Endocrine Abstracts

Introduction: Medical therapy of acromegaly is indicated in patients who failed to achieve remission after surgery, with contraindication or refusal for surgical therapy or following radiotherapy in order to bridge the interval until complete remission.

Objective: Evaluate the medical therapy – somatostatin analogs (SSA), dopamine agonist (DAs) and GH receptor-antagonist (Pegvisomant) – in acromegalic patients followed from 1988–2011.

Methods: We conducted a retrospective study of 52 acromegalic patients (32 women) submitted to medical therapy.

Criteria for disease control (normal age- and sex-adjusted IGF1 concentration and GH below 1 ng/ml) were evaluated by the average of three values. A reduction below 20% of those parameters after SSA was considered as an absence of response to this therapy.

Results: Medical treatment was the only option for eight patients, complemented surgery in 29, isolated radiotherapy in one, and radiotherapy combined with surgery in 14. SSA were used in 43 patients (seven experienced no response). A normal GH and IGF1 concentration was achieved in 16.2% of 36 patients, with an average IGF1 reduction of 54.2%.

DAs were added in 12 patients insufficiently responding to SSA monotherapy, with an IGF1 reduction of 10.7%. Only one case showed normalization of GH and IGF1 concentration.

Six patients on SSA plus DAs ab initio achieved IGF1 reduction of 66.8%, with only one case coming under control. Pegvisomant enabled the control of acromegaly in four of seven cases, with an IGF1 reduction of 48.7%

In total, 26.5% (n=13) of the patients were under control. Of those not controlled (n=36), 50% displayed a dissociated response (IGF1 or GH) and 40.6% registered IGF1 levels only 10% above upper limit of normal.

Conclusion: Around 25% of our patients were controlled. Half of patients not under control displayed a dissociated response. Adding DA to SSA doesn’t seem to improve the results.