title: Evaluation of CA19-9 as a tumor marker in urothelial malignancy.
abstract: OBJECTIVE
  Carbohydrate antigen 19-9 (CA19-9) is known to be a marker with a high positive rate in pancreatic cancer. There are limited data on the use of CA19-9 as a tumor marker in bladder carcinoma. We tested the expression of CA19-9 in transitional cell carcinoma (TCC) cell lines and bladder cancer patients to determine its usefulness in clinical applications.
  
  
  METHODS
  The expression of CA19-9 was determined in six TCC cell lines and 42 bladder carcinoma tissues using two approaches: immunohistochemistry and enzyme immunoassay (EIA) analysis. EIA was used for testing CA19-9 levels in spent medium of cultured TCC cells and the urine of bladder tumor patients.
  
  
  RESULTS
  The CA19-9 value was low in spent media of the MGH-U1, MGH-U1R and MGH-U3 cell lines, but high in that of reactivity in MGH-U4 cells, while negative reactivity was found in high-grade MGH-U1 and MGH-U1R cells, both of which were derived from a stage B, grade 3 TCC. High incidences of negative CA19-9 staining were found in high-grade and invasive tumor tissues: 69.6% (16/23) and 70.8% (17/24), respectively. The sensitivity and specificity of urinary CA19-9 for detecting tumor recurrence were 83.3% and 50.8%, respectively. However, urinary tract infection also resulted in a high false-positive rate.
  
  
  CONCLUSIONS
  CA19-9 is promising for use as a biomarker for the detection and monitoring of low-grade and low-stage bladder cancer, with the proviso that patients to be tested should be free of infection.
authors.affiliation: Division of Uro-oncology, Department of Surgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan. chuang89@cgmh.org.tw
authors.forename: Cheng-Keng
authors.initials: CK
authors.lastname: Chuang
authors.forename: Shuen-Kuei
authors.initials: SK
authors.lastname: Liao
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D001707:Biopsy, Needle; D018395:CA-19-9 Antigen / Q000235:genetics*; D002295:Carcinoma, Transitional Cell / Q000235:genetics* / Q000473:pathology*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D011379:Prognosis; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000473:pathology; D019459:Urothelium / Q000166:cytology / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen