title: Serum insulin-like growth factor binding protein-3/prostate-specific antigen ratio is a useful predictive marker in patients with advanced prostate cancer.
abstract: BACKGROUND
  Insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) play an important role in regulation of prostate cancer cell growth. We studied the prognostic significance of serum IGF-1 and IGFBP-3 levels, and IGF-1/prostate-specific antigen (PSA) and IGFBP-3/PSA ratios in patients with prostate cancer.
  
  
  METHODS
  Serum levels of IGF-1, IGFBP-3, and PSA were determined in 112 patients diagnosed with prostate cancer. Serum samples from 32 patients with histologically confined benign prostatatic hyperplasia (BPH) served as control.
  
  
  RESULTS
  Serum IGF-1 levels were significantly higher in advanced prostate cancer (n = 84) than in BPH patients (P < 0.01). IGFBP-3 levels were significantly lower in patients with advanced prostate cancer than in localized tumor (n = 28) or BPH (P < 0.05, each). Univariate analysis showed that serum PSA, IGF-1/PSA ratio, IGFBP-3/PSA ratio, T, N and M classifications correlated significantly with relapse-free survival of advanced prostate cancer patients treated with hormonal therapy. Multivariate analysis identified IGFBP-3/PSA ratio as the only significant variable for relapse-free survival (odds ratio 5.81, 95% CI 1.57-21.51). IGFBP-3/PSA ratio was also an independent predictor of cause-specific survival (stepwise analysis, odds ratio 4.86, P < 0.01).
  
  
  CONCLUSIONS
  Our results suggested that IGFBP-3/PSA ratio might be a useful prognostic marker of advanced prostate cancer.
authors.affiliation: Department of Urology, Nagasaki University School of Medicine, Nagasaki, Japan.
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Miyata
authors.forename: Hideki
authors.initials: H
authors.lastname: Sakai
authors.forename: Tomayoshi
authors.initials: T
authors.lastname: Hayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kanetake
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D018572:Disease-Free Survival; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I; D017430:Prostate-Specific Antigen