High-risk nonmuscle invasive bladder cancer: definition and epidemiology

Application of R2* and Apparent Diffusion Coefficient in Estimating Tumor Grade and T Category of Bladder Cancer

OBJECTIVE. The objective of our study was to compare the feasibility of R2* and apparent diffusion coefficient (ADC) for differentiating tumor grade and T category of bladder cancer. SUBJECTS AND METHODS. In this prospective study, 58 patients with pathologically confirmed bladder cancers underwent pretreatment T2*-weighted imaging and DWI on a 3-T MRI unit. The apparent transverse relaxation rate R2*, which is derived from T2*-weighted imaging, and ADC, which is derived from DWI, were calculated and compared between low- and high-grade bladder cancers as well as between non-muscle-invasive bladder cancers (NMIBCs) and muscle-invasive bladder cancers (MIBCs) using the Mann-Whitney U test. The diagnostic performances of R2*, ADC, and the combination of R2* and ADC were evaluated through an ROC analysis. RESULTS. Significant differences were found in R2* (mean ± SD, 16.55 ± 5.54 vs 20.96 ± 7.75 s^-1; p = 0.001) and ADC (1.62 ± 0.31 vs 1.33 ± 0.21 × 10^-3 mm²/s; p < 0.001) between lowand high-grade bladder cancers. R2* was significantly higher (22.56 ± 8.41 vs 18.06 ± 6.46 s^-1; p = 0.008) and ADC was considerably lower (1.21 ± 0.18 vs 1.53 ± 0.27 × 10^-3 mm²/s; p < 0.001) in MIBCs than in NMIBCs. The AUCs for differentiating low-from high-grade groups were 0.714 using R2* and 0.779 using ADC. AUCs for distinguishing between NMIBC and MIBC groups using R2* and ADC were 0.682 and 0.850, respectively. CONCLUSION. In addition to ADC, R2* can be used as a quantitative imaging biomarker to provide additional information for tumor characterization of bladder cancer.

Intravesical treatment of advanced urothelial bladder cancers with oncolytic HSV-1 co-regulated by differentially expressed microRNAs

Urothelial bladder cancer is the most common malignancy of the urinary tract. Although most cases are initially diagnosed as non-muscle-invasive, more than 80% of patients will develop recurrent or metastatic tumors. No effective therapy exists currently for late-stage metastatic tumors. By intravesical application, local administration of oncolytic Herpes Simplex virus (oHSV-1) can provide a promising new therapy for this disease. However, its inherent neurotoxicity has been a perceived limitation for such application. In this study, we present a novel microRNA-regulatory approach to reduce HSV-1-induced neurotoxicity by suppressing viral replication in neurons while maintaining oncolytic selectivity toward urothelial tumors. Specifically, we designed a recombinant virus that utilizes differentially expressed endogenous microR143 (non-cancerous, ubiquitous) and microR124 (neural-specific) to regulate expression of ICP-4, a gene essential for HSV-1 replication. We found that expression of ICP-4 must be controlled by a combination of both miR143 and miR124 to achieve the most effective attenuation in HSV-1-induced toxicity while retaining maximal oncolytic capacity. These results suggest that interaction between miR143 and miR124 may be required to successfully regulate HSV-1 replication. Our resent study is the first proof-in-principle that miRNA combination can be exploited to fine-tune the replication of HSV-1 to treat human cancers.