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.