Objectives. To assess the performance of urine markers determined in urine samples from the bladder compared to samples collected from the upper urinary tract (UUT) for diagnosis of UUT urothelial carcinoma (UC). Patients and Methods. The study comprised 758 urine samples either collected from the bladder (n=373) or UUT (n=385). All patients underwent urethrocystoscopy and UUT imaging or ureterorenoscopy. Cytology, fluorescence in situ hybridization (FISH), immunocytology (uCyt+), and nuclear matrix protein 22 (NMP22) were performed. Results. UUT UC was diagnosed in 59 patients (19.1%) (UUT urine) and 27 patients (7.2%) (bladder-derived urine). For UUT-derived samples, sensitivities for cytology, FISH, NMP22, and uCyt+ were 74.6, 79.0, 100.0, and 100.0, while specificities were 66.6, 50.7, 5.9, and 66.7%, respectively. In bladder-derived samples, sensitivities were 59.3, 52.9, 62.5, and 50.0% whereas specificities were 82.9, 85.0, 31.3, and 69.8%. In UUT-derived samples, concomitant bladder cancer led to increased false-positive rates of cytology and FISH. Conclusions. Urine markers determined in urine collected from the UUT exhibit better sensitivity but lower specificity compared to markers determined in bladder-derived urine. Concomitant or recent diagnosis of UC of the bladder can further influence markers determined in UUT urine.

This study investigates the feasibility of establishing urine-derived tumor organoids from bladder cancer (BC) patients as an alternative to tissue-derived organoids. BC is one of the most common cancers worldwide and current diagnostic methods involve invasive procedures. Here, we investigated the potential of using urine samples, which contain exfoliated tumor cells, to generate urine-derived BC organoids (uBCOs). Urine samples from 29 BC patients were collected and cells were isolated and cultured in a three-dimensional matrix. The establishment and primary expansion of uBCOs were successful in 83% of the specimens investigated. The culturing efficiency of uBCOs was comparable to cancer tissue-derived organoids. Immunohistochemistry and immunofluorescence to characterize the uBCOs exhibited similar expressions of BC markers compared to the parental tumor. These findings suggest that urine-derived BC organoids hold promise as a non-invasive tool for studying BC and evaluating therapeutic responses. This approach could potentially minimize the need for invasive procedures and provide a platform for personalized drug screening. Further research in this area may lead to improved diagnostic and treatment strategies for BC patients.