Biochemical Remission after Cabergoline Withdrawal in Hyperprolactinemic Patients with Visible Remnant Pituitary Adenoma

Context Dopamine agonists (DAs) are the first-line therapy for prolactinomas. Although pituitary tumors often do not completely disappear, discontinuing DAs in patients with no visible tumor on magnetic resonance imaging is advised. Objective To analyze biochemical remission after cabergoline (CAB) withdrawal in patients with visible remnant pituitary tumors. Design Retrospective cohort study. Setting Severance Hospital. Subjects We identified 734 patients with prolactinomas undergoing CAB therapy for at least 12 months from 2005 to 2018. We selected 44 patients with prolactinomas who discontinued CAB with normal prolactin levels; they were receiving a minimal CAB dose but had visible remnant tumors. Results Median age at diagnosis was 32 (18-58) years, and most patients were women (95.45%). Median treatment duration was 32 (12-120) months. Of 44 patients, 33 continued to have normoprolactinemia, but 11 patients developed hyperprolactinemia after drug withdrawal within 26 (12-97) months. Age, sex, maximal and remnant tumor size, and treatment duration were similar between the groups. The initial prolactin level and chances of cavernous sinus (CS) invasion were higher in the recurrence group. CS invasion at diagnosis was associated with an increased recurrence rate. Although treatment response did not correlate with the initial and final signal intensity assessments, a significant decrease in T2 intensity ratio after 6 months of CAB therapy was observed in the remission group (P = .043). Conclusion In patients with visible tumors, the presence of CS invasion at diagnosis may be an unfavorable predictor for biochemical remission after CAB discontinuation.