Impact of High-risk Features and Effect of Neoadjuvant Chemotherapy in Urothelial Cancer Patients with Invasion into the Lamina Propria on Transurethral Resection in the Absence of Deep Muscle Invasion

Treatment Outcomes of High-Risk Non-Muscle Invasive Bladder Cancer (HR-NMIBC) in Real-World Evidence (RWE) Studies: Systematic Literature Review (SLR)

Background

To date, there has been limited synthesis of RWE studies in high-risk non-muscle invasive bladder cancer (HR-NMIBC). The objective of this research was to conduct a systematic review of published real-world evidence to better understand the real-world burden and treatment patterns in HR-NMIBC.

Methods

An SLR was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with the scope defined by the Population, Intervention Comparators, Outcomes, and Study design (PICOS) criteria. EMBASE, MEDLINE, and Cochrane databases (Jan 2015–Jul 2020) were searched, and relevant congress abstracts (Jan 2018–Jul 2020) identified. The final analysis only included studies that enrolled ≥100 patients with HR-NMIBC from the US, Europe, Canada, and Australia.

Results

The SLR identified 634 RWE publications in NMIBC, of which 160 studies reported data in HR-NMIBC. The average age of patients in the studies was 71 years, and 79% were males. The rates of BCG intravesical instillations ranged from 3% to 86% (29–95% for induction and 8–83% for maintenance treatment). Five-year outcomes were 17–89% recurrence-free survival (longest survival in patients completing BCG maintenance), 58–89% progression-free survival, 71–96% cancer-specific survival (lowest survival in BCG-unresponsive patients), and 28–90% overall survival (lowest survival in patients who did not receive BCG or instillation therapy).

Conclusion

BCG treatment rates and survival outcomes in patients with HR-NMIBC vary in the real world, with better survival seen in patients completing maintenance BCG, responding to treatment, and not progressing to muscle-invasive disease. There is a need to better understand the factors associated with BCG use and discontinuation and for an effective treatment that improves outcomes in HR-NMIBC. Generalization of these results is limited by variations in data collection, reporting, and methodologies used across RWE studies.

Non-Muscle Invasive Bladder Cancer with Variant Histology: Biological Features and Clinical Implications

BACKGROUND

The most common bladder cancer (BC) histotype is pure urothelial carcinoma (UC), which may undergo divergent differentiation in some cases. Variant histology (VH) presents along variable morphologies, either single or combined between them or with pure UC. From a clinical standpoint, the vast majority of BC is diagnosed at non-invasive or minimally invasive stages, namely as non-muscle invasive BC (NMIBC). There is a wide range of therapeutic options for patients with NMIBC, according to their clinical and pathological features. However, current risk stratification models do not show optimal effectiveness. Evidence from the literature suggests that VH has peculiar biological features, and may be associated with poorer survival outcomes compared to pure UC.

SUMMARY

In order to describe the biological features and prognostic/predictive role of VH in NMIBC, and to discuss current treatment options, we performed a systematic literature search through multiple databases (PubMed/Medline, Google Scholar) for relevant articles according to the following terms, single and/or in combination: "non-muscle invasive bladder cancer," "variant histology," "micropapillary variant," "glandular differentiation," "squamous differentiation," "nested variant," "plasmacytoid variant," and "sarcomatoid variant." We extracted 99 studies including original articles, reviews, and systematic reviews, and subsequently analyzed data from 16 studies reporting on the outcome of NMIBC with VH. We found that the relative rarity of these forms as well as the heterogeneity in study populations and therapeutic protocols results in conflicting findings overall. Key Messages: The presence of VH should be taken into account when counseling a patient with NMIBC, since it may upgrade the disease to high-risk tumor and thus warrant a more aggressive treatment.

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

BACKGROUND

Nonurothelial carcinoma (UC) malignancies have traditionally been considered to have a more aggressive clinical course, and little is known about their response to neoadjuvant therapy. We examined the effect of neoadjuvant chemotherapy (NAC) on a large population of patients with bladder cancer (BCa) with different histologic variants (HVs).

