Clinical Restaging and Tumor Sequencing are Inaccurate Indicators of Response to Neoadjuvant Chemotherapy for Muscle-invasive Bladder Cancer

Performance of 18F-FDG PET/MRI and its parameters in staging and neoadjuvant therapy response evaluation in bladder cancer

18F-FDG PET/MRI shows potential efficacy in the diagnosis of bladder cancer (BLCA). However, the performance of 18F-FDG PET/MRI in staging and neoadjuvant therapy (NAT) response evaluation for BLCA patients remains elusive. Here, we conduct this study to evaluate the performance of 18F-FDG PET/MRI and its derived parameters for tumor staging and NAT response prediction in BLCA. Forty BLCA patients were retrospectively enrolled to evaluate the performance of 18F-FDG PET/MRI in staging and NAT response prediction in BLCA. The feasibility of using 18F-FDG PET/MRI-related parameters for tumor staging and NAT response evaluation was also analyzed. In conclusion, 18F-FDG PET/MRI is found to show good performance in the BLCA staging and NAT response prediction. Moreover, ΔSUVmean is an efficacious candidate parameter for NAT response prediction. This study highlights that 18F-FDG PET/MRI is a promising imaging approach in the clinical diagnosis and treatment for BLCA.

Novel bladder-sparing approaches in patients with muscle-invasive bladder cancer

The pursuit of surgeons and oncologists in fulfilling the inherent desire of patients to retain their urinary bladder despite having muscle-invasive bladder cancer (MIBC) has sparked years of research and multiple debates, given its aggressive nature and the high risk of fatal metastatic recurrence. Historically, several approaches to bladder-sparing treatment have been explored, ranging from radical transurethral resection to concurrent chemoradiation. A less well-established approach involves a risk-adapted approach with local therapy deferred based on the clinical response to transurethral resection followed by systemic therapy. Each approach is associated with potential risks, benefits, and trade-offs. In this review, we aim to understand, navigate, and suggest future perspectives on bladder-sparing approaches in patients with MIBC.

MRI evaluation of vesical imaging reporting and data system for bladder cancer after neoadjuvant chemotherapy

BACKGROUND

The Vesical Imaging-Reporting and Data System (VI-RADS) has demonstrated effectiveness in predicting muscle invasion in bladder cancer before treatment. The urgent need currently is to evaluate the muscle invasion status after neoadjuvant chemotherapy (NAC) for bladder cancer. This study aims to ascertain the accuracy of VI-RADS in detecting muscle invasion post-NAC treatment and assess its diagnostic performance across readers with varying experience levels.

METHODS

In this retrospective study, patients with muscle-invasive bladder cancer who underwent magnetic resonance imaging (MRI) after NAC from September 2015 to September 2018 were included. VI-RADS scores were independently assessed by five radiologists, consisting of three experienced in bladder MRI and two inexperienced radiologists. Comparison of VI-RADS scores was made with postoperative histopathological diagnosis. Receiver operating characteristic curve analysis (ROC) was used for evaluating diagnostic performance, calculating sensitivity, specificity, and area under ROC (AUC)). Interobserver agreement was assessed using the weighted kappa statistic.

RESULTS

The final analysis included 46 patients (mean age: 61 years ± 9 [standard deviation]; age range: 39-70 years; 42 men). The pooled AUC for predicting muscle invasion was 0.945 (95% confidence interval (CI): 0.893-0.977) for experienced readers, and 0.910 (95% CI: 0.831-0.959) for inexperienced readers, and 0.932 (95% CI: 0.892-0.961) for all readers. At an optimal cut-off value ≥ 4, pooled sensitivity and specificity were 74.1% (range: 66.0-80.9%) and 94.1% (range: 88.6-97.7%) for experienced readers, and 63.9% (range: 59.6-68.1%) and 86.4% (range: 84.1-88.6%) for inexperienced readers. Interobserver agreement ranged from substantial to excellent between all readers (k = 0.79-0.92).

CONCLUSIONS

VI-RADS accurately assesses muscle invasion in bladder cancer patients after NAC and exhibits good diagnostic performance across readers with different experience levels.

Tumorigenesis of basal muscle invasive bladder cancer was mediated by PTEN protein degradation resulting from SNHG1 upregulation

BACKGROUND

Phosphatase and tensin homolog deleted on chromosome ten (PTEN) serves as a powerful tumor suppressor, and has been found to be downregulated in human bladder cancer (BC) tissues. Despite this observation, the mechanisms contributing to PTEN's downregulation have remained elusive.

METHODS

We established targeted genes' knockdown or overexpressed cell lines to explore the mechanism how it drove the malignant transformation of urothelial cells or promoted anchorageindependent growth of human basal muscle invasive BC (BMIBC) cells. The mice model was used to validate the conclusion in vivo. The important findings were also extended to human studies.

RESULTS

In this study, we discovered that mice exposed to N-butyl-N-(4-hydroxybu-tyl)nitrosamine (BBN), a specific bladder chemical carcinogen, exhibited primary BMIBC accompanied by a pronounced reduction in PTEN protein expression in vivo. Utilizing a lncRNA deep sequencing high-throughput platform, along with gain- and loss-of-function analyses, we identified small nucleolar RNA host gene 1 (SNHG1) as a critical lncRNA that might drive the formation of primary BMIBCs in BBN-treated mice. Cell culture results further demonstrated that BBN exposure significantly induced SNHG1 in normal human bladder urothelial cell UROtsa. Notably, the ectopic expression of SNHG1 alone was sufficient to induce malignant transformation in human urothelial cells, while SNHG1 knockdown effectively inhibited anchorage-independent growth of human BMIBCs. Our detailed investigation revealed that SNHG1 overexpression led to PTEN protein degradation through its direct interaction with HUR. This interaction reduced HUR binding to ubiquitin-specific peptidase 8 (USP8) mRNA, causing degradation of USP8 mRNA and a subsequent decrease in USP8 protein expression. The downregulation of USP8, in turn, increased PTEN polyubiquitination and degradation, culminating in cell malignant transformation and BMIBC anchorageindependent growth. In vivo studies confirmed the downregulation of PTEN and USP8, as well as their positive correlations in both BBN-treated mouse bladder urothelium and tumor tissues of bladder cancer in nude mice.

