Place of Cabergoline in Acromegaly: A Meta-Analysis

Abstract

Context: Cabergoline is widely considered to be poorly effective in acromegaly. Objective: The aim of this study was to obtain a more accurate picture of the efficacy of cabergoline in acromegaly, both alone and in combination with somatostatin analogs. Design: We systematically reviewed all trials of cabergoline therapy for acromegaly published up to 2009 in four databases (PubMed, Pascal, Embase, and Google Scholar). We identified 15 studies (11 prospective) with a total of 237 patients; none were randomized or placebo-controlled. A meta-analysis was conducted on individual data (n = 227). Results: Cabergoline was used alone in nine studies. Fifty-one (34%) of the 149 patients achieved normal IGF-I levels. In multivariate analysis, the decline in IGF-I was related to the baseline IGF-I concentration (β = 1.16; P <0.001), treatment duration (β = 0.28; P < 0.001), and baseline prolactin concentration (β = −0.18; P = 0.01), and with a trend toward a relation with the cabergoline dose (β = 0.38; P =0.07). In five studies, cabergoline was added to ongoing somatostatin analog treatment that had failed to normalize IGF-I. Forty patients (52%) achieved normal IGF-I levels. The change in IGF-I was significantly related to the baseline IGF-I level (β = 0.74; P < 0.001) but not to the dose of cabergoline, the duration of treatment, or the baseline prolactin concentration. Conclusion: This meta-analysis suggests that cabergoline single-agent therapy normalizes IGF-I levels in one third of patients with acromegaly. When a somatostatin analog fails to control acromegaly, cabergoline adjunction normalizes IGF-I in about 50% of cases. This effect may occur even in patients with normoprolactinemia.