title: Are false-positive urine markers for the detection of bladder carcinoma really wrong or do they predict tumor recurrence?
abstract: OBJECTIVE
  A problem in the interpretation of noninvasive urine tests for detection of bladder carcinoma is the finding of false-positive results. Several authors have described that patients with false-positive results are at high risk for tumor recurrence or progression. Only few data are available for comparing the clinical course of patients with false-positive test results and patients with true-negative results. We studied whether patients with false-positive results of various urine test had a higher recurrence rate than patients with true-negative results.
  
  
  METHODS
  Urine samples from 61 patients without evidence of active bladder carcinoma were included. Of the 61 patients, 51 had a history of bladder cancer, and 10 underwent transurethral resection for suspect of bladder carcinoma but had negative pathologic findings. Immunocytology (Lewis X and 486p3/12) was performed on bladder washings, and BTAstat and NMP22 were performed on urine samples.
  
  
  RESULTS
  During the follow-up period, 22 patients had one or more false-positive BTAstat test results, 25 patients had one or more false-positive NMP22 tests, 42 patients had at least one false-positive Lewis X test, and 11 patients had one or more false-positive 486p3/12 test. During a follow-up period of 3-39 months (median, 17.6 months) four patients expected a tumor recurrence. Among patients with false-positive urine test results 2 of 22 (9.1%, BTAstat), 2 of 25 (8%, NMP22), 4 of 42 (9.5%, Lewis X), and 3 of 11 (27.2%, 486p3/12) suffered from tumor recurrence. In contrast, among patients with true-negative test results 2 of 39 (5.2%, BTAstat), 2 of 36 (5.6%, NMP22), 0 of 18 (0%, Lewis X), 1 of 50 (2.0%, 486p3/12) had a tumor recurrence.
  
  
  CONCLUSIONS
  Patients with a false-positive urine test result do not generally have a greater risk of tumor recurrence or progression than patients with a true-negative result. In our series, only patients with false-positive 486p3/12 test result had a higher recurrence rate. Our findings do not justify a more aggressive adjuvant treatment or surveillance for patients with false-positive urine tests.
authors.affiliation: University Hospital Eppendorf, Department of Urology, University of Hamburg, Martinistrasse 52, D-20246, Hamburg, Germany. friedrich@uke.uni-hamburg.de
authors.forename: Martin G
authors.initials: MG
authors.lastname: Friedrich
authors.forename: Angelika
authors.initials: A
authors.lastname: Hellstern
authors.forename: Marieta I
authors.initials: MI
authors.lastname: Toma
authors.forename: Peter
authors.initials: P
authors.lastname: Hammerer
authors.forename: Hartwig
authors.initials: H
authors.lastname: Huland
mesh_terms: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000652:urine*; D014408:Biomarkers, Tumor / Q000652:urine*; D005189:False Positive Reactions; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D016256:Lewis X Antigen / Q000652:urine*; D009367:Neoplasm Staging; D009687:Nuclear Proteins / Q000652:urine*; D011237:Predictive Value of Tests; D011379:Prognosis; D001749:Urinary Bladder Neoplasms / Q000473:pathology*
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D016256:Lewis X Antigen; D009687:Nuclear Proteins; C112999:bladder tumor-associated antigen; C100379:nuclear matrix protein 22