Using Grade of Recurrent Tumor to Guide Further Therapy While on Bacillus Calmette-Guerin: Low-grade Recurrences Are not Benign

Assessing the Predictive Accuracy of EORTC, CUETO and EAU Risk Stratification Models for High-Grade Recurrence and Progression after Bacillus Calmette-Guérin Therapy in Non-Muscle-Invasive Bladder Cancer

The currently available EORTC, CUETO and EAU2021 risk stratifications were originally developed to predict recurrence and progression in non-muscle-invasive bladder cancer (NMIBC). However, they have not been validated to differentiate between high-grade (HG) and low-grade (LG) recurrence-free survival (RFS), which are distinct events with specific implications. We aimed to evaluate the accuracy of available risk models and identify additional risk factors for HG RFS and PFS among NMIBC patients treated with Bacillus Calmette-Guérin (BCG). We retrospectively included 171 patients who underwent transurethral resection of the bladder tumor (TURBT), of whom 73 patients (42.7%) experienced recurrence and 29 (17%) developed progression. Initially, there were 21 low-grade and 52 high-grade recurrences. EORTC2006, EORTC2016 and CUETO recurrence scoring systems lacked accuracy in the prediction of HG RFS (C-index 0.63/0.55/0.59, respectively). EAU2021 risk stratification, EORTC2006, EORTC2016, and CUETO progression scoring systems demonstrated low to moderate accuracy (C-index 0.59/0.68/0.65/0.65) in the prediction of PFS. In the multivariable analysis, T1HG at repeat TURBT (HR = 3.17 p < 0.01), tumor multiplicity (HR = 2.07 p < 0.05), previous history of HG NMIBC (HR = 2.37 p = 0.06) and EORTC2006 progression risk score (HR = 1.1 p < 0.01) were independent predictors for HG RFS. To conclude, available risk models lack accuracy in predicting HG RFS and PFS in -NMIBC patients treated with BCG.

Machine learning models combining computed tomography semantic features and selected clinical variables for accurate prediction of the pathological grade of bladder cancer

Objective

The purpose of this research was to develop a radiomics model that combines several clinical features for preoperative prediction of the pathological grade of bladder cancer (BCa) using non-enhanced computed tomography (NE-CT) scanning images.

Materials and methods

The computed tomography (CT), clinical, and pathological data of 105 BCa patients attending our hospital between January 2017 and August 2022 were retrospectively evaluated. The study cohort comprised 44 low-grade BCa and 61 high-grade BCa patients. The subjects were randomly divided into training (n = 73) and validation (n = 32) cohorts at a ratio of 7:3. Radiomic features were extracted from NE-CT images. A total of 15 representative features were screened using the least absolute shrinkage and selection operator (LASSO) algorithm. Based on these characteristics, six models for predicting BCa pathological grade, including support vector machine (SVM), k-nearest neighbor (KNN), gradient boosting decision tree (GBDT), logical regression (LR), random forest (RF), and extreme gradient boosting (XGBOOST) were constructed. The model combining radiomics score and clinical factors was further constructed. The predictive performance of the models was evaluated based on the area under the receiver operating characteristic (ROC) curve, DeLong test, and decision curve analysis (DCA).

Results

The selected clinical factors for the model included age and tumor size. LASSO regression analysis identified 15 features most linked to BCa grade, which were included in the machine learning model. The SVM analysis revealed that the highest AUC of the model was 0.842. A nomogram combining the radiomics signature and selected clinical variables showed accurate prediction of the pathological grade of BCa preoperatively. The AUC of the training cohort was 0.919, whereas that of the validation cohort was 0.854. The clinical value of the combined radiomics nomogram was validated using calibration curve and DCA.

Conclusion

Machine learning models combining CT semantic features and the selected clinical variables can accurately predict the pathological grade of BCa, offering a non-invasive and accurate approach for predicting the pathological grade of BCa preoperatively.

Intravesical Therapy Compared to Radical Cystectomy Among Patients With Non-Muscle Invasive Bladder Cancer Requiring Additional Treatment After Induction BCG

BACKGROUND

Many patients with recurrent high-risk non-muscle invasive bladder cancer after intravesical bacillus calmette-guerin (BCG) face a difficult decision between radical cystectomy (RC) or salvage intravesical therapy (IVT). We sought to determine if there is a difference in overall survival RC and IVT after previous treatment with BCG.

METHODS

We performed a retrospective cohort study of patients with Ta, T1, and Tis bladder cancer treated with induction BCG in the SEER-Medicare dataset from 2000 to 2015. We used a proportional hazards regression model to compare differences in survival between patients having RC and IVT. We adjusted for confounding using a propensity score and stratified our analysis according to timing of treatment and stage at diagnosis.

RESULTS

We identified 3940 patients who received either IVT (79%) or RC (21%) following induction BCG. Among patients treated within 12 months of BCG, there was no significant difference in survival between RC and IVT (HR 0.92, 95% CI 0.81-1.04) and 17% of patients having early IVT ultimately required RC. Among patients treated at least 12 months after BCG, RC was associated with worse survival than IVT (HR 1.19, 95% CI 1.06-1.35) and 10% of patients having late IVT ultimately required RC.

