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.
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.
Luque-Ramírez
M
M
Department of Endocrinology, Hospital Universitario de La Princesa, Diego de León 62, 28006 Madrid, Spain. manuluque@gmail.com
Portoles
G R
GR
Varela
C
C
Albero
R
R
Halperin
I
I
Moreiro
J
J
Soto
A
A
Casamitjana
R
R
D049913:ACTH-Secreting Pituitary Adenoma / Q000188:drug therapy* / Q000473:pathology; D000172:Acromegaly / Q000175:diagnosis / Q000188:drug therapy* / Q000473:pathology; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000627:therapeutic use*; D010911:Pituitary Neoplasms / Q000188:drug therapy* / Q000473:pathology; D011446:Prospective Studies; D016896:Treatment Outcome; D047368:Tumor Burden / Q000187:drug effects
D015282:Octreotide