Bladder-sparing protocols in the treatment of muscle-invasive bladder cancer

Gold nanorod-assisted theranostic solution for nonvisible residual disease in bladder cancer

Residual nonvisible bladder cancer after proper treatment caused by technological and therapeutic limitations is responsible for tumor relapse and progression. This study aimed to demonstrate the feasibility of a solution for simultaneous detection and treatment of bladder cancer lesions smaller than one millimeter. The α5β1 integrin was identified as a specific marker in 81% of human high-grade nonmuscle invasive bladder cancers and used as a target for the delivery of targeted gold nanorods (GNRs). In a preclinical model of orthotopic bladder cancer expressing the α5β1 integrin, the photoacoustic imaging of targeted GNRs visualized lesions smaller than one millimeter, and their irradiation with continuous laser was used to induce GNR-assisted hyperthermia. Necrosis of the tumor mass, improved survival, and computational modeling were applied to demonstrate the efficacy and safety of this solution. Our study highlights the potential of the GNR-assisted theranostic strategy as a complementary solution in clinical practice to reduce the risk of nonvisible residual bladder cancer after current treatment. Further validation through clinical studies will support the findings of the present study.

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.

Is trimodal therapy the current standard for muscle-invasive bladder cancer?

OBJECTIVE

The aim of this review is to summarize the current evidence and future perspectives of bladder-sparing treatment for MIBC.

METHODS

A non-systematic literature search in Medline/Pubmed was performed in October 2023 with the following keywords "bladder cancer", "bladder-sparing", "trimodal therapy", "chemoradiation", "biomarkers", "immunotherapy", "neoadjuvant chemotherapy", "radiotherapy".

RESULTS

Urology guidelines recommend radical cystectomy as the standard curative treatment for muscle-invasive urothelial bladder cancer, reserving radiotherapy for patients who are unfit or who want to preserve their bladder. Given the morbidity and mortality of cystectomy and its impact on quality of life and bladder function, modern oncologic therapies are increasingly oriented toward organ preservation and maximizing functional outcomes while maintaining treatment efficacy. Trimodal therapy, which incorporates maximal transurethral resection followed by radiotherapy with concurrent radiosensitizing chemotherapy, is an effective regimen for bladder function preservation in well-selected patients. Despite the absence of comparative data from randomized trials, the two approaches seem to provide comparable oncologic outcomes. Studies are evaluating the expansion of eligibility criteria for trimodal therapy, the optimization of radiotherapy and immunotherapy delivery to further improve outcomes, and the validation of biomarkers to guide bladder preservation.

CONCLUSIONS

Trimodal therapy has shown acceptable outcomes for bladder preservation; therefore, it provides a valid treatment option in well-selected patients.

Bladder sparing by short-course radiotherapy combined with toripalimab in high-risk/extremely high-risk non-muscle invasive bladder cancer (HOPE-04): study protocol for a single-arm, prospective, phase II trial

INTRODUCTION

Radical cystectomy remains the standard treatment for intravesical Bacille Calmette-Guerin (BCG) unresponsive non-muscle invasive bladder cancer (NMIBC) because potential bladder-preserving therapies are not well established. Combination of radiotherapy with programmed death-1 (PD-1) antibody may offer an optional bladder preservation treatment for high-risk/extremely high risk NMIBC. Hence, the current study aims to investigate the safety and efficacy of short-course radiotherapy (5×5 Gy) and toripalimab (PD-1 antibody) as a novel bladder sparing treatment in this population.

METHODS AND ANALYSIS

HOPE-04 is an open-label, single-arm, phase II study, designed to evaluate the safety and efficacy of short-course radiotherapy and toripalimab in patients with high-risk/extremely high risk NMIBC. Fifty-five patients with pathological and imaging diagnosed NMIBC with or without BCG treatment will be recruited. Radiotherapy of 5×5 Gy will be given to the whole bladder followed by a focal tumour bed boost and concomitant administration of toripalimab of 240 mg intravenous infusion every 21 days for 12 cycles (about 1 year). The primary endpoints are disease-free survival and safety. The secondary endpoint is overall survival. Additional indicators include implementation rate of salvage surgery and quality of life.

ETHICS AND DISSEMINATION

This trial has been approved by the Ethics Committee of West China Hospital, Sichuan University. Trial findings will be disseminated via peer reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

Chinese Ethics Committee of Registering Clinical Trials (ChiCTR2200059970).