CONCLUSIONS

Our findings, for the first time, demonstrate that overexpressed SNHG1 competes with USP8 for binding to HUR. This competition attenuates USP8 mRNA stability and protein expression, leading to PTEN protein degradation, consequently, this process drives urothelial cell malignant transformation and fosters BMIBC growth and primary BMIBC formation.

Muscle invasive bladder cancer: where is the field headed?

INTRODUCTION

The standard treatment for muscle-invasive bladder cancer (MIBC) is cisplatin-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy or upfront radical cystectomy for cisplatin-ineligible patients. In those who are ineligible for or refuse radical cystectomy, trimodal therapy with chemoradiation is offered. However, with the success of immune checkpoint inhibitors (ICI) and antibody-drug conjugates such as enfortumab vedotin in the metastatic setting, several trials are implementing these drugs in the neoadjuvant setting for cisplatin ineligible patients. Indeed, nivolumab is approved as adjuvant therapy for high-risk muscle-invasive urothelial carcinoma.

AREAS COVERED

Clinical trials using ICI, ICI/ICI, and ICI/chemotherapy combination therapies in the perioperative setting have been completed. These clinical trials have demonstrated that neoadjuvant ICI are safe and have encouraging pCR, making them promising treatment options. Neoadjuvant enfortumab vedotin alone and in combination with pembrolizumab is also being studied, and preliminarily to have promising activity. ICI is also being combined with radiation therapy (RT) and early data indicate that ICI combined with RT or chemo-RT may be safe with promising activity.

EXPERT OPINION

Biomarkers are urgently needed to identify appropriate treatment options for individual patients. The use of novel treatment approaches and biomarkers will help shape the future of precision therapy for MIBC and enable bladder preservation.

Bladder preservation after neoadjuvant therapy - 2021 IBCN updates part 1

The morbidity associated with radical cystectomy (RC) for muscle-invasive bladder cancer (MIBC) has fueled investigations into the feasibility of bladder preservation strategies after a favorable clinical response to neoadjuvant therapy (NAT). Identifying optimal candidates for bladder preservation is predicated on our ability to identify tumors with inherent cisplatin sensitivity and accurately stage patients before and after NAT. In the present review, we evaluate the accuracy and limitations of contemporary staging modalities and investigate clinical outcomes in patients with MIBC who were managed with bladder preservation after NAT. Lastly, we discuss the predictive role of cisplatin-sensitizing DNA damage response (DDR) gene alterations as a foundational component to current prospective clinical trials evaluating bladder preservation in the setting of MIBC.

Emerging Roles of Circulating Tumor DNA for Increased Precision and Personalization in Radiation Oncology

Recent breakthroughs in circulating tumor DNA (ctDNA) technologies present a compelling opportunity to combine this emerging liquid biopsy approach with the field of radiogenomics, the study of how tumor genomics correlate with radiotherapy response and radiotoxicity. Canonically, ctDNA levels reflect metastatic tumor burden, although newer ultrasensitive technologies can be used after curative-intent radiotherapy of localized disease to assess ctDNA for minimal residual disease (MRD) detection or for post-treatment surveillance. Furthermore, several studies have demonstrated the potential utility of ctDNA analysis across various cancer types managed with radiotherapy or chemoradiotherapy, including sarcoma and cancers of the head and neck, lung, colon, rectum, bladder, and prostate . Additionally, because peripheral blood mononuclear cells are routinely collected alongside ctDNA to filter out mutations associated with clonal hematopoiesis, these cells are also available for single nucleotide polymorphism analysis and could potentially be used to detect patients at high risk for radiotoxicity. Lastly, future ctDNA assays will be utilized to better assess locoregional MRD in order to more precisely guide adjuvant radiotherapy after surgery in cases of localized disease, and guide ablative radiotherapy in cases of oligometastatic disease.

A Systematic Review of Oncological Outcomes Associated with Bladder-sparing Strategies in Patients Achieving Complete Clinical Response to Initial Systemic Treatment for Localized Muscle-invasive Bladder Cancer

CONTEXT

Bladder-sparing strategies (BSSs) have been proposed for the treatment of muscle-invasive bladder cancer (MIBC) patients achieving clinical complete response (cCR) to initial systemic treatment to avoid toxicity related to radical cystectomy.

OBJECTIVE

To systematically review the current literature evaluating oncological outcomes of BSSs in patients achieving cCR to initial systemic treatment for localized MIBC.

EVIDENCE ACQUISITION

A computerized bibliographic search of the Medline, Embase, and Cochrane databases was performed for all studies reporting oncological outcomes of MIBC patients undergoing either surveillance or radiation therapy after achieving cCR to initial systemic treatment. Using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, we identified 23 noncomparative prospective or retrospective studies published between 1990 and 2021. The mean bladder and metastatic recurrence rates (range) as well as the mean bladder preservation rate (BPR; range) were calculated, and overall survival (OS) was extracted from included reports.

