Recommendations for follow-up of muscle-invasive bladder cancer patients: A consensus by the international bladder cancer network

A Genomic Urine Assay for Surveillance of Patients with Bladder Cancer Treated with Radiotherapy

Background

Patients with muscle-invasive bladder cancer (MIBC) who receive radiotherapy with curative intent are followed by imaging, cystoscopy, and urine cytology. However, interpretation of cytology and cystoscopy is hampered by the impact of ionizing radiation on cells.

Objective

To assess the diagnostic performance of a genomic urine assay to detect urinary tract recurrences in patients with MIBC treated by (chemo)radiation.

Design setting and participants

Patients with nonmetastatic MIBC who underwent (chemo)radiation with curative intent from 2016 to 2020 were prospectively included. Follow-up consisted of cystoscopy and upper tract imaging. Prior to cystoscopy, a urine sample was analyzed to assess mutations in the genes FGFR3, HRAS, and TERT and methylation of OTX1, TWIST1, and ONECUT2. The treating physician was blinded for the assay result.

Outcome measurements and statistical analysis

The primary endpoint was a urinary tract recurrence. Cross-sectional sensitivity, specificity, and negative predictive value (NPV) were analyzed using a previously developed logistic regression model for the detection of bladder cancer with this assay. The secondary endpoint was the risk of a future urinary tract recurrence following a positive test and negative cystoscopy/imaging, using a time-dependent Cox proportional hazard analysis.

Results and limitations

A total of 143 patients were included, and 503 urine samples were analyzed. The median study duration was 20 mo (interquartile range [IQR] 10-33), and the median time to a recurrence was 16 mo (IQR 12-26). In 27 patients, 32 urinary tract recurrences were diagnosed, including three upper tract tumors. Of 32 recurrences, 18 (56%) had a concomitant urine test available. The diagnostic model had an area under the curve of 0.80 (95% confidence interval [CI] 0.69-0.90) with corresponding sensitivity, specificity, and NPV of 78 (95% CI 52-94), 77% (95% CI 73-81), and 99% (95% CI 97-100). When taking into account the anticipatory effect of the test, 28/32 (88%) recurrences were detected. A Cox regression analysis showed a hazard ratio of 14.8 for the development of a future recurrence (p < 0.001). A major limitation was the lack of a concomitant urine test result in 14/32 (44%) recurrences.

Conclusions

A genomic urine assay detected urinary tract recurrences after (chemo)radiation in patients with MIBC, and a positive test was strongly associated with future recurrences. Although validation in a large cohort is warranted, the test has the potential to limit frequent cystoscopies.

Patient summary

Radiotherapy is a bladder-sparing treatment in patients with bladder cancer. After treatment, these patients undergo visual inspection of the bladder by cystoscopy to detect possible recurrences. However, interpretation of cystoscopy is difficult due to the effects of radiation on the bladder lining. Hence, we analyzed the diagnostic value of a molecular urine test to detect recurrent disease in bladder cancer patients treated by radiotherapy, and we showed that the urine test has the potential to limit the number of cystoscopies.

[Quality assessment of radical cystectomy-opportunities, risks, challenges]

Radical cystectomy (RC) is the standard treatment for nonmetastatic muscle-invasive urothelial carcinoma of the urinary bladder. It is associated with relevant morbidity and mortality. After RC, the 5‑year overall survival rate is approximately 60%. In the context of the present work, quality parameters of RC divided into oncological/functional criteria and freedom from complications are identified and summarized. A PubMed search was performed. In addition to early criteria such as negative surgical margins, performance of pelvic lymphadenectomy, creation of a continent urinary diversion or preservation of sexual function, long-term criteria were identified such as the absence of higher-grade postoperative complications, recurrence-free survival and the preservation of health-related quality of life. The early criteria are suitable for individualized therapy planning, whereas the long-term criteria can be used for quality monitoring.

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.

Current Management of Localized Muscle-Invasive Bladder Cancer: A Consensus Guideline from the Genitourinary Medical Oncologists of Canada

BACKGROUND: Despite recent advances in the management of muscle-invasive bladder cancer (MIBC), treatment outcomes remain suboptimal, and variability exists across current practice patterns. OBJECTIVE: To promote standardization of care for MIBC in Canada by developing a consensus guidelines using a multidisciplinary, evidence-based, patient-centered approach who specialize in bladder cancer. METHODS: A comprehensive literature search of PubMed, Medline, and Embase was performed; and most recent guidelines from national and international organizations were reviewed. Recommendations were made based on best available evidence, and strength of recommendations were graded based on quality of the evidence. RESULTS: Overall, 17 recommendations were made covering a broad range of topics including pathology review, staging investigations, systemic therapy, local definitive therapy and surveillance. Of these, 10 (59% ) were level 1 or 2, 7 (41% ) were level 3 or 4 recommendations. There were 2 recommendations which did not reach full consensus, and were based on majority opinion. This guideline also provides guidance for the management of cisplatin-ineligible patients, variant histologies, and bladder-sparing trimodality therapy. Potential biomarkers, ongoing clinical trials, and future directions are highlighted. CONCLUSIONS: This guideline embodies the collaborative expertise from all disciplines involved, and provides guidance to further optimize and standardize the management of MIBC.

