title: Gene expression test for the non-invasive diagnosis of bladder cancer: A prospective, blinded, international and multicenter validation study.
abstract: OBJECTIVE
  This study aimed to validate, in a prospective, blinded, international and multicenter cohort, our previously reported four non-invasive tests for bladder cancer (BC) diagnosis based on the gene expression patterns of urine.
  
  
  METHODS
  Consecutive voided urine samples from BC patients and controls were prospectively collected in five European centres (n=789). Finally, 525 samples were successfully analysed. Gene expression values were quantified using TaqMan Arrays and previously reported diagnostic algorithms were applied to gene expression data. Results from the most accurate gene signature for BC diagnosis were associated with clinical parameters using analysis of variance test.
  
  
  RESULTS
  High diagnostic accuracy for the four gene signatures was found in the independent validation set (area under curve [AUC]=0.903-0.918), with the signature composed of two genes (GS_D2) having the best performance (sensitivity: 81.48%; specificity: 91.26%; AUC: 0.918). The diagnostic accuracy of GS_D2 was not affected by the number of tumours (p=0.58) but was statistically associated with tumour size (p=0.008). Also, GS_D2 diagnostic accuracy increases with increasing BC tumour risk. We found no differences in the performance of the GS_D2 test among the populations and centres in detecting tumours (p=0.7) and controls (p=0.2).
  
  
  CONCLUSIONS
  Our GS_D2 test is non-invasive, non-observer dependent and non-labour-intensive, and has demonstrated diagnostic accuracy in an independent, international and multicenter study, equal or superior to the current gold standard (cystoscopy combined with cytology). Additionally, it has higher sensitivity than cytology while maintaining its specificity. Consequently, it meets the requirements for consideration as a molecular test applicable to clinical practice in the management of BC.
authors.affiliation: Department and Laboratory of Urology, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Spain. Electronic address: mjribal@clinic.ub.es.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Ribal
authors.affiliation: Department and Laboratory of Urology, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Spain. Electronic address: lmengual@clinic.ub.es.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Mengual
authors.affiliation: CIBERehd, Plataforma de Bioinformática, Centro de Investigación Biomédica en red de Enfermedades Hepáticas y Digestivas, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Spain. Electronic address: juanjo.lozano@Ciberehd.org.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Lozano
authors.affiliation: Department and Laboratory of Urology, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Spain. Electronic address: INGELMO@clinic.ub.es.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Ingelmo-Torres
authors.affiliation: Department of Urology, Fundació Puigvert, Barcelona, Spain. Electronic address: jpalou@fundacio-puigvert.es.
authors.forename: Joan
authors.initials: J
authors.lastname: Palou
authors.affiliation: Department of Urology, Fundació Puigvert, Barcelona, Spain. Electronic address: orodriguez@fundacio-puigvert.es.
authors.forename: Oscar
authors.initials: O
authors.lastname: Rodríguez-Faba
authors.affiliation: Department of Urology, Radboud University Medical Centre, Nijmegen, The Netherlands. Electronic address: Fred.Witjes@radboudumc.nl.
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Witjes
authors.affiliation: Department of Urology, Radboud University Medical Centre, Nijmegen, The Netherlands. Electronic address: Toine.vanderHeijden@radboudumc.nl.
authors.forename: Antoine G
authors.initials: AG
authors.lastname: Van der Heijden
authors.affiliation: Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Spain. Electronic address: rantonio.medina.sspa@juntadeandalucia.es.
authors.forename: Rafael
authors.initials: R
authors.lastname: Medina
authors.affiliation: Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Spain. Electronic address: jose.conde.sspa@juntadeandalucia.es.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Conde
authors.affiliation: Department of Urology, Medical University of Vienna, Austria. Electronic address: michael.marberger@A1.net.
authors.forename: Michael
authors.initials: M
authors.lastname: Marberger
authors.affiliation: Department of Urology, Medical University of Vienna, Austria. Electronic address: joerg.schmidbauer@meduniwien.ac.at.
authors.forename: Joerg
authors.initials: J
authors.lastname: Schmidbauer
authors.affiliation: Pathology Department, Hospital Clínic, Universitat de Barcelona, Spain. Electronic address: PLFERNAN@clinic.ub.es.
authors.forename: Pedro L
authors.initials: PL
authors.lastname: Fernández
authors.affiliation: Department and Laboratory of Urology, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Spain. Electronic address: ALCARAZ@clinic.ub.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Alcaraz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000652:urine; D016022:Case-Control Studies; D005060:Europe; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D015588:Observer Variation; D010641:Phenotype; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D016482:Urinalysis; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000473:pathology / Q000652:urine
chemical_list: D014408:Biomarkers, Tumor
keywords: Biomarkers; Bladder cancer; Gene expression; Molecular test; Non-invasive diagnosis; Sensitivity and specificity; Urine