of cases. We did not observed any changes in concomitant diseases intensity.

Conclusions: In patients with minimal active acromegaly, biochemical control and symptoms release may be controlled by titration of intervals between injections of octreotide LAR. During 2 years of observation we proven effectiveness and safety of this approach.