The early detection and diagnosis of bladder cancer: a critical review of the options.

Bladder cancer has a high worldwide incidence matched by a tendency to recur, necessitating close and regular follow-up. Current methods of investigation of bladder cancer involve cystoscopy, ultrasound scanning and contrast urography, with additional information provided by cytology. These methods, although having a high detection rate, are expensive, time-consuming, invasive and uncomfortable. There is, therefore, a need for an inexpensive, noninvasive, quick and simple investigation with a high sensitivity and specificity for the detection of bladder cancer. There are an increasing number of molecular assays available for the detection of bladder cancer. From bladder tumour antigens to nuclear matrix proteins to adhesion molecules, cytoskeletal proteins and growth factors, urology has looked at them all to support the early detection and diagnosis of bladder cancer. This review critically discusses both the commercial as well as the research-based diagnostic assays available (their mode of action, overall accuracy - both by stage and grade, and their uses and limitations from both a clinical as well as a practical point of view). Aiming to give an insight into the options currently available for noninvasive bladder cancer diagnosis, it also provides prospective comment on what new methods/technologies may be useful in the medium term.