title: Urinary estrogen metabolites and prostate cancer risk: a pilot study.
abstract: BACKGROUND
  The high incidence of and few identified risk factors for prostate cancer underscore the need to further evaluate markers of prostate carcinogenesis. The aim of this pilot study was to evaluate urinary estrogen metabolites as a biomarker of prostate cancer risk.
  
  
  METHODS
  Using a liquid chromatography-tandem mass spectrometry method, urinary concentrations of 15 estrogen metabolites were determined in 77 prostate cancer cases, 77 healthy controls, and 37 subjects who had no evidence of prostate cancer after a prostate biopsy.
  
  
  RESULTS
  We observed an inverse association between the urinary 16-ketoestradiol (16-KE2) and 17-epiestriol (17-epiE3)--metabolites with high estrogenic activity--and prostate cancer risk. Men in the lowest quartile of 16-KE2, had a 4.6-fold risk of prostate cancer (OR=4.62, 95% CI=1.34-15.99), compared with those in the highest quartile.
  
  
  CONCLUSIONS
  We observed modest differences in estrogen metabolite concentrations between prostate cancer patients and subjects without cancer. Larger studies with both androgen and estrogen measurements are needed to confirm these results to clarify further whether estrogen metabolites are independent biomarkers for prostate cancer risk and whether androgen/estrogen imbalance influences prostate cancer risk.
authors.affiliation: Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057, USA.
authors.forename: Ourania
authors.initials: O
authors.lastname: Kosti
authors.forename: Xia
authors.initials: X
authors.lastname: Xu
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Veenstra
authors.forename: Ann W
authors.initials: AW
authors.lastname: Hsing
authors.forename: Lisa W
authors.initials: LW
authors.lastname: Chu
authors.forename: Lenka
authors.initials: L
authors.lastname: Goldman
authors.forename: Ionut
authors.initials: I
authors.lastname: Bebu
authors.forename: Sean
authors.initials: S
authors.lastname: Collins
authors.forename: Anatoly
authors.initials: A
authors.lastname: Dritschilo
authors.forename: John H
authors.initials: JH
authors.lastname: Lynch
authors.forename: Radoslav
authors.initials: R
authors.lastname: Goldman
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000652:urine*; D016022:Case-Control Studies; D002853:Chromatography, Liquid; D004967:Estrogens / Q000652:urine*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011471:Prostatic Neoplasms / Q000652:urine*; D018709:Statistics, Nonparametric; D053719:Tandem Mass Spectrometry
chemical_list: D014408:Biomarkers, Tumor; D004967:Estrogens