Bladder Preservation Therapy: Review of Literature and Future Directions of Trimodal Therapy

Radiation-based Therapy for Muscle-invasive Bladder Cancer: Contemporary Outcomes Across Tertiary Centers

BACKGROUND

Radiation therapy (RT) is an alternative to radical cystectomy (RC) for muscle-invasive bladder cancer (MIBC).

OBJECTIVE

To analyze predictors of complete response (CR) and survival after RT for MIBC.

DESIGN, SETTING, AND PARTICIPANTS

This was a multicenter retrospective study of 864 patients with nonmetastatic MIBC who underwent curative-intent RT from 2002 to 2018.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Regression models were used to explore prognostic factors associated with CR, cancer-specific survival (CSS), and overall survival (OS).

RESULTS AND LIMITATIONS

The median patient age was 77 yr and median follow-up was 34 mo. Disease stage was cT2 in 675 patients (78%) and cN0 in 766 (89%). Neoadjuvant chemotherapy (NAC) was given to 147 patients (17%) and concurrent chemotherapy to 542 (63%). A CR was experienced by 592 patients (78%). cT3-4 stage (odds ratio [OR] 0.43, 95% confidence interval [CI] 0.29-0.63; p < 0.001) and hydronephrosis (OR 0.50, 95% CI 034-0.74; p = 0.001) were significantly associated with lower CR. The 5-yr survival rates were 63% for CSS and 49% for OS. Higher cT stage (HR 1.93, 95% CI 1.46-2.56; p < 0.001), carcinoma in situ (HR 2.10, 95% CI 1.25-3.53; p = 0.005), hydronephrosis (HR 2.36, 95% CI 1.79-3.10; p < 0.001), NAC use (HR 0.66, 95% CI 0.46-0.95; p = 0.025), and whole-pelvis RT (HR 0.66, 95% CI 0.51-0.86; p = 0.002) were independently associated with CSS; advanced age (HR 1.03, 95% CI 1.01-1.05; p = 0.001), worse performance status (HR 1.73, 95% CI 1.34-2.22; p < 0.001), hydronephrosis (HR 1.50, 95% CI 1.17-1.91; p = 0.001), NAC use (HR 0.69, 95% CI 0.49-0.97; p = 0.033), whole-pelvis RT (HR 0.64, 95% CI 0.51-0.80; p < 0.001), and being surgically unfit (HR 1.42, 95% CI 1.12-1.80; p = 0.004) were associated with OS. The study is limited by the heterogeneity of different treatment protocols.

CONCLUSIONS

RT for MIBC yields a CR in most patients who elect for curative-intent bladder preservation. The benefit of NAC and whole-pelvis RT require prospective trial validation.

PATIENT SUMMARY

We investigated outcomes for patients with muscle-invasive bladder cancer treated with curative-intent radiation therapy as an alternative to surgical removal of the bladder. The benefit of chemotherapy before radiotherapy and whole-pelvis radiation (bladder plus the pelvis lymph nodes) needs further study.

Exploring the role of natural bioactive molecules in genitourinary cancers: how far has research progressed?

The primary approaches to treat cancerous diseases include drug treatment, surgical procedures, biotherapy, and radiation therapy. Chemotherapy has been the primary treatment for cancer for a long time, but its main drawback is that it kills cancerous cells along with healthy ones, leading to deadly adverse health effects. However, genitourinary cancer has become a concern in recent years as it is more common in middle-aged people. So, researchers are trying to find possible therapeutic options from natural small molecules due to the many drawbacks associated with chemotherapy and other radiation-based therapies. Plenty of research was conducted regarding genitourinary cancer to determine the promising role of natural small molecules. So, this review focused on natural small molecules along with their potential therapeutic targets in the case of genitourinary cancers such as prostate cancer, renal cancer, bladder cancer, testicular cancer, and so on. Also, this review states some ongoing or completed clinical evidence in this regard.

Trimodal therapy versus radical cystectomy for cT2N0M0 urothelial muscle-invasive bladder cancer: Single-center experience

BACKGROUND

Bladder cancer is ranked the ninth most common cancer in the world. Locally, the incidence of bladder cancer has increased tenfold over the past 26 years. Radical cystectomy (RC) is considered a gold standard management option for muscle-invasive bladder cancer (MIBC), but trimodal therapy (TMT) has shown comparable oncological outcomes in selected patients.

