Gross total resection or debulking of pituitary adenomas improves hormonal control of acromegaly by somatostatin analogs

Abstract

Introduction: Invasive GH-secreting pituitary adenomas are rarely cured by surgery and although long-term therapy with somatostatin analogs (SSAs) may be employed, hormonal control is achieved in only 60% of cases. The impact of tumor debulking on subsequent control of acromegaly with SSAs has not been studied previously. Methods: We studied retrospectively the response to SSA therapy in acromegalic patients before and after incomplete surgical tumor excision. A case review identified 24 acromegalic patients who had received SSA therapy for $1 month before and after gross total resection or debulking of adenomas. No patient received radiotherapy or combination treatment with SSAs and dopamine agonists during the study. GH and IGF-I responses to SSAs were recorded pre-and postoperatively. Postoperative SSA therapy was begun after a washout period of 1-3 months to assess the hormonal effects of the surgery alone. Results: Before preoperative SSA treatment, 24/24 (100%) patients had elevated GH levels and IGF-I levels were elevated in 19/21 (90.5%) patients with recorded values. During preoperative SSA treatment, GH and IGF-I levels were normalized in 7/24 (29.2%) and 11/24 (45.8%) patients respectively. Following postoperative washout, GH was controlled in only 3/24 (12.5%) patients, while IGF-I was controlled in 8/19 (42.1%) patients with available data. During the second SSA treatment period, normal GH levels were seen in 13/24 (54.2%) patients, while IGF-I control was noted in 18/23 (78.3%). Conclusion: Gross total tumor resection or debulking increases the likelihood of achieving biochemical disease control with SSAs in acromegalic patients with adenomas that were not amenable to complete surgical resection and in whom primary SSA therapy was unable to achieve good biochemical control.

Preliminary data on biochemical remission of acromegaly after somatostatin analogs withdrawal

“…First, a majority of five patients in longterm remission (more than 12 months) were previously operated by unsuccessful neurosurgery except one de novo patient (one showing the occurrence of hemorrhagical intratumoral area after 12 months of SSTa withdrawal). This observation is consistent with previous data demonstrating that about 75-80% removal of the tumor by neurosurgery (debulking) improves hormonal control of acromegaly by SSTa (28,29). Secondly, the patients in median term remission (24 weeks) showed IGF-I concentrations lower than those found in other patients also during SSTa treatment.…”

Prolactinomas resistant to standard doses of cabergoline: a multicenter study of 92 patients

“…An important finding of this study is the significant debulking effect of surgery, which could be documented in a subgroup of patients who received CAB before and after surgical treatment, and experienced during their postoperative follow-up a further significant reduction in PRL levels while reducing their weekly CAB dose by 50%. This finding extends the role of surgery in the endocrine control of secreting adenomas (37). At last follow-up, patients treated by combined surgical and pharmacological approaches achieved a rate of PRL normalization and/or complete tumor shrinkage of 33.0 and 36.8% respectively, with a minority showing disease progression (5.3%).…”

T2-weighted MRI signal predicts hormone and tumor responses to somatostatin analogs in acromegaly

“…The control rate in T2 hypo-intense adenomas is, however, similar to that achieved in other 'real world' clinical treatment settings, in which less than 25% of patients achieve strict control with octreotide or lanreotide (Mercado et al 2007, Espinosa-de-los-Monteros et al 2015. For those T2-hypo-intense macroadenomas that appear difficult to fully resect with primary surgery, it may be that surgical debulking of such tumors would lead to a better hormonal control rate with postoperative SSA therapy (Petrossians et al 2005, Jallad et al 2007, Karavitaki et al 2008.…”