Liquid biopsies for surveillance and monitoring treatment response of bladder cancer

Urinary bladder cancer is a frequent disease representing the ninth most common cancer worldwide with significant morbidity and mortality (1,2). Men are more often affected by bladder cancer than women, however for still unknown reasons women have a higher mortality rate (2). Besides external exposure to carcinogens such as tobacco, aromatic amines and polycyclic aromatic hydrocarbons inherent genetic predisposition is discussed as risk factor for bladder cancer (2,3). At initial diagnosis approximately 75% of patients have non-muscle-invasive bladder cancer (NMIBC) with a high recurrence rate of at least 50% and a progression rate to muscle-invasive bladder cancer (MIBC) of about 15% within 5 years (3,4). Urine cytology and cystoscopy are the gold standard for early bladder cancer diagnosis (5).