EVIDENCE SYNTHESIS

Overall, 16 and seven studies evaluated surveillance (n = 610) and radiation therapy (n = 175) in MIBC patients achieving cCR to initial systemic treatment, respectively. With regard to surveillance, the median follow-up ranged from 10 to 120 mo, with a mean bladder recurrence rate of 43% (0-71%), including 65% of non-muscle-invasive bladder cancer (NMIBC) and 35% of MIBC recurrences. The mean BPR was 73% (49-100%). The mean metastatic recurrence rate was 9% (0-27%), while 5-yr OS rates ranged from 64% to 89%. With regard to radiation therapy, the median follow-up ranged from 12 to 60 mo, with a mean bladder recurrence rate of 15% (0-29%), including 24% of NMIBC, 43% of MIBC, and 33% of unspecified recurrences. The mean BPR was 74% (71-100%). The mean metastatic recurrence rate was 17% (0-22%), while the 4-yr OS rate was 79%.

CONCLUSIONS

Our systematic review showed that only low-level evidence supports the effectiveness of BSSs in selected patients achieving cCR to initial systemic treatment for localized MIBC. These preliminary findings highlight the need for further prospective comparative research to demonstrate its efficacy.

PATIENT SUMMARY

We reviewed studies evaluating bladder-sparing strategies in patients achieving complete clinical response to initial systemic treatment for localized muscle-invasive bladder cancer. Based on low-level evidence, we observed that selected patients could benefit from surveillance or radiation therapy in this setting, but prospective comparative research is requested to confirm their efficacy.

Assessment of Predictive Genomic Biomarkers for Response to Cisplatin-based Neoadjuvant Chemotherapy in Bladder Cancer

Cisplatin-based neoadjuvant chemotherapy (NAC) followed by radical cystectomy is recommended for patients with muscle-invasive bladder cancer (MIBC). It has been shown that somatic deleterious mutations in ERCC2, gain-of-function mutations in ERBB2, and alterations in ATM, RB1, and FANCC are correlated with pathological response to NAC in MIBC. The objective of this study was to validate these genomic biomarkers in pretreatment transurethral resection material from an independent retrospective cohort of 165 patients with MIBC who subsequently underwent NAC and radical surgery. Patients with ypT0/Tis/Ta/T1N0 disease after surgery were defined as responders. Somatic deleterious mutations in ERCC2 were found in nine of 68 (13%) evaluable responders and two of 95 (2%) evaluable nonresponders (p = 0.009; FDR = 0.03). No correlation was observed between response and alterations in ERBB2 or in ATM, RB1, or FANCC alone or in combination. In an exploratory analysis, no additional genomic alterations discriminated between responders and nonresponders to NAC. No further associations were identified between the aforementioned biomarkers and pathological complete response (ypT0N0) after surgery. In conclusion, we observed a positive association between deleterious mutations in ERCC2 and pathological response to NAC, but not overall survival or recurrence-free survival. Other previously reported genomic biomarkers were not validated. PATIENT SUMMARY: It is currently unknown which patients will respond to chemotherapy before definitive surgery for bladder cancer. Previous studies described several gene mutations in bladder cancer that correlated with chemotherapy response. This study confirmed that patients with bladder cancer with a mutation in the ERCC2 gene often respond to chemotherapy.

High- or low-dose preoperative ipilimumab plus nivolumab in stage III urothelial cancer: the phase 1B NABUCCO trial

Cohort 1 of the phase 1B NABUCCO trial showed high pathological complete response (pCR) rates with preoperative ipilimumab plus nivolumab in stage III urothelial cancer (UC). In cohort 2, the aim was dose adjustment to optimize responses. Additionally, we report secondary endpoints, including efficacy and tolerability, in cohort 2 and the association of presurgical absence of circulating tumor DNA (ctDNA) in urine and plasma with clinical outcome in both cohorts. Thirty patients received two cycles of either ipilimumab 3 mg kg-1 plus nivolumab 1 mg kg-1 (cohort 2A) or ipilimumab 1 mg kg-1 plus nivolumab 3 mg kg-1 (cohort 2B), both followed by nivolumab 3 mg kg-1. We observed a pCR in six (43%) patients in cohort 2A and a pCR in one (7%) patient in cohort 2B. Absence of urinary ctDNA correlated with pCR in the bladder (ypT0Nx) but not with progression-free survival (PFS). Absence of plasma ctDNA correlated with pCR (odds ratio: 45.0; 95% confidence interval (CI): 4.9-416.5) and PFS (hazard ratio: 10.4; 95% CI: 2.9-37.5). Our data suggest that high-dose ipilimumab plus nivolumab is required in stage III UC and that absence of ctDNA in plasma can predict PFS. ClinicalTrials.gov registration: NCT03387761 .

Approaches to Clinical Complete Response after Neoadjuvant Chemotherapy in Muscle-Invasive Bladder Cancer: Possibilities and Limitations

In the surgical oncology field, the change from a past radical surgery to an organ preserving surgery is a big trend. In muscle-invasive bladder cancer treatment, neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) is the standard of care for muscle-invasive bladder cancer (MIBC) patients eligible for cisplatin. There is a growing interest in bladder preserving strategies after NAC because good oncologic outcome has been reported for pathologic complete response (pCR) patients after NAC, and many studies have continued to discuss whether bladder preservation treatment is possible for these patients. However, in actual clinical practice, decision-making should be determined according to clinical staging and there is a gap that cannot be ignored between clinical complete response (cCR) and pCR. Currently, there is a lack in a uniform approach to post-NAC restaging of MIBC and a standardized cCR definition. In this review, we clarify the gap between cCR and pCR at the current situation and focus on emerging strategies in bladder preservation in selected patients with MIBC who achieve cCR following NAC.

