title: Expression of glucose transporters in human pancreatic tumors compared with increased FDG accumulation in PET study.
abstract: Although overexpression of GLUT-1 glucose transporter has already been reported in human cancers, the mechanism of glucose entry into pancreatic cancers remains unknown. To evaluate the relationship between GLUT glucose transporters and FDG uptake, FDG-PET was performed in 34 preoperative patients (mean age, 60.9 yr) with suspected pancreatic tumors, including 28 malignant and 6 benign tumors.
  
  
  METHODS
  FDG uptake at 50 min after injection of 185 MBq of [18F]FDG with >5 hr of fasting was semiquantitatively analyzed as standardized uptake values (SUVs). The GLUT expression was studied by immunohistochemistry of paraffin sections from these tumors after operation using anti-GLUT-1, -2, -3, -4 and -5 antibodies to obtain immunohistochemical grading ("strong," "weak" and "negative") by three experienced physicians.
  
  
  RESULTS
  Of 26 malignant tumors proved by histological examination, 23 (88%) tumors were positive for the expression of GLUT-1 glucose transporter, and 17 (61%) showed strong expression. On the other hand, 13 (46%), 0 (0%), 9 (36%) and 13 (46%) malignant tumors were positive for the expression of GLUT-2, -3, -4 and -5 glucose transporters, respectively. Three of six benign tumors showed strong GLUT-1 expression. Concerning GLUT-2, -3, -4 and -5, only one benign tumor showed positive GLUT-5 expression. Thus, GLUT-1 showed relatively high sensitivity but low specificity (50%) for detecting malignant tumors, whereas GLUT-2, -3, -4 and -5 had lower sensitivities but higher specificities. Correlations between SUVs and grading of GLUT immunoreactivity were significant in GLUT-1 (strong, 4.49 +/- 2.95; weak, 3.42 +/- 1.21; negative, 2.52 +/- 0.84) (p < 0.05) but not in the remaining four GLUT transporters.
  
  
  CONCLUSIONS
  These data indicate that GLUT-1 has a significant role in the malignant glucose metabolism and may contribute to the increased uptake of FDG in PET imaging in patients with pancreatic tumor.
authors.affiliation: Department of Nuclear Medicine, Kyoto University Faculty of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Higashi
authors.forename: N
authors.initials: N
authors.lastname: Tamaki
authors.forename: T
authors.initials: T
authors.lastname: Honda
authors.forename: T
authors.initials: T
authors.lastname: Torizuka
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: T
authors.initials: T
authors.lastname: Inokuma
authors.forename: G
authors.initials: G
authors.lastname: Ohshio
authors.forename: R
authors.initials: R
authors.lastname: Hosotani
authors.forename: M
authors.initials: M
authors.lastname: Imamura
authors.forename: J
authors.initials: J
authors.lastname: Konishi
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005260:Female; D005462:Fluorine Radioisotopes / Q000493:pharmacokinetics; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009004:Monosaccharide Transport Proteins / Q000032:analysis*; D010179:Pancreas / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014055:Tomography, Emission-Computed
chemical_list: D014408:Biomarkers, Tumor; D005462:Fluorine Radioisotopes; D009004:Monosaccharide Transport Proteins; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose