Subtypes Of Muscle-invasive Bladder Cancer Research Articles

Genetic Alterations in Chromatin Regulatory Genes in Upper Tract Urothelial Carcinoma and Urothelial Bladder Cancer.

Upper tract urothelial carcinoma (UTUC) and urothelial carcinoma of the bladder (UCB) share histomorphological and therapeutic features but distinct epidemiologic and clinicopathologic characteristics. We examined alterations of chromatin regulatory genes in molecular subtypes, clonal relatedness, and T-cell receptor (TCR) diversity in UTUC and UCB. Targeted next-generation sequencing or whole-exome DNA sequencing and TCR sequencing were conducted with 34 UTUC and 49 UCB specimens from 63 patients. Tumors were subtyped based on the expression of CK5 and GATA3. Results of tissue microarray of 78 muscle-invasive bladder cancer (MIBC) samples were used as prognostic factors of different subtypes of MIBC. Chromatin regulatory genes were frequently mutated in both UTUC and UCB. Rapid relapse and progression of non-MIBC are correlated with alterations of KMT2C and EP300. Frequency of alterations in chromatin regulatory genes is higher in UTUC patients with SBS22 and SBS2 signatures and lower in UCB patients with SBS2 and SBS6 signatures. GATA3 and CK5 double-positive patients with higher frequencies of SMARCA4, ARID1A, and EP300 mutations have better prognoses than patients with basal subtypes. Although UTUC and UCB in the same patient can be either clonally related or developed independently, mutated genes in chromatin pathway were enriched in the related clones. Compared to UTUC, UCB had more deleterious mutations in DNA damage repair (DDR) genes, higher levels of tumor mutation burden (TMB) and copy number variations (CNVs), as well as higher TCR clonality and lower TCR diversity. Since genetic alterations of the chromatin pathway genes are important in both UTUC and UCB, they could serve as potential biomarkers for predicting disease progression and therapeutic targets. Differences in mutation frequencies of DDR pathway, TMB, CNV, and TCR might be the contributing factors for the distinct responses to immune checkpoint inhibitor (ICI) between UTUC and UCB.

Matrix Metalloproteinases -2 and -9, Vascular Endothelial Growth Factor, Basic Fibroblast Growth Factor and CD105- Micro-Vessel Density are Predictive Markers of Non-Muscle Invasive Bladder Cancer and Muscle Invasive Bladder Cancer Subtypes

Matrix Metalloproteinases -2 and -9, Vascular Endothelial Growth Factor, Basic Fibroblast Growth Factor and CD105- Micro-Vessel Density are Predictive Markers of Non-Muscle Invasive Bladder Cancer and Muscle Invasive Bladder Cancer Subtypes

Protein-Based Predictive Biomarkers to Personalize Neoadjuvant Therapy for Bladder Cancer-A Systematic Review of the Current Status.

The clinical outcome of patients with muscle-invasive bladder cancer (MIBC) is poor despite the approval of neoadjuvant chemotherapy or immunotherapy to improve overall survival after cystectomy. MIBC subtypes, immune, transcriptome, metabolomic signatures, and mutation burden have the potential to predict treatment response but none have been incorporated into clinical practice, as tumor heterogeneity and lineage plasticity influence their efficacy. Using the PRISMA statement, we conducted a systematic review of the literature, involving 135 studies published within the last five years, to identify studies reporting on the prognostic value of protein-based biomarkers for response to neoadjuvant therapy in patients with MIBC. The studies were grouped based on biomarkers related to molecular subtypes, cancer stem cell, actin-cytoskeleton, epithelial-mesenchymal transition, apoptosis, and tumor-infiltrating immune cells. These studies show the potential of protein-based biomarkers, especially in the spatial context, to reduce the influence of tumor heterogeneity on a biomarker's prognostic capability. Nevertheless, currently, there is little consensus on the methodology, reagents, and the scoring systems to allow reliable assessment of the biomarkers of interest. Furthermore, the small sample size of several studies necessitates the validation of potential prognostic biomarkers in larger multicenter cohorts before their use for individualizing neoadjuvant therapy regimens for patients with MIBC.

