MicroRNAs in tumor samples and urinary extracellular vesicles as a putative diagnostic tool for muscle-invasive bladder cancer.

PURPOSE: The identification of biomarkers characterizing the invasive potential of bladder cancer could enhance the clinical management of individual patients and therefore improve prognosis. The aim of this study was to define a miRNA panel in tumor tissues as well as in urinary extracellular vesicles (EVs) for discriminating muscle-invasive bladder cancer (MIBC) from non-muscle-invasive bladder cancer (NMIBC). METHODS: miRNA expression was analyzed in 24 formalin-fixed, paraffin-embedded (FFPE) tumor samples by microarray analysis and was further validated by qRT-PCR in 56 FFPE tumor samples as well as in 37 urinary EV samples. RESULTS: Microarray analysis revealed 63 miRNAs that were significantly differentially expressed (P < 0.05) between tissues from MIBC and NMIBC tumors. Five selected miRNAs (miR-146b-5p, miR-155-5p, miR-138-5p, miR-144-5p, and miR-200a-3p) were validated by qRT-PCR. The expression of all except miR-144-5p was significantly associated with high tumor grade. In urinary EVs, a different expression was verified for miR-146b-5p (P = 0.004) and miR-155-5p (P = 0.036), which exhibited significantly higher expression in urinary EVs from patients with MIBC. CONCLUSIONS: miRNAs are promising biomarkers for the identification of invasive bladder carcinomas. Tissue samples as well as urinary EVs may serve as sources for miRNA analysis. This method, in addition to histopathology, could provide a new diagnostic tool and facilitate individual therapeutic decisions to select patients for early cystectomy.

[Therapy of low-grade nonmuscle-invasive bladder cancer]. / Therapie des nicht-muskelinvasiven Low-grade-Harnblasenkarzinoms.

Nonmuscle-invasive bladder cancer (NMIBC) comprises a very heterogeneous group of malignancies; the biological behavior of these tumors depends primarily on their grading. Low-grade NMIBC are characterized by a high propensity for recurrence but a very low risk for progression to muscle invasion or metastatic disease. Thus, the first line goal of diagnostic procedures and therapy is reliable visualization and complete resection of all foci. Cytology and other urine-based markers fail due to insufficient sensitivity. A second resection might be necessary only in selected intermediate risk cases; the positive effect of maintenance instillation protocols beyond a single postoperative instillation is questionable for the majority of patients. Risk stratification, e.g., according to the EORTC or EAU proposals, also makes sense in low grade NMIBC.

Diagnosis of bladder cancer and prediction of survival by urinary metabolomics.

Bladder cancer (BC) is a common cancer but diagnostic modalities, such as cystoscopy and urinary cytology, have limitations. Here, high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOFMS) was used to profile urine metabolites of 138 patients with BC and 121 control subjects (69 healthy people and 52 patients with hematuria due to non-malignant diseases). Multivariate statistical analysis revealed that the cancer group could be clearly distinguished from the control groups on the basis of their metabolomic profiles, even when the hematuric control group was included. Patients with muscle-invasive BC could also be distinguished from patients with non-muscle-invasive BC on the basis of their metabolomic profiles. Successive analyses identified 12 differential metabolites that contributed to the distinction between the BC and control groups, and many of them turned out to be involved in glycolysis and betaoxidation. The association of these metabolites with cancer was corroborated by microarray results showing that carnitine transferase and pyruvate dehydrogenase complex expressions are significantly altered in cancer groups. In terms of clinical applicability, the differentiation model diagnosed BC with a sensitivity and specificity of 91.3% and 92.5%, respectively, and comparable results were obtained by receiver operating characteristic analysis (AUC = 0.937). Multivariate regression also suggested that the metabolomic profile correlates with cancer-specific survival time. The excellent performance and simplicity of this metabolomics-based approach suggests that it has the potential to augment or even replace the current modalities for BC diagnosis.

Prognostic significance of fluorescent in situ hybridisation in the follow-up of non-muscle-invasive bladder cancer.

AIM: To evaluate the potential contribution of a fluorescent in situ hybridization (FISH) as prognostic indicator of the risk of recurrence or progression in patients undergoing follow-up for non-muscle-invasive bladder cancer (NMIBC). PATIENTS AND METHODS: A total of 126 consecutive patients with a history of NMIBC being followed-up with urinary cytology and cystoscopy at a referral centre were studied. Patients with carcinoma in situ, or tumour stage higher than pT1 were excluded. A UroVysion FISH kit was used to detect four chromosomal abnormalities, specifically, locus 9p21, Ch 3, 7, and 17. Three FISH patterns were defined: negative; low-risk positive, i.e. positive staining for 9p21 and/or Ch3 abnormalities; and high-risk positive, i.e. positive staining for Ch7 and/or 17. RESULTS: Overall 73 out of 126 patients (57.9%) had a positive urinary FISH test. After a median time of 14 months, 46 FISH-positive patients underwent recurrence (36.5%) and in 15 patients there was progression of disease (11.9%). Among positive patients, the low-risk category was found in 34, and the high-risk in 39. Low-risk FISH-positive patients had a higher rate of recurrence as compared to FISH-negative patients, with a hazard ratio (HR) of 1.6. The recurrence rate was even greater in patients with a high-risk positive test, with an HR of 1.9. The limitation of the study was that the impact of intravesical treatment was not assessed. CONCLUSION: The urinary FISH test can be used as an aid in predicting the risk of recurrence during follow-up of patients with history of NMIBC.