Assay reproducibility of serum androgen measurements using liquid chromatography–tandem mass spectrometry

• The role of androgen metabolites in cancer etiology remains largely unexplored.
• LC–MS/MS methods measured 11 androgens and androgen metabolites in serum.
• Excellent reproducibility and comparability with an established method.
• Assays are suitable to measure endogenous androgens in epidemiologic studies.

BackgroundValid 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.MethodsAndrogen 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.ResultsThe 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.ConclusionOur 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.