Endocrine Abstracts

Introduction: The management of clinically non-functioning pituitary adenomas (NFPA) remains a debated issue. Surgery, which is indisputably indicated in invasive NFPA, is rarely curative. Moreover, it is not always feasible due to potential complications or contraindications. Expression of somatostatin receptors (SSTR) form the rationale for the use of somatostatin analogues (SSA) in NFPA.

Aim: To compare the risk of NFPA progression in patients treated with SSA vs those without pharmacotherapy.

Material and Methods: 57 patients with NFPA (subgroup A-40 after incomplete surgery + subgroup B-17 not operated) were enrolled into the study. SSTR scintigraphy and additionally immunohistochemistry (subgroup A) were performed. The presence of SSTR was confirmed in 25 patients (17 from subgroup A + 8 from subgroup B) in whom SSA therapy was started (every 4 weeks: octretide LAR 20 mg intramuscular or lanreotide autogel 120 mg deep subcutaneous injection). The duration of the therapy varied from 16 months to 18 years. Adenoma size was estimated in pituitary magnetic resonance imaging.

Results: Tumour progression rate was twice higher in patients who were not treated with SSA (71.9% vs 36%). In subgroup A tumour volume increased in 35.3% patients treated with SSA compared to 74% those without pharmacotherapy. Moreover, in subgroup B tumour progression was noticed in 37.5% SSA treated patients vs 66.7% not SSA treated patients.

Conclusions: SSA significantly decrease the probability of tumour progression in NFPA, however, further studies should be carried out.