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 were presenting 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 to 155). In this cohort, 14/114 (12%) patients were not cured by surgery, including 10 early surgical failures, and 4 late relapses occurring 37.4 months (33 to 41.8) after surgery. From Kaplan Meier estimates, 1-year and 5-year disease free survival were 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.