Which Patients To Consider for Bladder Preservation After a Complete Response to Neoadjuvant Chemotherapy

The decision on which patients with muscle-invasive bladder cancer to consider for bladder preservation remains controversial. New promising technologies and biomarkers may allow to precise selection of patients for bladder preservation in the future. Currently, bladder preservation should only be considered in highly selected cases and in the setting of clinical trials.

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.

Current and Future Landscape of Perioperative Treatment for Muscle-Invasive Bladder Cancer

Cisplatin-based neoadjuvant chemotherapy followed by radical cystectomy is the current standard of care for muscle-invasive bladder cancer (MIBC). However, less than half of patients are candidates for this treatment, and 50% will develop metastatic disease. Adjuvant chemotherapy could be offered if neoadjuvant treatment has not been administered for suitable patients. It is important to reduce the risk of systemic recurrence and improve the prognosis of localized MIBC. Systemic therapy for metastatic urothelial carcinoma has evolved in recent years. Immune checkpoint inhibitors and targeted agents, such as antibody-drug conjugates or FGFR inhibitors, are new therapeutic alternatives and have shown their benefit in advanced disease. Currently, several clinical trials are investigating the role of these drugs, as monotherapy and in combination with chemotherapy, in the neoadjuvant and adjuvant settings with promising outcomes. In addition, the development of predictive biomarkers could predict responses to neoadjuvant therapies.

Predictive Biomarkers of Response to Neoadjuvant Therapy in Muscle Invasive Bladder Cancer

Neoadjuvant cisplatin-based chemotherapy is recommended prior to surgical removal of the bladder for patients with non-metastatic muscle invasive bladder cancer. Despite a survival benefit, approximately half of patients do not respond to chemotherapy and are exposed potentially unnecessarily to substantial toxicity and delay in surgery. Therefore, biomarkers to identify likely responders before initiating chemotherapy would be a helpful clinical tool. Furthermore, biomarkers may be able to identify patients who do not need subsequent surgery after clinical complete response to chemotherapy. To date, there are no clinically approved predictive biomarkers of response to neoadjuvant therapy. Recent advances in the molecular characterization of bladder cancer have shown the potential role for DNA damage repair (DDR) gene alterations and molecular subtypes to guide therapy, but these need validation from prospective clinical trials. This chapter reviews candidate predictive biomarkers of response to neoadjuvant therapy in muscle invasive bladder cancer.

Predicting Complete Response to Neoadjuvant Chemotherapy in Muscle-Invasive Bladder Cancer

Muscle-invasive bladder cancer is a life-threatening disease best managed with multimodal therapy. Neoadjuvant chemotherapy prior to cystectomy significantly improves survival with the greatest benefit noted in patients with a complete pathologic response noted at cystectomy. While radical cystectomy is currently an important part of the treatment plan, surgical morbidity remains high. Accurate prediction of complete responses to chemotherapy would enable avoiding the morbidity of radical cystectomy. Multiple clinical, pathologic, molecular, and radiographic predictors have been evaluated. Clinical and standard pathologic findings have not been found to be accurate predictors of complete response. To date, tumor genomic findings have been the most promising and have led to multiple clinical trials to evaluate if bladder preservation is possible in select patients. Radiomics has shown initial promise with larger validation series needed. These predictors can be further characterized as treatment specific and non-treatment specific. With the potential changing landscape of neoadjuvant therapy prior to radical cystectomy and the limitations of individual predictors of a complete response, a panel of several biomarkers may enhance patient selection for bladder preservation. The aim of this review is to summarize predictors of complete response to neoadjuvant chemotherapy.

Is There A Benefit of Restaging Transurethral Resection of Bladder Tumor Prior to Radical Cystectomy With or Without Neoadjuvant Chemotherapy?

BACKGROUND: One of the best predictors of positive outcomes in bladder cancer (BC) is pT0 following radical cystectomy (RC). Discordance between clinical and pathologic staging affects decision-making in patients with clinical absence of disease (cT0). OBJECTIVES: We sought to determine whether a restaging transurethral resection of bladder tumor (re-TURBT) improves clinical staging accuracy relative to pathologic stage RC in patients treated with neoadjuvant chemotherapy (NAC) versus those who did not receive NAC. METHODS: We queried our prospectively maintained IRB approved institutional database to identify 129 patients who underwent RC from 2013 to 2019 with a re-TURBT prior to RC. 53 patients were treated with NAC between their initial and re-TURBT and 76 patients were not treated with NAC. RESULTS: The overall upstaging rate from re-TURBT to RC was 34.9% . There was no significant difference in the upstaging rate between the NAC and no-NAC groups - 31.0% vs. 37.0%, respectively. In patients who were cT0 on re-TURBT, the NAC group did not show a significantly greater rate of pathologic clinical CR (pT0) than the no NAC group - 38.5% vs. 37.5%, respectively. Re-TURBT with staging <  rT2 as a predictor for absence of MIBC on pathologic staging (<ypT2) did not show a significant difference between the NAC and no NAC group, with a negative predictive value (NPV) of 69.0% and 66.7%, respectively. CONCLUSIONS: Re-TURBT after NAC does not show statistically significant improvement in staging accuracy relative to pathologic stage at RC compared to re-TURBT in patients not treated with NAC.

Radical Transurethral Resection of Bladder Tumor in Seemingly Organ-confined Muscle-invasive Bladder Cancer: Con

Bladder-preserving therapy using radical transurethral resection of bladder tumor is currently not a reasonable curative treatment option given the inaccuracy of diagnostic modalities. However, owing to the disadvantages of radical cystectomy, research on bladder-preserving treatment options remains important.

