Endocrine Abstracts

Background: In many acromegalics neurosurgery is unable to control GH secretion while it may harm the normal pituitary.

Objective: To investigate the effect of pre-treatment with octreotide on surgical outcome in acromegaly.

Methods: Previously untreated acromegalics were randomised directly to surgery or octreotide for six month before transsphenoidal surgery. Three months postoperatively patients underwent OGTT and Insulin Tolerance Test (ITT). Cure was defined as IGF-1 ≤ upper reference value and GH-nadir during OGTT ≤ 2 mIE/l.

Results: Twenty-five of 61 patients (41%) were cured by surgery. In 7 patients ITT were contraindicated. Among the 54 patients performing ITT, 23 had a normal cortisol response (>550 nmol/l), 39 had a normal GH response (≥9 mIE/l) and 19 had a combined normal response. Twenty-three of 25 patients cured by standard criteria underwent ITT. Only 8 (3 pretreated; 5 direct surgery) who were cured by standard criteria had preserved pituitary function in terms of normal GH and cortisol response.

Discussion: This is probably the first study investigating the effect of octreotide pre-treatment and transsphenoidal surgery for acromegaly on both cure by standard criteria and on indices of pituitary function. We propose the concept of “extended cure” meaning cure by standard criteria combined with preserved pituitary-adrenal function and GH-secretion. In our series only 8 out of 54 (15%) achieved “extendid cure” while 15 out of 23 (65%) of those cured by standard criteria had indications of pituitary insufficiency. Pre-treatment with octreotide did not affect the results. We believe our data mirrors the clinical reality. Hence, we question whether or not surgery should remain the first line therapy for acromegaly. Future studies on the effect of both medical therapy and surgery in acromegaly should include evaluation of pituitary function and preserved pituitary function should be included in the definition of cure.