title: Assay reproducibility of serum androgen measurements using liquid chromatography-tandem mass spectrometry.
abstract: BACKGROUND
  Valid and precise measures of androgen concentrations are needed for etiologic studies of hormonally-related cancers. We developed a high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with two sample preparations to measure 11 androgens, including adrenal and gonadal androgenic precursors and their 5α-reduced metabolites.
  
  
  METHODS
  Androgen levels were measured in serum from 20 healthy volunteers (5 men, 10 premenopausal women, 5 postmenopausal women). Two blinded, randomized aliquots per individual were assayed in each of three batches. A fourth batch of samples was measured at an external laboratory using comparable methodology to measure 9 of the 11 androgens. Coefficients of variation (CV) and intraclass correlation coefficients (ICC) were calculated from the individual components of variance. Comparability of 9 androgens across laboratories was assessed using Spearman ranked correlations, Deming regression and bias plots.
  
  
  RESULTS
  The laboratory CVs were <5% and ICCs were uniformly high (>95%) for all androgens measured across sex/menopausal status groups. Spearman ranked correlations for 9 hormones measured in the comparison laboratory were high (>0.85), suggesting good agreement.
  
  
  CONCLUSIONS
  Our high-performance LC-MS/MS assays of 11 androgens, including adrenal and gonadal androgenic precursors and their 5α-reduced metabolites demonstrated excellent laboratory reproducibility, and good comparability with an established method that measured 9 of the 11 hormones tested. The serum androgen metabolite assays are suitable for use in epidemiologic research.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA. Electronic address: britton.trabert@nih.gov.
authors.forename: Britton
authors.initials: B
authors.lastname: Trabert
authors.affiliation: Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA.
authors.forename: Xia
authors.initials: X
authors.lastname: Xu
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA.
authors.forename: Roni T
authors.initials: RT
authors.lastname: Falk
authors.affiliation: Pharmacogenomics Laboratory, Centre Hospitalier Universitaire de Québec (CHUQ) Research Center, Laval University, Québec, Canada.
authors.forename: Chantal
authors.initials: C
authors.lastname: Guillemette
authors.affiliation: Departments of Obstetrics and Gynecology, and Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA 90033, USA.
authors.forename: Frank Z
authors.initials: FZ
authors.lastname: Stanczyk
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: McGlynn
mesh_terms: D000328:Adult; D000368:Aged; D000728:Androgens / Q000097:blood* / Q000378:metabolism; D002853:Chromatography, Liquid / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017698:Postmenopause; D017697:Premenopause / Q000097:blood; D053719:Tandem Mass Spectrometry / Q000379:methods* / Q000592:standards; D055815:Young Adult
chemical_list: D000728:Androgens
keywords: Endogenous hormones; Liquid chromatography tandem mass spectrometry; Metabolites; Reproducibility; Serum androgen assay