Integrating molecular subtype and CD8+ T cells infiltration to predict treatment response and survival in muscle-invasive bladder cancer

BackgroundLuminal and Basal are the primary intrinsic subtypes of muscle-invasive bladder cancer (MIBC). The presence of CD8+ T cells infiltration holds significant immunological relevance, potentially influencing the efficacy of antitumor responses. This study aims to synergize the influence of molecular subtypes and CD8+ T cells infiltration in MIBC.MethodsThis study included 889 patients with MIBC from Zhongshan Hospital, The Cancer Genome Atlas, IMvigor210 and NCT03179943 cohorts. We classified the patients into four distinct groups, based on the interplay of molecular subtypes and CD8+ T cells and probed into the clinical implications of these subgroups in MIBC.ResultsAmong patients with Luminal-CD8+Thigh tumors, the confluence of elevated tumor mutational burden and PD-L1 expression correlated with a heightened potential for positive responses to immunotherapy. In contrast, patients featured by Luminal-CD8+Tlow displayed a proclivity for deriving clinical advantages from innovative targeted interventions. The Basal-CD8+Tlow subgroup exhibited the least favorable three-year overall survival outcome, whereas their Basal-CD8+Thigh counterparts exhibited a heightened responsiveness to chemotherapy.ConclusionsWe emphasized the significant role of immune-molecular subtypes in shaping therapeutic approaches for MIBC. This insight establishes a foundation to refine the process of selecting subtype-specific treatments, thereby advancing personalized interventions for patients.

Pilot study on quantifying the epithelial/mesenchymal hybrid state in the non-muscle invasive and muscle invasive bladder tumors: A promising marker of diagnosis and prognosis

BackgroundManifestation of epithelial-to-mesenchymal transition (EMT) program in tumor cells is associated with the occurrence of multiple intermediate phenotypic states namely epithelial (E), mesenchymal (M) and hybrid E/M across the epithelial-mesenchymal spectrum and these states exhibit different invasive properties. Understanding the cellular and molecular mechanisms defining the E/M hybrid state of the cells during bladder tumor development may significantly aid in the identification of novel diagnostic and prognostic markers. Materials and methodsThe present study is taken up to identify hybrid E/M score based on the immunohistochemical localization and surface expressions of epithelial proteins [E-cadherin and Beta-catenin] and mesenchymal marker proteins [N-cadherin and Vimentin] on formalin fixed paraffin embedded tumor sections of the prospective series of 99 non-muscle invasive bladder cancer (NMIBC) and 87 muscle invasive bladder cancer (MIBC) patients. E/M score was then statistically examined with patients’ demographics to assess its potential in the diagnosis and prognosis of UCB patients. ResultsAmong the E (E-cadherinhigh, β-cateninhigh), hybrid E/M (E-cadherinlow, β-cateninlow, N- cadherinhigh and Vimentinhigh) and M (N-cadherinhigh and Vimentinhigh) phenotypes, E/M phenotype was observed to be more prevalent in MIBC compared to E phenotype in NMIBC subtype. The current study reports the statistical association of tumor stage and tumor grade with the hybrid E/M state of urothelial tumor cells across both the subtypes. Hybrid E/M phenotype in MIBC patients was significantly shown to lower the overall survival time period compared to NMIBC patients. This supports the contribution of hybrid E/M state of tumor cells to the.aggressiveness of the disease. ConclusionsCharacterizing the hybrid E/M state instead of all or none phenotype becomes an imperative to understand the dynamics of EMT and MET in the tumor pathophysiology of NMIBC and MIBC subtypes, and could contribute to better patient stratification and therapeutic strategies.

