Urine cell-free DNA integrity as a marker for early bladder cancer diagnosis: preliminary data

Abstract

Objectives: Urine cell-free (UCF) DNA has recently been proposed as a potential marker for early bladder cancer diagnosis. It is known that normal apoptotic cells produce highly fragmented DNA while cancer cells release longer DNA. Therefore, we verified the potential role of UCF DNA integrity in early bladder cancer diagnosis.

Materials and methods: UCF DNA was isolated from 51 bladder cancer patients, 46 symptomatic patients, and 32 healthy volunteers. To verify UCF DNA integrity, sequences longer than 250 bp, c-Myc, BCAS1, and HER2, were quantified by real time PCR.

Results: At the best cutoff value of 0.1 ng/μl, UCF DNA integrity analysis showed a sensitivity of 0.73 (95% CI 0.61-0.85), and a specificity of 0.84 (95% CI 0.71-0.97) in healthy individuals and 0.83 (95% CI 0.72-0.94) in symptomatic patients. Receiver operating characteristic (ROC) curve analysis revealed an area under the curve of 0.834 (95% CI 0.739-0.930) for healthy individuals and 0.796 (95% CI 0.707-0.885) for symptomatic patients.

Conclusions: These preliminary data suggest that UCF DNA integrity is a potentially good marker for early noninvasive diagnosis of bladder cancer. Its diagnostic performance does not seem to vary significantly, even in an "at risk" population of symptomatic individuals.

Keywords: Bladder cancer; Early diagnosis; Urine cell-free DNA integrity.