Survival outcomes of patients with muscle-invasive bladder cancer according to pathological response at radical cystectomy with or without neo-adjuvant chemotherapy: a case-control matching study

Objectives

To assess survival of patients with muscle-invasive bladder cancer (MIBC) who underwent radical cystectomy (RC) with or without neo-adjuvant chemotherapy (NAC) according to the pathological response at RC.

Methods

965 patients with MIBC (cT2-4aN0M0) who underwent RC with or without NAC were analyzed. Among the collected data were comorbidity, clinical and pathological tumor stage, tumor grade, nodal status (y)pN, and OS. Case–control matching of 412 patients was performed to compare oncological outcomes. Kaplan–Meier curves were created to estimate OS for patients who underwent RC with or without NAC, and for those with complete response (pCR), partial response (pPR), or residual or progressive disease (PD).

Results

Patients with a pCR or pPR at RC, with or without NAC, had better OS than patients who had PD (both p values < 0.001). Moreover, the incidence of pCR was significantly higher in patients receiving NAC prior to RC than in patients undergoing RC only (31% versus 15%, respectively; p < 0.001). Case–control matching displayed better OS of patients who underwent RC with NAC, median survival not reached, than of those who underwent RC only, median 4.5 years (p = 0.023).

Conclusions

This study showed that patients with MIBC who underwent NAC with RC had a significant better OS than those who underwent RC only. The proportion of patients with a pCR was higher in those who received NAC and RC than in those who were treated by RC only. The favorable OS rate in the NAC and RC cohort was probably attributed to the higher observed pCR rate.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11255-022-03339-6.

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.

The past, present, and future of pT0 in bladder cancer clinical trials

PURPOSE OF REVIEW

Since the establishment of neoadjuvant chemotherapy as the standard of care for patients with muscle invasive bladder cancer, the pathologic absence of disease, denoted pT0, was found to be predictive of improved overall survival. Accordingly, it has been used in clinical trials as an optimal surrogate outcome measure, even in contemporary nonchemotherapeutic interventions. We review the role of pT0 as a catalyst for change in trial design and its suitability to facilitate more efficient and timely results. In addition, we explore the present and future of cT0, the clinical absence of disease, in defining treatment response and enabling bladder-sparing management options.

RECENT FINDINGS

The use of pT0 as a surrogate has provided initial results for the efficacy of immunotherapy in the neoadjuvant space. In combination with molecular markers, pT0 has improved our ability to identify treatment responders and its clinical counterpart, cT0, has been integrated into multiple trials to redefine postneoadjuvant chemotherapy management algorithms.

SUMMARY

The use of pT0 as a surrogate endpoint in bladder cancer trials has improved clinical trial design, defined efficacy of emerging therapeutics, and has the potential to redefine the postneoadjuvant treatment management for patients seeking bladder-sparing options.

Disease Management of Clinical Complete Responders to Neoadjuvant Chemotherapy of Muscle-Invasive Bladder Cancer: A Review of Literature

Muscle-invasive bladder cancer (MIBC) is an aggressive disease requiring active management. Neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) is considered the standard treatment paradigm for MIBC patients, which could result in significant perioperative mortality and morbidity, as well as the significant alteration of the quality of life (QOL). Notably, multimodal bladder-preserving treatment strategies have been recommended for highly selected patients. Pathologic complete response (pCR) after NAC is a powerful prognostic indicator of survival for patients with MIBC. Clinical complete response (cCR) is then introduced as a complementary endpoint for pCR to assess disease status preoperatively. Bladder preservation strategy for patients who achieve cCR following NAC is emerging as a new treatment concept. However, the efficiency of the conservative strategy remains controversial. In this state-of-the-art review, we discuss the advantages and limitations of cCR and the feasibility and safety of bladder preservation strategy in highly selected MIBC patients who achieve cCR following NAC. We conclude that a conservative strategy can be considered a reasonable alternative to RC in carefully selected cCR MIBC patients, leading to acceptable oncological outcomes.

Vesical Imaging-Reporting and Data System (VI-RADS) for assessment of response to systemic therapy for bladder cancer: preliminary report

PURPOSE

The Vesical Imaging-Reporting and Data System (VI-RADS) criteria are expanding, providing fine differentiation of bladder wall layers involvement. We aimed to explore the feasibility of a novel categorical scoring, the Neoadjuvant chemotherapy VI-RADS (nacVI-RADS) for radiologic assessment of response (RaR), to define the spectrum of treatment response among patients with muscle invasive bladder cancer (MIBC).

METHODS

Ten consecutive patients diagnosed with non-metastatic MIBC were prospectively enrolled and addressed to NAC and underwent mpMRI before staging resection and after the chemotherapy cycles. The follow-up MRI assessment was performed using the nacVI-RADS algorithm for evaluation of response to therapy. NacVI-RADS categorically define complete RaR, based on prior VI-RADS score, presence of residual disease, tumor size, and infiltration of the muscularis propria.

RESULTS

NacVI-RADS categories were able to match all the final radical cystectomy pathology both for complete pT0 responders and for the patients defined as partial or minimal responders, who only showed some RaR inter-scoring class downstaging.

CONCLUSION

This report is the preliminary evidence of the feasibility of nacVI-RADS criteria. These findings might lead to possible paradigmatic shifts for cancer-specific survival risk assessment and to possibly drive the therapeutic decision through active surveillance programs, bladder-sparing modalities, or to the standard of care.