Does Bladder Cancer Subtype Influence Pathologic Complete Response (pCR) and Pelvic Diffusion-Weighted Magnetic Resonance Imaging (DW-MRI) Response Evaluation After Neoadjuvant Chemotherapy? Pathological Perspective

IntroductionWe aimed to provide a pathological perspective on the management of muscle-invasive bladder cancer (MIBC) by correlating the prechemotherapy transurethral resection of bladder tumor findings and postchemotherapy radiologic evaluation with final radical cystectomy (RC) findings. Materials and MethodsThis retrospective study included 79 MIBC patients treated with neoadjuvant chemotherapy (NAC) and RC. Pelvic diffusion-weighted magnetic resonance imaging (DW-MRI) and pathologic reports were retrieved from our institutional database. All pathology slides were reviewed based on diagnostic criteria with high interobserver reproducibility. ResultsPathologic complete response (pCR) was confirmed in 32 patients (40.5%). The concordance and discordance between MRI and RC findings occurred in 68.3% and 31.7% of cases, respectively. The 21.5% of cases that were clinical CR (cCR) on MRI actually achieved pCR on RC specimens and 46.8% of cases that were non-cCR on MRI were actually non-pCR on RC specimens. In 19.0% of cases, RC findings were pCR, but MRI demonstrated residual tumor and the opposite was 12.7%. The greatest discrepancy between the 2 methods (75%, 3/4) was for the plasmacytoid subtype. Plasmacytoid histology was the most common histological subtype identified in RC specimens after NAC, followed by micropapillary and squamous histologies. ConclusionsWe found that all cases with plasmacytoid and micropapillary subtypes, and squamous differentiation did not show pCR. In particular, the largest discrepancy between MRI findings and RC pathology after NAC was seen in the plasmacytoid subtype. An accurate pathologic diagnosis based on strict criteria to identify histological subtypes of MIBC is necessary for proper treatment.

Feasibility and Impact of Immunohistochemistry-based Molecular Subtyping for Muscle-invasive Bladder Cancer in Patients Treated with Radiation-based Therapy

BackgroundDistinct molecular subtypes of muscle-invasive bladder cancer (MIBC) have been identified via gene expression profiling. ObjectiveWe investigated the feasibility of a simple immunohistochemistry (IHC)-based Lund subtyping method and the association of MIBC subtypes with oncological outcomes for patients after bladder-preserving radiation-based therapy. Design, setting, and participantsTransurethral resected tumor tissues from 104 patients treated with radiation-based therapy were sampled on tissue microarray blocks. Outcome measurements and statistical analysisThe expression of KRT5, GATA3, and p16 proteins was scored via digital image analysis. Hierarchical clustering was used to classify tumors as the basal subtype or one of two luminal subtypes: genomically unstable (GU) or urothelial-like (URO). Subtypes were evaluated for association with complete response (CR), recurrence-free survival (RFS), and overall survival (OS). Results and limitationsThe median OS was 43 mo (95% confidence interval 19–77) and median follow-up was 55 mo (interquartile range 39–75). Age and clinical stage had a significant impact on OS (p < 0.05). IHC-based subtype classification was feasible in most patients (89%). The subtype was basal in 23.6%, GU in 14.0%, URO in 31.2%, and unclassified in 31.2% of patients. No significant differences in CR, RFS, or OS were observed between the molecular subtypes. Limitations include the retrospective design and relatively small sample size. ConclusionsIHC-based molecular MIBC subtyping using a three-antibody algorithm is feasible in most patients treated with radiation-based therapy. MIBC subtype was not associated with response or survival. Further prospective studies are warranted to confirm the lack of association between molecular subtype and survival in patients treated with trimodal therapy. Patient summaryFor patients with invasive bladder cancer treated with radiation-based therapy, we classified tumors into different subtypes using just three molecular stains. This method is cheaper and more widely available than the usual approach. However, we did not find an association between different cancer subtypes and survival.

