Molecular followup of newly diagnosed bladder cancer using urine samples

Purpose: Patients with superficial bladder cancer can be treated with trans urethral resection. However, 50% to 70% of them have intravesical recurrenc e after transurethral resection and muscle invasive disease develops in 10% to 20%, which is eventually indicated for radical cystectomy. Therefore, r eliable predictors of intravesical recurrence are required for management o f superficial bladder cancer. We investigated whether detection of the loss of heterozygosity in urine samples would be available as a sensitive diagn ostic modality for recurrence of bladder cancer. Materials and Methods: Urine samples, cancer tissue and peripheral blood ly mphocytes were obtained from 37 patients with newly diagnosed bladder cance r, and analyzed for the loss of heterozygosity on chromosomes 9 and 17p by single strand DNA conformation polymorphism analysis. Results: Chromosomal loss was detected on 24 (65%) cancer tissues and 26 (7 0%) urine samples. The loss of heterozygosity on chromosome 17p was detecte d in 19 (51%) urine samples, mostly in cancers with higher grades and/or st ages. During postoperative followup of 24 patients with superficial bladder cancer who had undergone transurethral resection, intravesical recurrence did not develop in 9 of 10 without chromosomal aberrations in urine samples . In contrast, intravesical recurrence developed in 11 of 14 patients who h ad a loss of heterozygosity in urine samples. This loss showed a significan t correlation with the intravesical disease-free period (p = 0.004). Multiv ariate analysis revealed that the loss of heterozygosity in urine samples w as a significant predictor of intravesical recurrence. Conclusions: Detection of the loss of heterozygosity in urine samples is av ailable as a sensitive marker for predicting intravesical recurrence of sup erficial bladder cancer.