PATIENTS AND METHODS

We relied on a retrospective, multicenter database of 2858 patients with BCa who had undergone radical cystectomy with or without NAC from 1990 to 2017. Pure and mixed HVs were grouped into 6 categories: squamous cell carcinoma (SCC; n = 283; 45%), other subtypes (n = 95; 15%), micropapillary (n = 85; 14%), adenocarcinoma (n = 65; 10%), small cell (n = 54; 8.6%), and sarcomatous (n = 47; 7.6%). Kaplan-Meier and Cox regression analyses were used to examine cancer-specific survival (CSS) according to the HV, using pure UC as the reference. Logistic regression models were used to examine the odds of clinical-to-pathologic downstaging after NAC according to the HV.

RESULTS

Overall, we identified 2229 cases of pure UC and 629 cases of BCa with HVs at radical cystectomy. Of the 450 NAC-treated patients, only those patients with SCC (n = 44; 9.8%) had had worse CSS (median CSS, 33 vs. 116 months; P < .001) and higher mortality rates (hazard ratio, 2.1; P = .03) compared with those with pure UC (n = 328; 72.9%). The results of the analyses were also confirmed when the pure and mixed cases were considered separately. After adjusting for NAC, only SCC showed a lower rate of clinical-to-pathologic downstaging (odds ratio, 0.4; P = .03) compared with UC.

CONCLUSIONS

SCC was the HV exhibiting the lowest effect of NAC in terms of activity and CSS. Compared with pure UC, SCC seemed to be insensitive to traditional NAC regimens.

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.

Morphologic and genomic characterization of urothelial to sarcomatoid transition in muscle-invasive bladder cancer

INTRODUCTION

The sarcomatoid morphology of muscle-invasive bladder cancer (MIBC) is associated with unfavorable prognosis. However, the genomic, transcriptomic, and proteomic relationship between conventional urothelial and synchronous sarcomatoid morphology is poorly defined.

METHODS

We compiled a cohort of 21 MIBC patients with components of conventional urothelial and adjacent sarcomatoid morphology within the same tumor focus. We performed comprehensive pathologic and immunohistochemical characterization and in 4 selected cases, subjected both morphologic components to targeted DNA sequencing and whole transcriptome analysis.

RESULTS

Synchronous sarcomatoid and urothelial morphology from the same MIBC foci shared truncal somatic mutations, indicating a common ancestral clone. However, additional mutations or copy number alterations restricted to the either component suggested divergent evolution at the genomic level. This was confirmed at the transcriptome level since while the urothelial component exhibited a basal-like subtype (TCGA2014: cluster III, LundTax: basal/squamous-like), the sarcomatoid morphology was predominantly cluster IV (claudin-low). Protein expression was consistent with a basal-like phenotype in both morphologies in 18/21 of cases. However, most cases had evidence of active epithelial-to-mesenchymal transition (E-Cad ↓ and Zeb1 or TWIST1 ↑) from urothelial toward the sarcomatoid morphology. Drug response signatures nominated different targets for each morphology and proposed agents under clinical investigation in liposarcoma or other sarcoma. PD-L1 expression was higher in the sarcomatoid than the urothelial component.

CONCLUSIONS

Conventional urothelial and adjacent sarcomatoid morphologies of MIBC arise from the same common ancestor and share a basal-like phenotype. However, divergence between the morphologies at the genome, transcriptome, and proteome level suggests differential sensitivity to therapy.

Morphologic and genomic characterization of urothelial to sarcomatoid transition in muscle-invasive bladder cancer

INTRODUCTION

The sarcomatoid morphology of muscle-invasive bladder cancer (MIBC) is associated with unfavorable prognosis. However, the genomic, transcriptomic, and proteomic relationship between conventional urothelial and synchronous sarcomatoid morphology is poorly defined.

METHODS

We compiled a cohort of 21 MIBC patients with components of conventional urothelial and adjacent sarcomatoid morphology within the same tumor focus. We performed comprehensive pathologic and immunohistochemical characterization and in 4 selected cases, subjected both morphologic components to targeted DNA sequencing and whole transcriptome analysis.