Optimizing identification of consensus molecular subtypes in muscle-invasive bladder cancer: a comparison of two sequencing methods and gene sets using FFPE specimens

BackgroundMolecular subtypes predict prognosis in muscle-invasive bladder cancer (MIBC) and are explored as predictive markers. To provide a common base for molecular subtyping and facilitate clinical applications, a consensus classification has been developed. However, methods to determine consensus molecular subtypes require validation, particularly when FFPE specimens are used. Here, we aimed to evaluate two gene expression analysis methods on FFPE samples and to compare reduced gene sets to classify tumors into molecular subtypes.MethodsRNA was isolated from FFPE blocks of 15 MIBC patients. Massive analysis of 3’ cDNA ends (MACE) and the HTG transcriptome panel (HTP) were used to retrieve gene expression. We used normalized, log2-transformed data to call consensus and TCGA subtypes with the consensusMIBC package for R using all available genes, a 68-gene panel (ESSEN1), and a 48-gene panel (ESSEN2).ResultsFifteen MACE-samples and 14 HTP-samples were available for molecular subtyping. The 14 samples were classified as Ba/Sq in 7 (50%), LumP in 2 (14.3%), LumU in 1 (7.1%), LumNS in 1 (7.1%), stroma-rich in 2 (14.3%) and NE-like in 1 (7.1%) case based on MACE- or HTP-derived transcriptome data. Consensus subtypes were concordant in 71% (10/14) of cases when comparing MACE with HTP data. Four cases with aberrant subtypes had a stroma-rich molecular subtype with either method. The overlap of the molecular consensus subtypes with the reduced ESSEN1 and ESSEN2 panels were 86% and 100%, respectively, with HTP data and 86% with MACE data.ConclusionDetermination of consensus molecular subtypes of MIBC from FFPE samples is feasible using various RNA sequencing methods. Inconsistent classification mainly involves the stroma-rich molecular subtype, which may be the consequence of sample heterogeneity with (stroma)-cell sampling bias and highlights the limitations of bulk RNA-based subclassification. Classification is still reliable when analysis is reduced to selected genes.

Intratumoral Heterogeneity of Molecular Subtypes in Muscle-invasive Bladder Cancer—An Extensive Multiregional Immunohistochemical Analysis

BackgroundMolecular bladder cancer (BC) subtypes define distinct biological entities and were shown to predict treatment response in neoadjuvant and adjuvant settings. The extent of intratumoral heterogeneity (ITH) might affect subtyping of individual patients. ObjectiveTo comprehensively assess the ITH of molecular subtypes in a cohort of muscle-invasive BC. Design, setting, and participantsA total of 251 patients undergoing radical cystectomy were screened. Three cores of the tumor center (TC) and three cores of the invasive tumor front (TF) of each patient were assembled in a tissue microarray. Molecular subtypes were determined employing 12 pre-evaluated immunohistochemical markers (FGFR3, CCND1, RB1, CDKN2A, KRT5, KRT14, FOXA1, GATA3, TUBB2B, EPCAM, CDH1, and vimentin). A total of 18 072 spots were evaluated, of which 15 002 spots were assessed based on intensity, distribution, or combination. Outcome measurements and statistical analysisAllocation to one of five different molecular subtypes—urothelial like, genomically unstable, small-cell/neuroendocrine like, basal/squamous cell carcinoma like, and mesenchymal like—was conducted for each patient for the complete tumor, individual cores, TF, and TC separately. The primary objective was to assess the ITH between the TF and TC (n = 208 patients). The secondary objective was the evaluation of multiregion ITH (n = 191 patients). An analysis of the composition of ITH cases, association with clinicopathological parameters, and prognosis was conducted. Results and limitationsITH between the TF and TC was seen in 12.5% (n = 26/208), and ITH defined by at least two different subtypes of any location was seen in 24.6% (n = 47/191). ITH was more frequent in locally confined (pT2) versus advanced (pT ≥3) BC stages (38.7% vs 21.9%, p = 0.046), and pT4 BC presented with significantly more basal subtypes than pT2 BC (26.2% vs 11.5%, p = 0.049). In our cohort, there was no association of subtype ITH with prognosis or accumulation of specific molecular subtypes in ITH cases. The key limitations were missing transcriptomic and mutational genetic validation as well as investigation of ITH beyond subtypes. ConclusionsSeveral molecular subtypes can be found in nearly every fourth case of muscle-invasive BC, when using immunohistochemistry. ITH must be given due consideration for subtype-guided strategies in BC. Genomic validation of these results is needed. Patient summaryDifferent molecular subtypes can be found in many cases of muscle-invasive bladder cancer. This might have implications for individualized, subtype-based therapeutic approaches.

