Bladder cancer screening and future directions in urine-based markers for bladder urothelial carcinoma

At present, bladder cancer screening is not an accepted standard of care; however, there is potential for non-invasive screening for this disease. Urine cytology has a high sensitivity and specificity for the detection of high-grade urothelial carcinoma, but lacks the sensitivity to detect low-grade tumors and is not cost-effective for screening. Use of hemoglobin dipstick has been utilized for screening but suffers from a low positive predictive value. An accurate bladder tumor marker would be useful for both screening of high-risk populations and for monitoring of patients with a history of bladder cancer to help identify recurrence early and prevent disease progression. A number of markers that take advantage of exfoliated cells in the urine for detection of cell surface antigens, nuclear morphology, or gene expression as well as markers for detection of excreted proteins have been studied in bladder cancer. In our previous review, we have discussed cytology and commercially available FDA-approved urine markers. Herein, we review the potential for bladder cancer screening as well as the most promising urine-based markers that are currently under investigation.