Outcomes of transsphenoidal surgery in prolactinomas: improvement of hormonal control in dopamine agonist-resistant patients

Context: Few studies have recently re-examined the efficacy of neurosurgery in prolactinoma patients operated for various indications. Objective: To analyze outcomes of patients with a prolactinoma treated by transsphenoidal surgery, to identify factors associated with remission and relapse, and to evaluate if surgical debulking allows for better hormonal control in patients with preoperative resistance to dopamine agonists (DAs). Patients and methods: This was a retrospective review of patients with a benign prolactinoma followed preoperatively and postoperatively in our department and treated by transsphenoidal surgery (n = 63; 45 women; mean age: 31 +/- 14 years). Results: Postoperative remission was obtained in 63% of microprolactinomas, 60% of noninvasive macroprolactinomas, and none of the invasive macroprolactinomas. Better remission rate was independently predicted by lower diagnostic prolactin (PRL) levels and by the lack of abnormal postoperative residual tissue (P < 0.05). A recurrence of hyperprolactinemia was observed in 34% of patients after a median follow-up period of 36 (7-164) months. In patients with preoperative DA resistance treated again after surgery, there was a significant reduction in PRL levels postoperatively (26 (6-687) ng/ml) vs preoperatively (70 (22-1514) ng/ml; P < 0.01) under a lower DA dose, and about half of the patients had PRL normalization. Conclusions: Recurrence of hyperprolactinemia is observed in one-third of prolactinoma patients after surgical remission and may occur as late as 13 years after surgery. Resistance to DA can be considered as a good surgical indication, as partial tumor resection allows for better hormonal control with a lower dose of DAs.