[Urine-based diagnostics: an update on the Kiel Tumor Bank]

The heterogeneity of bladder tumors in their ability to invade and metastasize and their frequent recurrence pose a challenge for physicians who treat bladder cancer patients and for the researchers who work on bladder cancer diagnosis, recurrence, and treatment-related areas. For most new bladder cancer cases, investigation begins when patients are symptomatic (i.e., hematuria or irritative voiding). This mode of detection is often inadequate for nearly 15-30% of these new cases with high-grade bladder cancer, since the tumor is already in the invasive stage at the time of diagnosis. Bladder cancer patients are on a mandatory 3-month to 6-month surveillance schedule because bladder tumors frequently recur. The current mode of detecting bladder cancer involves cystoscopy, which is an invasive and relatively expensive procedure. Voided urine cytology, the standard noninvasive marker, is highly tumor specific and has good sensitivity for detecting high-grade tumors. However, its sensitivity for detecting low-grade tumors is low; its accuracy depends on the examiner's expertise; and it is not available everywhere. Marker systems are readily available for use in practice. Their utility remains under discussion.