Long-term remission following withdrawal of dopamine agonist therapy in subjects with microprolactinomas.
OBJECTIVE
Reports suggest that up to 70% of patients with microprolactinomas treated with dopamine agonist therapy may achieve long-term normoprolactinaemic remission following drug withdrawal. Yet, there is no consensus on the duration of therapy nor is therapeutic interruption universally practised. We have assessed remission rates in a large cohort of treatment-naive subjects with microprolactinomas. Subjects received dopamine agonist (DA) therapy with either cabergoline or bromocriptine for a period of 2 to 3 years in the majority of cases, followed by a trial of treatment withdrawal.


METHODS
Retrospective analysis of clinic records of 89 patients (mean age 32.7 +/- 8.4 years, 84 women and 5 men) who had received either cabergoline (n = 67) (0.5-3 mg weekly) or bromocriptine (n = 22) (2.5-10 mg daily) for a mean duration of 3.1 years.


RESULTS
Following withdrawal of therapy, 57 subjects developed recurrence (64%) and the mean time to recurrence was 9.6 months (range 1-44 months), while 32 subjects (36%) remained in remission beyond 1 year (mean 3.6 years, range 1-7 years). There was no difference in remission rates between subjects treated with cabergoline (n = 21) and bromocriptine (n = 11), but a direct relationship between pretreatment prolactin concentration and risk of recurrent symptomatic hyperprolactinaemia was observed. No subjects developed clinical features to suggest tumour expansion following therapeutic discontinuation.


CONCLUSIONS
This study confirms that abrupt withdrawal of chronic dopamine agonist therapy, following 2 to 3 years of treatment is safe and associated with long-term remission in 30-40% of subjects with microprolactinomas. This therapeutic strategy is convenient and applicable in clinical practice.
Biswas
M
M
Department of Endocrinology, University Hospital of Wales, Heath Park, Cardiff, Wales, UK.
Smith
J
J
Jadon
D
D
McEwan
P
P
Rees
D A
DA
Evans
L M
LM
Scanlon
M F
MF
Davies
J S
JS
D000293:Adolescent; D000328:Adult; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001971:Bromocriptine / Q000627:therapeutic use; D000077465:Cabergoline; D018491:Dopamine Agonists / Q000627:therapeutic use*; D004873:Ergolines / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000188:drug therapy*; D015175:Prolactinoma / Q000188:drug therapy*; D012008:Recurrence; D012074:Remission Induction; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D018491:Dopamine Agonists; D004873:Ergolines; D001971:Bromocriptine; D000077465:Cabergoline