title: Interest of Chromogranin A for diagnosis and follow-up of endocrine tumours.
abstract: OBJECTIVE
  To determine the interest of Chromogranin A (CgA) determination for diagnosis and follow-up in patients with gastroenteropancreatic endocrine tumours (GEP-ET) and multiple endocrine neoplasia type 1 (MEN-1).
  
  
  METHODS
  CgA levels were measured with an immunoradiometric assay in 124 sporadic GEP-ET, 34 MEN-1 and 127 controls. Serial determinations were performed in 56 patients (212 visits). Changes in CgA levels over 25% were considered as significant.
  
  
  RESULTS
  Using a cut-off value of 130 micro g/l, established from a receiver-operating characteristic curve, the specificity of CgA was 98.4%, with a sensitivity of 62.9%, higher in secreting than in nonsecreting tumours (73%vs. 45%; P < 0.003) and related to the extent of metastatic spreading (P < 0.001). In nonsecreting tumours, the positive predictive value (PPV) of CgA for the presence of metastases was 100% but the negative predictive value (NPV) was only 50%. In MEN-1, high CgA levels indicated a pancreatic tumour with a 100% specificity but the sensitivity was 59%. During the follow-up, the concordance between CgA and tumour evolution was 80%, whatever the secretory status. In patients with carcinoid tumours, the concordance was higher for CgA than for serotonin (81%vs. 54%; P < 0.001).
  
  
  CONCLUSIONS
  Due to its high specificity, CgA determination may help to discriminate the endocrine character of a GEP tumour and to indicate a pancreatic tumour in MEN-1. However, its low NPV in nonsecreting tumours limits its interest for diagnosis and staging. By contrast, serial evaluation of CgA seems of particular interest for the follow-up of GEP-ET tumours.
authors.affiliation: Service de Radioanalyse and Centre de Médecine Nucléaire, Hôpital Neuro-cardiologique, Hopital Edouard Herriot, Lyon, France.
authors.forename: D
authors.initials: D
authors.lastname: Nehar
authors.forename: C
authors.initials: C
authors.lastname: Lombard-Bohas
authors.forename: S
authors.initials: S
authors.lastname: Olivieri
authors.forename: B
authors.initials: B
authors.lastname: Claustrat
authors.forename: J-A
authors.initials: JA
authors.lastname: Chayvialle
authors.forename: M-C
authors.initials: MC
authors.lastname: Penes
authors.forename: G
authors.initials: G
authors.lastname: Sassolas
authors.forename: F
authors.initials: F
authors.lastname: Borson-Chazot
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D053379:Chromogranin A; D002864:Chromogranins / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015592:Immunoradiometric Assay / Q000379:methods; D008297:Male; D008875:Middle Aged; D018761:Multiple Endocrine Neoplasia Type 1 / Q000097:blood / Q000175:diagnosis*; D010190:Pancreatic Neoplasms / Q000097:blood / Q000175:diagnosis*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000097:blood / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; C506150:CHGA protein, human; D053379:Chromogranin A; D002864:Chromogranins