title: Guidelines for development of diagnostic markers in bladder cancer.
abstract: OBJECTIVE
  Advances in understanding cancer at the molecular level have identified numerous alterations associated with cancer development and progression. The efforts in evaluating these putative biomarkers in clinical studies of patients with cancer are increasing in order to improve the clinical management of the disease. However, despite numerous attempts, the results of such biomarker studies are frequently inconsistent and sometimes even contradictory. Aim of this work is to discuss some of the recognized problems which have impeded our understanding of the role of new markers and prevented the introduction of these markers into patient management.
  
  
  RESULTS
  These Problems include standardization issues, selection of patient cohorts and endpoints and statistical considerations. In order to improve and standardize marker development a stepwise procedure in four phases, analogous to clinical trials is proposed. Furthermore, a common terminology, considerations on the population to study as well as general recommendations for planning and conducting the evaluation of markers will be presented.
  
  
  CONCLUSIONS
  The implementation of this discussion may foster the integration of new tools and strategies screening, diagnosis and surveillance of patients with bladder cancer.
authors.affiliation: Department of Urology, Friedrich-Alexander University of Erlangen, Maximiliansplatz 1, 91054 Erlangen, Germany. peter.goebell@uk-erlangen.de
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Goebell
authors.forename: Susan L
authors.initials: SL
authors.lastname: Groshen
authors.forename: Bernd J
authors.initials: BJ
authors.lastname: Schmitz-Dräger
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D003937:Diagnosis, Differential; D006801:Humans; D017410:Practice Guidelines as Topic; D015203:Reproducibility of Results; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor