title: Chromogranin A is a sensitive marker of progression or regression in ileo-cecal neuroendocrine tumors.
abstract: OBJECTIVE
  The correlation between plasma Chromogranin A concentrations and changes in tumor size evaluated by computed tomography (CT) - as a gold standard - was evaluated.
  
  
  METHODS
  One hundred and sixteen patients with CgA-producing ileo-cecal neuroendocrine tumors were evaluated by events, which were recorded when a CT was followed by another CT 1 - 12 months later. Change in tumor size was defined as regression, progression, or stable disease using RECIST criteria 1.1. Of 426 events, there were 97 with progression, 279 with stable disease, and 50 with regression. Based on the ROC curves a cutoff value of 25% change was selected to discriminate between increased, decreased, or unchanged CgA concentrations in plasma, using a sensitive radioimmunoassay with well-defined epitope specificity.
  
  
  RESULTS
  In the 97 events showing tumor progression diagnostic sensitivity and specificity of an increased CgA concentration were 86% and 86%, respectively. The positive and negative predictive values were 64% and 85%, respectively. In the 279 events with unchanged tumor size the diagnostic sensitivity and specificity of an unchanged CgA concentration were 73% and 86%, and the positive and negative predictive values were 91% and 63%, respectively. In the 50 events showing tumor regression, diagnostic sensitivity and specificity of a decrease in CgA concentration were 78% and 91%, the positive and negative predictive values being 55% and 97%.
  
  
  CONCLUSIONS
  CgA concentrations in plasma have a high diagnostic accuracy in monitoring patients with ileo-cecal neuroendocrine tumors. In particular, an increase in plasma CgA concentration was useful to indicate tumor progression.
authors.affiliation: Departments of Surgical Gastroenterology, Neuroendocrine Tumour Centre of Excellence, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Kenneth Højsgaard
authors.initials: KH
authors.lastname: Jensen
authors.forename: Linda
authors.initials: L
authors.lastname: Hilsted
authors.forename: Claus
authors.initials: C
authors.lastname: Jensen
authors.forename: Tommie
authors.initials: T
authors.lastname: Mynster
authors.forename: Jens F
authors.initials: JF
authors.lastname: Rehfeld
authors.forename: Ulrich
authors.initials: U
authors.lastname: Knigge
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002430:Cecal Neoplasms / Q000097:blood* / Q000473:pathology; D053379:Chromogranin A / Q000097:blood*; D005260:Female; D006801:Humans; D007078:Ileal Neoplasms / Q000097:blood* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000097:blood* / Q000473:pathology*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies
chemical_list: D015415:Biomarkers; D053379:Chromogranin A