Unfavorable Cancer-specific Survival After Neoadjuvant Chemotherapy and Radical Cystectomy in Patients With Bladder Cancer and Squamous Cell Variant: A Multi-institutional Study

One Size Fits Some: Approaching Rare Malignancies of the Urinary Tract

OPINION STATEMENT

Urothelial carcinoma is the predominant cancer of the urinary tract but when divergent and subtype histology (non-urothelial) are identified at time of pathologic diagnosis, therapeutic and diagnostic challenges transpire. To this end, pathologic review to confirm any non-urothelial histology is key since these subtypes can often be overlooked. Few prospective trials are dedicated to understanding these non-urothelial histologic types; however, current, and past trials did allow patients with these non-urothelial histologic types to enroll, and inferences can be made about treatment efficacy and survival. Existing treatment regimens for non-urothelial bladder cancers are akin to standard urothelial cancer regimens using surgical approaches for localized disease and platinum-based chemotherapy for advanced disease. The reported clinical trials, that will be discussed, center on non-urothelial histologic types. These studies, albeit limited, provide critical insight into tumor biology and response to standard platinum-based chemotherapy, immune checkpoint inhibitors, and antibody drug conjugates. The inclusion of non-urothelial histologic types will be essential for clinical trials in development to provide further therapeutic advances and provide essential efficacy data.

Pesticides and Bladder Cancer: Mechanisms Leading to Anti-Cancer Drug Chemoresistance and New Chemosensitization Strategies

Multiple risk factors have been associated with bladder cancer. This review focuses on pesticide exposure, as it is not currently known whether agricultural products have a direct or indirect effect on bladder cancer, despite recent reports demonstrating a strong correlation. While it is known that pesticide exposure is associated with an increased risk of bladder cancer in humans and dogs, the mechanism(s) by which specific pesticides cause bladder cancer initiation or progression is unknown. In this narrative review, we discuss what is currently known about pesticide exposure and the link to bladder cancer. This review highlights multiple pathways modulated by pesticide exposure with direct links to bladder cancer oncogenesis/metastasis (MMP-2, TGF-β, STAT3) and chemoresistance (drug efflux, DNA repair, and apoptosis resistance) and potential therapeutic tactics to counter these pesticide-induced affects.

Conditional survival after radical cystectomy for non-metastatic muscle-invasive squamous cell carcinoma of the urinary bladder: A population-based analysis

PURPOSE

To assess the effect of event-free survival duration on cancer-specific mortality (CSM) after radical cystectomy (RC) in nonmetastatic muscle-invasive squamous cell carcinoma of the urinary bladder.

METHODS

RC patients treated for non-metastatic muscle-invasive squamous cell carcinoma of the urinary bladder were identified within the Surveillance, Epidemiology, and End Results database (2000-2018). Independent predictor status for CSM of T and N stage groupings (i.e., T2N0, T3N0, T4N0, and TanyN1-3) was tested in multivariable Cox-regression models. Conditional 5-year CSM-free estimates were assessed at baseline and at 4 specific event-free survival times (i.e. 6, 12, 18 and 24 months), within each of the 4 examined stage groups.

RESULTS

Of 981 RC patients, 206 (21%), 416 (42%), 152 (16%), and 207 (21%) were T2N0, T3N0, T4N0, and TanyN1-3, respectively. In multivariable Cox-regression models T3N0 (HR 1.94), T4N0 (HR 5.22), and TanyN1-3 (HR 6.62) were independent predictors of CSM, relative to T2N0. In conditional survival analyses based on 24 months event-free status, survival estimates were: 89% for T2N0 vs. 76% at baseline (Δ = 13%), 84% for T3N0 vs. 58% at baseline (Δ = 26%), 69% for T4N0 vs. 25% at baseline (Δ = 44%), 69% for TanyN1-3 vs. 22% at baseline (Δ = 47%).

CONCLUSIONS

Event-free status at 24 months of follow-up is associated with substantially higher CSM-free survival than when CSM-free survival is predicted at baseline. The magnitude of this effect is most pronounced in TanyN1-3 and T4N0 patients, intermediate in T3N0 and more modest, nonetheless important, in T2N0.

