Predictors of long-term remission in acromegaly – an updated review

Abstract

Abstract Acromegaly is a rare chronic disorder due to growth hormone (GH) - secreting pituitary tumor. The first-line treatment of acromegaly is a transsphenoidal adenomectomy. Surgical remission rates range from 30-50% for macroadenomas to 70-90% for microadenomas. Thus in patients with active acromegaly after surgery, medical treatment is recommended. Treatment outcome on medical therapy differs a lot depending on medications. The aim of this paper is to summerize the current knowledge of factors predicting acromegaly remission after surgery and biochemical control on medical treatment. Factors affecting treatment outcome, not related to the patient and the tumor, are neurosurgeon’s experience and visualisation tools used during surgery. Younger patients, as well as women tend to achieve acromegaly remission after surgery less often. Patients with lower GH and insulin-like growth factor-1 (IGF-1) concentrations at diagnosis, in oral glucose tolerance test (OGTT) and postoperatively have a greater chance of surgical remission. However, some publications do not confirm that. Patients presenting with larger and more invasive tumors achieve surgical remisson less often. Hypointensive tumors on T2-weighted magnetic resonance imaging (MRI) scans are associated with better response to first-generation somatostatin receptor ligands (SRLs) and to pasireotide. Pathologic factors increasing the chance of acromegaly remission are densely granulated tumors, lower Ki-67 index, high expression of somatostatin receptors (SSTRs) and high expression of E-cadherin. A thorough analysis of the abovementioned factors predicting the treatment outcome in acromegaly may be helpful for selecting the best treatment option for each patient.