MATERIALS AND METHODS

This is a retrospective study in which we reviewed medical records of patients diagnosed with MIBC without nodal disease or distant metastasis (cT2N0M0) who underwent either RC or TMT. Demographic data, comorbidities, histopathological and clinical staging, neoadjuvant/adjuvant therapy, and follow-up were analyzed.

RESULTS

We included a total of 31 patients in the study, with 10 patients in the TMT group and 21 patients in the RC group. There was no significant difference in recurrence between the TMT and RC groups (P = 0.58). The TMT group had a higher percentage of local recurrence (40% vs. RC 5.2%, P = 0.018) but no significant difference in metastasis (0% vs. 10%, P = 0.420). The difference in overall survival between the TMT and RC groups was not significant (P = 0.25).

CONCLUSION

TMT may be considered an alternative option for patients unwilling to undergo RC due to related complications and prioritize a better quality of life. However, the decision should be made after considering the cost of extensive follow-ups and patient compliance with surveillance.

Targeting barriers to wider use of trimodality therapy in localized muscle invasive bladder cancer

Radical cystectomy with bilateral pelvic lymphadenectomy and trimodality bladder-sparing therapy or TMT, are both curative options for patients with nonmetastatic muscle invasive bladder cancer. Patients should be afforded the opportunity for a multidisciplinary evaluation with equipoise in discussing these options for eligible patients. We discuss the barriers to broader acceptance and utilization of TMT and encourage support of clinical trials of TMT.

Trimodal therapy vs. radical cystectomy for muscle-invasive bladder cancer: A Canadian cost-effectiveness analysis

INTRODUCTION

Trimodal therapy (TMT) is a suitable alternative to neoadjuvant chemotherapy (NAC) and radical cystectomy (RC) for patients with muscle-invasive bladder cancer (MIBC). In this study, we conducted a cost-effectiveness evaluation of RC±NAC vs. TMT for MIBC in the universal and publicly funded Canadian healthcare system.

METHODS

We developed a Markov model with Monte-Carlo microsimulations. Rates and probabilities of transitioning within different health states (e.g., cure, locoregional recurrence, distant metastasis, death) were input in the model after a scoped literature review. Two main scenarios were considered: 1) academic center; and 2) populational-level. Results were reported in life-years gained (LYG), quality-adjusted life years (QALY), and incremental cost-effectiveness ratio (ICER). A sensitivity analysis was performed.

RESULTS

A total of 20 000 patients were simulated. For the academic center model, TMT was associated with increased effectiveness (both in LYG and QALY) at a higher cost compared to RC±NAC at five and 10 years. This resulted in an ICER of $19 746/QALY per patient undergoing the TMT strategy at 10 years of followup. For the populational-level model, RC±NAC was associated with higher effectiveness at 10 years, with an ICER of $3319/QALY per patient. This study was limited by heterogeneity within the studies used to build the model.

CONCLUSIONS

In this study, TMT performed in academic centers was cost-effective compared to RC±NAC, with higher effectiveness at a higher cost. On the other hand, RC±NAC was considered cost-effective compared to TMT at the populational-level. Further studies are needed to confirm these results.

A Multicenter Retrospective Cohort Series of Muscle-invasive Bladder Cancer Patients Treated with Definitive Concurrent Chemoradiotherapy in Daily Practice

Background

Concurrent chemoradiotherapy (CRT) as a definitive treatment option for patients with nonmetastatic muscle-invasive bladder carcinoma (MIBC) is increasingly being applied in clinical practice.

Objective

To assess the oncological and toxicity outcomes in a contemporary cohort of nonmetastatic MIBC patients treated with concurrent CRT in daily practice.

Design, setting, and participants

Patients with nonmetastatic MIBC (cT2-4aN0M0) who had received CRT with curative intent between January 2010 and April 2020 in three centers were retrospectively identified. The CRT consisted of 66 Gy (or biologically equivalent) plus either mitomycin C and fluorouracil/capecitabine or cisplatinum.

Outcome measurements and statistical analysis

The primary endpoint was the 2-yr locoregional disease-free survival (LDFS) estimate. Secondary endpoints were complete response, disease-specific survival (DSS), overall survival (OS), bladder intact event-free survival (BI-EFS), and severe adverse events (<90 d of starting CRT). Kaplan-Meier survival and Cox multivariable regression analyses were performed.