Clinicopathological Features and Survival Analysis in Molecular Subtypes of Muscle-Invasive Bladder Cancer.

Molecular subtyping of bladder cancer (BC) aims to capture the biological heterogeneity of this complex disease in order to provide better patient risk stratification. Immunohistochemical (IHC) markers are regarded as promising surrogates to classify BCs into luminal and basal subtypes in routine practice. We investigated the correlation between the molecular subclassification, assessed through IHC, and the conventional prognostic variables of a cohort of 93 muscle-invasive BCs (MIBCs), with a focus on the pattern of muscularis propria (MP) invasion, and evaluated their association with outcome. Basal, luminal, double-positive (DP), and double-negative (DN) phenotypes were identified according to the coordinate expression of 1 basal (CK5/6) and 2 luminal (CK20, GATA3) markers, and accounted for 33.3%, 32.3%, 3.2%, and 31.2% (Scheme #1) and 9.7%, 60.2%, 26.9%, and 3.2% (Scheme #2). There was a significant association between the pattern of MP invasion and the molecular subtypes according to Scheme #2, in that all 8 basal and DN cases, as well as 83% of DP cases, had a non-infiltrative invasion pattern. No consistent differences were observed in terms of OS and CSS between the molecular subtypes obtained through surrogate IHC markers. In keeping with previous studies, we report the correlation between the identification of BC subtypes and the presence of morphological prognostic factors, supporting the need for a comprehensive pathological evaluation, including clinicopathological and molecular parameters, in order to improve the diagnosis and management of MIBC.

Immunohistochemical based molecular subtypes of muscle-invasive bladder cancer: association with HER2 and EGFR alterations, neoadjuvant chemotherapy response and survival

Muscle-invasive bladder cancers (MIBCs) is a group of molecularly heterogonous diseases that could be stratified into subtypes with distinct clinical courses and sensitivities to chemotherapy. Clinical application of molecular subtypes could help in prediction of neoadjuvant chemotherapy (NAC) responders. Immunohistochemical (IHC) markers such as GATA3, cytokeratin (CK) 5/6, and p53 are associated with these subtypes and are widely available. Human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR) are mutated in multiple cancers including MIBC and are potential therapeutic targets. HER2/EGFR status of MIBC subtypes has not been investigated. Tissue microarrays (TMAs) were constructed from transurethral resection of the bladder tumor (TURB) specimens and stained with GATA3,CK5/6,p53 and HER2 in addition to Quantitative Reverse Transcription PCR for detection of EGFR gene. Of the total cases, 45% were luminal, 36.7% basal and 18.3% p53 wild subtype (p53-WT). Univariate analysis showed that overall survival (OS) and disease-free progression survival (DFS) were significantly longer for luminal subtype. In multivariate analysis, molecular subtype, HER2 status and LV invasion were independent prognostic factors for DFS and OS. Basal subtype showed a significantly better response to NAC. HER2 expression was significantly higher in luminal while EGFR expression was significantly higher in basal subtype. Kaplan-Meier survival curves revealed a significant longer OS and DFS for HER2 negative than positive cases. MIBC can be stratified using a simple IHC panel [GATA3,CK5/6,P53] into clinically relevant prognostic molecular subtypes. Basal tumors are aggressive and respond well to NAC while luminal have better OS. P53-WT tumors are chemoresistant and require further treatments. HER2 and EGFR are potential therapeutic targets for molecular subtypes of MIBC where luminal tumors are more likely to benefit from HER2 and basal from EGFR directed therapies.

Intratumoral heterogeneity of molecular subtypes in muscle-invasive bladder cancer – An extensive multi-regional immunohistochemical analysis

Intratumoral heterogeneity of molecular subtypes in muscle-invasive bladder cancer – An extensive multi-regional immunohistochemical analysis

Immunohistochemical Study of Bladder Cancer Molecular Subtypes and Their Association with PD-L1 Expression.