Refining neoadjuvant therapy clinical trial design for muscle-invasive bladder cancer before cystectomy: a joint US Food and Drug Administration and Bladder Cancer Advocacy Network workshop

The success of the use of novel therapies in the treatment of advanced urothelial carcinoma has contributed to growing interest in evaluating these therapies at earlier stages of the disease. However, trials evaluating these therapies in the neoadjuvant setting must have clearly defined study elements and appropriately selected end points to ensure the applicability of the trial and enable interpretation of the study results. To advance the development of rational trial design, a public workshop jointly sponsored by the US Food and Drug Administration and the Bladder Cancer Advocacy Network convened in August 2019. Clinicians, clinical trialists, radiologists, biostatisticians, patients, advocates and other stakeholders discussed key elements and end points when designing trials of neoadjuvant therapy for muscle-invasive bladder cancer (MIBC), identifying opportunities to refine eligibility, design and end points for neoadjuvant trials in MIBC. Although pathological complete response (pCR) is already being used as a co-primary end point, both individual-level and trial-level surrogacy for time-to-event end points, such as event-free survival or overall survival, remain incompletely characterized in MIBC. Additionally, use of pCR is limited by heterogeneity in pathological evaluation and the fact that the magnitude of pCR improvement that might translate into a meaningful clinical benefit remains unclear. Given existing knowledge gaps, capture of highly granular patient-related, tumour-related and treatment-related characteristics in the current generation of neoadjuvant MIBC trials will be critical to informing the design of future trials.

Neoadjuvant Chemotherapy plus Bevacizumab Combined with Total Mesorectal Excision in Treating Locally Advanced Rectal Cancer Patients with BRAF Mutation: Clinical Benefit and Safety

Objective

To investigate clinical benefit and safety of neoadjuvant chemotherapy (NAC) plus bevacizumab combined with total mesorectal excision (TME) in treating patients with BRAF-mutated locally advanced rectal cancer (LARC).

Methods

This study included LARC patients with BRAF mutation admitted to the Oncology Department of Fujian Medical University Cancer Hospital, Fujian Cancer Hospital, between June 2013 and December 2018. Patients in the control group received a standard treatment regimen of TME combined with NAC (n = 45), and patients in the observation group received NAC plus bevacizumab combined with TME (n = 55). The short-term clinical efficacy of the two groups after NAC treatment was observed and compared, including differences in the pathological downstaging rate. The incidence of perioperative complications and adverse reactions during neoadjuvant therapy was compared to evaluate the safety of the treatment. Besides, the relapse-free survival (RFS) and overall survival (OS) of patients were analyzed to evaluate the long-term clinical benefit of the treatment.

Results

Compared with the control group, the ypT staging rate (p = 0.014) in the observation group was markedly lower. In addition, patients in the observation group had a prominently lower overall incidence of complications (p < 0.001) during the perioperative period and a remarkably lower incidence of leukopenia (p = 0.037) during neoadjuvant therapy. In terms of long-term clinical benefit, the RFS of patients in the observation group was evidently longer (p = 0.037) than that in the control group.

Conclusion

Compared with TME plus NAC treatment, the short-term and long-term clinical benefits are higher and safety is more favorable of NAC plus bevacizumab combined with TME in treating LARC patients.

A prospective multicenter study of visual response-evaluation by cystoscopy in patients undergoing neoadjuvant chemotherapy for muscle invasive urinary bladder cancer

PURPOSE

To evaluate a method of transurethral visual response-staging in patients with urothelial muscle-invasive urinary bladder cancer (MIBC), undergoing neoadjuvant chemotherapy (NAC) and radical cystectomy (RC).

METHODS

A prospective study at four Swedish cystectomy centers, cystoscopy was performed after final NAC-cycle for MIBC. Fifty-six participants underwent cystoscopy for visual staging of the tumor immediately pre-RC. Visual assessments were correlated to pathoanatomical outcomes post-RC.

RESULTS

Seventeen tumors were classified as complete response (CR), i.e. pT0. Twenty-five patients had residual MIBC and 14 had non-muscle invasive residual tumors (NMIBC). Of the 39 patients with residual tumor, 25 were correctly identified visually (64%). Eleven patients were pN+. The diagnostic accuracy of cystoscopy to correctly identify complete response or remaining tumor was 70% (CI = 56-81%) with a sensitivity of 64% (CI = 47-79%), specificity 82% (CI = 57-96%), PPV 89% (CI = 74-96%) and NPV 50% (CI =38-61%). Twenty-eight cystoscopy evaluations showed signs of residual tumors and 3/28 (11%) were false positive. In 4/14 patients assessed having residual NMIBC the estimates were correct, 8/14 had histopathological MIBC and 2/14 had CR. In 11/14 patients (79%), the suggested visual assessment of MIBC was correct, 2/14 had NMIBC and 1/14 had CR. Twenty-eight cystoscopies had negative findings, 14 were false negatives (50%), when cystoscopy falsely predicted pT0. Among them there were eight patients with pTa, pT1 or pTis and six MIBC-tumors. In 17 patients with histopathological pT0, 14 were correctly identified with cystoscopy (82%).

CONCLUSION

Cystoscopy after the final NAC-cycle cannot robustly differentiate between NAC-responders and non-responders. Visually, negative MIBC-status cannot be determined safely.

