This review article is devoted to the main problems of early diagnostic and prognosis of non-muscle-invasive bladder cancer, which accounts for 75 % of all newly detected cases of bladder cancer according to statistics. Chromosomal disorders that have been detected in urothelial cells can lead to the development of non-muscle-invasive bladder cancer. The review highlights the main problems of existing diagnostic systems for bladder cancer, their disadvantage and limitations of use in practice. Special attention is given to tumor stem cells, which are actively involved in the development of relapses of malignant neoplasms, and, also play an important role in the development of chemo - and radioresistance of tumor cells. Their significance in the diagnosis, detection of disease recurrence and the possibility of using the data obtained to adjustment therapeutic methods of treatment in oncology is one of the main tasks in cancer pathology.