The significant heterogeneity in clinical outcomes among patients with bladder cancer has highlighted the existence of different biological subtypes of muscle-invasive bladder cancer (MIBC) and non-muscle-invasive bladder cancer (NMIBC). Meanwhile, immune checkpoint proteins and their interference with tumor-related immune-evasive strategies has led to the development of several immunotherapeutic drugs targeting programmed death-1 (PD-1) or programmed death ligand-1 (PD-L1). However, the lack of any known biomarker that could predict responses to immunotherapy has led to a more agnostic therapeutic approach. Here, we present a study conducted in 77 bladder cancer (BC) patients (n = 77), ranging from stages pTa to pT2. Tumor specimens were resected via transurethral resection of bladder tumor (TURBT) and consistuted of 24 low-grade (LG) and 53 high-grade (HG) tumors. Patients' tumors were then categorized into molecular subtypes, via immunohistochemistry (CK5/6 and GATA3). Furthermore, all tumor specimens were stained with anti-PD-L1 and demonstrated significant correlations with basal immunophenotype, stage pT2 and HG tumors. As such, we attempted to stratify patients into groups of likely-responders and likely-not-responders to immunotherapy with anti-PD-L1, based on their molecular phenotype. Finally, in acknowledging the fact that there is a universal lack of biomarkers associated with predicting BC response to immunotherapeutic drugs, we tested all tumors for deficiency of mismatch repair proteins (MMR).

Molecular Subtyping in Muscle-Invasive Bladder Cancer on Predicting Survival and Response of Treatment.

Molecular classifications for urothelial bladder cancer appear to be promising in disease prognostication and prediction. This study investigated the novel molecular subtypes of muscle invasive bladder cancer (MIBC). Tumor samples and normal tissues of MIBC patients were submitted for transcriptome sequencing. Expression profiles were clustered using K-means clustering and principal component analysis. The molecular subtypes were also applied to The Cancer Genome Atlas (TCGA) dataset and analyzed for clinical outcome correlation. Three molecular subtypes of MIBC were discovered, clusters A, B, and C. The most differentially upregulated genes in cluster A were BDKRB1, EDNRA, AVPR1A, PDGFRB, and TNC, while the most upregulated genes in cluster C were collagen-related genes, PDGFRB, and PRKG1. For cluster B, COL6A3, COL1A2, COL6A2, tenascin C, and fibroblast growth factor 2 were statistically suppressed. When the centroids of clustering on PCA were applied to TCGA data, the clustering significantly predicted survival outcomes. Cluster B had the best overall survival (OS), and cluster C was associated with poor OS but exhibited the best response to perioperative chemotherapy. Among all groups, cluster B had a better pathologic response to neoadjuvant chemotherapy (40%). Based on the results of the present study, the novel clusters of subtype MIBC appear potentially suitable for integration into clinical practice.

High-Content Drug Discovery Targeting Molecular Bladder Cancer Subtypes.

Molecular subtypes of muscle-invasive bladder cancer (MIBC) display differential survival and drug sensitivities in clinical trials. To date, they have not been used as a paradigm for phenotypic drug discovery. This study aimed to discover novel subtype-stratified therapy approaches based on high-content screening (HCS) drug discovery. Transcriptome expression data of CCLE and BLA-40 cell lines were used for molecular subtype assignment in basal, luminal, and mesenchymal-like cell lines. Two independent HCSs, using focused compound libraries, were conducted to identify subtype-specific drug leads. We correlated lead drug sensitivity data with functional genomics, regulon analysis, and in-vitro drug response-based enrichment analysis. The basal MIBC subtype displayed sensitivity to HDAC and CHK inhibitors, while the luminal subtype was sensitive to MDM2 inhibitors. The mesenchymal-like cell lines were exclusively sensitive to the ITGAV inhibitor SB273005. The role of integrins within this mesenchymal-like MIBC subtype was confirmed via its regulon activity and gene essentiality based on CRISPR–Cas9 knock-out data. Patients with high ITGAV expression showed a significant decrease in the median overall survival. Phenotypic high-content drug screens based on bladder cancer cell lines provide rationales for novel stratified therapeutic approaches as a framework for further prospective validation in clinical trials.

