Pituitary surgery as alternative to dopamine agonists treatment for microprolactinomas: a cohort study.

OBJECTIVE: Microprolactinomas are currently treated with dopamine agonists. Outcome information on microprolactinoma patients treated by surgery is limited. This study reports the first large series of consecutive non-invasive microprolactinoma patients treated by pituitary surgery and evaluates the efficiency and safety of this treatment. DESIGN: Follow-up of a cohort of consecutive patients treated by surgery. METHODS: Between January 2008 and October 2020, 114 adult patients with pure microprolactinomas were operated on in a single tertiary expert neurosurgical department, using an endoscopic endonasal transsphenoidal approach. Eligible patients presented with a microprolactinoma with no obvious cavernous invasion on MRI. Prolactin was assayed before and after surgery. Disease-free survival was modeled using Kaplan-Meier representation. A cox regression model was used to predict remission. RESULTS: Median follow-up was 18.2 months (range: 2.8-155). In this cohort, 14/114 (12%) patients were not cured by surgery, including ten early surgical failures and four late relapses occurring 37.4 months (33-41.8) after surgery. From Kaplan-Meier estimates, 1-year and 5-year disease free survival was 90.9% (95% CI: 85.6-96.4%) and 81% (95% CI: 71.2-92.1%) respectively. The preoperative prolactinemia was the only significant preoperative predictive factor for remission (P < 0.05). No severe complication was reported, with no anterior pituitary deficiency after surgery, one diabetes insipidus, and one postoperative cerebrospinal fluid leakage properly treated by muscle plasty. CONCLUSIONS: In well-selected microprolactinoma patients, pituitary surgery performed by an expert neurosurgical team is a valid first-line alternative treatment to dopamine agonists.