Molecular profile of bladder cancer progression to clinically aggressive subtypes.

Bladder cancer is a histologically and clinically heterogenous disease. Most bladder cancers are urothelial carcinomas, which frequently develop distinct histological subtypes. Several urothelial carcinoma histological subtypes, such as micropapillary, plasmacytoid, small-cell carcinoma and sarcomatoid, show highly aggressive behaviour and pose unique challenges in diagnosis and treatment. Comprehensive genomic characterizations of the urothelial carcinoma subtypes have revealed that they probably arise from a precursor subset of conventional urothelial carcinomas that belong to different molecular subtypes - micropapillary and plasmacytoid subtypes develop along the luminal pathway, whereas small-cell and sarcomatoid subtypes evolve along the basal pathway. The subtypes exhibit distinct genomic alterations, but in most cases their biological properties seem to be primarily determined by specific gene expression profiles, including epithelial-mesenchymal transition, urothelial-to-neural lineage plasticity, and immune infiltration with distinct upregulation of immune regulatory genes. These breakthrough studies have transformed our view of bladder cancer histological subtype biology, generated new hypotheses for therapy and chemoresistance, and facilitated the discovery of new therapeutic targets.

Oncologic Outcomes in Patients with Residual Upper Tract Urothelial Carcinoma Following Neoadjuvant Chemotherapy.

BACKGROUND AND OBJECTIVE: Growing evidence supports the use of neoadjuvant chemotherapy (NAC) for upper tract urothelial carcinoma (UTUC). However, the implications of residual UTUC at radical nephroureterectomy (RNU) after NAC are not well characterized. Our objective was to compare oncologic outcomes for pathologic risk-matched patients who underwent RNU for UTUC who either received NAC or were chemotherapy-naïve. METHODS: We retrospectively identified 1993 patients (including 112 NAC recipients) who underwent RNU for nonmetastatic, high-grade UTUC between 1985 and 2022 in a large, international, multicenter cohort. We divided the cohort into low-risk and high-risk groups defined according to pathologic findings of muscle invasion and lymph node involvement at RNU. Recurrence-free survival (RFS), overall survival (OS), and cancer-specific survival (CSS) estimates were calculated using the Kaplan-Meier method. Multivariable analyses were performed to determine clinical and demographic factors associated with these outcomes. KEY FINDINGS AND LIMITATIONS: Among patients with low-risk pathology at RNU, RFS, OS, and CSS were similar between the NAC and chemotherapy-naïve groups. Among patients with high-risk pathology at RNU, the NAC group had poorer RFS (hazard ratio [HR] 3.07, 95% confidence interval [CI] 2.10-4.48), OS (HR 2.06, 95% CI 1.33-3.20), and CSS (subdistribution HR 2.54, 95% CI 1.37-4.69) in comparison to the pathologic risk-matched, chemotherapy-naïve group. Limitations include the lack of centralized pathologic review. CONCLUSIONS AND CLINICAL IMPLICATIONS: Patients with residual invasive disease at RNU after NAC represent a uniquely high-risk population with respect to oncologic outcomes. There is a critical need to determine an optimal adjuvant approach for these patients. PATIENT SUMMARY: We studied a large, international group of patients with cancer of the upper urinary tract who underwent surgery either with or without receiving chemotherapy beforehand. We identified a high-risk subgroup of patients with residual aggressive cancer after chemotherapy and surgery who should be prioritized for clinical trials and drug development.

Association of Molecular Subtypes with Pathologic Response, PFS, and OS in a Phase II Study of COXEN with Neoadjuvant Chemotherapy for Muscle-invasive Bladder Cancer.

