title: Serum Cyfra 21.1 and galectin-3 protein levels in relation to immunohistochemical cytokeratin 19 and galectin-3 expression in patients with thyroid tumors.
abstract: OBJECTIVE
  The aim of this study was to assess the clinical utility of circulating preoperative Cyfra 21.1 [soluble fragment of cytokeratin (CK) 19] and galectin-3 (gal-3) in patients with thyroid tumors, to compare their serum values with tissue expression and to analyze the prognostic significance of these markers in relation to the clinical status of postsurgical differentiated thyroid carcinoma (DTC) patients.
  
  
  METHODS
  Concentrations of Cyfra 21.1 and gal-3 were evaluated by immunoassays in sera of 9 healthy subjects, 97 preoperative patients with diverse thyroid tumors (10 FTA, 63 PTC, 11 FTC, 5 PDTC, 4 ATC, 4 LNM) and 25 postoperative DTC patients (14 remissions and 11 metastases).
  
  
  RESULTS
  Low Cyfra 21.1 values were found in all subgroups, but with a tendency toward higher values in poorly differentiated DTC patients. Compared to the control (0.23 ng/mL), serum levels of gal-3 were significantly elevated in patients with thyroid tumors but with overlapping between adenoma (4.16 ng/mL) and carcinoma (3.85, 4.37, 4.64, 6.07 ng/mL for PTC, PDTC, ATC and LNM, respectively). The tissue expression of CK19 and gal-3 was immunohistochemically determined on 45 matched paraffin-embedded sections. Most thyroid carcinomas showed positive CK19 (27/35) and gal-3 immunostaining (31/35), while adenomas were mostly immunonegative (8/10 and 7/10, respectively). However, there was no significant correlation between their serum and tissue levels. Clinical status of postoperative DTC patients had no influence on serum concentrations of the tested markers.
  
  
  CONCLUSIONS
  While CK19 and gal-3 are accurate as tissue markers, their serum levels could not be used as reliable markers for identification of thyroid malignancy or in thyroid cancer follow-up. On the other hand, a tendency toward higher serum levels of Cyfra 21.1 in the small number of PDTC patients examined adds weight to previous reports postulating a role for cytokeratins in predicting a high degree of malignancy.
authors.affiliation: Institute for the Application of Nuclear Energy, INEP, University of Belgrade, Banatska 31b, 11080 Zemun, Belgrade, Serbia.
authors.forename: Tijana
authors.initials: T
authors.lastname: Išić
authors.forename: Svetlana
authors.initials: S
authors.lastname: Savin
authors.forename: Dubravka
authors.initials: D
authors.lastname: Cvejić
authors.forename: Ilona
authors.initials: I
authors.lastname: Marečko
authors.forename: Svetislav
authors.initials: S
authors.lastname: Tatić
authors.forename: Marija
authors.initials: M
authors.lastname: Havelka
authors.forename: Ivan
authors.initials: I
authors.lastname: Paunović
mesh_terms: D000951:Antigens, Neoplasm / Q000096:biosynthesis* / Q000097:blood; D014408:Biomarkers, Tumor / Q000096:biosynthesis / Q000097:blood; D018450:Disease Progression; D005500:Follow-Up Studies; D037502:Galectin 3 / Q000096:biosynthesis* / Q000097:blood; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D015592:Immunoradiometric Assay / Q000379:methods; D053539:Keratin-19 / Q000096:biosynthesis* / Q000097:blood; D015203:Reproducibility of Results; D013964:Thyroid Neoplasms / Q000097:blood / Q000378:metabolism* / Q000473:pathology
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D037502:Galectin 3; D053539:Keratin-19; C102012:antigen CYFRA21.1