Urothelial Bladder Cancer: An Update on Molecular Pathology with Clinical Implications

Proliferation and immunohistochemistry for p53, CD25 and CK20 in predicting prognosis of non-muscle invasive papillary urothelial carcinomas

Non-muscle invasive papillary urothelial carcinoma is a prevalent disease with a high recurrence tendency. Good prognostic and reproducible biomarkers for tumor recurrence and disease progression are lacking. Currently, WHO grade and tumor stage are essential in risk stratification and treatment decision-making. Here we present the prognostic value of proliferation markers (Ki67, mitotic activity index (MAI) and PPH3) together with p53, CD25 and CK20 immunohistochemistry (IHC). In this population-based retrospective study, 349 primary non-muscle invasive bladder cancers (NMIBC) were available. MAI and PPH3 were calculated manually according to highly standardized previously described methods, Ki-67 by the semi-automated QPRODIT quantification system, p53 and CD25 by the fully automated digital image analysis program Visipharm® and CK20 with the help of the semi-quantitative immunoreactive score (IRS). Survival analyses with log rank test, as well as univariate and multivariate Cox regression analyses were performed for all investigated variables. Age and multifocality were the only significant variables for tumor recurrence. All investigated variables, except gender, were significantly associated with stage progression. In multivariate analysis, MAI was the only prognostic variable for stage progression (p<0.001).

RNAseq expression patterns of canine invasive urothelial carcinoma reveal two distinct tumor clusters and shared regions of dysregulation with human bladder tumors

BACKGROUND

Invasive urothelial carcinoma (iUC) is highly similar between dogs and humans in terms of pathologic presentation, molecular subtypes, response to treatment and age at onset. Thus, the dog is an established and relevant model for testing and development of targeted drugs benefiting both canine and human patients. We sought to identify gene expression patterns associated with two primary types of canine iUC tumors: those that express a common somatic mutation in the BRAF gene, and those that do not.

METHODS

We performed RNAseq on tumor and normal tissues from pet dogs. Analysis of differential expression and clustering, and positional and individual expression was used to develop gene set enrichment profiles distinguishing iUC tumors with and without BRAFV595E mutations, as well as genomic regions harboring excessive numbers of dysregulated genes.

RESULTS

We identified two expression clusters that are defined by the presence/absence of a BRAFV595E (BRAFV600E in humans) somatic mutation. BRAFV595E tumors shared significantly more dysregulated genes than BRAF wild-type tumors, and vice versa, with 398 genes differentiating the two clusters. Key genes fall into clades of limited function: tissue development, cell cycle regulation, immune response, and membrane transport. The genomic site with highest number of dysregulated genes overall lies in a locus corresponding to human chromosome 8q24, a region frequently amplified in human urothelial cancers.

CONCLUSIONS

These data identify critical sets of genes that are differently regulated in association with an activating mutation in the MAPK/ERK pathway in canine iUC tumors. The experiments also highlight the value of the canine system in identifying expression patterns associated with a common, shared cancer.

The future of bladder cancer therapy: Optimizing the inhibition of the fibroblast growth factor receptor

Therapeutic options for metastatic bladder cancer (BC) have seen minimal evolution over the past 30 years, with platinum-based chemotherapy remaining the mainstay of standard of care for metastatic BC. Recently, five immune checkpoint inhibitors (ICIs) have been approved by the FDA as second-line therapy, and two ICIs are approved as first-line treatment in selected patients. Molecular alterations of muscle-invasive bladder cancer (MIBC) have been reported by The Cancer Genome Atlas. About 15% of patients with MIBC have molecular alterations in the fibroblast growth factor (FGF) axis. Several ongoing trials are testing novel FGF receptor (FGFR) inhibitors in patients with FGFR genomic aberrations. Recently, erdafitinib, a pan-FGFR inhibitor, was approved by the FDA in patients with metastatic BC who have progressed on platinum-based chemotherapy. We reviewed the literature over the last decade and provide a summary of current knowledge of FGF signaling, and the prognosis associated with FGFR mutations in BC. We cover the role of FGFR inhibition with non-selective and selective tyrosine kinase inhibitors as well as novel agents in metastatic BC. Efficacy and safety data including insights from mechanism-based toxicity are reported for selected populations of metastatic BC with FGFR aberrations. Current strategies to managing resistance to anti-FGFR agents is addressed, and the importance of developing reliable biomarkers as the therapeutic landscape moves towards an individualized therapeutic approach.

miR-143 expression profiles in urinary bladder cancer: correlation with clinical and epidemiological parameters

Hsa-mir-143 and hsa-let-7c have been reported to be deregulated in multiple neoplasms. The main purpose of this study was to investigate the expression of these miRNAs in bladder cancer (BCa) and to analyze the association between their expression profiles and clinical and epidemiological parameters. Ninety BCa specimens were included. Expression patterns of miR-143 and let-7c were assessed by qRT-PCR using Taqman specific probes. Validated and predicted targets of these miRNA's were identified using CSmiRTar and DAVID tools, respectively. miR-143 was downregulated in tumors compared to controls (mean fold-change (FC) = 0.076). Its expression was significantly higher in MIBC compared to NMIBC (p = 0,001). Its value as a potential biomarker discriminating non invasive tumors from the invasive ones was confirmed by ROC curve (AUC = 0.768; p = 0.0001). Also, this down-regulation positively correlates with frequency of tobacco use (p = 0,04) and chronic alcohol consumption (p = 0,04). Let-7c was overexpressed in BCa samples (mean (FC = 9.92) compared to non tumoral ones but was not associated to clinical and epidemiological parameters. A comprehensive overview of miR-143 targets and pathways implicated in BCa initiation, diagnosis or prognosis using bioinformatical analysis, was conducted. While both deregulated miRNAs may contribute to urothelial tumorigenesis, the deregulation of miR-143 was significantly correlated to epidemiological and clinical parameters.

[Predictive biomarkers in oncologic uropathology]

BACKGROUND

Tumors of the genitourinary system are common. In recent years, our understanding of their molecular background and therefore the number of potential predictive biomarkers has massively increased.

OBJECTIVES

The aim of the current work is to give an overview of recent (molecular) developments and predictive biomarkers in urologic oncology and to give a perspective of what might become relevant in the future of the field.

MATERIAL AND METHODS

We considered the recent literature and study data and combined it with our own expertise in tumors of the urinary system, kidneys, and prostate.

RESULTS AND CONCLUSIONS

The molecular subtypes of muscle-invasive urothelial bladder cancer (MIBC) hold a predictive and prognostic significance and correlate with clinicopathological features. Immune therapy with checkpoint inhibitors (CPI) has a major role in urothelial carcinoma (UC), but also in renal cell carcinoma and a subgroup of prostate cancers. The first-line use in UC is restricted to PD-L1-"positive" cases (≥IC2/3, CPS ≥ 10). Further predictive markers are currently under evaluation, while the predictive significance of tumor mutational burden (TMB) is under debate. In addition to a subgroup of renal cell carcinomas, a subgroup of prostate carcinomas with alterations in the DNA repair system might benefit from a customized therapy approach (PARP inhibitors, platin-containing chemotherapy). The multitude of potentially therapy-relevant molecular alterations and related predictive biomarkers calls for the implementation of sophisticated molecular analyses in daily routine. This will lead to an even more rapid dynamic in the field of genitourinary pathology.