Standard Treatment Options for Growth Hormone (GH)-Producing Pituitary Tumors
Standard treatment options for GH-producing pituitary tumors include the following:
- Surgery (usually a transsphenoidal approach).
- Dopamine analogues, such as bromocriptine.
- Somatostatin analogues, such as octreotide.
- The GH-receptor antagonist, pegvisomant.[1,2]
- Surgery and postoperative radiation therapy.
Treatment for patients with acromegaly includes surgical, radiation, and medical therapies. Treatment will depend on the size and extent of the tumor and the need for rapid cessation of hormone function that results in serious clinical sequelae (i.e., hypertension and cardiomyopathy).
Microadenomectomy or macroadenoma decompression is approached transsphenoidally in most patients. Increasingly, endoscopic surgery is used to allow the entire surgical field to be viewed and to allow tumor tissue that would otherwise be inaccessible with rigid instruments to be safely resected. Complete return of GH concentrations to normal, however, is not often achieved. Increasingly, adjunctive radiation therapy is reserved for tumors that extend beyond the safe operative area and appear to pose an ongoing threat.
Drug treatment, whether used as an adjuvant or primary therapy in appropriately selected patients, which is advocated by some, includes the use of somatostatin analogues, such as octreotide; dopamine analogues, such as bromocriptine; and, the GH-receptor antagonist, pegvisomant. As the first of a new class of GH-receptor antagonists, pegvisomant works by inhibiting functional dimerization of GH receptors and thereby inhibits GH action. Preliminary results indicate that it may be the most effective medical treatment for acromegaly reported to date.[1,2]
In acromegalic patients, impaired glucose tolerance, hypertension, and hyperlipidemia should be vigorously treated concurrently with definitive therapy. A multidisciplinary clinical approach may be required for the treatment of arthritis, carpal tunnel syndrome, obstructive sleep apnea, and prognathism. Mortality is related primarily to cardiovascular and respiratory diseases.
Current Clinical Trials
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with pituitary tumor. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.
General information about clinical trials is also available from the NCI Web site.
Stewart PM: Pegvisomant: an advance in clinical efficacy in acromegaly. Eur J Endocrinol 148 (Suppl 2): S27-32, 2003.
Muller AF, Kopchick JJ, Flyvbjerg A, et al.: Clinical review 166: Growth hormone receptor antagonists. J Clin Endocrinol Metab 89 (4): 1503-11, 2004.
Levy A: Pituitary disease: presentation, diagnosis, and management. J Neurol Neurosurg Psychiatry 75 (Suppl 3): iii47-52, 2004.
Kleinberg DL: Primary therapy for acromegaly with somatostatin analogs and a discussion of novel peptide analogs. Rev Endocr Metab Disord 6 (1): 29-37, 2005.
Colao A, Ferone D, Marzullo P, et al.: Systemic complications of acromegaly: epidemiology, pathogenesis, and management. Endocr Rev 25 (1): 102-52, 2004.