Efficacy and Cerebrospinal Fluid Rhinorrhea after Cabergoline Treatment in Patients with Bioactive Macroprolactinoma

SIMPLE SUMMARY: Predicting dopamine agonist resistance in patients with macroprolactinoma is essential for clinicians to prevent treatment failure and subsequent complications such as medication–induced cerebrospinal fluid (CSF) rhinorrhea. In this retrospective cross-sectional study that included 140 patients with newly diagnosed and cabergoline-treated prolactinoma with prolactin levels ≥1000 ng/mL, non-responders and patients with CSF rhinorrhea included a significantly higher number of patients receiving hormone replacement therapy than responders. Hormone deficiency was associated with a greater odds ratio for the risk of non-responders (adjusted odds ratio = 5.13, 95% CI 1.96–13.46, p = 0.001). Cabergoline was effective in bioactive macroprolactinoma and initial cabergoline dose in long-term responsiveness and development of CSF rhinorrhea was not significantly different. Hypopituitarism was independently associated with an increased risk of cabergoline resistance and CSF rhinorrhea. ABSTRACT: Predicting dopamine agonist resistance in patients with macroprolactinoma is essential for clinicians to prevent treatment failure and subsequent complications such as medication-induced cerebrospinal fluid (CSF) rhinorrhea. We evaluated the features of patients with cabergoline resistance and CSF rhinorrhea in patients with prolactinomas with prolactin levels ≥1000 ng/mL. A total of 140 patients who were newly diagnosed with prolactinoma secreting only prolactin ≥1000 ng/mL and treated with cabergoline for the first time were included in this study. Based on the hormonal and radiologic response of the prolactinoma, the patients were divided into responders and non-responders. Non-responders (36/140, 25.8%) included a higher number of patients receiving hormone replacement than responders (responders, n (%) = 12(11.5) vs. non-responders = 13(36.1), p = 0.001). In propensity score matching analysis, patients who developed CSF rhinorrhea presented more frequent hormone deficiency than responders regardless of initial cabergoline dose. Hormone deficiency was associated with a greater odds ratio for the risk of non-responders (adjusted odds ratio = 5.13, 95% CI 1.96–13.46, p = 0.001). Cabergoline was effective in bioactive macroprolactinoma. Furthermore, initial cabergoline dose was not significantly associated with long-term responsiveness and development of CSF rhinorrhea but the hypopituitarism was independently associated with an increased risk of cabergoline resistance and CSF rhinorrhea.