Allelic deletion fingerprinting of urine cell sediments in bladder cancer

Abstract

Background: Bladder cancer shows frequent nonrandom allelic deletion at various chromosomal regions. Genotypic detection methods could potentially identify patients at risk for recurrent progressive disease. In this study, we examined allelic deletion at specific chromosomal loci in tumor tissue and urine cell sediment samples using a microsatellite-based protocol. Although both allelic deletion and microsatellite instability have been reported in primary bladder cancer, microsatellite instability was not specifically examined in this study. We report a pilot study of 40 patients with bladder cancer in which allelic deletion in tumor tissue and urine cell sediment was compared with conventional urine cytology results. Methods and Results: Forty tumors were analyzed using a set of microsatellite primers from chromosomes 3, 4, 8, 11, 14, and 17 to construct allelic deletion fingerprints. Cy5.5-labeled PCR products were analyzed using the OpenGene System and GeneObjects software. Eighty-eight percent of tumors showed allelic deletion. In urine cell sediments, the tumor detection rate was 80% compared with 50% for routine urine cytology. The allelic deletion fingerprinting (ADF) procedure identified 69% of incipient tumors, cases initially classified as normal by routine urine cytology. Conclusion: ADF analysis provides a reliable noninvasive method for the detection and monitoring of recurrent cancer in urine cell sediment samples from patients with bladder cancer.