Prediction of pathological response following neoadjuvant chemotherapy in patients with muscle-invasive bladder cancer: the PRE-PREVENCYS trial

Background

The recommended treatment for patients with non-metastatic muscle-invasive bladder cancer (MIBC) is neoadjuvant chemotherapy (NAC) and radical cystectomy (RC). Following NAC, 20–40% of patients experience a complete pathological response (pCR) in the RC specimen and these patients have excellent long-term overall survival. Subject to debate is, however, whether patients with a pCR to NAC benefit from RC, which is a major surgical procedure with substantial morbidity, and if these patients might be candidates for close surveillance instead. However, currently it is not possible to accurately identify patients with a pCR to NAC in whom RC might be withheld. The objective of this study is to assess whether pathological response in the RC specimen after NAC can be predicted based on clinical, radiological, and histological variables and on a wide set of molecular biomarkers assessed in tissue, blood and urine.

Methods

This is a multicentre, prospective cohort study, including patients with cT2a-T4a N0-N1 M0 urothelial cell MIBC who are scheduled to undergo cisplatin-based NAC followed by RC. Prior to start of therapy, a 2-Deoxy-2-[18F] fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) is performed. Response to NAC is evaluated by CT-scan. Blood and urine, including cytology, are prospectively collected for biomarker analyses before and after NAC. Immediately before RC, participants undergo cystoscopy with bimanual examination and a re-staging transurethral resection (TUR) of all visible cancerous lesions or with biopsies from scar tissue. Subsequently, RC is performed in all patients. Tissue from the diagnostic TUR, the re-staging TUR, and the RC specimen is examined for the presence of urothelial cancer carcinoma and DNA and RNA is isolated for molecular analysis. The primary endpoint is the pathological stage (ypTN) in the RC and ePLND specimen and its association with clinical response.

Discussion

If the PRE-PREVENCYS trial shows that the absence of residual disease after NAC in patients with MIBC is accurately predicted, a randomized controlled trial is scheduled comparing the overall survival of NAC plus RC versus NAC followed by close surveillance for patients with a clinically complete response (PREVENCYS trial).

Trial registration

Netherlands Trial Register: NL8678; Registered 20 May 2020 https://www.trialregister.nl/trial/8678

Genome-wide screening for the G-protein-coupled receptor (GPCR) pathway-related therapeutic gene RGS19 (regulator of G protein signaling 19) in bladder cancer

Bladder cancer is one of the most severe genitourinary cancers, causing high morbidity worldwide. However, the underlying molecular mechanism is not clear, and it is urgent to find target genes for treatment. G-protein-coupled receptors are currently a target of high interest for drug design. Thus, we aimed to identify a target gene-related to G-protein-coupled receptors for therapy. We used The Cancer Genome Atlas (TCGA) and DepMap databases to obtain the expression and clinical data of RGS19. The results showed that RGS19 was overexpressed in a wide range of tumor, especially bladder cancer. We also explored its effect on various types of cancer. High expression of RGS19 was also shown to be significantly associated with poor prognosis. Cell models were constructed for cell cycle detection. shRGS19 can halt the cell cycle at a polyploid point. RGS19 is a G-protein-coupled receptor signaling pathway-related gene with a significant effect on survival. We chose RGS19 as a therapeutic target gene in bladder cancer. The drug GSK1070916 was found to inhibit the effect of RGS19 via cell rescue experiments in vitro.

Multiparametric magnetic resonance imaging for bladder cancer: a comprehensive systematic review of the Vesical Imaging-Reporting and Data System (VI-RADS) performance and potential clinical applications

Background:

The Vesical Imaging-Reporting and Data System (VI-RADS) score is a novel standardized approach to image and report bladder cancer (BC) with multiparametric MRI (mpMRI).

Objectives:

To describe and evaluate the performance of the VI-RADS score using mpMRI and assess its potential clinical applications and limitations.

Methods:

A systematic review was conducted using the MEDLINE and EMBASE electronic bibliographic databases between June 2020 and December 2020. All reports deemed relevant to describe the VI-RADS score and assess its performance and applications were retrieved. Results presentation stands as narrative, purely descriptive synthesis based on aggregate studies data.

Results:

A total of 20 relevant studies were retrieved: three meta-analyses, five prospective studies, and twelve retrospective studies. The retrospective studies covered 1676 patients, while the prospective studies included a total number of 468 patients. Pooled sensitivity, specificity to differentiate muscle-invasive from non-muscle-invasive bladder cancer, ranged from 74.1% to 97.3%, and 77% to 100%, respectively. The chosen VI-RADS score thresholds for this discrimination varied across studies. The interreader agreement ranged from 0.73 to 0.95. Currently, the potential clinical applications of VI-RADS consist of initial BC risk stratification, assessment of neoadjuvant therapies response, and bladder sparing approaches, although further validation is required.

Conclusions:

The VI-RADS score helps to discriminate muscle invasive from non-muscle invasive BC with good performance and reproducibility. A simple algorithm based on four basic questions may enhance its popularization. Further studies are required to validate the clinical applications.

Urine tumor DNA detection of minimal residual disease in muscle-invasive bladder cancer treated with curative-intent radical cystectomy: A cohort study

BACKGROUND

The standard of care treatment for muscle-invasive bladder cancer (MIBC) is radical cystectomy, which is typically preceded by neoadjuvant chemotherapy. However, the inability to assess minimal residual disease (MRD) noninvasively limits our ability to offer bladder-sparing treatment. Here, we sought to develop a liquid biopsy solution via urine tumor DNA (utDNA) analysis.