SPP1 mRNA determination based on molecular beacon for the recurrence prognosis of bladder cancer

Background

Bladder cancer (BC) has attracted significant attention on account of its recurrence as well as mortality. Tumor recurrence plays a significant role in cancer patients' individual treatment. Secreted phosphoprotein 1 (SPP1) has been recognized as a potential target for treating BC and served as a useful biomarker for prognosis; it is commonly tested by immunohistochemistry (IHC). However, this conventional method has the disadvantage of being time-consuming and costly. This study aimed to develop a molecular beacon (MB) for the detection of SPP1 messenger RNA (mRNA) for the recurrence prognosis of BC.

Methods

An MB was constructed and applied to image SPP1 mRNA level at both molecular and cellular level. The fluorescence spectra were recorded with a fluorescence spectrophotometer. The effect of SPP1 MB toward the cell viability was performed by Cell Counting Kit-8 (CCK-8) assays. The SPP1 mRNA expression level was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cancer cells and tissues were analyzed with confocal fluorescence imaging. Correlation, sensitivity, and specificity parameters were calculated.

Results

It was demonstrated that both cancer cells and BC tissues expressed high signal which reflected the expression of SPP1. In addition, 42 cases were detected by MB and divided into two groups according to the fluorescence intensity. The results further suggested that highly expressed SPP1 could predict early tumor recurrence in BC.

Conclusions

The SPP1 MB could be applied as an appropriate approach to predict BC recurrence and patients' prognosis.

Multiparametric MRI in Era of Artificial Intelligence for Bladder Cancer Therapies

This review focuses on the principles, applications, and performance of mpMRI for bladder imaging. Quantitative imaging biomarkers (QIBs) derived from mpMRI are increasingly used in oncological applications, including tumor staging, prognosis, and assessment of treatment response. To standardize mpMRI acquisition and interpretation, an expert panel developed the Vesical Imaging-Reporting and Data System (VI-RADS). Many studies confirm the standardization and high degree of inter-reader agreement to discriminate muscle invasiveness in bladder cancer, supporting VI-RADS implementation in routine clinical practice. The standard MRI sequences for VI-RADS scoring are anatomical imaging, including T2w images, and physiological imaging with diffusion-weighted MRI (DW-MRI) and dynamic contrast-enhanced MRI (DCE-MRI). Physiological QIBs derived from analysis of DW- and DCE-MRI data and radiomic image features extracted from mpMRI images play an important role in bladder cancer. The current development of AI tools for analyzing mpMRI data and their potential impact on bladder imaging are surveyed. AI architectures are often implemented based on convolutional neural networks (CNNs), focusing on narrow/specific tasks. The application of AI can substantially impact bladder imaging clinical workflows; for example, manual tumor segmentation, which demands high time commitment and has inter-reader variability, can be replaced by an autosegmentation tool. The use of mpMRI and AI is projected to drive the field toward the personalized management of bladder cancer patients.

Bladder-sparing treatment for muscle-invasive bladder carcinoma using immune checkpoint inhibitors

Multimodal bladder preservation therapy is already an alternative for patients with muscle-invasive bladder cancer (MIBC) who are unable or unwilling to undergo radical cystectomy. Various bladder-preserving strategies that employ immune checkpoint inhibitors (ICIs) for MIBC have been investigated. There are three common modes of ICI-based bladder preservation therapy, of which the most studied is ICIs combined with chemoradiotherapy. The bladder-preserving strategy of ICIs combined with radiation has been investigated in patients who poorly tolerate chemotherapy. ICIs combined with chemotherapy have also been explored in patients who responded to neoadjuvant therapy with a clinical complete response. All the above-described strategies have shown promising efficacy and manageable safety profiles. However, the value of programmed death-ligand 1 (PD-L1) expression, tumor mutation burden and gene alterations for predicting the efficacy of immune-based bladder preservation therapy is still controversial. There remain some challenges for immune-based bladder preservation therapy, and large-sample randomized trials are needed.

Analysis of the efficacy of a single subumbilical stoma for bilateral cutaneous ureterostomy after radical cystectomy

BACKGROUND

Radical cystectomy and urinary diversion are the standard surgical treatments for patients with muscle-invasive or high-risk, or recurrent non-muscle-invasive bladder cancer. Although this approach significantly prolongs patient survival, it can lead to postoperative complications. This study aims to compare the efficacy and complications of bilateral cutaneous ureterostomy with a single subumbilical stoma to those of cutaneous ureterostomy with two stomas and an ileal conduit as a means of urinary diversion after radical cystectomy. The findings of this study will provide valuable information for healthcare providers in selecting the appropriate urinary diversion method for their patients.