Differences in Cancer-Specific Mortality after Trimodal Therapy for T2N0M0 Bladder Cancer according to Histological Subtype

We aimed at assessing the impact of non-urothelial variant histology (VH), relative to urothelial carcinoma of the urinary bladder (UCUB), on cancer-specific mortality (CSM) in T2N0M0 bladder cancer patients treated with trimodal therapy (TMT). TMT patients treated for T2N0M0 bladder cancer were identified within the Surveillance, Epidemiology, and End Results database (2000−2018). Patients who underwent TMT received trans-urethral resection of the bladder tumor, chemotherapy, and radiotherapy. CSM-FS rates were tested using Kaplan−Meier plots and multivariable Cox-regression (MCR) models according to histological subtype: UCUB vs. neuroendocrine carcinoma vs. squamous cell carcinoma vs. adenocarcinoma. A total of 3846 T2N0MO bladder cancer patients treated with TMT were identified. Of these, 3627 (94.3%) harbored UCUB, while 105 (2.7%), 85 (2.2%), and 29 (0.8%) harbored neuroendocrine carcinoma, squamous cell carcinoma, and adenocarcinoma, respectively. In Kaplan−Meier analyses, 3-yr CSM-FS rates were 57% for UCUB, 51% for neuroendocrine carcinoma, 35% for squamous cell carcinoma, and 60% for adenocarcinoma (p-value < 0.0001). In MCR models, only squamous cell carcinoma exhibited higher CSM than UCUB (HR 1.98, 95%CI 1.5−2.61, p-value < 0.001). Despite the small number of observations, squamous cell carcinoma distinguished itself from UCUB based on worse survival in T2N0M0 patients after TMT.

Neoadjuvant therapy for muscle-invasive bladder cancer: Current clinical scenario, future perspectives, and unsolved questions

Cisplatin-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy is the standard treatment for patients with muscle-invasive bladder cancer (MIBC). However, the implementation of NAC is lower than desirable mainly due to its limited impact on overall survival, patients' comorbidities and the lack of predictive biomarkers to select those patients most likely to benefit from NAC. In the last decade, improved molecular MIBC characterisation, the identification of potential predictive and prognostic biomarkers as well as the incorporation of new effective therapies with a better toxicity profile, such as immunotherapy, has changed the treatment paradigm for MIBC. Therefore, the main goal for the near future is to introduce these clinical and translational advances into routine clinical practice to personalise treatment for each patient and increase the opportunity to implement bladder preservation strategies. The present review focuses on the current status of NAC in MIBC, unsolved questions and future therapeutic approaches.

Molecular profile of pure squamous cell carcinoma of the bladder identifies major roles for OSMR and YAP signalling

Pure squamous cell carcinoma (SCC) is the most common pure variant form of bladder cancer, found in 2–5% of cases. It often presents late and is unresponsive to cisplatin‐based chemotherapy. The molecular features of these tumours have not been elucidated in detail. We carried out whole‐exome sequencing (WES), copy number, and transcriptome analysis of bladder SCC. Muscle‐invasive bladder cancer (MIBC) samples with no evidence of squamous differentiation (non‐SD) were used for comparison. To assess commonality of features with urothelial carcinoma with SD, we examined data from SD samples in The Cancer Genome Atlas (TCGA) study of MIBC. TP53 was the most commonly mutated gene in SCC (64%) followed by FAT1 (45%). Copy number analysis revealed complex changes in SCC, many differing from those in samples with SD. Gain of 5p and 7p was the most common feature, and focal regions on 5p included OSMR and RICTOR. In addition to 9p deletions, we found some samples with focal gain of 9p24 containing CD274 (PD‐L1). Loss of 4q35 containing FAT1 was found in many samples such that all but one sample analysed by WES had FAT1 mutation or deletion. Expression features included upregulation of oncostatin M receptor (OSMR), metalloproteinases, metallothioneins, keratinisation genes, extracellular matrix components, inflammatory response genes, stem cell markers, and immune response modulators. Exploration of differentially expressed transcription factors identified BNC1 and TFAP2A, a gene repressed by PPARG, as the most upregulated factors. Known urothelial differentiation factors were downregulated along with 72 Kruppel‐associated (KRAB) domain‐containing zinc finger family protein (KZFP) genes. Novel therapies are urgently needed for these tumours. In addition to upregulated expression of EGFR, which has been suggested as a therapeutic target in basal/squamous bladder cancer, we identified expression signatures that indicate upregulated OSMR and YAP/TAZ signalling. Preclinical evaluation of the effects of inhibition of these pathways alone or in combination is merited.

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

Simple Summary

Although 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.

Abstract

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.

