Endocrine Abstracts

Introduction: Treatment with somatostatin analogues (SSA) leads to shrinkage of pituitary adenoma in acromegaly naïve patients, as shown by the PRIMARYS study. Therefore the effect of this treatment on surgery was investigated.

Aim: To evaluate the efficacy of pre-treatment with SSA in acromegaly patients qualified for neurosurgery.

Material and methods: Group A (46 patients: 36 female, 10 male) were pre-treated with SSA. Group B (49 patients: 30 female, 19 male) were not treated, their mean ages at diagnosis: 49.2±13.9 years and 41.2 yrs±13.1, respectively (P=0.005). Group A- patients were treated with SSA (octreotide 30 mg and lanreotide autogel 120 mg every 4 weeks) for 3–6 months before surgery.The percentage of microadenomas/macroadenomas in group A and group B was 21.7/78.3% and 6.3/93.7%, respectively (P=0.026).

Results: In groups A and B, GH concentration at 120 min in OGTT and IGF-1 ULN concentration before surgery did not differ. Median values of IGF-1 before surgery in groups A and B were 748.0 (range 113.0–1872.9) ng/ml and 1026.5 (447.0–1998.9) ng/ml, respectively, P=0.031. Three months after surgery, significant difference of median GH concentrations at 120 min was observed between group A: 0.58 (0.20–24.30) ng/ml and group B: 1.10 (0.15–58.40) ng/ml, P=0.035, as well as between median of IGF-1 concentrations: group A: 240.5 (62-912) ng/ml and group: B 352.4 (88–1150) ng/ml, P=0.05. In group A 73.3% of patients were considered cured, and 26.7% required further SSA treatment. In group B 32.6% of patients were considered cured, and 67.4% required further SSA treatment, P=0.0001.Of those patients who required further SSA treatment 75% in group A and 64.5% in group B were well controlled. According to our most recent evaluation, in group A the levels of GH, IGF-1and ULN were: 1.57 (0.35–10.00) ng/m; 174.5 (51–558) ng/ml and 0.48 (0.16–1.87), respectively, while these levels in group B were: 1.40 (0.20–7.70) ng/ml; 226.5 (79-559) ng/ml and 0.60 (0.25-2.73), respectively. Only the difference in IGF-1 levels between groups A and B was statistically significant, P=0.0489.Following multidimentional step-wise regression, pituitary microadenoma, IGF-1ULN after surgery, and SSA pre-treatment, were positive predictors of the final outcome, with respective odds ratios: 32.02 (±95% CL 2.17–472.0, P=0.0104), 0.11 (±95% CL 0.02–0.53, P=0.0054) and 34.97 (±95% CL 7.63-160.38, P=0.0000).

Conclusion: SSA pre-treatment improves the final outcome of pituitary surgery in acromegaly patients.