PURPOSE: The Coexpression Extrapolation (COXEN) gene expression model with chemotherapy-specific scores [for methotrexate, vinblastine, adriamycin, cisplatin (ddMVAC) and gemcitabine/cisplatin (GC)] was developed to identify responders to neoadjuvant chemotherapy (NAC). We investigated RNA-based molecular subtypes as additional predictive biomarkers for NAC response, progression-free survival (PFS), and overall survival (OS) in patients treated in S1314. EXPERIMENTAL DESIGN: A total of 237 patients were randomized between four cycles of ddMVAC (51%) and GC (49%). On the basis of Affymetrix transcriptomic data, we determined subtypes using three classifiers: TCGA (k = 5), Consensus (k = 6), and MD Anderson (MDA; k = 3) and assessed subtype association with path response to NAC and determined associations with COXEN. We also tested whether each classifier contributed additional predictive power when added to a model based on predefined stratification (strat) factors (PS 0 vs. 1; T2 vs. T3, T4a). RESULTS: A total of 155 patients had gene expression results, received at least three of four cycles of NAC, and had pT-N response based on radical cystectomy. TCGA three-group classifier basal-squamous (BS)/neuronal, luminal (Lum), Lum infiltrated, and GC COXEN score yielded the largest AUCs for pT0 (0.59, P = 0.28; 0.60, P = 0.18, respectively). For downstaging (

Definitions, End Points, and Clinical Trial Designs for Bladder Cancer: Recommendations From the Society for Immunotherapy of Cancer and the International Bladder Cancer Group.

PURPOSE: There is a significant unmet need for new and efficacious therapies in urothelial cancer (UC). To provide recommendations on appropriate clinical trial designs across disease settings in UC, the Society for Immunotherapy of Cancer (SITC) and the International Bladder Cancer Group (IBCG) convened a multidisciplinary, international consensus panel. METHODS: Through open communication and scientific debate in small- and whole-group settings, surveying, and responses to clinical questionnaires, the consensus panel developed recommendations on optimal definitions of the disease state, end points, trial design, evaluations, sample size calculations, and pathology considerations for definitive studies in low- and intermediate-risk nonmuscle-invasive bladder cancer (NMIBC), high-risk NMIBC, muscle-invasive bladder cancer in the neoadjuvant and adjuvant settings, and metastatic UC. The expert panel also solicited input on the recommendations through presentations and public discussion during an open session at the 2021 Bladder Cancer Advocacy Network (BCAN) Think Tank (held virtually). RESULTS: The consensus panel developed a set of stage-specific bladder cancer clinical trial design recommendations, which are summarized in the table that accompanies this text. CONCLUSION: These recommendations developed by the SITC-IBCG Bladder Cancer Clinical Trial Design consensus panel will encourage uniformity among studies and facilitate drug development in this disease.

Phase 2 Trial of Atezolizumab in Bacillus Calmette-Guérin-unresponsive High-risk Non-muscle-invasive Bladder Cancer: SWOG S1605.

BACKGROUND: Although radical cystectomy (RC) is the standard of care for patients with bacillus Calmette-Guérin (BCG)-unresponsive high-risk non-muscle-invasive bladder cancer (NMIBC), many patients are ineligible for surgery or elect bladder preservation. OBJECTIVE: To evaluate the efficacy and safety of atezolizumab in BCG-unresponsive high-risk NMIBC. DESIGN, SETTING, AND PARTICIPANTS: This was a single-arm phase 2 trial in patients with BCG-unresponsive high-risk NMIBC who were ineligible for or declined RC. INTERVENTION: Intravenous atezolizumab every 3 wk for 1 yr. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint was the pathological complete response (CR) rate for patients with carcinoma in situ (CIS) determined via mandatory biopsy at 6 mo. Event-free survival (EFS) at 18 mo for patients with non-CIS tumors and treatment-related adverse events (TRAEs) were key secondary endpoints. RESULTS AND LIMITATIONS: Of 172 patients enrolled in the trial, 166 received at least one dose of atezolizumab (safety analysis) and 129 were eligible (efficacy analysis). Of the 74 patients with CIS, 20 (27%) experienced a CR at 6 mo. The median duration of response was 17 mo, and 56% (95% confidence interval [CI] 34-77%) of the responses were durable to at least 12 mo. The 18-mo actuarial EFS rate among 55 patients with Ta/T1 disease was 49% (90% CI 38-60%). Twelve of 129 eligible patients experienced progression to muscle-invasive or metastatic disease. Grade 3-5 TRAEs occurred in 26 patients (16%), including three treatment-related deaths. The study was limited by the small sample size and a high rate of patient ineligibility. CONCLUSIONS: The efficacy of atezolizumab observed among patients with BCG-unresponsive NMIBC is similar to results from similar trials with other agents, but did not meet the prespecified efficacy threshold. Modest efficacy needs to be balanced with a significant rate of TRAEs and the risk of disease progression when considering systemic immunotherapy in early-stage bladder cancer. PATIENT SUMMARY: We tested intravenous immunotherapy (atezolizumab) in patients with high-risk non-muscle-invasive bladder cancer that recurred after BCG (bacillus Calmette-Guérin) treatment. Although we found similar outcomes to previous trials, the benefit of this therapy is modest and needs to be carefully balanced with the significant risk of side effects. This trial is registered on ClinicalTrials.gov as NCT02844816.

