title: Biologic correlation of 2-[18F]-fluoro-2-deoxy-D-glucose uptake on positron emission tomography in thymic epithelial tumors.
abstract: OBJECTIVE
  The usefulness of 2-[(18)F]-fluoro-2-deoxy-D-glucose ([(18)F]FDG) positron emission tomography (PET) can help predict the grade of malignancy and staging in thymic epithelial tumors. However, no satisfactory biologic explanation exists for this phenomenon. The aim of this study was to investigate the underlying biologic mechanisms of [(18)F]FDG uptake.
  
  
  METHODS
  Forty-nine patients with thymic epithelial tumors who underwent [(18)F]FDG PET were included in this study. Tumor sections were stained by immunohistochemistry for glucose transporter 1 (GLUT1), glucose transporter 3 (GLUT3), hypoxia-inducible factor-1 alpha (HIF-1alpha), vascular endothelial growth factor (VEGF), microvessels (CD31 and CD34), cell cycle control marker (p53), and apoptosis marker (bcl-2). We also conducted an in vitro study of [(18)F]FDG uptake in a thymic tumor cell line.
  
  
  RESULTS
  There was a positive correlation between [(18)F]FDG uptake and GLUT1 (P < .0001), HIF-1alpha (P = .0036), VEGF (P < .0001), microvessel density (MVD; P < .0001), and p53 (P = .0002). GLUT3 and bcl-2 showed no positive correlation with [(18)F]FDG uptake. The expression of Glut1, HIF-1alpha, VEGF, CD31, CD34, and p53 was also significantly associated with the grade of malignancy and poor outcome in thymic epithelial tumors, whereas this relationship was not observed in GLUT3 and bcl-2. Our in vitro study demonstrated that upregulation of GLUT1 and HIF-1alpha was closely associated with [(18)F]FDG uptake into thymic tumor cell.
  
  
  CONCLUSIONS
  [(18)F]FDG uptake in thymic epithelial tumors is determined by the presence of glucose metabolism (GLUT1), hypoxia (HIF-1alpha), angiogenesis (VEGF and MVD), and cell cycle regulator (p53).
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center, Shizuoka, Japan. kkaira1970@yahoo.co.jp
authors.forename: Kyoichi
authors.initials: K
authors.lastname: Kaira
authors.forename: Masahiro
authors.initials: M
authors.lastname: Endo
authors.forename: Masato
authors.initials: M
authors.lastname: Abe
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Ohde
authors.forename: Takehiro
authors.initials: T
authors.lastname: Okumura
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Takahashi
authors.forename: Haruyasu
authors.initials: H
authors.lastname: Murakami
authors.forename: Asuka
authors.initials: A
authors.lastname: Tsuya
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Tateaki
authors.initials: T
authors.lastname: Naito
authors.forename: Isamu
authors.initials: I
authors.lastname: Hayashi
authors.forename: Masakuni
authors.initials: M
authors.lastname: Serizawa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Koh
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Hanaoka
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Tominaga
authors.forename: Noboru
authors.initials: N
authors.lastname: Oriuchi
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Kondo
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakajima
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Yamamoto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D013953:Thymus Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18