ANALYSIS OF PREDICTIVE FACTORS FOR REACHING DOPAMINE AGONIST WITHDRAWAL CONDITIONS IN PROLACTINOMAS
Thursday, May 7, 2020
11:15 AM – 11:30 AM
Participants should be aware of the following financial/non-financial relationships: Roberto Salvatori, MD: I do not have any relevant financial / non-financial relationships with any proprietary interests.
Objective : The possible need for lifetime treatment worries patients initiated on dopamine agonist (DA) upon the diagnosis of a prolactinoma. The current guidelines from the endocrine and pituitary societies suggest withdrawal in normoprolactinemic patients who have been treated with DA for at least 2 years and exhibit a marked reduction in tumor volume. Yet, no clear criteria are available as predictors for reaching withdrawal conditions based upon first clinical visit characteristics
Methods: A retrospective analysis was conducted on 200 patients with prolactinoma treated with DA in a single academic medical center by a single physician from 2000 until the latest follow-up date by November 2019. After excluding individuals that lacked initial prolactin levels, were not followed for at least 2 years, or had a pregnancy during treatment, 119 patients (66 females) were included with a median age of 38 (range 12-79) years. 108 patients were treated with cabergoline (0.25-2 mg/week), and 11 with bromocriptine (8.75–105 mg/week). 44 patients had microprolactinomas, 73 had macroprolactinomas and 2 had nontumoral hyperprolactinemia. Societies’ guidelines were used to determine appropriateness of withdrawal. Predictors were evaluated via t-test and chi-square statistics for initial descriptive analysis, while outcomes were reported with a 95% confidence interval via logistic regression modeling
Results: The overall withdrawal attempt ratio in this population was 47% (56/119). The odds ratio of attempting withdrawal in female patients was significantly higher than for male patients (OR 2.64, 95% CI 1.25–5.58, p=.01). No other demographic characteristics were different. Tumor features at diagnosis were mostly similar except for invasiveness into parasellar space, which reduced the odds of reaching withdrawal conditions by 64% (OR 0.36, 95% CI 0.16-0.79, p=.01). Prolactin levels upon diagnosis were not significantly different between the 2 groups, with a median value of 386 ng/mL (range 30.7–14,340) for no attempts compared to 207.3 ng/mL (range 12.9–10,705) for attempts. The mean prolactin percent change upon the first follow up visit following initiation of DA within 2 months was statistically significantly different between the 2 groups with 75.17% (SD 3.70) for failure and 88.85% (SD 2.21) for attempt (t(74)=-3.70, p=.003). There was a 4% increase in odds for withdrawal for every 1% increase in percent prolactin change upon first follow-up (OR 1.04, 95% CI 1.01-1.06, p=.001)
Discussion/Conclusion: Male patients with parasellar tumor invasiveness and low percentage change in prolactin levels upon first follow up are less likely to reach conditions of DA withdrawal, and more likely to require long-term treatment