Wednesday, September 17, 2008

Medical therapy of pituitary adenomas: Effects on tumor shrinkage

Medical therapy of pituitary adenomas: Effects on tumor shrinkage

Journal Reviews in Endocrine & Metabolic Disorders

Publisher Springer Netherlands
ISSN 1389-9155 (Print) 1573-2606 (Online)
DOI 10.1007/s11154-008-9107-z
Subject Collection Medicine
SpringerLink Date Saturday, September 13, 2008

Annamaria Colao1 Contact Information, Rosario Pivonello, Carolina Di Somma, Silvia Savastano, Ludovica F. S. Grasso and Gaetano Lombardi
(1) Department of Molecular & Clinical Endocrinology and Oncology, “Federico II” University of Naples, via S. Pansini 5, 80131 Naples, Italy

Published online: 13 September 2008

Abstract The efficacy of dopamine-agonists (DA) in patients with prolactinomas and that of somatostatin analogues (SSA) in those with GH- and TSH-secreting adenomas is well established. More recently, data are accumulating suggesting a potential therapeutic role of DA also in patients with ACTH-secreting and clinically non-functioning (NFA) pituitary adenomas.

This review aims at summarizing published results of DA and SSA on tumor shrinkage in patients with different histotypes of pituitary adenomas. Results of tumor shrinkage are of clinical relevance as tumor size is the one of the most important determinant of surgical outcome. While reduction of tumor size more than 50% of baseline size in macroprolactinomas treated with DA is a frequent finding in patients with GH-secreting adenomas treated with SSA tumor shrinkage only recently is becoming frequent thanks to the availability of depot formulations. Data on tumor shrinkage in patients with TSH-secreting adenomas treated with SSA are limited because of the rarity of these tumors. Very recently, DA have been reported of some efficacy also in patients with ACTH-secreting adenomas but data are still very limited. NFA respond very scantly to both DA and SSA even if receptors targeting these drugs are present. Whether this is due to limited receptor number or alterations of post-receptor pathway is still unknown.

Keywords GH - PRL - ACTH - TSH - Pituitary tumors - Somatostatin - Dopamine