title: Is conventional urinary cytology still reliable for diagnosis of primary bladder carcinoma? Accuracy based on data linkage of a consecutive clinical series and cancer registry.
abstract: OBJECTIVE
  Reported urine cytology accuracy, particular sensitivity, is highly variable. We evaluated the accuracy of urinary cytology for primary bladder cancer using population data linkage to provide valid estimates.
  
  
  METHODS
  Consecutive cytology tests processed through a major service between January 2000 and December 2004 were linked to a regional population cancer registry (allowing outcome ascertainment). Sensitivity and specificity were calculated using different thresholds, based on standardized reporting categories (C1 = negative, C2 = reactive, C3 = atypical, C4 = suspicious, C5 = malignant, Cx = inadequate).
  
  
  RESULTS
  Cancer registry matching of 2,594 tests revealed 130 incident bladder cancers, of which 97 occurred within 12 months of cytology and were included in calculating accuracy. Sensitivity (C3-C5 considered positive) ranged between 40.2 and 42.3%, and specificity was 93.7-94.1%. If C3 results are counted as negative, sensitivity estimates reduced to 24.7-26.0%. The positive predictive value of a C3, C4 or C5 report was 11.7, 39.2, and 66.6%, respectively. High tumor grade was associated with significantly higher sensitivity compared to low and intermediate grades combined (p = 0.02).
  
  
  CONCLUSIONS
  Urine cytology is highly specific but has intermediate sensitivity, indicating that it has a role in adjunct diagnosis, but not in screening for primary bladder cancer. C3 results should be considered 'positive' and further investigated, and all positive results should prompt further intervention.
authors.affiliation: Istituto Scientifico per lo Studio e la Prevenzione Oncologica, Florence, Italy.
authors.forename: Patricia
authors.initials: P
authors.lastname: Turco
authors.forename: Nehmat
authors.initials: N
authors.lastname: Houssami
authors.forename: Paolo
authors.initials: P
authors.lastname: Bulgaresi
authors.forename: Grazia Maria
authors.initials: GM
authors.lastname: Troni
authors.forename: Laura
authors.initials: L
authors.lastname: Galanti
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Cariaggi
authors.forename: Paola
authors.initials: P
authors.lastname: Cifarelli
authors.forename: Emanuele
authors.initials: E
authors.lastname: Crocetti
authors.forename: Stefano
authors.initials: S
authors.lastname: Ciatto
mesh_terms: D003581:Cytodiagnosis / Q000379:methods*; D003625:Data Collection / Q000706:statistics & numerical data*; D006801:Humans; D012042:Registries / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000652:urine*; D014556:Urine / Q000166:cytology*