Results and limitations

We included data of 240 MIBC patients with a median age of 74 yr and a median follow-up of 27 mo (interquartile range 11–44). Complete response on first cystoscopy after CRT was seen in 209 cases (90%). The 2-yr LDFS was 76% (95% confidence interval [CI] 70–82%); the 5-yr OS and DSS were 50% (95% CI 42–59%) and 70% (95% CI 62–79%), respectively. On multivariable analysis, cT2 versus cT3–4 tumor stage was significantly associated with better DSS (hazard ratio 1.02, 95% CI 1–1.05, p = 0.024). The 2-yr BI-EFS was 75% (95% CI 69–82%). Forty-three (17%) patients experienced a severe adverse event (grade ≥3). Limitations include retrospective design and heterogeneous administration of CRT.

Conclusions

Concurrent CRT is a safe and effective treatment modality for nonmetastatic MIBC.

Patient summary

Chemoradiotherapy for the treatment of muscle-invasive bladder carcinoma is increasingly being applied. In this study, we reviewed the outcomes of this bladder-sparing treatment using a series of patients treated in three hospitals in daily practice. We found that administration of chemoradiotherapy can be safe and effective.

Evaluation of PD-1 and PD-L1 expression in canine urothelial carcinoma cell lines

Urothelial carcinoma (UC) is the most common urinary tumor in dogs and despite combinational therapies, only modest improvements in survival have been achieved in recent years. Given the utility of monoclonal antibodies against PD-1 and PD-L1 in human UC, we evaluated the protein and mRNA expression in three established canine urothelial carcinoma cell lines. Flow cytometry and western blot analysis confirmed cell line expression of both molecules in varying degrees. Reverse transcription PCR (RT-PCR) documented mRNA expression in all three cell lines for both PD-1 and PD-L1. Fluorescence microscopy was consistent with strong PD-1 and PD-L1 expression in the canine cell lines and was in line with previous human literature. Importantly, the flow cytometry work described in this study revealed higher cell intrinsic PD-1 expression in these cell lines which may have implications for tumor behavior and potential treatment opportunities in the future. Further work is necessary to determine the expression patterns in canine UC and potential for benefit with immunotherapy directed against PD-1 and PD-L1.

Bladder preservation in urothelial carcinoma: current trends and future directions

PURPOSE OF REVIEW

To provide a contemporary rationale for bladder preservation as a treatment strategy for muscle-invasive urothelial carcinoma of the bladder. Although the standard of care for this important and serious clinical condition has been radical cystectomy augmented with neoadjuvant systemic chemotherapy, it is associated with substantial morbidity and quality of life (QoL) implications. This article explores the bladder sparing alternatives to radical cystectomy and urinary diversion to assist Urologists, Medical Oncologists, and Palliative Care providers in their informed decision making with patients.

RECENT FINDINGS

Bladder sparing strategies such as partial cystectomy and trimodality therapy offer long-term cancer outcomes comparable to radical cystectomy in carefully selected patients. Moreover, the toxicity profile in patients, having improved over time, is acceptable, including a low risk of salvage cystectomy.

SUMMARY

Bladder preservation therapy offers an alternative to radical cystectomy. In some patients, it can be done with curative intent and in others it can assist with symptom palliation. Bladder preservation can maintain QoL and provide similar oncologic outcomes to radical surgery, although randomized controlled trials have not been performed. Understanding patient selection is a critical step in balancing bladder preservation and cancer survival.

TNM staging towards a personalized approach in metastatic urothelial carcinoma: what will the future be like?-a narrative review

The American Joint Committee of Cancer (AJCC) tumor-node-metastasis (TNM) classification, with its periodical updates and modifications, has represented and still represents the basis of cancer staging. The historical, long-standing limitations of anatomic-based TNM staging have been recently “threatened” by the impressive amount of data derived from molecular analyses, which have led to an unprecedented level of understanding of cancer genomics. In fact, current era of personalized oncology has witnessed important efforts towards the integration between clinical, anatomical and molecular features; however, despite the promises, personalized oncology faces many obstacles, due to the complex relationship between tumor biomarkers, previously unknown cancer subtypes and clinical and anatomical characteristics. With regard to urothelial carcinoma (UC), the characterization of tumors in large cohorts of patients has provided important information concerning genetic alterations, revealing the presence of biologically relevant subtypes of UC. In the current review, we will provide an overview regarding this recent “translation” from the anatomic-based TNM to a novel horizon, aiming at further “tailoring” personalized oncology, especially focusing on recently published data about the molecular landscape of UC with its therapeutic and prognostic implications.

