NECESSITY OF MULTIMODAL TREATMENT OF ACROMEGALY AND OUTCOMES.

Uncontrolled acromegaly is associated with increased morbidity and mortality. Despite multimodal therapeutic options, adequate control can be challenging and lead to prolonged exposure to growth hormone excess. The aim of this study was to assess treatment patterns and outcomes in patients with acromegaly following surgery at a single institution. A retrospective analysis of response to treatment modalities for patients with a new diagnosis of acromegaly at the Mayo Clinic in Rochester, Minnesota, from 1995-2015. A total of 245 patients with newly diagnosed acromegaly (mean age at diagnosis, 47 ± 14 years; mean follow-up, 5.5 ± 5 years) were evaluated. Primary surgical intervention was performed in 236 patients; 117 (54%) did not achieve remission. Among those with ≥3 months follow-up, 76/217 (35%) patients required three or more forms of treatment. Mean tumor size at diagnosis was 1.6 ± 0.8 cm (80% macroadenomas), and 35% (75/217) had cavernous sinus invasion on pre-operative imaging. The most common second-line treatment was radiation treatment (RT) (50%, 59/117). Among those with persistent disease following surgery, a normal insulin-like growth factor 1 (IGF-1) was achieved in 52% (61/117), with a median time to acromegaly control of 4.5 years. The rate of IGF-1 normalization was 2.1-fold higher in those who received RT compared to those who did not. In patients with persistent acromegaly following surgery, multiple treatment modalities, including RT, may be required to achieve remission. Treatment outcome uncertainty and the need for multiple interventions add to the disease burden associated with persistent acromegaly. CI = confidence interval; GH = growth hormone; IGF-1 = insulin like growth factor-1; KM = Kaplan-Meier; RT = radiation treatment.