Long-term effects of lanreotide SR and octreotide LAR® on tumour shrinkage and GH hypersecretion in patients with previously untreated acromegaly.

Summarybackground and objectiveThe therapeutic efficacy of lanreotide SR and octreotide LAR^® has been studied widely in patients treated previously with neurosurgery and/or radiotherapy. These therapies limit the evaluation of the long-term effects of somatostatin analogues on tumour shrinkage. Neurosurgical and radiotherapy treatments cause irreversible anatomical changes in pituitary morphology, which can make accurate evaluation of tumour shrinkage difficult. The aim of this study was to investigate the therapeutic efficacy of lanreotide SR and octreotide LAR^® in previously untreated patients with acromegaly. We aimed to investigate the long-term effects of these drugs on tumour shrinkage and growth hormone (GH) hypersecretion without the confounding influences of previous therapy. patients and methodsTwenty-three newly diagnosed patients with acromegaly (14 women, nine men) with active disease began the study; of these, three were lost for follow-up, leaving a total of 20 patients to complete the study. Patients were assigned randomly to lanreotide SR (12 patients) and octreotide LAR^® (eight patients), and the randomization stratified patients to assure a balance between the groups with respect to baseline tumour dimension, age and sex. Tumour volume was evaluated by magnetic resonance imaging of the sella, and calculated with the rotating ellipsoid formula. A morphological and biochemical evaluation was performed at baseline, 12 and 24 months after beginning lanreotide SR and octreotide LAR^® treatment. A reduction of tumour volume of at least 10% was considered significant. resultsBiochemical control increased progressively throughout the study in patients with microadenomas more than in patients with macroadenomas (70%vs. 10%; P < 0·05) and without a difference between lanreotide SR and octreotide LAR^® (41·0%vs. 37·5%; P not significant). After 12 months of... [ABSTRACT FROM AUTHOR]