Acromegaly is a
chronic disease with signs and symptoms due to
growth hormone (GH) excess. The most frequent cause of
acromegaly is a GH-producing
pituitary adenoma. Chronic GH excess is accompanied by long-term complications of the locomotor (
arthrosis) and cardiovascular (
atherosclerosis,
cardiomyopathy) systems and is, when untreated, associated with an increased mortality. The aim of treatment of
acromegaly is to improve symptoms, to achieve local tumour mass control, and to decrease morbidity and mortality. Treatment options include surgery, medical
therapy and
radiotherapy. Transsphenoidal surgery is the first choice of treatment when a definitive cure can be achieved, particularly in the case of microadenomas and when
decompression of surrounding structures (optic chiasm, ophthalmic motor nerves) is indicated. Primary medical
therapy has been increasingly applied in recent years, especially when a priori chances of surgical cure are low (because of
adenoma size and localization) and in patients with advanced age and/or serious co-morbidity. In addition, preoperative primary medical
therapy may result in tumour shrinkage, facilitating tumour resection, and may reduce perioperative complications due to GH excess. Within the spectrum of medical
therapy, long-acting
somatostatin analogues (somatostatins) are considered as first-line treatment. Treatment with
somatostatin analogues results in GH control in approximately 60% of patients. In addition,
somatostatin analogues induce tumour shrinkage in 30-50% of patients, particularly when applied as primary
therapy. Prolonged treatment with
somatostatin analogues appears to be safe and is usually well tolerated. The currently available
somatostatin analogues,
octreotide and
lanreotide, seem to be equally effective; however, this should still be evaluated in prospective, randomized trials evaluating efficacy with respect to GH control and tumour shrinkage. In patients with an insufficient clinical and biochemical response to
somatostatin analogues, combination
therapy with
dopamine receptor agonists or the GH receptor antagonist
pegvisomant usually leads to disease control. New developments in the medical
therapy of
acromegaly include the universal
somatostatin receptor agonist
pasireotide, which has a broader affinity for all
somatostatin receptor (sst) subtypes compared with the currently available
somatostatin analogues with preferential affinity for the sst2 receptor, and chimeric compounds that interact with both
somatostatin and
dopamine receptors with synergizing effects on GH secretion.