Treatment Outcome Results from the Bulgarian Acromegaly Database: Adjuvant Dopamine Agonist Therapy is Efficient in Less than One Fifth of Non-irradiated Patients

Objective: We described biochemical outcome in regards to different treatment modalities in patients with acromegaly in Bulgaria. Patients and methods: It was a retrospective analysis using data from the Bulgarian Acromegaly Database. Patients with eligible data on at least one treatment modality were included in the study. Disease control was assessed by both GH and IGF-1 values or by GH/IGF-1 alone in cases with one marker. Last follow-up was median 7.0 (range 0.5-51) years after diagnosis. Results: We identified 534 patients with interpretable data, 65.4% of whom were females. Overall surgical cure rate was 28.8%. Adjuvant bromocriptine and cabergoline treatment was analyzed in 133 and 70 patients with disease control achieved in 18.8% and 31.4% respectively. Patients without prior radiotherapy had 16.3% and 18.2% control rates respectively. Predictors of response to dopamine agonist (DA) therapy were disease activity, radiotherapy and medication dose. Adjuvant somatostatin analog (SSA) treatment led to biochemical control in 38.6% of 70 patients. Combination of SSA and cabergoline led to remission in 25% of 20 patients. Growth hormone receptor antagonist (GHRA) alone or in combination resulted in remission in 61.5% of 13 patients. Approximately one third of the patients were cured median 10 years after irradiation. Overall disease control was observed in 51.4% of our patients increasing to 70.3% in the last 5 years of the study period. Conclusion: DAs are efficient in less than 20% of non-irradiated patients. They are a good cost-effective alternative for carefully selected patients.