Multicenter Validation of Histopathologic Tumor Regression Grade After Neoadjuvant Chemotherapy in Muscle-invasive Bladder Carcinoma

Response classification after neoadjuvant chemotherapy in muscle-invasive bladder carcinoma is based on the TNM stage at radical cystectomy. We recently showed that histopathologic tumor regression grades (TRGs) add prognostic information to TNM. Our aim was to validate the prognostic significance of TRG in muscle-invasive bladder cancer in a multicenter setting. We enrolled 389 patients who underwent cisplatin-based chemotherapy before radical cystectomy in 8 centers between 2010 and 2016. Median follow-up was 2.2 years. TRG was determined in radical cystectomy specimens by local pathologists. Central pathology review was conducted in 20% of cases, which were randomly selected. The major response was defined as ≤pT1N0. The remaining patients were grouped into partial responders (≥ypT2N0-3 and TRG 2) and nonresponders (≥ypT2N0-3 and TRG 3). TRG was successfully determined in all cases, and interobserver agreement in central pathology review was high (κ=0.83). After combining TRG and TNM, 47%, 15%, and 38% of patients were major, partial, and nonresponders, respectively. Combination of TRG and TNM showed significant prognostic discrimination of overall survival (major responder: reference; partial responder: hazard ratio 3.5 [95% confidence interval: 1.8-6.8]; nonresponder: hazard ratio 6.1 [95% confidence interval: 3.6-10.3]). This discrimination was superior compared with TNM staging alone, supported by 2 goodness-of-fit criteria (P=0.041). TRG is a simple, reproducible histopathologic measurement of response to neoadjuvant chemotherapy in muscle-invasive bladder cancer. Integrating TRG with TNM staging resulted in significantly better prognostic stratification than TNM staging alone.

Trimodality Therapy for Muscle-Invasive Bladder Cancer: Recent Advances and Unanswered Questions

PURPOSE OF REVIEW

Bladder-sparing trimodality therapy (TMT) has become an accepted alternative to cystectomy for selected muscle invasive bladder cancer (MIBC) patients unfit for cystectomy or opting for bladder preservation. This review will summarize recent advances in TMT for MIBC.

RECENT FINDINGS

A growing body of literature has emerged which supports the use of TMT. However, its delivery is yet to be standardized. The role of chemotherapy and predictive biomarkers remain to be elucidated. Novel bladder-sparing approaches, drug combinations including immunotherapy and targeted therapies are under investigation in clinical trials, with the goal of ultimately enhancing survival and quality of life outcomes. Recent advances in TMT have made bladder preservation possible for MIBC patients seeking an alternative local therapy to cystectomy. With careful patient selection, TMT offers comparable survival outcomes to cystectomy, and improved quality of life as patients are able to successfully retain their bladder.

[Follow-up surveillance of muscle-invasive urinary bladder cancer after curative treatment]

Follow-up care of patients with muscle-invasive bladder cancer is subdivided into oncological and functional surveillance. More than 80% of local relapses and distant metastases occur within the first 2 years. Recurrences in the remnant urothelium also occur several years after radical cystectomy. Urinary cytology and a computed tomography (CT) scan of the abdomen and thorax including a urography phase are the standard diagnostics for tumor follow-up. There is no clear evidence for a survival benefit for the detection of asymptomatic vs. symptomatic recurrences. After partial cystectomy or trimodal treatment, there is no established follow-up schedule; however, the relatively high incidence of intravesical recurrences should be considered as there are curative treatment approaches including salvage cystectomy. Functional surveillance, which should be carried out lifelong, encompasses prevention and diagnostics of metabolic complications, urethral/ureteral strictures, problems with the urinary stoma, urinary incontinence, sexual dysfunction and urinary tract infections.

The impact of perivesical lymph node metastasis on clinical outcomes of bladder cancer patients undergoing radical cystectomy

Background

Perivesical lymph nodes (PVLNs) are occasionally isolated during grossing of cystectomy specimens. However, the prognostic implications of the involvement of PVLNs in bladder cancer patients, especially those with comparisons to pN0 disease, remain poorly understood.

Methods

A retrospective review identified 115 radical cystectomy cases where PVLNs had been histologically assessed. These cases were then divided into 4 groups – Group 1 (n = 76): PVLN-negative/other pelvic lymph node (non-PVLN)-negative; Group 2 (n = 5): PVLN-positive/non-PVLN-negative; Group 3 (n = 17): PVLN-negative/non-PVLN-positive; and Group 4 (n = 17): PVLN-positive/non-PVLN-positive.

