MON-112 - Prolactinoma from a Patients’ Perspective: Clinical Manifestations, Treatment Experiences and Associated Adverse Effects, and a Novel Impulse Control Disorder Questionnaire – Results from an International Survey Study –

OBJECTIVE Prolactinomas are commonly treated with dopamine agonists (DAs), which normalise prolactin levels in most patients. However, long-term patient-reported tolerability remains insufficiently characterised. Adverse effects-particularly impulse control disorders (ICDs)-may be underrecognized due to the lack of disease-specific screening tools and the limited applicability of instruments developed for other conditions. This study aimed to assess patient-reported treatment experiences and adverse effects and to evaluate a novel, brief ICD screening tool tailored to patients with prolactinoma.

PATIENTS/METHODS This international, cross-sectional survey study (June 2025-January 2026), coordinated by the University Hospital Basel, included adults (=18 years) with prolactinoma recruited via their treating physicians. The survey assessed symptoms at diagnosis, treatment history, DA-associated adverse effects, and behavioural changes. Impulsivity and ICDs were evaluated using the Barratt Impulsiveness Scale (BIS), the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (QUIP), and the newly developed BASEL-ICD-S questionnaire. Patients were analysed according to current DA exposure. Receiver operating characteristic (ROC) analyses were used to derive cut-offs in development and validation cohorts.

RESULTS A total of 528 patients were included (median age 40 years [IQR 31-49], 73% female, median disease duration 5 years [2-11]). Common symptoms at diagnosis included menstrual irregularities in women (82%), reduced libido in men (80%), tiredness (70%), and mood changes (64%). Primary treatment was medical in 87% and surgical in 9%; 4% were untreated. Among DA-treated patients (n=406), frequent side effects included fatigue (51%), dizziness (43%), headache (38%), and gastrointestinal complaints (36%). BIS, QUIP, and BASEL-ICD-S scores were higher in DA-treated patients (all p< 0.001). High impulsivity (BIS >74) was more frequent under DA treatment (22% vs 7%). A BASEL-ICD-S score =25 showed good discrimination for high impulsivity (AUC 0.88-0.89) with high negative predictive value (96%). ICDs included gambling (7.4%), compulsive buying (28.1%), and hypersexual behaviour (17.7%).

DISCUSSION Prolactinomas are associated with a substantial symptom burden. DA therapy is frequently accompanied by adverse effects, increased impulsivity, and ICDs. The BASEL-ICD-S represents a robust, brief screening tool for behavioural side effects in this population.

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