title: Urinary cytokeratin 20 as a marker for transitional cell carcinoma.
abstract: OBJECTIVE
  To determine if detection of cytokeratin 20 (CK20) gene expression, by reverse transcriptase-polymerase chain reaction (RT-PCR) in urine from transitional cell carcinoma (TCC) patients, can provide a new noninvasive tool for the follow-up of patients with urothelial carcinoma of the bladder.
  
  
  METHODS
  Urine was collected from 95 patients previously diagnosed as TCC during their follow-up, and from 27 healthy volunteers. All patients had a transurethal resection of tumor or biopsies obtained from 'suspicious' areas in the bladder. RNA was extracted from cells collected from the urine and RT-PCR was performed with specific primers for the amplification of cytokeratin 8, a general marker for epithelial cells, and of CK 20, a marker for TCC urothelium.
  
  
  RESULTS
  CK20 expression was detected in 86.7% of TCC patients, and only in 3.3% of healthy volunteers (specificity 96.7%). Strong correlation was found between tumor grade and expression of CK20 in urine. All grade III and IV tumors demonstrated positive CK20 expression (100% sensitivity), whereas the sensitivity for lower grades was between 71 and 80%. Among 11 patients with a previous biopsy-proven diagnosis of TCC and a current negative biopsy, in 9 patients CK20 expression was detected. Further follow-up of these patients for a period of 6 months revealed recurrence of TCC in 4 patients.
  
  
  CONCLUSIONS
  CK20 detection in urine cells is a simple, noninvasive method with a high potential to become the marker of choice for monitoring and follow-up of TCC patients. More information is needed regarding CK20 expression in nonmalignant urological disease, to evaluate its use for routine screening purposes.
authors.affiliation: Hematology Laboratory, Carmel Medical Center, Haifa, Israel.
authors.forename: D
authors.initials: D
authors.lastname: Rotem
authors.forename: A
authors.initials: A
authors.lastname: Cassel
authors.forename: N
authors.initials: N
authors.lastname: Lindenfeld
authors.forename: Y
authors.initials: Y
authors.lastname: Mecz
authors.forename: Y
authors.initials: Y
authors.lastname: Sova
authors.forename: M
authors.initials: M
authors.lastname: Resnick
authors.forename: A
authors.initials: A
authors.lastname: Stein
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics / Q000652:urine*; D002295:Carcinoma, Transitional Cell / Q000652:urine*; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D006801:Humans; D007381:Intermediate Filament Proteins / Q000235:genetics / Q000652:urine*; D053554:Keratin-20; D008297:Male; D011237:Predictive Value of Tests; D020133:Reverse Transcriptase Polymerase Chain Reaction; D001749:Urinary Bladder Neoplasms / Q000652:urine*
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D007381:Intermediate Filament Proteins; C507499:KRT20 protein, human; D053554:Keratin-20