Treatment of patients with stage pT1 urothelial bladder cancer (UBC) continues to be a challenge due to its unpredictable clinical course. Reliable molecular markers that help to determine appropriate individual treatment are still lacking. Loss of aquaporin (AQP) 3 protein expression has previously been shown in muscle-invasive UBC. The aim of the present study was to investigate the prognostic value of AQP3 protein expression with regard to the prognosis of stage pT1 UBC. AQP 3 protein expression was investigated by immunohistochemistry in specimens of 87 stage T1 UBC patients, who were diagnosed by transurethral resection of the bladder (TURB) and subsequent second resection at a high-volume urological centre between 2002 and 2009. Patients underwent adjuvant instillation therapy with Bacillus Calmette-Guérin (BCG). Loss of AQP3 protein expression was defined as complete absence of the protein within the whole tumour. Expression status was correlated retrospectively with clinicopathological and follow-up data (median: 31 months). Multivariate Cox regression analysis was used to assess the value of AQP3 tumour expression with regard to recurrence-free (RFS), progression-free (PFS) and cancer-specific survival (CSS). RFS, PFS and CSS were calculated by Kaplan-Meier analysis and Log rank test. 59% of patients were shown to exhibit AQP3-positive tumours, whereas 41% of tumours did not express the marker. Loss of AQP3 protein expression was associated with a statistically significantly worse PFS (20% vs. 72%, p=0.020). This finding was confirmed by multivariate Cox regression analysis (HR 7.58, CI 1.29 – 44.68; p=0.025). Loss of AQP3 protein expression in pT1 UBC appears to play a key role in disease progression and is associated with worse PFS. Considering its potential prognostic value, assessment of AQP3 protein expression could be used to help stratify the behavior of patients with pT1 UBC.

Optimal urine-based diagnostic tests (UBDT) minimize unnecessary follow-up cystoscopies in patients with non-muscle-invasive bladder-cancer (NMIBC), while accurately detecting high-grade bladder-cancer without false-negative results. Such UBDTs have not been comprehensively described upon a broad, validated dataset, resulting in cautious guideline recommendations. Uromonitor^®, a urine-based DNA-assay detecting hotspot alterations in TERT, FGFR3, and KRAS, shows promising initial results. However, a systematic review merging all available data is lacking. Studies investigating the diagnostic performance of Uromonitor^® in NMIBC until November 2023 were identified in PubMed, Embase, Web-of-Science, Cochrane, Scopus, and medRxiv databases. Within aggregated analyses, test performance and area under the curve/AUC were calculated. This project fully implemented the PRISMA statement. Four qualifying studies comprised a total of 1190 urinary tests (bladder-cancer prevalence: 14.9%). Based on comprehensive analyses, sensitivity, specificity, positive-predictive value/PPV, negative-predictive value/NPV, and test accuracy of Uromonitor^® were 80.2%, 96.9%, 82.1%, 96.6%, and 94.5%, respectively, with an AUC of 0.886 (95%-CI: 0.851–0.921). In a meta-analysis of two studies comparing test performance with urinary cytology, Uromonitor^® significantly outperformed urinary cytology in sensitivity, PPV, and test accuracy, while no significant differences were observed for specificity and NPV. This systematic review supports the use of Uromonitor^® considering its favorable diagnostic performance. In a cohort of 1000 patients with a bladder-cancer prevalence of ~15%, this UBDT would avert 825 unnecessary cystoscopies (true-negatives) while missing 30 bladder-cancer cases (false-negatives). Due to currently limited aggregated data from only four studies with heterogeneous quality, confirmatory studies are needed.

Objective. Due to their variable oncological course, clinical stage T1 (cT1) urothelial carcinomas of the bladder (UCBs) are the subject of controversial discussion with regard to indication for radical cystectomy (RC).This study aimed to evaluate the frequency and prognosis of upstaging in patients undergoing RC due to UCB. Material and methods. Clinical and pathological records of 607 patients, having undergone RC for treatment of UCB in cT1N0M0, were summarized in a multi-institutional database. Cancer-specific survival (CSS) and overall survival (OS) rates were calculated. A multivariable prognostic model predicting the possibility of an upstaging in RC specimens was developed based on clinical information. Results. In 210patients (35%) an upstaging (> pT1 and/or pN+) was detected in the RC specimen. Five-year CSS was 86%, 78%, 60%and 34%, respectively, for tumour stages < pT2N0 (n = 397), pT2N0 (n = 78), > pT2N0 (n = 63)and pN+ (n = 69) (p < 0.001). In a multivariable Cox regression model, pN stage, pT stage and lymphovascular invasion (LVI) revealed an independent influence on CSS (OS: pN, pT, age). An upstaging of cT1 tumours was enhanced by the criteria of G3 tumour grading and absent Tis in the transurethral resection of the bladder (TURB)specimen. Detection of LVI in RC specimens was also independently associated with an upstaging and, therefore, is recommended as a relevant prognostic parameter for the histopathological evaluation of TURB specimens. Conclusions. More than one-third of patients with cT1 tumours had an upstaging that was associated with significant prognosis deterioration. Further valid markers are required for an early identification of these patients. LVI represents such a criterion and, therefore, should be evaluated in prospectively designed trials with accurate histopathological assessment of TURB specimens.