Results

pT stage at cystectomy was significantly higher in Group 3 (P = 0.013), Group 4 (P < 0.001), Groups 2 and 4 (P < 0.001), or Groups 2–4 (P < 0.001) than in Group 1. However, the number of positive PVLNs (mean: 1.8 vs. 2.1; P = 0.718) or the rate of extracapsular extension in the PVLNs (40% vs. 65%, P = 0.609) was not significantly different between Group 2 and Group 4. Kaplan-Meier analysis and log-rank test revealed significantly (P < 0.05) higher risks of disease progression (Group 3/Group 4), cancer-specific mortality (Group 2/Group 3/Group 4), and overall mortality (Group 4), compared with Group 1. Multivariate analysis further showed metastasis to both PVLN and non-PVLN (Group 4), PVLN (Groups 2 and 4), or PVLN and/or non-PVLN (Groups 2–4) as an independent prognosticator for cancer-specific mortality and overall survival. There were also insignificant (P = 0.096) and significant (P = 0.036) differences in cancer-specific survival and overall survival, respectively, between Group 3 versus Group 4, and the trend of the latter was confirmed by subset multivariate analysis (hazard ratio = 3.769; P = 0.099).

Conclusions

Worse prognosis was observed in bladder cancer patients with isolated PVLN metastasis (vs. pN0 disease especially for cancer-specific survival), PVLN metastasis with or without non-PVLN metastasis (vs. pN0 disease), and concurrent PVLN and non-PVLN metastases (vs. PVLN-negative/non-PVLN-positive disease especially for overall survival). These findings indicate the importance of thorough histopathological assessment of PVLNs in radical cystectomy specimens.

Editorial: Basic research in bladder cancer - refining the tools. 3rd IBCN seminars series1

This editorial highlights submissions to part II of the 3rd IBCN Seminars Series particularly focusing on the tools required for conduction of translational research in bladder cancer. One of the submissions describe the ex vivo culture of primary tumor cells from N-methyl-N-nitrosourea-induced bladder tumors in rats and subsequent establishment of an immortalized cell line. In a next step the authors thoroughly characterize this cell line. They conclude that differentiation marker expression patterns observed in the original tumors are largely retained in the spheroids. Although new cancer models, such as organoid tissue cultures, hold great promise for studying cancer progression and might have a potential for development and selection of an optimal treatment, their limitations must be kept in mind. The second submission, therefore, critically questions the current role of organoid tissue culture as a predictive tool in urothelial cancer patients. The third manuscript of this series provides a broader overview of post-translational modification in bladder cancer is presented and how PTMs can be exploited as potential therapeutic targets. The 3 manuscripts featured in this issue demonstrate especially how basic research is being channeled to inform clinically actionable discoveries.

Neoadjuvant Chemotherapy Before Bladder-Sparing Chemoradiotherapy in Patients With Nonmetastatic Muscle-Invasive Bladder Cancer

BACKGROUND

Cisplatin-based neoadjuvant chemotherapy (NAC) before cystectomy improves survival in muscle-invasive urothelial bladder cancer (MIBC). The use of NAC before chemoradiation (CRT) has been limited, as these patients are often elderly, frail, and ineligible for cisplatin. However, the role of NAC in fit, cisplatin-eligible patients who opt for bladder preservation warrants further evaluation.

PATIENTS AND METHODS

Patients with MIBC treated with NAC followed by CRT at the Princess Margaret and Durham Regional cancer centers from 2008 to 2017 were retrospectively reviewed. Gemcitabine-cisplatin NAC was given for 2 to 4 cycles, followed by reassessment for CRT. External-beam radiotherapy (60-66 Gy) over 6 weeks was given with concurrent weekly cisplatin at 40 mg/m². Kaplan-Meier method was used for survival analyses.

RESULTS

We identified 57 consecutive patients. Median age was 72 (range 45-87), and all had an Eastern Cooperative Oncology Group performance status of 0 (60%) or 1 (40%). Stage II disease (65%), stage III disease (25%), and regional nodal metastases (11%) were included. Most completed planned NAC (95%). All patients completed external-beam radiotherapy, and 84% completed at least 60% of the planned concurrent weekly cisplatin doses. Median (range) follow-up was 19.3 (4.8-96.1) months. Median overall survival (OS) was not reached. Two-year OS and disease-specific survival rates were 74% (95% confidence interval, 57.7-84.9) and 88% (95% confidence interval, 78.5-98.1), respectively. Two-year bladder-intact disease-free survival was 64%. Salvage cystectomy was performed in 14%. Distant relapse occurred in 11%, and 9% died of metastatic disease. OS was associated with baseline hydronephrosis and with bladder-intact disease-free survival with residual disease on cystoscopy.

CONCLUSION

NAC followed by CRT can result in encouraging outcomes and tolerability in cisplatin-eligible patients.