Comparison of clinicopathological characteristics, gene expression profiles, mutational analysis, and clinical outcomes of pure and mixed small-cell carcinoma of the bladder.

AIMS: Small cell bladder carcinoma (SCBC) is a rare, divergent form of urothelial carcinoma (UC). We aimed to determine whether pure (n = 16) and mixed (SCBC and UC; n = 30) tumours differed in pathology, gene expression characteristics, genetic alterations, and clinical outcomes. METHODS AND RESULTS: Forty (87%) patients received first-line chemotherapy. Twenty-nine patients had no metastatic disease at diagnosis and underwent radical cystectomy. There were no differences in age, sex, race distribution, tumour size, stage at presentation, therapy response with pathological downstaging to ≤ypT1N0, or overall or progression-free survival (PFS) between pure and mixed tumours. There was a longer PFS among downstaged chemotherapy-responding tumours ≤ypT2N0M0 than among unresponsive tumours ≥ypT2 ≥ yN1M1 (P = 0.001). Patients who achieved pathological downstaging with neoadjuvant chemotherapy (n = 10) were stage cT2N0M0 at the time of diagnosis and were alive at the last follow-up (median 37 months), while 46% of patients who failed to achieve pathological downstaging were alive at the last follow-up (median 38 months; P = 0.008). RNA sequencing showed that the UC of mixed SCBC had similar neural expression signatures to pure SCBC. DNA sequencing revealed alterations in TERT (83%), P53 (56%), ARID1A (28%), RB1 (22%), and BRCA2 (11%). Immunohistochemistry for RB1 showed loss of expression in 18/19 (95%) patients, suggesting frequent pathway downregulation despite a low prevalence of RB1 mutation. CONCLUSION: Patients with pure and mixed SCBC have similar outcomes and these outcomes are determined by the pathological stage at RC and are best among patients who have pathological downstaging after NAC.

A Phase 1 Trial of Durvalumab in Combination with Bacillus Calmette-Guerin (BCG) or External Beam Radiation Therapy in Patients with BCG-unresponsive Non-muscle-Invasive Bladder Cancer: The Hoosier Cancer Research Network GU16-243 ADAPT-BLADDER Study.