METHODS AND FINDINGS

We applied urine Cancer Personalized Profiling by Deep Sequencing (uCAPP-Seq), a targeted next-generation sequencing (NGS) method for detecting utDNA, to urine cell-free DNA (cfDNA) samples acquired between April 2019 and November 2020 on the day of curative-intent radical cystectomy from 42 patients with localized bladder cancer. The average age of patients was 69 years (range: 50 to 86), of whom 76% (32/42) were male, 64% (27/42) were smokers, and 76% (32/42) had a confirmed diagnosis of MIBC. Among MIBC patients, 59% (19/32) received neoadjuvant chemotherapy. utDNA variant calling was performed noninvasively without prior sequencing of tumor tissue. The overall utDNA level for each patient was represented by the non-silent mutation with the highest variant allele fraction after removing germline variants. Urine was similarly analyzed from 15 healthy adults. utDNA analysis revealed a median utDNA level of 0% in healthy adults and 2.4% in bladder cancer patients. When patients were classified as those who had residual disease detected in their surgical sample (n = 16) compared to those who achieved a pathologic complete response (pCR; n = 26), median utDNA levels were 4.3% vs. 0%, respectively (p = 0.002). Using an optimal utDNA threshold to define MRD detection, positive utDNA MRD detection was highly correlated with the absence of pCR (p < 0.001) with a sensitivity of 81% and specificity of 81%. Leave-one-out cross-validation applied to the prediction of pathologic response based on utDNA MRD detection in our cohort yielded a highly significant accuracy of 81% (p = 0.007). Moreover, utDNA MRD-positive patients exhibited significantly worse progression-free survival (PFS; HR = 7.4; 95% CI: 1.4-38.9; p = 0.02) compared to utDNA MRD-negative patients. Concordance between urine- and tumor-derived mutations, determined in 5 MIBC patients, was 85%. Tumor mutational burden (TMB) in utDNA MRD-positive patients was inferred from the number of non-silent mutations detected in urine cfDNA by applying a linear relationship derived from The Cancer Genome Atlas (TCGA) whole exome sequencing of 409 MIBC tumors. We suggest that about 58% of these patients with high inferred TMB might have been candidates for treatment with early immune checkpoint blockade. Study limitations included an analysis restricted only to single-nucleotide variants (SNVs), survival differences diminished by surgery, and a low number of DNA damage response (DRR) mutations detected after neoadjuvant chemotherapy at the MRD time point.

CONCLUSIONS

utDNA MRD detection prior to curative-intent radical cystectomy for bladder cancer correlated significantly with pathologic response, which may help select patients for bladder-sparing treatment. utDNA MRD detection also correlated significantly with PFS. Furthermore, utDNA can be used to noninvasively infer TMB, which could facilitate personalized immunotherapy for bladder cancer in the future.

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.

Incidence and Clinical Impact of Inflammatory Fluorodeoxyglucose Positron Emission Tomography Uptake After Neoadjuvant Pembrolizumab in Patients with Organ-confined Bladder Cancer Undergoing Radical Cystectomy

BACKGROUND

Data regarding the incidence and prognostic impact of immune-related imaging changes, assessed by ¹⁸[F] fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scan, in patients receiving immune-checkpoint inhibitors (ICIs) are lacking. We relied on the population of patients enrolled in the PURE-01 study to evaluate such changes.

OBJECTIVE

To evaluate the role of PET/CT to visualize the immune-related adverse events (irAEs) following pembrolizumab.

DESIGN, SETTING, AND PARTICIPANTS

From February 2017 to August 2019, in 103 patients with nonmetastatic, clinical T2-4aN0M0 bladder cancer, PET/CT scan was performed before and after neoadjuvant pembrolizumab (N = 206 scans), before radical cystectomy.

INTERVENTION

PET/CT before and after neoadjuvant pembrolizumab, before radical cystectomy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We analyzed the occurrence of irAEs, evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0, against the development of inflammatory FDG uptake described at PET/CT (irAEs + PET/CT). Logistic regression analyses evaluated the association between irAEs + PET/CT and the pathological response to pembrolizumab. Kaplan-Meier curves tested their association with progression-free survival (PFS) after pembrolizumab and radical cystectomy.

RESULTS AND LIMITATIONS

Forty patients (39%) developed irAEs + PET/CT in several target organs. The most frequent target organs were the thyroid (N = 18), stomach (N = 14), mediastinal lymph nodes (N = 9), and lung (N = 5). These changes were clinically evident in 18 (45%) and were not associated with the pathological response, neither in terms of complete response (ypT0N0, p = 0.07) nor as downstaging to ypT≤1N0 disease (p = 0.1), although ypT0N0 responses were numerically more frequent in patients with irAEs+ PET/CT (47.5% vs 32%). Furthermore, irAE+ PET/CT events were associated with longer, not statistically significant, 24-mo PFS: 88.3% versus 76.5% (p = 0.5). Our results warrant further validation in larger datasets.

CONCLUSIONS

We presented unique surrogate data of PET/CT that could help improve our understanding of nonclinically evident effects of ICI administration, especially in patients at the early disease stage.

PATIENT SUMMARY

We evaluated the utility of PET/CT to visualize the occurrence of inflammatory changes after pembrolizumab in patients with localized bladder cancer without metastases. After immunotherapy, 39% of the patients developed ¹⁸[F] fluorodeoxyglucose uptake consistent of inflammatory changes. Overall, our data improve our knowledge on the effects induced by immunotherapy, which may have a clinical impact at longer follow-up. Take Home Message ● In the PURE-01 study, T2-4N0M0 muscle-invasive bladder cancer patients were staged with fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) before and after pembrolizumab. ● PET/CT after pembrolizumab revealed inflammatory FDG uptake in 39% of patients, but only 45% of these cases of uptake corresponded to clinically evident adverse events. ● The development of inflammatory uptake was associated with a higher pathological complete response rate and longer progression-free survival, although these differences were not statistically significant.