Endoscopic optical coherence tomography in urology

Clinical statistics has shown a stable prevalence of bladder cancer in recent years, which by far remains among the most common types of malignancy in the USA. With smoking as the most well-established risk factor, bladder cancer is the fourth most common cancer occurrences in male population [1]. In the year of 2014, an estimated 74,690 new cases are expected to occur with estimated 15,580 deaths. Bladder cancer often refers to transitional cell carcinoma (TCC) as it originates primarily from the epithelial cell layer (i.e., urothelium) of the bladder. Unlike prostate-specific antigen (PSA) for prostate cancer screening, there is currently no effective screening technique approved or recommended for the population at average risk [2–5]. As a result, hematuria (i.e., blood in the urine) is often the first clinical symptom of bladder cancer. Fortunately, urinary bladder is more accessible than prostate glands endoscopically; thus cytology following white-light cystoscopy has been the gold standard for current clinical detection of bladder cancer. This is important because bladder cancer if diagnosed prior to muscle invasion (e.g., superficial or at ,pT2 stages) is curable by transurethral resection (TUR) following intravesical therapy [6]. Therefore, noninvasive early detection is crucial for the management of bladder cancer patients.