A Novel DNA Methylation Signature as an Independent Prognostic Factor in Muscle-Invasive Bladder Cancer

Background

Muscle-invasive bladder cancer (MIBC) accounts for approximately 20% of all urothelial bladder carcinomas (UBC) at time of diagnosis, and up to 30% of patients with non-muscle invasive UBC will progress to MIBC over time. An increasing body of evidence has revealed a strong correlation between aberrant DNA methylation and tumorigenesis in MIBC.

Results

Using The Cancer Genome Atlas (TCGA) molecular data for 413 patients, we described a DNA methylation-based signature as a prognostic factor for overall survival (OS) in MIBC patients. By using a least absolute shrinkage and selection operator (LASSO) model, differentially methylated regions were first identified using multiple criteria followed by survival and LASSO analyses to identify DNA methylation probes related to OS and build a classifier to stratify patients with MIBC. The prognostic value of the classifier, referred to as risk score (RS), was validated in a held-out testing set from the TCGA MIBC cohort. Finally, receiver operating characteristic (ROC) analysis was used to compare the prognostic accuracy of the models built with RS alone, RS plus clinicopathologic features, and clinicopathologic features alone. We found that our seven-probe classifier-based RS stratifies patients into high- and low-risk groups for overall survival (OS) in the testing set (n = 137) (AUC at 3 years, 0.65; AUC at 5 years, 0.65). In addition, RS significantly improved the prognostic model when it was combined with clinical information including age, smoking status, Tumor (T) stage, and Lymph node metastasis (N) stage.

Conclusions

The DNA methylation-based RS can be a useful tool to predict the accuracy of preoperative and/or post-cystectomy models of OS in MIBC patients.

Bladder preservation therapy in combination with atezolizumab and radiation therapy for invasive bladder cancer (BPT-ART) - A study protocol for an open-label, phase II, multicenter study

Radical cystectomy (RC) is recommended for muscle-invasive bladder cancer (MIBC) or highest-risk non-muscle-invasive bladder cancer (NMIBC). Trimodal therapy (TMT) is the most favorable strategy among bladder preservation therapies (BPT) for patients who are ineligible for or refuse RC. However, referrals for TMT, especially following chemotherapy, are limited by the patient's condition. Therefore, new BPT approaches are needed. Atezolizumab inhibits programmed death-ligand 1, is well-tolerated in patient populations heavily dominated by renal insufficiency, and is expected to have synergistic anti-tumor effects in combination with radiation therapy (RT). Therefore, we have conducted this open-label phase II multicenter study to evaluate the efficacy and safety of RT in combination with atezolizumab for T2-3 MIBC and highest-risk T1 NMIBC patients. This study was initiated in January 2019, and we aimed to enroll a total of 45 patients. The study is registered in the Japan Registry of Clinical Trials (Identifier: RCT2031180060).

Refining assessment of response to radiation-based therapy for muscle-invasive bladder cancer: Is post-treatment tumor bed biopsy always necessary?

INTRODUCTION

Radiation-based therapy (RT) has emerged as a suitable alternative to radical cystectomy (RC) and pelvic lymph node dissection for muscle-invasive bladder cancer (MIBC) patients. Routine biopsy after RT to rule out residual disease remains inconsistent across guidelines. Our objective was to review the significance of a bladder biopsy in terms of assessment of response post-RT and its potential impact on survival.

PATIENTS AND METHODS

This was a single-center retrospective study on patients with MIBC (cT2-4aN0-2M0) treated with curative intent RT. A total of 169 patients with primary urothelial carcinoma were analyzed. Patients' demographic, clinical and pathological variables, imaging, cystoscopy, urine cytology, and biopsy reports after RT were collected and compiled. Whenever urine cytology was positive or cystoscopy showed any malignant-appearing lesion, the first assessment post-RT was considered suspicious for residual disease. A descriptive population analysis was reported. Cox regression multivariable analysis was performed to identify independent variables associated with survival outcomes.