Uroplakin II as a single marker for luminal versus basal molecular subtypes in muscle invasive urothelial carcinoma.

Bladder cancer is a heterogeneous disease classified into two broad molecular subtype categories, basal and luminal, with critical treatment and prognostic implications. Recent studies have shown the utility of immunohistochemistry in predicting bladder cancer molecular subtypes, with a two-marker approach using GATA3 and CK5/6 showing over 80% reliability. In the current study, we calculated the accuracy of uroplakin II (UPII), a marker of urothelial differentiation, with different scores (0: <1%, 1+: 1-10%, 2+: 10-50%, 3+: >50%) to predict RNA-based luminal versus basal subtypes in a cohort of muscle-invasive bladder cancer-received neoadjuvant chemotherapy followed by radical cystectomy. The 1% cutoff of the UPII stain predicts the luminal subtype with the sensitivity and specificity of 95% and 56%, respectively. With a UPII cutoff of 10%, the sensitivity and specificity were 93% and 81%, respectively, and with a UPII cutoff of 50%, the sensitivity and specificity were 91% and 96%, respectively. The prediction performance of UPII was better than either GATA3 or CK5/6. There was no significant difference in prognoses between UPII 0-2+ and UPII 3+ patients in this cohort. The current study shows that evaluating the staining proportion score of UPII can accurately predict basal and luminal subtypes of muscle-invasive bladder cancer.

Molecular Subtypes as a Basis for Stratified Use of Neoadjuvant Chemotherapy for Muscle-Invasive Bladder Cancer-A Narrative Review.

Simple SummaryAlthough it is one disease, cancer of the urinary bladder occurs in several molecular subtypes that can be identified by laboratory tests. Tumors of advanced stages are treated with surgical removal of the urinary bladder with or without addition of chemotherapy. About 50% of patients are cured by surgery and this proportion is increased slightly by the addition of chemotherapy. Still, many patients do not benefit from chemotherapy, which also comes with significant toxicity. Recent advances in the field suggest that molecular subtypes can help identify patient categories that do or do not benefit from adding chemotherapy to surgery. In this article, we review the literature and conclude that molecular subtypes are likely to have such a role in the future but that there are differences between studies that make them challenging to compare. The current evidence is insufficient to guide clinical practice.There are no established biomarkers to guide patient selection for neoadjuvant chemotherapy prior to radical cystectomy for muscle-invasive bladder cancer. Recent studies suggest that molecular subtype classification holds promise for predicting chemotherapy response and/or survival benefit in this setting. Here, we summarize and discuss the scientific literature examining transcriptomic or panel-based molecular subtyping applied to neoadjuvant chemotherapy-treated patient cohorts. We find that there is not sufficient evidence to conclude that the basal subtype of muscle-invasive bladder cancer responds well to chemotherapy, since only a minority of studies support this conclusion. More evidence indicates that luminal-like subtypes may have the most improved outcomes after neoadjuvant chemotherapy. There are also conflicting data concerning the association between biopsy stromal content and response. Subtypes indicative of high stromal infiltration responded well in some studies and poorly in others. Uncertainties when interpreting the current literature include a lack of reporting both response and survival outcomes and the inherent risk of bias in retrospective study designs. Taken together, available studies suggest a role for molecular subtyping in stratifying patients for receiving neoadjuvant chemotherapy. The precise classification system that best captures such a predictive effect, and the exact subtypes for which other treatment options are more beneficial remains to be established, preferably in prospective studies.

RAF1 amplification: an exemplar of MAPK pathway activation in urothelial carcinoma.

