title: uPA receptor expression in benign and malignant thyroid tumors.
abstract: BACKGROUND
  Urokinase type plasminogen activator receptor (uPAR) plays an important role in cancer invasion and metastasis. However, the uPAR expression has been rarely investigated in thyroid carcinomas. The aim of this study was to evaluate the clinical relevance of uPAR in thyroid tumors.
  
  
  METHODS
  Samples included 53 benign tumors (follicular adenoma 34, Graves' disease 8, adenomatous goiter 7 and others 4) and 62 cancers (papillary thyroid cancer (PTC) 47, follicular TC (FTC) 5, medullary TC (MTC) 5 and anaplastic TC (ATC) 5). uPAR expression was prospectively investigated with a labeled streptavidin-biotin method using an anti-uPAR monoclonal antibody. Patients were classified into a low- and high-staining group according to the percentage of positive cells (cut-off value=10%).
  
  
  RESULTS
  uPAR was more strongly expressed in thyroid cancers (35.5%) than benign tumors (7.5%). FTC had a significantly higher uPAR expression compared to follicular adenoma (p<0.01). The positivity of uPAR was as follows: PTC 36.2%, FTC 60%, MTC 0% and ATC 40%. In PTC, high uPAR expression was associated with poorly-differentiated PTC (p<0.01) while had a trend to develop more distant metastases than those with low uPAR expression (p=0.17, by the Kaplan-Meier method).
  
  
  CONCLUSIONS
  This study has shown that uPAR expression might be useful for the discrimination between FTC and follicular adenoma and could possibly be used as a prognostic factor in PTC.
authors.affiliation: Department of Surgical Oncology, Osaka University Medical School, Suita City, Japan. kimsj@onsurg.med.osaka-u.ac.jp
authors.forename: Seung Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Eiichi
authors.initials: E
authors.lastname: Shiba
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Taguchi
authors.forename: Fumine
authors.initials: F
authors.lastname: Tsukamoto
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Miyoshi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tanji
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Takai
authors.forename: Shinzaburo
authors.initials: S
authors.lastname: Noguchi
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000378:metabolism / Q000473:pathology; D000236:Adenoma / Q000378:metabolism / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011956:Receptors, Cell Surface / Q000096:biosynthesis*; D055293:Receptors, Urokinase Plasminogen Activator; D013959:Thyroid Diseases / Q000378:metabolism; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000628:therapy
chemical_list: C524898:PLAUR protein, human; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator