Endocrine Abstracts

Introduction: Prolactinomas are the most common pituitary adenomas. Dopamine agonists (DAs) are the treatment of choice for prolactinomas. Patients with prolactinomas normally are treated in ambulatory. In some patients there are challenges in therapy, and they need to be hospitalized.

Objective: To study the clinical features and outcomes of in-patients with prolactinoma.

Materials and methods: A retrospective analysis of 40 hospitalized Patients with prolactinomas was done. MRI-findings, type and the effect of therapy have been analyzed.

Results: Forty patients (18 (45%) men, 22 (55%) women) were included into the study. Eight patients (20%) had microprolactinomas and 32 (80%) harbored macroprolactinomas. The main reasons for hospitalization were: 30 (75%) patients were referred from different regions of Russian Federation due to ineffectiveness of routine treatment, 8 (20%) were transferred from the neurosurgery department after adenomectomy and 2 (5%) were hospitalized due to the suspicion on MEN1 syndrome. 11/40 (40%) patients used cabergoline in dose less than 2 mg/week with prolactin levels normalization and adenoma volume reduction. This group of patients can be considered as sensitive to DAs. Due to an allergic reaction, cabergoline therapy was discontinued in one patient; after that was performed adenomectomy followed by normalization of prolactin levels. 2/40 patients were initially treated with bromocriptine (7.5–12.5 mg/day) and led to the normalization of prolactin and a decrease in adenoma volume. 16/40 (40%) patients used cabergoline in dose more than 2 mg/week without prolactin levels normalization. This group of patients can be considered as resistant to DAs. In 8/16 (50%) patients doses were increased (to 3.5–4.5 mg/week), in 4 patients it led to normalization of prolactin levels. In 2/16 (12.5%) patients cabergoline was changed to bromocriptine (7.5–10 mg/day), in 1 patient it led to normalization of prolactin levels. Adenomectomy was performed in 6/16 (38%) patients; however, surgery did not lead to normalization of prolactin in 3 cases. 10/40 patients (25%) underwent adenomectomy without achieving the maximum tolerated doses of DAs, only 3 of them had emergency indications for surgery.

Conclusions: The use of high doses of DAs can lead to normalization of prolactin levels, as well as a reduction of more than 30% of the tumor volume with long-term treatment. The increasing of doses of DAs to the maximum tolerated, using a combination of non-selective and selective DAs can lead to prolactin levels normalization and reduce the number of surgical interventions among patients with prolactinomas.

Keywords: bromocriptine, cabergoline, prolactinoma, resistance.