title: Growth hormone tumor histological subtypes predict response to surgical and medical therapy.
abstract: Growth hormone (GH) pituitary tumors are associated with significant morbidity and mortality. Current treatments, including surgery and medical therapy with somatostatin analogs (SSA), dopamine agonists and/or a GH receptor antagonist, result in disease remission in approximately half of patients. Predictors of GH tumor response to different therapies have been incompletely defined based on histologic subtype, particularly densely (DG) versus sparsely (SG) granulated adenomas. The aim of this study was to examine our own institutional experience with GH adenomas and correlate how subtype related to clinical parameters as well as response to surgery and medical therapies. A retrospective chart review of 101 acromegalic patients operated by a single neurosurgeon was performed. Clinical data were correlated with histologic subtype and disease control, as defined by IGF-1 levels, and random growth hormone levels in response to surgery and/or medical therapies. SG tumors, compared to DG, occurred in younger patients (p = 0.0010), were 3-fold larger (p = 0.0030) but showed no differences in tumor-invasion characteristics (p = 0.12). DG tumors had a higher rate of remission in response to surgery compared to SG, 65.7 vs. 14.3 % (p < 0.0001), as well as to medical therapy with SSAs (68.8 % for DG vs. 28.6 % for SG tumors; p = 0.028). SG tumors not controlled with SSAs consistently responded to a switch to, or addition of, a GH receptor antagonist. Histological GH tumor subtyping implicates a different clinical phenotype and biologic behavior, and provides prognostic significance for surgical success and response to medical therapies.
authors.affiliation: Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado Anschutz Medical Campus, 12801 East 17th Ave, RC1 South Room 7402A, Aurora, CO, 80045, USA, katja.kiseljak-vassiliades@ucdenver.edu.
authors.forename: Katja
authors.initials: K
authors.lastname: Kiseljak-Vassiliades
authors.forename: Nichole E
authors.initials: NE
authors.lastname: Carlson
authors.forename: Manuel T
authors.initials: MT
authors.lastname: Borges
authors.forename: B K
authors.initials: BK
authors.lastname: Kleinschmidt-DeMasters
authors.forename: Kevin O
authors.initials: KO
authors.lastname: Lillehei
authors.forename: Janice M
authors.initials: JM
authors.lastname: Kerr
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Wierman
mesh_terms: D000172:Acromegaly / Q000145:classification / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D000236:Adenoma / Q000145:classification / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000145:classification / Q000188:drug therapy / Q000473:pathology / Q000601:surgery; D019382:Human Growth Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies
chemical_list: D019382:Human Growth Hormone; C406545:pegvisomant