BACKGROUND: Novel treatments and trial designs remain a high priority for bacillus Calmette-Guerin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC) patients. OBJECTIVE: To evaluate the safety and preliminary efficacy of anti-PD-L1 directed therapy with durvalumab (D), durvalumab plus BCG (D + BCG), and durvalumab plus external beam radiation therapy (D + EBRT). DESIGN, SETTING, AND PARTICIPANTS: A multicenter phase 1 trial was conducted at community and academic sites. INTERVENTION: Patients received 1120 mg of D intravenously every 3 wk for eight cycles. D + BCG patients also received full-dose intravesical BCG weekly for 6 wk with BCG maintenance recommended. D + EBRT patients received concurrent EBRT (6 Gy × 3 in cycle 1 only). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Post-treatment cystoscopy and urine cytology were performed at 3 and 6 -mo, with bladder biopsies required at the 6-mo evaluation. The recommended phase 2 dose (RP2D) for each regimen was the primary endpoint. Secondary endpoints included toxicity profiles and complete response (CR) rates. RESULTS AND LIMITATIONS: Twenty-eight patients were treated in the D (n = 3), D + BCG (n = 13), and D + EBRT (n = 12) cohorts. Full-dose D, full-dose BCG, and 6 Gy fractions × 3 were determined as the RP2Ds. One patient (4%) experienced a grade 3 dose limiting toxicity event of autoimmune hepatitis. The 3-mo CR occurred in 64% of all patients and in 33%, 85%, and 50% within the D, D + BCG, and D + EBRT cohorts, respectively. Twelve-month CRs were achieved in 46% of all patients and in 73% of D + BCG and 33% of D + EBRT patients. CONCLUSIONS: D combined with intravesical BCG or EBRT proved feasible and safe in BCG-unresponsive NMIBC patients. Encouraging preliminary efficacy justifies further study of combination therapy approaches. PATIENT SUMMARY: Durvalumab combination therapy can be safely administered to non-muscle-invasive bladder cancer patients with the goal of increasing durable response rates.

Lentiviral interferon: A novel method for gene therapy in bladder cancer.

Interferon alpha (IFNα) gene therapy is emerging as a new treatment option for patients with non-muscle invasive bladder cancer (NMIBC). Adenoviral vectors expressing IFNα have shown clinical efficacy treating bacillus Calmette-Guerin (BCG)-unresponsive bladder cancer (BLCA). However, transient transgene expression and adenoviral immunogenicity may limit therapeutic activity. Lentiviral vectors can achieve stable transgene expression and are less immunogenic. In this study, we evaluated lentiviral vectors expressing murine IFNα (LV-IFNα) and demonstrate IFNα expression by transduced murine BLCA cell lines, bladder urothelium, and within the urine following intravesical instillation. Murine BLCA cell lines (MB49 and UPPL1541) were sensitive to IFN-mediated cell death after LV-IFNα, whereas BBN975 was inherently resistant. Upregulation of interleukin-6 (IL-6) predicted sensitivity to IFN-mediated cell death mediated by caspase signaling, which when inhibited abrogated IFN-mediated cell killing. Intravesical therapy with LV-IFNα/Syn3 in a syngeneic BLCA model significantly improved survival, and molecular analysis of treated tumors revealed upregulation of apoptotic and immune-cell-mediated death pathways. In particular, biomarker discovery analysis identified three clinically actionable targets, PD-L1, epidermal growth factor receptor (EGFR), and ALDHA1A, in murine tumors treated with LV-IFNα/Syn3. Our findings warrant the comparison of adenoviral and LV-IFNα and the study of novel combination strategies with IFNα gene therapy for the BLCA treatment.

Race reporting and disparities regarding clinical trials in bladder cancer: a systematic review.

PURPOSE: To systematically review the literature to investigate racial disparities among bladder cancer clinical trial enrollees. METHODS: A systematic review was conducted using Ovid, MEDLINE® to identify clinical trials between 1970 and 2020. Articles were reviewed and were included if they assessed race in their outcomes reporting among bladder cancer patients enrolled in clinical trials. The review was conducted in accordance with the PRISMA statement. RESULTS: We identified 544 clinical trials meeting our initial search criteria, with only 24 (4.4%) studies reporting racial demographic data. Enrollees were largely Caucasian (81-98%), with a strikingly small proportion of enrolled patients consisting of African-Americans (2-8%) and Hispanics (2-5%). Only one of the studies reported results on the efficacy and safety/tolerability of the tested treatment separately for racial groups and performed analyses stratified by race. CONCLUSION: Race is poorly studied in bladder cancer clinical trials. Trial cohorts may not reflect multicultural populations. The potential association between race and efficacy, safety or tolerability of the tested interventions is unknown. Given the up to twofold increase in bladder cancer-specific death among African-Americans, further research is needed to address the impact of race in clinical trials, while encompassing socioeconomic factors and disease risk factor exposures.