RESULTS

Median age was 75 years (interquartile range 66-82) and clinical staging was cT2 in 152 (90%) patients. Cytology and cystoscopy were normal in 140 (83%) after RT. Of patients with a control biopsy, residual MIBC was present in 3 (5%) and non-MIBC in another 6 (11%). On the contrary, a for-cause biopsy due to a suspicious assessment post-RT did not yield residual cancer in 45% of patients. Multivariable analysis showed that age (hazard ratio [HR] 1.04, P< 0.001), lymphovascular invasion (HR 1.68, P = 0.03) and a suspicious assessment after RT (HR 3.21; P< 0.001) were significantly associated with worse OS. This study was limited by its retrospective design.

CONCLUSIONS

A routine biopsy after RT may be warranted to assess treatment response. This might be particularly important for patients who may benefit from early surgical intervention for residual MIBC. Further prospective studies are needed to confirm our findings.

Naturally-Occurring Invasive Urothelial Carcinoma in Dogs, a Unique Model to Drive Advances in Managing Muscle Invasive Bladder Cancer in Humans

There is a great need to improve the outlook for people facing urinary bladder cancer, especially for patients with invasive urothelial carcinoma (InvUC) which is lethal in 50% of cases. Improved outcomes for patients with InvUC could come from advances on several fronts including emerging immunotherapies, targeted therapies, and new drug combinations; selection of patients most likely to respond to a given treatment based on molecular subtypes, immune signatures, and other characteristics; and prevention, early detection, and early intervention. Progress on all of these fronts will require clinically relevant animal models for translational research. The animal model(s) should possess key features that drive success or failure of cancer drugs in humans including tumor heterogeneity, genetic-epigenetic crosstalk, immune cell responsiveness, invasive and metastatic behavior, and molecular subtypes (e.g., luminal, basal). Experimental animal models, while essential in bladder cancer research, do not possess these collective features to accurately predict outcomes in humans. These key features, however, are present in naturally-occurring InvUC in pet dogs. Canine InvUC closely mimics muscle-invasive bladder cancer in humans in cellular and molecular features, molecular subtypes, immune response patterns, biological behavior (sites and frequency of metastasis), and response to therapy. Thus, dogs can offer a highly relevant animal model to complement other models in research for new therapies for bladder cancer. Clinical treatment trials in pet dogs with InvUC are considered a win-win-win scenario; the individual dog benefits from effective treatment, the results are expected to help other dogs, and the findings are expected to translate to better treatment outcomes in humans. In addition, the high breed-associated risk for InvUC in dogs (e.g., 20-fold increased risk in Scottish Terriers) offers an unparalleled opportunity to test new strategies in primary prevention, early detection, and early intervention. This review will provide an overview of canine InvUC, summarize the similarities (and differences) between canine and human InvUC, and provide evidence for the expanding value of this canine model in bladder cancer research.

Emerging therapeutic agents for genitourinary cancers

The treatment of genitourinary malignancies has dramatically evolved over recent years. Renal cell carcinoma, urothelial carcinoma of the bladder, and prostate adenocarcinoma are the most commonly encountered genitourinary malignancies and represent a heterogeneous population of cancers, in both histology and approach to treatment. However, all three cancers have undergone paradigm shifts in their respective therapeutic landscapes due to a greater understanding of their underlying molecular mechanisms and oncogenic drivers. The advance that has gained the most recent traction has been the advent of immunotherapies, particularly immune checkpoint inhibitors. Immunotherapy has increased overall survival and even provided durable responses in the metastatic setting in some patients. The early success of immune checkpoint inhibitors has led to further drug development with the emergence of novel agents which modulate the immune system within the tumor microenvironment. Notwithstanding immunotherapy, investigators are also developing novel agents tailored to a variety of targets including small-molecule tyrosine kinase inhibitors, mTOR inhibitors, and novel fusion proteins to name a few. Erdafitinib has become the first targeted therapy approved for metastatic bladder cancer. Moreover, the combination therapy of immune checkpoint inhibitors with targeted agents such as pembrolizumab or avelumab with axitinib has demonstrated both safety and efficacy and just received FDA approval for their use. We are in an era of rapid progression in drug development with multiple exciting trials and ongoing pre-clinical studies. We highlight many of the promising new emerging therapies that will likely continue to improve outcomes in patients with genitourinary malignancies.