title: Calcitonin screening in patients with thyroid nodules. Diagnostic value.
abstract: OBJECTIVE
  The positive predictive value (PPV) of a slightly elevated basal calcitonin (CT) for the diagnosis of medullary thyroid cancer (MTC) is still under debate.
  
  
  METHODS
  A total of 11270 patients with thyroid nodules underwent calcitonin screening. Patients with known elevation of CT, renal insufficiency, bacterial infection, alcohol abuse, proton-pump inhibitor therapy or autoimmune thyroid disease were excluded from further analysis. Serum CT was determined by the solid-phase, enzyme-labeled, two-site chemiluminescent immunoassay Immulite 2000. If possible, a pentagastrin test was done to differentiate cases of hypercalcitoninaemia.
  
  
  RESULTS
  Hypercalcitoninsemia was found in 32 patients. 20 patients underwent surgery. In 10 patients a MTC was found. The PPV of hypercalcitoninaemia for MTC was 31%. The PPV increased to 50% for those patients who underwent surgery (10/20). A subgroup of 26 patients presented with basal CT between 13 and 50 pg/ml, 14 of them underwent surgery, in 4 cases evidence of MTC was revealed. This resulted in a PPV of 15% (4/26), although the value increased to 28% when only surgically treated patients were considered (4/14).
  
  
  CONCLUSIONS
  Taking all clinical data into account, calcitonin screening has an acceptable PPV for medullary thyroid cancer in patients with thyroid nodules. Therefore, we recommend calcitonin screening in centers for thyroid disorders.
authors.affiliation: Department of Nuclear Medicine, University Hospital of Cologne, Kerpener Str. 62, 50937 Cologne, Germany. christina.schneider_@uk-koeln.de
authors.forename: C
authors.initials: C
authors.lastname: Schneider
authors.forename: C
authors.initials: C
authors.lastname: Kobe
authors.forename: M
authors.initials: M
authors.lastname: Schmidt
authors.forename: D
authors.initials: D
authors.lastname: Kahraman
authors.forename: G
authors.initials: G
authors.lastname: Malchau
authors.forename: M
authors.initials: M
authors.lastname: Faust
authors.forename: H
authors.initials: H
authors.lastname: Schicha
authors.forename: M
authors.initials: M
authors.lastname: Dietlein
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D002116:Calcitonin / Q000097:blood*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000706:statistics & numerical data*; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016606:Thyroid Nodule / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology*
chemical_list: D014408:Biomarkers, Tumor; D002116:Calcitonin