Characterizing molecular subtypes of high-risk non-muscle-invasive bladder cancer in African American patients.

BACKGROUND: We sought to determine whether differences in subtype distribution and differentially expressed genes exist between African Americans (AAs) and European Americans (EAs) in patients with high-risk nonmuscle-invasive bladder cancer (NMIBC). METHODS: We performed a retrospective cohort study including 26 patients (14 AAs and 12 EAs) from the University of Texas Medical Branch and the Durham Veterans Affair Health Care System from 2010 to 2020 among treatment naïve, high-risk NMIBC. Profiled gene expressions were performed using the UROMOL classification system. RESULTS: UROMOL racial subtype distributions were similar with class 2a being most common with 10 genes commonly upregulated in AAs compared to EAs including EFEMP1, S100A16, and MCL1 which are associated with progression to muscle-invasive bladder cancer, mitomycin C resistance, and bacillus Calmette-Guérin durability, respectively. We used single nuclei analysis to map the malignant cell heterogeneity in urothelial cancer which 5 distinct malignant epithelial subtypes whose presence has been associated with different therapeutic response prediction abilities. We mapped the expression of the 10 genes commonly upregulated by race as a function of the 5 malignant subtypes. This showed borderline (P = 0.056) difference among the subtypes suggesting AAs and EAs may be expected to have different therapeutic responses to treatments for bladder cancer. AAs were enriched with immune-related, inflammatory, and cellular regulation pathways compared to EAs, yet appeared to have reduced levels of the aggressive C3/CDH12 bladder tumor cell population. CONCLUSIONS: While premature, gene expression differed between AAs and EAs, supporting potential race-based etiologies for muscle-invasion, response to treatments, and transcriptome pathway regulations.

Gender-specific Stratification of Survival Following Immune Checkpoint Inhibitor Therapy Based on Intratumoral Expression of a B cell Gene Signature.

BACKGROUND: There is a great need to identify biomarkers that can accurately identify patients who will obtain the most clinical benefit from immune checkpoint inhibitor (ICI) therapy. While high intratumoral B cell gene expression correlated with an ICI response in melanoma, whether it adds predictive value in other cancers is unknown. OBJECTIVE: To examine the relationship between B cell gene signature (BCGS) expression and overall survival (OS) following ICI treatment. DESIGN, SETTING, AND PARTICIPANTS: A total of 348 patients with advanced urothelial carcinoma from the IMvigor 210 phase 2 clinical trial of atezolizumab and 406 patients with muscle-invasive bladder cancer from The Cancer Genome Atlas (TCGA) were included. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We analyzed tumor RNA sequencing data of included patients to examine the relationships between a BCGS and clinical outcomes. RESULTS AND LIMITATIONS: Tumors with high levels of B cell and CD8+ T cell gene signatures (BCGS/CD8TGS or B8T high/high) were associated with the longest OS of all B8T groups. Moreover, the B8T cell signature stratified patients whose tumors had a high tumor mutational burden or high programmed death ligand 1 (PD-L1) into subsets with differential OS outcomes. Whereas the B8T high/high tumors were associated with the best clinical outcomes in ICI-treated men, they were not associated with better OS in women. Conversely, women with B8T high/high tumors had the best clinical outcomes in non-ICI-treated muscle-invasive bladder cancer. CONCLUSIONS: These data suggest that the B8T signature can enhance OS stratification in patients with advanced urothelial carcinoma who are treated with ICI therapy and that sex-specific differences in the tumor immune microenvironment may drive disparate outcomes. PATIENT SUMMARY: We examined whether the presence of two immune cell gene signatures within tumor samples impact survival in patients with bladder cancer. High levels of both of these signatures (B cells and CD8+ T cells) associate with superior survival in patients who receive immune therapy.

