title: Predicting extravesical extension of bladder carcinoma: a novel method based on micrometer measurement of the depth of invasion in transurethral resection specimens.
abstract: OBJECTIVE
  Patients with bladder cancer and extravesical extension (Stage T3 or greater) have worse survival than those with organ-confined cancer. We sought to determine whether the depth of invasion in transurethral resection of the bladder (TURB) specimens will predict extravesical extension in patients treated by radical cystectomy.
  
  
  METHODS
  We studied 90 patients diagnosed with invasive bladder carcinoma between 1979 and 1984. The 1997 TNM (tumor, lymph node, metastasis) system was used for pathologic staging. The mean patient age was 65 years (range 44 to 78). The male/female ratio was 5:1. All patients had invasive bladder cancer at TURB. Muscle invasion was identified in 35 patients (39%) and lamina propria invasion was present in 55 patients (61%) in the TURB specimens. The depth of invasion in the TURB specimens was measured by an ocular micrometer. All patients were treated by radical cystectomy. The median interval from TURB to cystectomy was 44 days (range 2 to 159). Extravesical extension (Stage T3 or greater) at cystectomy was present in 39 patients (43%).
  
  
  RESULTS
  The depth of invasion was associated with final pathologic stage (Spearman correlation r = 0. 58, P <0.001). The overall accuracy of the depth of invasion for the prediction of extravesical extension, measured by the area under the receiver operating characteristic curve, was 0.81 (standard error 0. 045). The mean depth of invasion among patients with extravesical extension at cystectomy was 4.0 mm compared with 2.2 mm for those without extravesical extension. On the basis of a 4.0-mm cutoff point, the sensitivity, specificity, positive predictive value, and negative predictive value for extravesical extension were 54%, 90%, 81%, and 72%, respectively.
  
  
  CONCLUSIONS
  Patients with a bladder cancer depth of invasion greater than 4 mm in the TURB specimens, as measured by micrometer, are likely to have extravesical extension, and more aggressive treatment should be considered.
authors.affiliation: Departments of Pathology and Urology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
authors.forename: L
authors.initials: L
authors.lastname: Cheng
authors.forename: A L
authors.initials: AL
authors.lastname: Weaver
authors.forename: D G
authors.initials: DG
authors.lastname: Bostwick
mesh_terms: D000328:Adult; D000368:Aged; D015653:Cystectomy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011237:Predictive Value of Tests; D001749:Urinary Bladder Neoplasms / Q000473:pathology* / Q000601:surgery*