Despite recent therapeutic gains in the treatment of advanced bladder cancer, the overall survival in patients with metastatic disease remains poor and further therapeutic discovery is needed. Advanced bladder cancer is a molecularly heterogeneous disease, and the identification of driver genetic alterations has led to effective targeted therapeutic agents, such as fibroblast growth factor receptor (FGFR) inhibitors. In this issue of the JCI, Bekele et al. identify a subtype of muscle-invasive bladder cancer (MIBC) that harbors RAF1 amplification. The authors showed that RAF1 inhibition, with pan-RAF inhibitors, and the combination of RAF1 inhibition with MEK inhibition were efficacious in preclinical models harboring RAF1 amplifications as well as in tumors with HRAS and NRAS mutations. This study highlights RAF1 amplification as a driver event in bladder cancer and establishes the central role of the MAPK pathway in bladder tumorigenesis.

Impact of immunohistochemistry-based subtyping of GATA3, CK20, CK5/6, and CK14 expression on survival after radical cystectomy for muscle-invasive bladder cancer

Molecular subtyping of muscle-invasive bladder cancer (MIBC) predicts disease progression and treatment response. However, standard subtyping based on transcriptomic analysis is relatively expensive. This study tried to use immunohistochemistry (IHC) to subtype MIBC based on GATA3, CK20, CK5/6, and CK14 protein expression. The IHC-based subtypes in MIBC subtypes were classified as luminal (GATA3+ CK5/6−, 38.6%), basal (GATA3−CK5/6+, 12.9%), mixed (GATA3+ CK5/6+, 37.9%), and double-negative (GATA3−CK5/6−, 10.6%) in 132 MIBC patients. All individual markers and clinicopathological parameters were analyzed against treatment outcomes after radical cystectomy. The mean patient age was 65.6 years, and the male to female ratio was 6.8:1. Positive IHC expression of GATA3, CK20, CK5/6, and CK14 were 80.3%, 50.8%, 42.4%, and 28.0%, respectively. Only GATA3 and CK5/6 were significantly associated with survival outcome (p values = 0.004 and 0.02). The mixed subtype was significantly better in 5-year OS at 42.8%, whereas the double-negative subtype had the worst prognosis (5-year OS 7.14%). The double-negative subtype had a hazard ratio of 3.29 (95% CI 1.71–6.32). Subtyping using GATA3 and CK5/6 was applicable in MIBCs, and patients with the double-negative subtype were at the highest risk and may require more intensive therapy.

A quantitative polymerase chain reaction based method for molecular subtype classification of urinary bladder cancer-Stromal gene expressions show higher prognostic values than intrinsic tumor genes.

Transcriptome-based molecular subtypes of muscle-invasive bladder cancer (MIBC) have been shown to be both prognostic and predictive, but are not used in routine clinical practice. We aimed to develop a feasible, reverse transcription quantitative polymerase chain reaction (RT-qPCR)-based method for molecular subtyping. First, we defined a 68-gene set covering tumor intrinsic (luminal, basal, squamous, neuronal, epithelial-to-mesenchymal, in situ carcinoma) and stromal (immune, extracellular matrix, p53-like) signatures. Then, classifier methods with this 68-gene panel were developed in silico and validated on public data sets with available subtype class information (MD Anderson [MDA], The Cancer Genome Atlas [TCGA], Lund, Consensus). Finally, expression of the selected 68 genes was determined in 104 frozen tissue samples of our MIBC cohort by RT-qPCR using the TaqMan Array Card platform and samples were classified by our newly developed classifiers. The prognostic value of each subtype classification system and molecular signature scores were assessed. We found that the reduced marker set combined with the developed classifiers were able to reproduce the TCGA II, MDA, Lund and Consensus subtype classification systems with an overlap of 79%, 76%, 69% and 64%, respectively. Importantly, we could successfully classify 96% (100/104) of our MIBC samples by using RT-qPCR. Neuronal and luminal subtypes and low stromal gene expressions were associated with poor survival. In conclusion, we developed a robust and feasible method for the molecular subtyping according to the TCGA II, MDA, Lund and Consensus classifications. Our results suggest that stromal signatures have a superior prognostic value compared to tumor intrinsic signatures and therefore underline the importance of tumor-stroma interaction during the progression of MIBC.