Antiadenovirus Antibodies Predict Response Durability to Nadofaragene Firadenovec Therapy in BCG-unresponsive Non-muscle-invasive Bladder Cancer: Secondary Analysis of a Phase 3 Clinical Trial.

A recent phase 3 trial of intravesical nadofaragene firadenovec reported a promising complete response rate for patients with bacillus Calmette-Guérin-unresponsive non-muscle-invasive bladder cancer. This study examined the ability of antiadenovirus antibody levels to predict the durability of therapeutic response to nadofaragene firadenovec. A standardized and validated quantitative assay was used to prospectively assess baseline and post-treatment serum antibody levels among 91 patients from the phase 3 trial, of whom 47 (52%) were high-grade recurrence free at 12 mo (responders). While baseline titers did not predict treatment response, 3-mo titer >800 was associated with a higher likelihood of durable response (p = 0.026). Peak post-treatment titers >800 were noted in 42 (89%) responders versus 26 (59%) nonresponders (p = 0.001; assay sensitivity, 89%; negative predictive value, 78%). Moreover, 22 (47%) responders compared with eight (18%) nonresponders had a combination of peak post-treatment titers >800 and peak antibody fold change >8 (p = 0.004; assay specificity, 82%; positive predictive value, 73%). A majority of responders continued to have post-treatment antibody titers >800 after the first 6 mo of therapy. In conclusion, serum antiadenovirus antibody quantification may serve as a novel predictive marker for nadofaragene firadenovec response durability. Future studies will focus on large-scale validation and clinical utility of the assay. PATIENT SUMMARY: This study reports on a planned secondary analysis of a phase 3 multicenter clinical trial that established the benefit of nadofaragene firadenovec, a novel intravesical gene therapeutic, for the treatment of patients with bacillus Calmette-Guérin (BCG)-unresponsive high-risk non-muscle-invasive bladder cancer. Prospective assessment of serum anti-human adenovirus type-5 antibody levels of patients in this trial indicated that a combination of post-treatment titers and fold change from baseline can predict treatment efficacy. While this merits additional validation, our findings suggest that serum antiadenovirus antibody levels can serve as an important predictive marker for the durability of therapeutic response to nadofaragene firadenovec.

γδ T Cells Support Antigen-Specific αß T cell-Mediated Antitumor Responses during BCG Treatment for Bladder Cancer.

Bacillus Calmette-Guérin (BCG) is the most effective intravesical agent at reducing recurrence for patients with high-grade, non-muscle-invasive bladder cancer. Nevertheless, response to BCG is variable and strategies to boost BCG efficacy have not materialized. Prior work demonstrated a requirement for either conventional αß or nonconventional γδ T cells in mediating BCG treatment efficacy, yet the importance of T-cell antigen specificity for BCG's treatment effect is unclear. Here, we provide direct evidence to show that BCG increases the number of tumor antigen-specific αß T cells in patients with bladder cancer and protects mice from subsequent same-tumor challenge, supporting BCG induction of tumor-specific memory and protection. Adoptive T-cell transfers of antigen-specific αß T cells into immunodeficient mice challenged with syngeneic MB49 bladder tumors showed that both tumor and BCG antigen-specific αß T cells contributed to BCG efficacy. BCG-specific antitumor immunity, however, also required nonconventional γδ T cells. Prior work shows that the mTOR inhibitor rapamycin induces the proliferation and effector function of γδ T cells. Here, rapamycin increased BCG efficacy against both mouse and human bladder cancer in vivo in a γδ T cell-dependent manner. Thus, γδ T cells augment antitumor adaptive immune effects of BCG and support rapamycin as a promising approach to boost BCG efficacy in the treatment of non-muscle-invasive bladder cancer.

Unique somatic variants in DNA from urine exosomes of individuals with bladder cancer.

