Medical treatment of acromegaly-experience from the Croatian acromegaly registry.

Purpose: The aim of this study was to review therapeutic outcomes of the medical treatment of patients with acromegaly based on real-world data from the Croatian Acromegaly Registry.

Methods: In this retrospective study we investigated 163 patients (101 female, 62 male, age at diagnosis 47.2 ± 13.4 years) treated between 1990 and 2020, of which 53 were treated medically (32.5%). The duration of follow-up was 115.8 ± 304.4 months. The remission rate after the pituitary surgery was achieved in 66.5% (n = 105/158; 5 patients refused surgery). Patients who did not achieve disease remission or had a relapse during follow-up (n = 2), underwent reoperation (n = 18/60, 30%) and/or radiotherapy (n = 33/60, 55%) and/or medical treatment (n = 53/60, 88.3%). One patient refused further treatment after the failure of the first pituitary surgery.

Results: Out of 53 patients treated with medical therapy, monotherapy was used in 34 (64.2%) and combination therapy in 19 (35.8%) patients. Remission (IGF-I < 1.2 upper limit of normal, ULN) was achieved in 51 patients (96.2%). Out of 53 patients, 21 (39.6%) were treated with first-generation somatostatin receptor ligand (SRL-1) monotherapy, 10 (18.9%) with dopamine agonist (DA) monotherapy, one (1.9%) with pegvisomant monotherapy, 13 (24.4%) with a combination of SRL-1 and DA, three (5.7%) with a combination of SRL-1, DA and pegvisomant, two (3.8%) with a combination of second-generation somatostatin receptor ligand (SRL-2), DA and pegvisomant and in one (1.9%) temozolomide was added on top of SRL-1 and DA. Two patients currently have active disease, both on SRL-1 monotherapy, of whom one is non-adherent to the treatment. Radiotherapy was applied to 27 (50.9%) patients on medical therapy.

Conclusion: Our results indicate that almost all patients with active acromegaly after pituitary surgery can achieve biochemical control with medical treatment.