Work

Tumor expression of dopamine receptor and prolactin is associated with acute dopamine agonist response in acromegaly

Year: 2026

Type: article

Abstract: Objectives: In acromegaly, primary treatment is usually pituitary surgery. Remission rates are approximately 50% with pituitary tumor size and invasiveness playing important roles. Medical therapy is the secondary treatment for many patients. Yet, dopamine agonist responsiveness is variable, and reliable prognostic markers are lacking. We aimed to identify markers of dopamine agonist responsiveness. We hypothesized that (i) dopamine agonist response correlates with high dopamine receptor D2 expression and prolactin expression and secretion and (ii) estrogen receptor α expression is associated with tumor properties. Design: Single-center retrospective cohort analysis with treatment-naive patients who had undergone a bromocriptine test as a marker for dopamine agonist response. Methods: Sixty-nine patients with newly diagnosed acromegaly between 2008 and 2017 were included. During this period, the bromocriptine test was performed routinely at our center. Baseline hormone concentrations and MR images were evaluated retrospectively. Immunohistochemical staining of hormones and receptors and gene expression of dopamine receptor D2 in tumor tissue were performed and assessed. Results: ≤ 0.001), and both were associated with higher serum prolactin concentration and tumor prolactin expression, assessed by immunohistochemistry. Prolactin and estrogen receptor α expression were correlated, and strong expression was associated with smaller and less invasive tumors. Conclusions: Dopamine receptor D2 and prolactin expression are markers for dopamine agonist test response, providing valuable insights for personalized management and optimization of medical therapy in patients with acromegaly. Although prolactin and estrogen receptor α expression may be associated with tumor growth, the clinical applicability remains unclear.

Source: Frontiers in Endocrinology

DOI: 10.3389/fendo.2026.1930467