Primary Medical Treatment of Thyrotropin-Secreting Pituitary Adenomas by First-Generation Somatostatin Analogs: A Case Study of Seven Patients.

Abstract

BACKGROUND:

The first-choice treatment of thyrotropin (TSH)-secreting pituitary adenomas is surgical adenomectomy, with 40-60% of patients cured after surgery. The presence of somatostatin receptors on the adenomatous cells suggests that first-generation somatostatin analogs (octreotide, lanreotide) could be used as an adjuvant treatment to surgery for TSH-secreting pituitary adenomas. The aim of this study is to describe the efficacy and safety of primary medical treatment with first-generation somatostatin analogs in patients with a TSH-secreting pituitary adenoma.

METHODS:

Retrospective study on 7 patients (5 women, 2 men) aged 57±14 years with pure TSH (n=4) or mixed TSH/GH (n=3) secreting pituitary adenomas primarily treated with first generation somatostatin analogs. Magnetic resonance imaging revealed a microadenoma in 3 patients and a macroadenoma in 4 patients. The follow-up period was 8.5±7.3 years.

RESULTS:

At initial diagnosis, the patients presented with thyrotoxicosis with elevated free thyroxine (26.5±6.5 pg/mL) and free triiodothyronine (7.3±0.9 pg/mL) levels and a mean TSH of 4.3±1.4 mU/L. During somatostatin analog treatment, free thyroid hormones and TSH levels normalized after 4.4±3.9 and 7.0±8.4 months, respectively. At the time of the last visit, 6 patients were biochemically controlled. Adenoma volume decreased in 6 patients and a decrease in adenoma volume persisted in 2 patients several years after initiation of somatostatin analog treatment. Safety of treatment was good and no patients discontinued somatostatin analogs due to side effects.

CONCLUSION:

This study confirms the efficacy of primary medical treatment with first-generation somatostatin analogs in terms of hormonal control and tumor volume reduction in patients with TSH-secreting pituitary adenomas, and its good safety profile. First-generation somatostatin analogs may serve as a medical alternative to surgical treatment, especially in patients where surgery is contraindicated or in subjects presenting with invasive macroadenomas that render complete surgical resection difficult.

• Authors: Frédérique Rimareix, Solange Grunenwald, Delphine Vezzosi, Louis-David Rivière, Antoine Bennet, Philippe Caron
• Journal: Thyroid : official journal of the American Thyroid Association (Thyroid) Vol. 25 Issue 8 Pg. 877-82 (Aug 2015) ISSN: 1557-9077 [Electronic] United States
• PMID: 26244412 (Publication Type: Case Reports, Journal Article)

Chemical References

• Triiodothyronine
• Somatostatin
• Insulin-Like Growth Factor I
• Thyrotropin
• Growth Hormone
• Thyroxine
• Octreotide

Topics

• Adenoma (metabolism, pathology, surgery)
• Adult
• Aged
• Female
• Follow-Up Studies
• Growth Hormone (blood)
• Humans
• Injections, Intramuscular
• Insulin-Like Growth Factor I (metabolism)
• Magnetic Resonance Imaging
• Male
• Middle Aged
• Octreotide (therapeutic use)
• Pituitary Neoplasms (metabolism, pathology, surgery)
• Retrospective Studies
• Somatostatin (analogs & derivatives, therapeutic use)
• Thyrotropin (metabolism)
• Thyroxine (blood)
• Triiodothyronine (blood)