title: The metabolites citrate, myo-inositol, and spermine are potential age-independent markers of prostate cancer in human expressed prostatic secretions.
abstract: OBJECTIVE
  Due to specific physiological functions, prostatic tissues and fluids have unique metabolic profiles. In this study, proton nuclear magnetic resonance spectroscopy ((1)H-NMRS) is used to assess potential metabolic markers of prostate cancer (PCa) in human expressed prostatic secretions (EPS).
  
  
  METHODS
  Metabolic profiles of EPS from 52 men with PCa and from 26 healthy controls were analyzed using quantitative (1)H-NMRS. The metabolites quantified included citrate, spermine, myo-inositol, lactate, alanine, phosphocholine, glutamine, acetate, and hydroxybutyrate. Logistic regression (LR) was used to model the risk of PCa based on metabolite concentrations while adjusting for age.
  
  
  RESULTS
  The average age of the EPS donors with PCa was 58.0+/-7.0 years and 52.2+/-12.1 for the healthy donors. The median Gleason score for the men with PCa was 7 (range 5-9). The LR models indicated that the absolute concentrations of citrate, myo-inositol, and spermine were highly predictive of PCa and inversely related to the risk of PCa. The areas under the receiver operating characteristic curves (AUROC) for citrate, myo-inositol and spermine were 0.89, 0.87, and 0.79, respectively. At 90% sensitivity, these metabolites had specificities of 74%, 51%, and 34%, respectively. The LR analysis indicated that absolute levels of these three metabolites were independent of age.
  
  
  CONCLUSIONS
  The results indicate that citrate, myo-inositol and spermine are potentially important markers of PCa in human EPS. Further, the absolute concentrations of these metabolites in EPS appear to be independent of age, increasing the potential utility of these markers due to elimination of age as a confounding variable.
authors.affiliation: Department of Anesthesiology and Radiology, Biomedical MRI/MRS, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA. natalie.serkova@uchsc.edu
authors.forename: Natalie J
authors.initials: NJ
authors.lastname: Serkova
authors.forename: Eduard J
authors.initials: EJ
authors.lastname: Gamito
authors.forename: Richard H
authors.initials: RH
authors.lastname: Jones
authors.forename: Colin
authors.initials: C
authors.lastname: O'Donnell
authors.forename: Jaimi L
authors.initials: JL
authors.lastname: Brown
authors.forename: Spencer
authors.initials: S
authors.lastname: Green
authors.forename: Holly
authors.initials: H
authors.lastname: Sullivan
authors.forename: Tammy
authors.initials: T
authors.lastname: Hedlund
authors.forename: E David
authors.initials: ED
authors.lastname: Crawford
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001826:Body Fluids / Q000737:chemistry; D019343:Citric Acid / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D007294:Inositol / Q000032:analysis / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008660:Metabolism; D008875:Middle Aged; D011467:Prostate / Q000378:metabolism*; D012372:ROC Curve; D013096:Spermine / Q000032:analysis / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D019343:Citric Acid; D013096:Spermine; D007294:Inositol