The effect of neoadjuvant chemotherapy among patients undergoing radical cystectomy for variant histology bladder cancer: A systematic review

Objective

To systematically review the evidence about the effect of neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) with pure urothelial carcinoma (pUC) in radical cystectomy (RC) candidates affected by variant histology (VH) bladder cancer.

Methods

A review of the current literature was conducted through the Medline and National Center for Biotechnology Information (NCBI) PubMed, Scopus databases in May 2020. The updated Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed for this systematic review. Keywords used were ‘bladder cancer’, ‘bladder carcinoma’, ‘bladder tumour’ and ‘bladder cancer variants’ and ‘neoadjuvant chemotherapy’. Only original articles in English published after 2000 and reporting oncological outcomes a series of more than five patients with VH were included. We excluded series in which the oncological outcomes of patients with pUC and VH were undistinguishable.

Results

The literature search identified 2231 articles. A total of 51 full-text articles were assessed for eligibility, with 17 eventually considered for systematic review, for a cohort of 450,367 patients, of which 5010 underwent NAC + RC. The median age at initial diagnosis ranged from 61 to 71 years. Most patients received cisplatin-gemcitabine, methotrexate-vinblastine-adriamycin-cisplatin, or carboplatin-based chemotherapy. Only one study reported results of neoadjuvant immunotherapy. The median follow-up ranged from 1 to 120 months. The results showed that squamous cell carcinoma (SCC) is less sensitive to NAC than pUC and that SCC predicts poorer prognosis. NAC was found to be a valid approach in treating small cell carcinoma and may have potential benefit in micropapillary carcinoma.

Conclusions

NAC showed the best oncological outcomes in small cell variants and micropapillary carcinoma, while NAC survival benefit for SCC and adenocarcinoma variants needs further studies. Drawing definite considerations on the efficacy of NAC in VH is complicated due to the heterogeneity of present literature. Present results need to be confirmed in randomised controlled trials.

[French ccAFU guidelines - update 2020-2022: bladder cancer]

OBJECTIVE

- To update French guidelines for the management of bladder cancer specifically non-muscle invasive (NMIBC) and muscle-invasive bladder cancers (MIBC).

METHODS

- A Medline search was achieved between 2018 and 2020, notably regarding diagnosis, options of treatment and follow-up of bladder cancer, to evaluate different references with levels of evidence.

RESULTS

- Diagnosis of NMIBC (Ta, T1, CIS) is based on a complete deep resection of the tumor. The use of fluorescence and a second-look indication are essential to improve initial diagnosis. Risks of both recurrence and progression can be estimated using the EORTC score. A stratification of patients into low, intermediate and high risk groups is pivotal for recommending adjuvant treatment: instillation of chemotherapy (immediate post-operative, standard schedule) or intravesical BCG (standard schedule and maintenance). Cystectomy is recommended in BCG-refractory patients. Extension evaluation of MIBC is based on contrast-enhanced pelvic-abdominal and thoracic CT-scan. Multiparametric MRI can be an alternative. Cystectomy associated with extended lymph nodes dissection is considered the gold standard for non-metastatic MIBC. It should be preceded by cisplatin-based neoadjuvant chemotherapy in eligible patients. An orthotopic bladder substitution should be proposed to both male and female patients with no contraindication and in cases of negative frozen urethral samples; otherwise transileal ureterostomy is recommended as urinary diversion. All patients should be included in an Early Recovery After Surgery (ERAS) protocol. For metastatic MIBC, first-line chemotherapy using platin is recommended (GC or MVAC), when performans status (PS <1) and renal function (creatinine clearance >60 mL/min) allow it (only in 50% of cases). In second line treatment, immunotherapy with pembrolizumab demonstrated a significant improvement in overall survival.

CONCLUSION

- These updated French guidelines will contribute to increase the level of urological care for the diagnosis and treatment of patients diagnosed with NMIBC and MIBC.

Neoadjuvant immunotherapy is reshaping cancer management across multiple tumour types: The future is now!

