Dopamine agonist therapy induces significant recovery of HPA axis function in prolactinomas independent of tumor size: a large single center experience.

Our objective was to compare prevalence and rates of recovery of hypothalamic-pituitary-adrenal axis dysfunction in prolactinoma patients before and after dopamine agonist therapy with nonfunctioning pituitary adenoma patients pre-transsphenoidal and post-transsphenoidal surgery. We retrospectively compared hypothalamic-pituitary-adrenal axis function in patients with prolactinomas naïve to dopamine agonist therapy with a cohort of nonfunctioning pituitary adenoma patients matched for gender and tumor size by classification (n = 57; 30 male/27 female; 27 microadenoma/30 macroadenoma). Patients with <52 weeks follow up, previous medical therapy, surgery, or radiation therapy were excluded. At baseline, there was no difference between groups for age, mean tumor size, or prevalence of adrenal insufficiency. Recovery from baseline adrenal insufficiency was demonstrated in patients with microprolactinomas and macroprolactinomas at a 52 week follow up (p  = 0.003 and p  = 0.004). These rates were similar to nonfunctioning pituitary adenoma patients after surgery. We show, in a large uniform study, that adrenal insufficiency significantly recovered after dopamine agonist treatment, independent of tumor size and gender in patients with prolactinomas naïve to therapy.