Highly specific urine-based marker of bladder cancer.
OBJECTIVE
Bladder cancer represents a major health problem throughout the world, but advances in tumor biomarker development are revolutionizing how physicians diagnose the disease. We previously used an indirect immunoassay to demonstrate that the bladder cancer specific biomarker, BLCA-4, is present in urine samples from patients with bladder cancer, but not in samples from healthy individuals. In this study, a sandwich immunoassay was used to measure BLCA-4 in urine samples from patient populations with various urologic conditions and healthy individuals.


METHODS
Urine was collected from healthy individuals and from patients with bladder cancer, benign urologic conditions, or prostate cancer. BLCA-4 levels were evaluated by a sandwich immunoassay using two antibodies directed against distinct epitopes on BLCA-4.


RESULTS
Using a prospectively determined cutoff of an absorbance unit (OD) of 0.04, 67 of the 75 samples from patients with bladder cancer were positive for BLCA-4, resulting in an assay sensitivity of 89%. Also, 62 of the 65 samples from individuals without bladder cancer were negative for BLCA-4, resulting in an assay specificity of 95%.


CONCLUSIONS
The high sensitivity and specificity of the sandwich BLCA-4 immunoassay may allow for earlier detection and treatment of disease, thus greatly improving patient care.
Van Le
Thu-Suong
TS
Department of Urology, University of Pittsburgh, Cancer Institute, Pittsburgh, Pennsylvania, USA.
Miller
Raymond
R
Barder
Timothy
T
Babjuk
Marko
M
Potter
Douglas M
DM
Getzenberg
Robert H
RH
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000652:urine*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000652:urine*; D012680:Sensitivity and Specificity; D001749:Urinary Bladder Neoplasms / Q000652:urine*; D014570:Urologic Diseases / Q000652:urine*; D009363:Neoplasm Proteins
D014408:Biomarkers, Tumor; D009687:Nuclear Proteins; C413062:BLCA-4 protein, human; D009363:Neoplasm Proteins