The Italian Network for Tumor Biotherapy (Network Italiano per la Bioterapia dei Tumori [NIBIT]) Foundation hosted its annual 2020 Think Tank meeting virtually, at which representatives from academic, clinical, industry, philanthropic, and regulatory organisations discussed the role of neoadjuvant immunotherapy for the treatment of cancer. Although the number of neoadjuvant immunotherapeutic trials is increasing across all malignancies, the Think Tank focused its discussion on the status of neoadjuvant trials in cutaneous melanoma (CM), muscle-invasive urothelial bladder cancer (MIBC), head and neck squamous cell carcinoma (HNSCC), and pancreatic adenocarcinoma (PDAC). Neoadjuvant developments in CM are nothing short of trailblazing. Pathologic Complete Response (pCR), pathologic near Complete Response, and partial Pathologic Responses reduce 90-100% of recurrences. This is in sharp contrast to targeted therapies in neoadjuvant CM trials, where only a pCR seems to reduce recurrence. The pCR rate after neoadjuvant immunotherapy varies among the different malignancies of CM, MIBC, HNSCC, and PDAC and may be associated with different reductions of recurrence rates. In CM, emerging evidence suggests that neoadjuvant immunotherapy with anti-CTLA-4 plus anti-PD1 is a game changer in patients with palpable nodal Stage III or resectable Stage IV disease by curing more patients, reducing recurrences and the need for surgical interventions, such as lymph node dissections and metastasectomies. The Think Tank panel discussed future approaches on how to optimise results across different tumour types. Future approaches should include reducing monocyte-mediated (tumour-associated macrophages) and fibroblast-mediated (cancer-associated fibroblasts) barriers in the tumour microenvironment to facilitate the recruitment of immune cells to the tumour site, to reduce immune-suppressive mediators, and to increase antigen presentation at the site of the tumour.

Racial differences in the distribution of bladder cancer metastases: a population-based analysis

INTRODUCTION

Bladder cancer is the second most common genitourinary malignancy in the United States. The incidence of bladder cancer rises with age, and it is two times more common in Caucasians than in African-Americans (23.1 vs. 12.6 cases/100,000 persons). We aimed to investigate the racial and age-related differences in the distribution of metastasis in a large, contemporary cohort of metastatic bladder cancer patients.

MATERIAL AND METHODS

Within the National Inpatient Sample database (2008-2015) we identified 5,767 patients with metastatic bladder cancer. Trend test, Chi-square test and multivariable logistic regression models were used to evaluate the relationship between ethnicity, age, and site of metastasis.

RESULTS

Of 5,767 patients with metastatic bladder cancer, 598 (10.4%) were African-American. Lung was the most common metastatic site in African-Americans (28.6%) vs. bone in Caucasians (21.7%). Overall, African-Americans showed higher rates of lung (+10.2%), liver (+7.5%) and bone (+5.2%) metastases, compared to Caucasians (all p <0.01). Brain metastases were rare in both ethnicities (3.3 vs. 2.4%; p = 0.2). Rates of exclusive bone, lung or liver metastases increased with age, but were higher in African-Americans, regardless of age strata. In the multivariable logistic regression models, African-American ethnicity independently predicted higher risk of lung (Odds ratio: 1.69), liver (odds ratio: 1.50) and bone (odds ratio: 1.27) metastases, relative to Caucasians. Moreover, a dose-response effect was found after combining the three main risk factors for developing bone metastases, namely African-American ethnicity, younger age and male gender.

CONCLUSIONS

Racial differences exist in the distribution of metastatic bladder cancer metastasis. Moreover, based on higher risk of bone metastases in African-American patients, bone imaging may be warranted in this patient population, especially in the presence of other risk factors for bone metastases, namely male gender or younger age.

Neoadjuvant Chemotherapy or Immunotherapy for Clinical T2N0 Muscle-invasive Bladder Cancer: Time to Change the Paradigm?

A 41-yr-old, otherwise healthy, premenopausal woman presented at our uro-oncology clinic with a diagnosis of muscle-invasive bladder cancer following a transurethral resection of the bladder performed at another center. After a thorough discussion with the patient, she was enrolled in the phase II PURE-01 trial (NCT02736266), testing three cycles of neoadjuvant pembrolizumab (200mg) every 3 wk before radical cystectomy. Before treatment, imaging studies were obtained as per the protocol using computed tomography (CT), [¹⁸F]fluorodeoxyglucose positron emission tomography/CT, and multiparametric magnetic resonance imaging of the bladder, defining a clinically localized T2N0M0 stage. As per the protocol, potential biomarkers were assessed, including PD-L1 expression (84% combined positive score), tumor mutational burden (16.67 mut/Mb), and genomic profiling (FoundationONE assay; somatic mutation in TP53, EZH2, APC, TERT, CDKN1A, CDKN1B, and ARID1A genes, and truncation in BRCA2 gene). After immunotherapy, the patient underwent a robot-assisted radical cystectomy with extended pelvic lymph node dissection. The final pathology report revealed absence of residual disease (ie, pathological complete response, ypT0ypN0). During follow-up, the only relevant and permanent immune-mediated adverse event was hypothyroidism secondary to an autoimmune thyroiditis. It appeared 2 mo after radical cystectomy and it was managed successfully with hormonal replacement therapy. Two years after treatment, the patient is asymptomatic and free from disease recurrence. PATIENT SUMMARY: Increasing evidence suggests that frontline neoadjuvant immunotherapy may be beneficial for patients diagnosed with non-locally advanced, muscle-invasive bladder cancer (cT2N0), with fewer drawbacks than traditional chemotherapy. Although further studies are needed in support, this vision opens the opportunity for future clinical trials testing the potential incremental benefits of immunotherapy and the utility of novel biomarker- and imaging-based strategies to assess response to therapy.

