Aim: Dopamine agonist (DA) therapy is recommended as first-line treatment for prolactinomas, albeit with long treatment duration and high recurrence rate after treatment withdrawal. The aim of this retrospective study was to evaluate predictors for successful DA withdrawal.
Methods: The study included 59 prolactinoma patients (39 female, 20 male; age 34 (1882) years) that were treated with DA (35.6% on cabergoline); the duration of treatment was 71 (12216) months. Median tumor size at diagnosis was 10 (247) mm. Thirty two patients had macroprolactinomas. Thirty seven patients had disease recurrence or significant increase in PRL level during DA dose tapering, while 22 patients had normal PRL level on low DA dose (bromocriptine <2.5 mg/day or cabergoline ≤ 0.25 mg/week), hence treatment withdrawal was attempted. Patients were divided in remission and recurrence group, and factors that predict recurrence were evaluated.
Results: Patients in whom withdrawal was attempted had lower prolactin (PRL) level at diagnosis (104 (506780) ng/L vs 340 (588870) ng/L, P=0.021), smaller baseline tumor diameter (7 mm (243) vs 15 mm (2-47), P=0.028) and lower maximal bromocriptine dose during treatment (5 mg (123) vs. 10 mg (143), (P=0.003). Eleven of 22 patients (50%) had recurrence of disease after cessation of DA. Patients in remission, compared to those with recurrence, had lower baseline PRL level (P=0.055, OR 0.984, CI 0.9691.000) and larger tumor size (P=0.06, OR 1.557, CI 0.9822.467) but the differences were not significant.
Conclusion: Long term DA treatment resulted in remission in 18.6% of our patients. Pretreatment prolactin level and tumour size have no predictive value for disease remission.
18 - 21 May 2019
European Society of Endocrinology