Biomarkers for bladder cancer: The search continues!

Cystoscopy has remained the gold standard for the detection of bladder cancer for decades. Although many new fancy molecular markers have been developed and are widely applied in the diagnosis and management of various cancers today, no single marker has dethroned cystoscopy as " the tool " in the detection of bladder cancer. Although advances in technology have provided fluorescence and narrow-band imaging, cystoscopy is still considered an invasive and expensive diagnostic tool by physicians and patients. Through the years, efforts have been made to improve the way we detect bladder cancer. Numerous urine markers have been introduced for the diagnosis of bladder cancer. Several newly developed markers exhibit sensitivity superior to urine cytology. To my knowledge, however, none of these has been included as a standard diagnostic tool in major clinical guidelines. In this issue of Investigative and Clinical Urology, findings are reported from an elegant study by Kim et al. [1] on the value of urinary topoisomerase-II alpha (TopoIIA) cell-free DNA for diagnosis of bladder cancer. In this study, Kim et al. [1] observed significantly higher expression of urinary TopoIIA cell-free DNA in bladder cancer patients compared with controls and nonmalignant hematuria patients. Also, expression of urinary TopoIIA cell-free DNA was revealed to be significantly higher in patients with muscle-invasive bladder cancer than in those with non– muscle-invasive bladder cancer in this study. TopoIIA is a DNA gyrase isoform that plays a significant role in the cell cycle. Previously, the same group reported that increased expression of TopoIIA is significantly related to a higher rate of recurrence and progression of non–muscle-invasive bladder cancer [2]. These breakthrough findings suggest TopoIIA as a promising marker for the management of bladder cancer. The current literature offers many markers that are labeled to detect bladder cancer. However, it is still unclear how much they can improve clinical decision-making. Technical innovations have brought us many potential new biomarkers. However, because these innovations can be costly, they are usually evaluated in small-scale studies. Obviously, new markers for bladder cancer detection should be developed for implementation among patients with symptoms or signs of the disease rather than in healthy control subjects. In the actual clinical setting, patients without hematuria, voiding symptoms, or other signs of bladder cancer are not offered any tests to detect bladder cancer. Such an approach is certainly quite dif ferent from that for prostate cancer, which is a disease of higher …