Bladder Urothelial Carcinoma

This study characterized the prevalence of KRAS G12C mutations in genitourinary malignancies, an area with limited data despite the approval of targeted therapies. Comprehensive genomic profiling was performed on over 13,000 samples of renal clear cell carcinomas, urothelial bladder carcinomas, and prostate acinar adenocarcinomas. Results indicated that KRAS G12C mutations are infrequent in these tumors, with an incidence of 0% in renal carcinomas, 0.6% in urothelial bladder carcinomas, and less than 0.01% in prostate adenocarcinomas. Despite their low frequency, these mutations represent an emerging therapeutic target, warranting further investigation, particularly in basket trials for patients harboring this actionable alteration.

This article outlines the protocol for an umbrella review aiming to synthesize evidence on prognostic biomarkers in bladder cancer. The objective is to compare all identified prognostic biomarkers in the literature to assess their clinical value. The authors plan to search systematic reviews and meta-analyses across multiple databases, extract relevant data, and assess the risk of bias. Statistical analysis will include pooled HR estimation, evaluation of heterogeneity and small-study effects, and an assessment of evidence credibility.

The prospective phase 2 DUTRENEO study demonstrated that a retrospectively validated 18-gene tumor inflammation signature (TIS) failed to predict response to neoadjuvant immune checkpoint inhibitors (ICIs) in muscle-invasive bladder cancer. This outcome indicates that bulk gene-expression stratification is insufficient to enrich for responders. Single-cell spatial transcriptomic analysis revealed that response is instead governed by spatial architectures, such as CD8+ T cell proximity to cancer cells and localized checkpoint co-expression, which are invisible to bulk assays. A quantitative framework was developed, suggesting that at least 77 genes and tissue regions of at least 3-mm diameter are required to preserve predictive spatial signals.

This study performed an integrated multi-omic analysis on a cohort of 48 bladder cancer patients to explore the molecular mechanisms of disease progression. Researchers identified frequent and active somatic LINE-1 (L1) insertions occurring early in cancer development. These L1 insertions are linked to downstream genomic rearrangements, chromosomal instability, and an increase in structural variants and extrachromosomal DNA (ecDNA). The study proposes a model where L1 retrotransposition triggers genomic instability and a viral mimicry response.