METHODS

The clinical data for 108 patients who received bilateral cutaneous ureterostomy with a single subumbilical stoma (ureterostomy with a single stoma group), cutaneous ureterostomy with two stomas (ureterostomy with two stomas group), or an ileal conduit (ileal conduit group) after radical cystectomy were retrospectively analysed. The operative time, pathological stage, survival status, perioperative complication rate, rate of successful first extubation, rehospitalization rate at 6 months after surgery,ostomy-related medical costs,and postoperative quality of life were compared between the three groups of patients.

RESULTS

A significant difference in the operative time was found between the three groups (P = 0.001). No significant differences in pathological stage, survival status, perioperative complication rate, rehospitalization rate at 6 months after surgery, or bladder cancer index (BCI) score were identified among the three groups. The difference in the successful first extubation rate between the three groups of patients was significant (P = 0.001). Significant differences in ostomy-related medical costs were observed among the three groups of patients (P = 0.006).

CONCLUSION

A single subumbilical stoma for bilateral cutaneous ureterostomy after radical cystectomy may result in shorter surgery time, increased success rates for initial catheter removal, and lower medical expenses. However, to confirm these findings, further prospective randomized clinical trials are necessary.

Real-world retrospective study of immune checkpoint inhibitors in combination with radiotherapy or chemoradiotherapy as a bladder-sparing treatment strategy for muscle-invasive bladder urothelial cancer

Background

Recent developments in MIBC treatment suggest good efficacy of bladder sparing treatment combined with immune checkpoint inhibitor. However, there is no standard treatment mode. A retrospective analysis was conducted to reveal the efficacy and safety of PD-1 inhibitor in combination with radiotherapy or chemoradiotherapy.

Methods

We retrospectively analyzed 25 patients with MIBC T2-T3N0M0 disease who were unfit or unwilling to undergo RC. These patients underwent the maximum TURBT followed by PD-1 inhibitor (Tislelizumab or Toripalimab) in combination with radiotherapy or chemoradiotherapy (gemcitabine plus cisplatin) between April 2020 and May 2022. The primary outcome was clinical complete response (cCR) rate. The secondary outcomes were disease free survival (DFS) and overall survival (OS).

Results

Revised: Of 25 patients, 22 were T2 (88%), while 3 were T3 (12%). The median age is 65 years (51-80). Twenty-one patients had programmed cell death ligand 1 (PD-L1) combined positive score (CPS) of 1 or more, and 4 patients had CPS<1 or unknown. Sixteen patients received chemoradiotherapy. Tislelizumab and Toripalimab were administered to 19 and 6 patients, respectively. The median number of cycles of immunotherapy was 8. Twenty-three patients (92%) achieved cCR. Following a median of 13 months of follow-up (range, 5-34 months), 1-year DFS and OS rate were 92% and 96%, respectively. In the univariate analysis, T stage significantly influenced OS and ORR, and efficacy evaluation significantly influenced OS, DFS, and ORR. The expression of PD-L1 and chemotherapy had no effect on prognosis. In the multivariate analysis, no independent prognostic factors were found. Grade 3 or 4 adverse events (AE) were reported in 35.7% patients.

Conclusions

Bladder sparing therapy with PD-1 inhibitor in combination with radiotherapy or chemoradiotherapy is feasible, safe, and highly effective for patients who were unfit or unwilling to undergo RC.

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.

The Current Progress and Future Options of Multiple Therapy and Potential Biomarkers for Muscle-Invasive Bladder Cancer

Bladder cancer is a common disease in men and the elderly. Current treatment paradigms include radical resection of the bladder and lymph nodes or transurethral resection, both supported by chemotherapy and/or radiation. New modalities, such as illumination-based therapies are also being translationally pursued. However, while survival rates have increased due to combined therapies (particularly chemotherapy, radiation, immune checkpoint inhibitors, and surgery), a lack of diagnostic markers leads clinical professionals to rely on frequently invasive and expensive means of monitoring, such as magnetic resonance imaging or bladder cystoscopy. To improve real-time diagnostic capabilities, biomarkers that reflect both the metabolic and metastatic potential of tumor cells are needed. Furthermore, indicators of therapy resistance would allow for rapid changes in treatment to optimize survival outcomes. Fortunately, the presence of nanoscale extracellular vesicles in the blood, urine, and other peripheral fluids allow for proteomic, genomic, and transcriptomic analyses while limiting the invasiveness of frequent sampling. This review provides an overview of the pathogenesis and progression of bladder cancer, standard treatments and outcomes, some novel treatment studies, and the current status of biomarker and therapy development featuring exosome-based analysis and engineering.

