title: Serum insulin-like growth factor I/free prostate specific antigen (IGF-I/fPSA) ratio enhances prostate cancer detection in men with total PSA 4.0-10.0 ng/ml.
abstract: BACKGROUND
  Recent studies have suggested that IGF-I and IGFBP-3, in combination with PSA, may enhance PCa detection. This study was to investigate the use of serum IGF-I and IGFBP-3, and their combinations with prostate volume and fPSA in enhancing the discriminatory diagnosis of PCa in men with tPSA of 4.0-10.0 ng/ml.
  
  
  METHODS
  Serum IGF-I and IGFBP-3 were determined by ELISA from 586 men with tPSA between 4.0 and 10.0 ng/ml. Of them, 281 were diagnosed with PCa and 305 without. ROC, univariate and multivariate logistic regression analyses were performed to evaluate the predictive performance of those parameters.
  
  
  RESULTS
  IGF-I, IGFD, IGF-I/fPSA, and IGFBP-3/fPSA were significantly higher in PCa cases than benign controls, whereas the differences of IGFBP-3 and IGFBPD were statistically insignificant between the two groups, respectively. The AUC values indicated enhanced performance of IGF-I/fPSA ratio (AUC = 0.753) in PCa detection compared with the currently used f/tPSA (AUC = 0.689). Multivariate logistic regression confirmed the observed relationships and identified IGF-I/fPSA as independent factor in PCa presence.
  
  
  CONCLUSIONS
  Our data show that IGF-I/fPSA as a promising marker can enhance PCa detection in ambiguous cases often found in the tPSA between 4.0 and 10.0 ng/ml.
authors.affiliation: Department of Urology, The Second Affiliated Hospital, Shantou University Medical, College, Shantou, Guangdong Province, China. zgzhaodr@yahoo.com.cn
authors.forename: Zhao
authors.initials: Z
authors.lastname: Zhigang
authors.forename: Liu
authors.initials: L
authors.lastname: Jieming
authors.forename: Li
authors.initials: L
authors.lastname: Su
authors.forename: Shen
authors.initials: S
authors.lastname: Wenlu
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I; D017430:Prostate-Specific Antigen