title: A systematic review of methods for quantifying serum testosterone in patients with prostate cancer who underwent castration.
abstract: BACKGROUND
  The clinical practice guidelines recommend measuring serum testosterone in patients with prostate cancer (PC) who undergo castration. The serum testosterone concentration should be <50ng/dL, a level established by using a radioimmunoassay method. The use of chemiluminescent immunoassays (IA) has become widespread, although their metrological characteristics do not seem appropriate for quantifying low testosterone concentrations. The objective of this review is to analyse the methods for quantifying testosterone and to establish whether there is scientific evidence that justifies measuring it in patients with PC who undergo castration, through liquid chromatography attached to a mass spectrometry in tandem (LC-MSMS).
  
  
  METHODS
  We performed a search in PubMed with the following MeSH terms: measurement, testosterone, androgen suppression and prostate cancer. We selected 12 studies that compared the metrological characteristics of various methods for quantifying serum testosterone compared with MS detection methods.
  
  
  RESULTS
  IAs are standard tools for measuring testosterone levels; however, there is evidence that IAs lack accuracy and precision for quantifying low concentrations. Most chemiluminescent IAs overestimate their concentration, especially below 100ng/dL. The procedures that use LC-MSMS have an adequate lower quantification limit and proper accuracy and precision. We found no specific evidence in patients with PC who underwent castration.
  
  
  CONCLUSIONS
  LC-MSMS is the appropriate method for quantifying low serum testosterone concentrations. We need to define the level of castration with this method and the optimal level related to better progression of the disease.
authors.affiliation: Servicio de Bioquímica Clínica, Laboratoris Clínics, Hospital Vall d'Hebron, Universitat Autónoma de Barcelona, Barcelona, España. Electronic address: icomas@vhebron.net.
authors.forename: I
authors.initials: I
authors.lastname: Comas
authors.affiliation: Servicio de Bioquímica Clínica, Laboratoris Clínics, Hospital Vall d'Hebron, Universitat Autónoma de Barcelona, Barcelona, España.
authors.forename: R
authors.initials: R
authors.lastname: Ferrer
authors.affiliation: Servicio de Urología, Hospital Vall d'Hebron, Universitat Autónoma de Barcelona, Barcelona, España.
authors.forename: J
authors.initials: J
authors.lastname: Planas
authors.affiliation: Servicio de Urología, Hospital Vall d'Hebron, Universitat Autónoma de Barcelona, Barcelona, España.
authors.forename: A
authors.initials: A
authors.lastname: Celma
authors.affiliation: Servicio de Urología, Hospital Vall d'Hebron, Universitat Autónoma de Barcelona, Barcelona, España.
authors.forename: L
authors.initials: L
authors.lastname: Regis
authors.affiliation: Servicio de Urología, Hospital Vall d'Hebron, Universitat Autónoma de Barcelona, Barcelona, España.
authors.forename: J
authors.initials: J
authors.lastname: Morote
mesh_terms: D002853:Chromatography, Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D019317:Evidence-Based Medicine; D006801:Humans; D008163:Luminescent Measurements; D008297:Male; D009919:Orchiectomy; D011471:Prostatic Neoplasms / Q000097:blood* / Q000601:surgery; D011863:Radioimmunoassay; D053719:Tandem Mass Spectrometry; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone
keywords: Castration concentration; Concentración de castración; Espectrometría de masas; Immunoassay; Inmunoanálisis; Mass spectrometry; Testosterona; Testosterone