Pathological and Survival Outcomes Associated with Variant Histology Bladder Cancers Managed by Cystectomy with or without Neoadjuvant Chemotherapy

PURPOSE

Although neoadjuvant chemotherapy is associated with a survival advantage in pure urothelial, muscle invasive bladder cancer, the role of neoadjuvant chemotherapy is less clear in variant histology or urothelial carcinoma with divergent differentiation. We compared chemotherapy response and survival outcomes of patients with nonpure urothelial carcinoma histology who were managed with neoadjuvant chemotherapy followed by cystectomy vs cystectomy alone.

MATERIALS AND METHODS

We analyzed 768 patients with clinical muscle invasive bladder cancer (cT2-4N0M0) who were treated with cystectomy at a tertiary care center from 2007 to 2017. Patients were stratified by histology and treatment strategy. Adjusted logistic and Cox regression models were used to evaluate pathological downstaging, cancer specific survival and overall survival.

RESULTS

The cohort consisted of 410 patients (53%) with pure urothelial carcinoma, 185 (24%) with urothelial carcinoma with divergent differentiation and 173 (23%) with variant histology. Overall, 314 patients (41%) received neoadjuvant chemotherapy prior to cystectomy. There were similar rates of complete (18% to 30%) and partial (37% to 46%) pathological downstaging with neoadjuvant chemotherapy across all histological subgroups (p=0.30 and p=0.40, respectively). However, while patients with pure urothelial carcinoma experienced an overall survival benefit (HR 0.71, 95% CI 0.51-0.98, p=0.0013) and those with variant histology experienced a cancer specific survival benefit (HR 0.55, 95% CI 0.30-0.99, p=0.0495) with neoadjuvant chemotherapy, patients with urothelial carcinoma with divergent differentiation did not experience overall or cancer specific survival benefits with the use of neoadjuvant chemotherapy prior to cystectomy.

CONCLUSIONS

Among patients with muscle invasive bladder cancer those with nonpure urothelial carcinoma histology with variant histology achieved nearly equivalent response rates and survival benefits with the use of neoadjuvant chemotherapy as those with pure urothelial carcinoma, while patients with urothelial carcinoma with divergent differentiation experienced significantly worse survival outcomes regardless of the use of neoadjuvant chemotherapy prior to cystectomy.

Neoadjuvant therapy for muscle-invasive bladder cancer

INTRODUCTION

Muscle-invasive bladder cancer (MIBC) is generally a highly aggressive malignancy with early and mostly distant recurrences. Cisplatin-based combinations have been established as neoadjuvant chemotherapy (NAC) prior to radical cystectomy (RC) providing overall survival as well as disease-free survival benefit. Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of metastatic urothelial carcinoma and are being tested in the neoadjuvant setting as well.

AREAS COVERED

This review covers the existing guidelines for the management of MIBC. It summarizes the use of different NAC regimens. It also discusses the published literature of ICIs in this setting and explores future perspectives.

EXPERT OPINION

Cisplatin-based NAC is the standard of care in MIBC prior to RC. Cisplatin-ineligible MIBC patients have not demonstrated to clearly benefit from a chemotherapy regimen and proceed directly to RC, although novel agents have been evaluated in this setting. Pembrolizumab and atezolizumab as monotherapy have shown feasibility and promising pathologic response rates. The combination of cisplatin-based chemotherapy with ICIs and chemotherapy-free ICI alone approaches are being investigated in randomized trials. Molecular subclassification and development of predictive biomarkers in MIBC will further help to identify optimal treatment strategies in these patients.