A Prospective Study of a Resorbable Intravesical Fiducial Marker for Bladder Cancer Radiation Therapy

Purpose

We conducted a prospective pilot study to evaluate safety and feasibility of TraceIT, a resorbable radiopaque hydrogel, to improve image guidance for bladder cancer radiation therapy (RT).

Methods and Materials

Patients with muscle invasive bladder cancer receiving definitive RT were eligible. TraceIT was injected intravesically around the tumor bed during maximal transurethral resection of bladder tumor. The primary endpoint was the difference between radiation treatment planning margin on daily cone beam computed tomography based on alignment to TraceIT versus standard-of-care pelvic bone anatomy. The Van Herk margin formula was used to determine the optimal planning target volume margin. TraceIT visibility, recurrence rates, and survival were estimated by Kaplan-Meier method. Toxicity was measured by Common Terminology Criteria for Adverse Events version 4.03.

Results

The trial was fully accrued and 15 patients were analyzed. TraceIT was injected in 4 sites/patient (range, 4-6). Overall, 94% (95% confidence interval [CI], 90%-98%) of injection sites were radiographically visible at RT initiation versus 71% (95% CI, 62%-81%) at RT completion. The median duration of radiographic visibility for injection sites was 106 days (95% CI, 104-113). Most patients were treated with a standard split-course approach with initial pelvic radiation fields, then midcourse repeat transurethral resection of bladder tumor followed by bladder tumor bed boost fields, and 14/15 received concurrent chemotherapy. Alignment to fiducials could allow for reduced planning target volume margins (0.67 vs 1.56 cm) for the initial phase of RT, but not for the boost (1.01 vs 0.96 cm). This allowed for improved target coverage (D_95% 80%-83% to 91%-94%) for 2 patients retrospectively planned with both volumetric-modulated arc therapy and 3-dimensional conformal RT. At median follow-up of 22 months, no acute or late complications attributable to TraceIT placement occurred. No patients required salvage cystectomy.

Conclusions

TraceIT intravesical fiducial placement is safe and feasible and may facilitate tumor bed delineation and targeting in patients undergoing RT for localized muscle invasive bladder cancer. Improved image guided treatment may facilitate strategies to improve local control and minimize toxicity.

Optimizing Sequence of PD-L1 Immune-Checkpoint Inhibitors and Radiation Therapy in Bladder Cancer

BACKGROUND: New bladder preserving strategies are needed for muscle invasive bladder cancer (MIBC). Combined therapy of immune-checkpoint inhibitors and radiation was shown to have synergistic antitumoral effects in preclinical studies. OBJECTIVES: We aim to evaluate whether the sequence of administration of this combined therapy impacts antitumoral response. METHODS: We developed an in-vivo syngeneic MIBC mouse model where murine bladder cancer cells (MB49) were injected subcutaneously in the right flank of C57BL/6 mice. Mice were then randomized to the following treatments: control, anti-programmed cell death ligand 1 (PD-L1) alone, radiation alone (XRT) consisting of 6.25 Gy x2 fractions, concurrent anti-PD-L1 with XRT, neoadjuvant anti-PD-L1 followed by XRT, or XRT followed by adjuvant anti-PD-L1 therapy. Tumor growth, survival, and rate of response were analyzed. RESULTS: Total of 60 mice were randomized. One-way analysis of variance showed statistically significant difference in tumor growth rate across the treatment arms (p = 0.029). Importantly, timing of immunotherapy (neoadjuvant, concurrent, or adjuvant) did not alter either tumor growth or survival (p > 0.05). The rate of response was also similar in each combination arm (p > 0.05). CONCLUSION: Combining anti-PD-L1 immunotherapy and radiation therapy offers optimal antitumoral responses. Timing of immunotherapy (neoadjuvant, concurrent, or adjuvant) does not appear to affect outcomes. Whether the toxicity profile differs across various sequential deliveries of combination therapy requires further evaluation.