RESULTS

Synchronous sarcomatoid and urothelial morphology from the same MIBC foci shared truncal somatic mutations, indicating a common ancestral clone. However, additional mutations or copy number alterations restricted to the either component suggested divergent evolution at the genomic level. This was confirmed at the transcriptome level since while the urothelial component exhibited a basal-like subtype (TCGA2014: cluster III, LundTax: basal/squamous-like), the sarcomatoid morphology was predominantly cluster IV (claudin-low). Protein expression was consistent with a basal-like phenotype in both morphologies in 18/21 of cases. However, most cases had evidence of active epithelial-to-mesenchymal transition (E-Cad ↓ and Zeb1 or TWIST1 ↑) from urothelial toward the sarcomatoid morphology. Drug response signatures nominated different targets for each morphology and proposed agents under clinical investigation in liposarcoma or other sarcoma. PD-L1 expression was higher in the sarcomatoid than the urothelial component.

CONCLUSIONS

Conventional urothelial and adjacent sarcomatoid morphologies of MIBC arise from the same common ancestor and share a basal-like phenotype. However, divergence between the morphologies at the genome, transcriptome, and proteome level suggests differential sensitivity to therapy.

Urothelial cancer: a narrative review of the role of novel immunotherapeutic agents with particular reference to the management of non-muscle-invasive disease

AIM

This narrative review describes current guidelines for treating NMIBC, provides an overview of the principle behind immune checkpoint inhibition, and summarizes current evidence for checkpoint inhibitors in urothelial malignancy. Further, we discuss potential strategies for immune checkpoint inhibition in the management of NMIBC.

BACKGROUND

Adjuvant intravesical BCG immunotherapy has been the mainstay of treatment for high-risk non-muscle-invasive bladder cancer (NMIBC) for decades but is associated with both a significant side effect profile and failure rate. Recently, a substantial body of trial data has been published demonstrating the successful use of systemic immunotherapy in the treatment of advanced urothelial malignancy and, in particular, a class of drugs known as 'immune checkpoint inhibitors'. This has led to the approval of a number of these drugs by the UK National Institute of Health and Care Excellence and the US Food and Drug Administration, and ongoing trials are examining use in the management of NMIBC.

METHODS

To identify relevant published data, using the PubMed/ Medline search engine, an online search of the Pubmed/ Medline archives was conducted using the terms bladder cancer' in combination with 'checkpoint inhibitors', and limited to articles in English published between 1966 and September 2017.To identify ongoing trials of interest but not yet published, a further search of the clinical trials.gov search engine was conducted using the term 'non-muscle-invasive bladder cancer'.

CONCLUSION

There has been little advance in available adjuvant therapy for NMIBC treated with TURBT. Current intravesical therapies are associated with a high recurrence rate and significant side effect profile. The impending publication of the wealth of ongoing trials, both into the delivery and efficacy of checkpoint inhibition will direct the future treatment of NMIBC.

A risk-stratified approach to the management of high-grade T1 bladder cancer

PURPOSE OF REVIEW

A bladder-preserving approach for high-grade nonmuscle invasive bladder cancer that has invaded the lamina propria (T1HG) may result in increased recurrence, progression, and even death from bladder cancer in some patients. Initial radical cystectomy does have increased cancer-specific survival (CSS), but represents significant overtreatment for many patients. An evidence-based, risk-stratified approach is required to select patients for immediate radical cystectomy in order to improve CSS.

RECENT FINDINGS

A restaging transurethral resection aids in optimal staging and treatment of T1HG. Intravesical Bacillus Calmette-Guerin induction followed by 3 years of maintenance is the standard adjuvant management. However, when very high-risk (hydronephrosis, abnormal bimanual examination, variant histology, lymphovascular invasion, or residual disease on re-resection, and Bacillus Calmette-Guerin failure or early recurrence) or multiple high-risk factors (concomitant CIS, size >3 cm, multifocality, unfavorable tumor location, extensive lamina propria invasion, and elderly) are present, the risk of progression often outweighs the risk associated with radical cystectomy. In these cases, an immediate radical cystectomy likely provides an improved opportunity for cure compared to a bladder-preserving strategy.

SUMMARY

In order to increase the CSS of patients diagnosed with T1HG bladder cancer, an aggressive approach may benefit those with increased risk of progression.