title: Evaluation of a new quantitative point-of-care test platform for urine-based detection of bladder cancer.
abstract: OBJECTIVE
  Several commercial point-of-care (POC) tests are available for urine-based detection of bladder cancer (BC). However, these tests are restricted to dichotomized results (positive or negative), which limits their diagnostic value. Quantitative protein-based tests offer improved risk stratification but require complex methods restricted to specialized centers. Recently, the first quantitative POC system based on the detection of cytokeratin fragments became available. The aim of the study was to evaluate the diagnostic accuracy of this quantitative POC test.
  
  
  METHODS
  A total of 198 patients having symptoms suspicious for BC were included. All patients received urethrocystoscopy and upper-tract imaging. Urine samples were analyzed by the urine BC antigen (UBC) rapid POC system and evaluated both visually and quantitatively using the concile Omega 100 POC reader. For visual evaluation, different thresholds of band intensity for considering a test positive were applied. Moreover, the UBC enzyme-linked immunosorbent assay (ELISA), urine cytology, and the nuclear matrix protein 22 BladderChek were performed. Sensitivities and specifities were calculated by contingency analyses. Optimal cutoffs of quantitative tests were determined by receiver operating characteristic curves.
  
  
  RESULTS
  A total of 61 patients (30.8%) were diagnosed with BC. Visual evaluation of the UBC revealed sensitivities of 38.1% to 71.4% with corresponding specificities of 54.1% to 89.1%, dependent on the threshold of band intensity applied. The quantitative UBC rapid showed a sensitivity of 60.7% and a specificity of 70.1% at optimal cutoff (area under the curve = 0.68). A constant increase of both the probability of BC and high-risk BC with increasing UBC rapid values was observed. UBC concentrations determined by the reader significantly correlated with the UBC ELISA (P<0.001). The UBC ELISA, the nuclear matrix protein22 BladderChek and cytology showed sensitivities of 48.3%, 16.4%, and 51.7% with specificities of 71.3%, 95.3%, and 78.1%, respectively.
  
  
  CONCLUSIONS
  The UBC rapid in combination with a quantitative POC-reader system for the first time enables quantitative determination of a BC marker under POC conditions. Diagnostic accuracy is at least equivalent to elaborate ELISA-based measurement. The quantitative use of the UBC rapid test facilitates risk prediction compared with conventional nonquantitative dichotomized POC testing.
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Rene
authors: R
authors: Ritter
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Jörg
authors: J
authors: Hennenlotter
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Ursula
authors: U
authors: Kühs
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Udo
authors: U
authors: Hofmann
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Stefan
authors: S
authors: Aufderklamm
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Pia
authors: P
authors: Blutbacher
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Angelika
authors: A
authors: Deja
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Andrea
authors: A
authors: Hohneder
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Valentina
authors: V
authors: Gerber
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Georgios
authors: G
authors: Gakis
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Arnulf
authors: A
authors: Stenzl
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany.
authors: Christian
authors: C
authors: Schwentner
authors: Department of Urology, Eberhard-Karls University of Tuebingen, Tuebingen, Germany. Electronic address: tilman.todenhoefer@med.uni-tuebingen.de.
authors: Tilman
authors: T
authors: Todenhöfer
mesh_terms: D014408:Biomarkers, Tumor / Q000652:urine*; D002295:Carcinoma, Transitional Cell / Q000175:diagnosis* / Q000652:urine*; D006801:Humans; D053538:Keratin-18 / Q000652:urine; D053533:Keratin-8 / Q000652:urine; D019095:Point-of-Care Systems; D012680:Sensitivity and Specificity; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000652:urine*
chemical_list: D014408:Biomarkers, Tumor; D053538:Keratin-18; D053533:Keratin-8
keywords: NMP22; UBC rapid; bladder cancer; cytology; point of care; surveillance; urine markers