Effect of Cabergoline Treatment on Disease Control in Acromegaly Patients

The aim of this study was to evaluate the efficacy of cabergoline in normalizing plasma IGF-I levels in acromegaly patients with elevated IGF-I levels after surgery and/or SRL therapy. Acromegaly patients (n: 143) were evaluated retrospectively. Patients with elevated IGF-I levels after surgery and/or SRLs therapy and a fixed dose of SRLs treatment for the last six months with no history of radiotherapy in the last three years were included in the study (n: 12). Previous treatment regimens, baseline PRL and IGF-I levels (ULNR), sella MRI, and immunohistochemical findings were evaluated. Cabergoline was used as an add on (n: 11) or single medical treatment (n: 1). The median duration of treatment with SRL alone was 12 months (range 6-48 months). The mean IGF-I value before cabergoline therapy was 1.45±0.4 ULNR. The mean cabergoline dose and duration of treatment were 1.55±0.75 mg/week and 9±6.3 months, respectively. IGF-I normalization was only achieved in patients with serum IGF-I concentration<1.5×ULNR before the onset of cabergoline treatment (n: 9). In some of the patients with IGF-I normalization, baseline prolactin levels were normal (n: 3). Immunopositivity for prolactin in adenoma tissue was found in three patients with IGF-I normalization. Cabergoline therapy is effective in the normalization of IGF-I levels even in normoprolactinemic acromegaly patients when IGF-I levels are mildly or moderately elevated during SRL therapy.