ECE2022 Poster Presentations Pituitary and Neuroendocrinology (127 abstracts)
1University of Turin, Department of medical sciences, Division of Endocrinology, Diabetology and Metabolism, Turin, Italy; 2A.O.U. Città della Salute e della Scienza, Department of medical sciences, Division of Endocrinology, Diabetology and Metabolism, Turin, Italy; 3ASL Città di Torino, Maria Vittoria Hospital, Division of Endocrinology and Metabolic Diseases, Turin, Italy
Purpose: The aim of this study was to identify any predictive factors for need of high doses of cabergoline (CAB) in prolactinomas and to study any relationship between adverse events onset and CAB cumulative dose.
Methods: Forty-two patients harboring resistant prolactinomas (High Dose group-HD; cabergoline dose ≥ 3.5 mg/week) were matched by gender, age and pituitary tumor diameter at diagnosis with subjects under standard doses (Standard Dose group - SD). All 84 patients were evaluated in terms of response to treatment and for adverse events onset.
Results: Except for higher PRL levels at diagnosis, no significant differences were documented between HD and SD, nor at diagnosis neither at last follow-up. In HD overall treatment duration was significantly longer (P 0.041) and CAB cumulative dose significantly higher (P 0.0001), with lower response rate, both in biochemical (P 0.0007) and morphological (P 0.03) terms. In particular, PRL levels were significantly lower in SD both at diagnosis and after 3, 6, 12 month of CAB and at nadir (respectively p 0.016, P0.0009, P< 0.0001, P0.0001 and P0.003), this last occurring with a CAB dose lower in SD (P<0.0001). Adenoma diameter was smaller in SD (P 0.021) after 12 months of CAB. ROC curves highlighted a threshold PRL value of 1081 ng/ml al diagnosis (sensitivity 62% and specificity 71%, AUC 0.67; P0.007) as predictive for high doses necessity, of 75 ng/ml after 3 months of therapy (sensitivity 81% and specificity 60%, AUC 0.74; P0.0001), of 58 ng/ml after 6 months (sensitivity 76% and specificity 81%; AUC 0.80; P< 0.0001) and of 10 ng/ml after 12 months (sensitivity 97% and specificity 48%; AUC 0.77; P<0.0001). All ten patients (over 45 studied, 22.2%) who developed valvular fibrosis were in HD (P 0.019) and underwent a higher cumulative dose of CAB (P 0.003). Five patients (5.9%) developed impulse control disorder, equally distributed among two groups (P 0.67), without significant difference (P 0.40) in CAB cumulative dose.
Conclusion: A PRL value higher than 58 ng/ml after 6 months resulted as the best predictive factor for high doses necessity. No additional risk of impulse control disease was detected in HD, but a higher prevalence of heart valvular fibrosis was recorded. Even though this finding may be partly due to echocardiographic test mainly being performed in such patients, this data should not be underestimated.