Bladder cancer (BC), a heterogeneous disease characterized by high recurrence rates, is diagnosed and monitored by cystoscopy. Accurate clinical staging based on biopsy remains a challenge, and additional, objective diagnostic tools are needed urgently. We used exosomal DNA (exoDNA) as an analyte to examine cancer-associated mutations and compared the diagnostic utility of exoDNA from urine and serum of individuals with BC. In contrast to urine exosomes from healthy individuals, urine exosomes from individuals with BC contained significant amounts of DNA. Whole-exome sequencing of DNA from matched urine and serum exosomes, bladder tumors, and normal tissue (peripheral blood mononuclear cells) identified exonic and 3' UTR variants in frequently mutated genes in BC, detectable in urine exoDNA and matched tumor samples. Further analyses identified somatic variants in driver genes, unique to urine exoDNA, possibly because of the inherent intra-tumoral heterogeneity of BC, which is not fully represented in random small biopsies. Multiple variants were also found in untranslated portions of the genome, such as microRNA (miRNA)-binding regions of the KRAS gene. Gene network analyses revealed that exoDNA is associated with cancer, inflammation, and immunity in BC exosomes. Our findings show utility of exoDNA as an objective, non-invasive strategy to identify novel biomarkers and targets for BC.

Molecular subtypes of upper tract urothelial cancer: Setting the stage for precision therapy.

A comprehensive genomic characterization of a large, high-quality cohort of upper tract urothelial carcinomas (UTUCs) in this issue of Cancer Cell reveals that UTUCs can be divided into five DNA-based molecular subtypes. Feasibility data establish that molecular subtyping can be performed non-invasively by sequencing tumor DNA in urine.

Molecular Biology of Bladder Cancer: Potential Implications for Therapy.

Recently completed studies provided high-resolution descriptions of the molecular biological characteristics of urothelial bladder cancers. Whole transcriptome messenger RNA expression profiling revealed that they can be grouped into basal and luminal molecular subtypes resembling the ones described in breast cancers. Retrospective DNA sequencing efforts revealed roles for disruption of DNA damage response pathways in response to conventional chemotherapy and immune checkpoint blockade, and completed and ongoing studies indicate that the molecular biological properties of infiltrating host cells dictate also influence therapeutic outcomes. This article reviews these findings and identify gaps in knowledge that represent opportunities for future research.

Expression Analysis of Same-Patient Metachronous and Synchronous Upper Tract and Bladder Urothelial Carcinoma.

PURPOSE: We compared upper tract urothelial carcinoma (UTUC) and bladder urothelial carcinoma (BUC) in same-patient metachronous UTUC and synchronous UTUC and BUC using next-generation sequencing. MATERIALS AND METHODS: Consecutive untreated same-patient samples of UTUC and BUC were macrodissected from unstained formalin-fixed, paraffin-embedded slides after quality control. Samples were divided into 4 groups: 1) UTUC-metachronous BUC, 2) BUC-metachronous UTUC, 3) synchronous UTUC-BUC, 4) UTUC without BUC. Exclusions were inadequate clinical data or histological tumor purity <30%. Whole transcriptome RNA sequencing was performed. After quality assessment, gene expression clusters using unsupervised hierarchical consensus clustering and correlation with pertinent clinicopathologic variables, a prior RNASeq data set and other published data were performed. RESULTS: RNAseq was performed on 95 samples (UTUC=61, BUC=34) from 40 untreated patients. Unsupervised consensus clustering segregated the tumors into 2 clusters that were enriched with BASE47 basal-like or luminal-like gene expression. Almost two-thirds (61.9%) of Group 2 tumors were basal-like, while the majority of Groups 1, 3, 4 (80.6%, 70.0% and 69.6%, respectively) were luminal-like (p=0.017). Further analyses revealed that the differences in basal-like and luminal-like gene expression were associated with differential fibroblast and immune cell gene expression signatures. In all, 87.5% of metachronous tumors maintained subtype membership. CONCLUSIONS: Gene expression analysis of same-patient metachronous UTUC-BUC suggests that the majority of mUTUC developing after BUC appear more basal-like, while synchronous and initial UTUC tumors appear luminal-like. Metachronous tumors largely maintain molecular subtype membership of the initial tumor regardless of chronologic development or anatomical origin.