Treatment of Growth Hormone-Secreting Pituitary Tumors

Primary Treatment Approach

Transsphenoidal surgery should be offered as initial treatment to the majority of patients with GH-secreting adenomas, with the goal of normalizing growth velocity, preventing excessive height, suppressing IGF-1 to normal range, and preserving or restoring vision 1, 2
Surgical success rates in experienced pituitary neurosurgical centers achieve approximately 50% remission in children and adolescents with GH excess 1, 3
Even when complete remission is unlikely, tumor debulking significantly reduces circulating GH burden and improves response to subsequent medical therapy and/or radiotherapy 1, 2
Re-operation should be considered in patients with notable residual tumor who show inadequate response to somatostatin analogue therapy or experience considerable tumor regrowth 1, 3

Offer monotherapy or combination medical therapy for patients with post-operative residual disease 1, 4
Cabergoline can be used alone in patients with mild GH excess, co-administered with somatostatin analogues when GH hypersecretion is inadequately controlled, or substituted when somatostatin analogues are poorly tolerated 1, 3
Pegvisomant normalizes serum IGF-1 levels in adequate doses and can suppress growth velocity, a clinical priority in patients with gigantism 1, 3

Offer pituitary radiotherapy to patients with GH-secreting adenoma and uncontrolled tumor growth with incomplete surgical and medical response, except for patients with skull base fibrous dysplasia 3, 5
Radiotherapy may take up to 10 years to be fully effective in suppressing GH, so medical therapy is required at least as a temporary measure 3, 5
After radiotherapy, offer intermittent dose reduction or withdrawal of medical therapy to assess radiation efficacy on GH hypersecretion 3, 5
Hypopituitarism develops in approximately 20% at 5 years and 80% at 10-15 years post-radiotherapy, requiring lifelong monitoring 6

Offer clinical evaluation for associated syndromic causes of somatotrophinomas, including McCune-Albright syndrome, Carney complex, MEN1, and X-linked acrogigantism 2, 4
GH-releasing hormone-secreting pancreatic tumors should be considered as a cause of GH excess in patients with MEN1 syndrome 2, 4

First-line: Transsphenoidal surgery by experienced pituitary neurosurgeon 1, 2
If residual disease: Medical therapy with somatostatin analogues, dopamine agonists, or GH receptor antagonist as monotherapy or combination 1, 4
If medical therapy fails and tumor growth continues: Radiotherapy (except in McCune-Albright syndrome with fibrous dysplasia) 3, 5
Monitor continuously with IGF-1, GH levels, growth velocity measurements, and MRI surveillance 1, 4