The efficacy of octreotide LAR as firstline therapy for patients with newly diagnosed acromegaly is independent of tumor extension: predictive factors of tumor and biochemical response

Horm Metab Res. 2010 Jan;42(1):38-44.
Luque-Ramírez M, Portoles GR, Varela C, Albero R, Halperin I, Moreiro J, Soto A, Casamitjana R; Spanish Multicentre Group for the Study of Acromegaly.
Horm Metab Res. 2010 Jan;42(1):38-44.
Octreotide LAR (long-acting repeatable/lunga durata di azione ripetibile) è un trattamento di prima linea efficace per un ampio gruppo di pazienti acromegalici indipendemente dell'estensione del tumore iniziale.
Octreotide LAR/pazienti acromegalici.

Surgical outcome of acromegaly depends on the preoperatory tumor size and extension. Somatostatin analogues are also a highly effective treatment for acromegalic patients. Nevertheless, the response of GH-secreting adenomas to primary medical therapy is variable. The aim of the present study was to evaluate the efficacy of octreotide LAR as primary therapy for acromegalic patients as a function of initial tumor extension. We performed a multicentre, prospective, observational and analytical study recruiting 19 "naive" acromegalic patients (5 microadenomas, 10 intrasellar, and 4 extrasellar macroadenomas). All of them were treated with octreotide LAR for 12 months. Basal GH and fasting IGF-I concentrations, and tumor volume were measured at baseline and after 6 and 12 months of treatment. Six patients withdrew the study. The patients who completed the protocol showed a significant reduction of tumor volume (25+/-23%, Wilk's lambda=0.506, F=4.400, p=0.046) independently of tumor extension at study entry (Wilk's lambda=0.826, F=0.452, p=0.769). A shrinkage >25% of baseline tumor volume was achieved in 8 (42%) patients with no differences between tumor extension subgroups. Basal GH levels (76+/-18%) and fasting IGF-I (52+/-31%) decreased throughout the study. Six (46%) patients normalized their IGF-I levels. Octreotide LAR is an effective first-line treatment for a large group of acromegalic patients independent of initial tumor extension.