Related Experiment Videos
Cabergoline modulation of alpha-subunits and FSH secretion in a gonadotroph adenoma
1Dipartimento di Scienze Endocrinologiche e Metaboliche, Centro di Studio dei Tumori Ipofisari, University of Genova, Italy. magius@unige.it
Abstract:
Most non-functioning pituitary adenomas respond poorly to medical therapy. We describe the case of a 62-year-old man who presented with clinical features of an invasive macroadenoma. Baseline hormonal evaluation revealed increased FSH and alpha-subunit (alpha-SU) levels. Transsphenoidal exeresis followed by radiotherapy (RT) was performed. Almost all neoplastic cells were intensely immunoreactive for alpha-SU. On PCR analysis, specific amplification products were observed for somatostatin 2, 3 and 5 receptors as well as for both short and long isoforms of the dopamine D2 receptor. In vitro, alpha-SU and FSH were released into the medium by adenoma cells and increased after TRH stimulation. After surgery, alpha-SU and FSH levels were still elevated. Short-term slow-release lanreotide treatment did not modify either alpha-SU or FSH levels. Cabergoline was started and a fast and long-lasting decrease in alpha-SU and, to a lesser extent, in FSH was observed. The tumor remnant was unmodified on magnetic resonance imaging 3 years after surgery and RT. This case report shows that the in vitro expression of somatostatin receptors may not be directly associated to the in vivo response of alpha-SU and FSH to lanreotide, probably because of a functional uncoupling of the receptors. Cabergoline should be considered as an effective therapy for hormonal, and perhaps proliferative, control of gonadotroph adenoma remnants before the effects of RT are fully effective.
Insights
This study highlights cabergoline as an effective treatment for controlling elevated hormones in gonadotroph adenoma remnants. It suggests that while somatostatin receptors may be present, they might not respond to lanreotide in vivo.
Area of Science:
- Endocrinology
- Oncology
- Molecular Biology
Background:
- Non-functioning pituitary adenomas (NFAs) often show poor response to medical treatments.
- Invasive macroadenomas require comprehensive management strategies.
- Gonadotroph adenomas are a subset of pituitary tumors with specific hormonal profiles.
Observation:
- A 62-year-old man with an invasive macroadenoma presented with elevated Follicle-Stimulating Hormone (FSH) and alpha-subunit (alpha-SU) levels.
- Tumor cells expressed somatostatin and dopamine D2 receptors, and released alpha-SU and FSH in vitro, with increased release after TRH stimulation.
- Post-surgery, hormonal levels remained elevated, and lanreotide treatment showed no significant effect.
Findings:
- Cabergoline administration resulted in a rapid and sustained decrease in alpha-SU and FSH levels.
- Tumor remnant size remained stable on MRI three years post-surgery and radiotherapy.
- In vitro receptor expression did not correlate with in vivo response to lanreotide, suggesting potential receptor uncoupling.
Implications:
- Cabergoline may be a crucial therapy for hormonal and potentially proliferative control of residual gonadotroph adenomas.
- This finding is particularly relevant while awaiting the full effects of radiotherapy.
- Understanding receptor function is key to optimizing medical therapy for pituitary adenomas.