Efficacy and safety of dopamine agonists in patients treated with antipsychotics and presenting a macroprolactinoma.

CONTEXT: In patients treated with antipsychotics, the rare occurrence of a macroprolactinoma represents a therapeutic challenge. OBJECTIVE: Our aim was to evaluate the efficacy and psychiatric safety of dopamine agonists (DAs) prescribed for large macroprolactinomas in patients with psychosis treated with antipsychotics. DESIGN: This was a multicenter (France and Belgium) retrospective study. PATIENTS: Eighteen patients treated with antipsychotics were included. RESULTS: Under DA, median PRL levels decreased from 1247 (117-81 132) to 42 (4-573) ng/mL (P = 0.008), from 3850 (449-38 000) to 141 (60-6000) ng/mL (P = 0.037) and from 1664 (94-9400) to 1215 (48-5640) ng/mL (P = 0.56) when given alone (n = 8), before surgery (n = 7), or after surgery (n = 6), respectively. The prolactinoma median largest diameter decreased by 28% (0-57) in patients under DAs alone (P = 0.02) but did not change when given after surgery. Optic chiasm decompression was achieved in 82% of patients. Five patients (28%) were admitted for psychotic relapse while receiving DAs (but three of them had stopped antipsychotic treatment at that time). A more severe underlying psychosis, rather than the DA treatment itself, may explain such psychiatric admissions. CONCLUSIONS: Even if the DA efficacy on PRL levels and tumor volume in patients with macroprolactinoma under antipsychotic drugs is less impressive than that typically observed, it may be considered satisfactory for half of our patients, particularly in cases of optic chiasm compression. Psychotic exacerbation was unusual in these patients, occurring mostly in those with the most severe psychotic forms. DAs may therefore be used as antitumor treatment for macroprolactinoma in patients with visual involvement, severe headaches or invasion into the skull base who receive antipsychotics.

MRI T2 signal intensity and tumor response in patients with GH-secreting pituitary macroadenoma: PRIMARYS post-hoc analysis.

Objective Pituitary adenoma MRI T2 signal intensity associates with tumor characteristics including responsiveness to somatostatin analogs (SSAs). These analyses determined whether baseline T2 signal intensity predicts response to primary medical treatment with long-acting SSA. Design Post-hoc analyses of the prospective multicenter, open-label, single-arm PRIMARYS study in which patients with treatment-naïve GH-secreting pituitary macroadenomas received fixed-dose lanreotide autogel (120mg) every 4-weeks for 48-weeks. Methods Associations were investigated between adenoma T2-signal hypo/iso/hyperintensity and treatment responses at week 48/last visit: hormonal control (GH ≤2.5µg/L and IGF-1 normalization); tumor response (tumor volume reduction [TVR] ≥20%); separate GH/IGF-1 control; and change-from-baseline in GH/IGF-1 and tumor volume. Results Adenomas were hypointense at baseline in 50/85 (59%) patients using visual assessment. Of these, 40% achieved hormonal control and 76% achieved a tumor response. Significant univariate associations arose for hypo- vs isointensity with tumor response and achievement of GH ≤2.5 µg/L, but not IGF-1 normalization or overall hormonal control. In multivariate analysis, tumor response was 6-times more likely for hypo- vs isointense tumors (=6.15; 95% CI [1.36;27.88]). In univariate change-from-baseline analyses, hypo- vs isointensity was associated with greater TVR and IGF-1 reduction but not change in GH. In multivariate analysis, IGF-1 decreased by an estimated additional 65 µg/L [P=0.0026]) for hypo- vs isointense. Conclusions Patients with hypointense vs isointense GH-secreting macroadenomas had greater reductions in IGF-1 following primary treatment with lanreotide autogel, and were more likely to achieve tumor response. Assessment of T2 signal intensity at baseline may help to predict long-term responses to primary treatment with SSAs.