CONCLUSION

Among patients with bladder cancer who required additional treatments after induction BCG, we did not observe a difference in overall survival between IVT and RC within 12 months of starting BCG. While RC remains the gold-standard for high risk recurrent NMIBC after BCG, bladder preservation with IVT may be appropriate for well-selected patients.

International Bladder Cancer Group Consensus Statement on Clinical Trial Design for Patients with Bacillus Calmette-Guérin-exposed High-risk Non-muscle-invasive Bladder Cancer

CONTEXT

A large proportion of patients with non-muscle-invasive bladder cancer (NMIBC) fall in the gap between bacillus Calmette-Guérin (BCG)-naïve and BCG-unresponsive disease. As multiple therapeutic agents move into this gray area, there is a critical need to define the disease state and establish recommendations for optimal trial design.

OBJECTIVE

To develop a consensus on optimal trial design for patients with BCG-exposed NMIBC, defined as high-grade recurrence after BCG treatment that does not meet the criteria for BCG-unresponsive disease.

EVIDENCE ACQUISITION

We conducted a literature review using the Cochrane Library, Medline, and Embase and a review of clinical trials in ClinicalTrials.gov as a basis to generate consensus recommendations for clinical trial design in BCG-exposed NMIBC.

EVIDENCE SYNTHESIS

BCG-exposed NMIBC encompasses BCG resistance (presence of high-grade Ta or carcinoma in situ [CIS] at 3-mo evaluation after induction BCG) and delayed relapse. Randomized controlled trials are required to compare experimental therapies to a control arm receiving additional BCG, although ongoing BCG shortages may impact our ability to follow an optimal trial design. A placebo should be used in combination with BCG if the treatment arm includes BCG plus a study drug. Trials will either need to separate patients with and without CIS into two cohorts, or stratify by the presence of CIS at the time of randomization. If two cohorts are used, the primary endpoint for CIS patients should be complete response within a predetermined time. The primary endpoint in a cohort with Ta/T1 only, or if a single combined cohort is used, should be the duration of event-free survival. Suggested efficacy thresholds and corresponding sample sizes are provided.

CONCLUSIONS

The International Bladder Cancer Group has developed recommendations regarding definitions, endpoints, and clinical trial design for BCG-exposed NMIBC to encourage uniformity among studies in this disease state.

PATIENT SUMMARY

Our consensus provides a precise definition of the disease state for bladder cancer not invading the bladder muscle and exposed to bacillus Calmette-Guérin (BCG) treatment. Clear guidance for conducting optimal clinical trials in this disease setting was established and we believe that this will promote further progress in this field.

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

Background

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

Methods

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

Results

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

Conclusion

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

Discovery of Molecular DNA Methylation-Based Biomarkers through Genome-Wide Analysis of Response Patterns to BCG for Bladder Cancer

Background: Bacillus Calmette-Guérin (BCG) immunotherapy, the standard adjuvant intravesical therapy for some intermediate and most high-risk non-muscle invasive bladder cancers (NMIBCs), suffers from a heterogenous response rate. Molecular markers to help guide responses are scarce and currently not used in the clinical setting. Methods: To identify novel biomarkers and pathways involved in response to BCG immunotherapy, we performed a genome-wide DNA methylation analysis of NMIBCs before BCG therapy. Genome-wide DNA methylation profiles of DNA isolated from tumors of 26 BCG responders and 27 failures were obtained using the Infinium MethylationEPIC BeadChip. Results: Distinct DNA methylation patterns were found by genome-wide analysis in the two groups. Differentially methylated CpG sites were predominantly located in gene promoters and gene bodies associated with bacterial invasion of epithelial cells, chemokine signaling, endocytosis, and focal adhesion. In total, 40 genomic regions with a significant difference in methylation between responders and failures were detected. The differential methylation state of six of these regions, localized in the promoters of the genes GPR158, KLF8, C12orf42, WDR44, FLT1, and CHST11, were internally validated by bisulfite-sequencing. GPR158 promoter hypermethylation was the best predictor of BCG failure with an AUC of 0.809 (p-value < 0.001). Conclusions: Tumors from BCG responders and BCG failures harbor distinct DNA methylation profiles. Differentially methylated DNA regions were detected in genes related to pathways involved in bacterial invasion of cells or focal adhesion. We identified candidate DNA methylation biomarkers that may help to predict patient prognosis after external validation in larger, well-designed cohorts.

Evidence-based Assessment of Current and Emerging Bladder-sparing Therapies for Non-muscle-invasive Bladder Cancer After Bacillus Calmette-Guerin Therapy: A Systematic Review and Meta-analysis

CONTEXT

Currently, there is no standard of care for patients with non-muscle-invasive bladder cancer (NMIBC) who recur despite bacillus Calmette-Guerin (BCG) therapy. Although radical cystectomy is recommended, many patients decline to undergo or are ineligible to receive it. Multiple agents are being investigated for use in this patient population.

OBJECTIVE

To systematically synthesize and describe the efficacy and safety of current and emerging treatments for NMIBC patients after treatment with BCG.

EVIDENCE ACQUISITION

A systematic literature search of MEDLINE, Embase, and the Cochrane Controlled Register of Trials (period limited to January 2007-June 2019) was performed. Abstracts and presentations from major conference proceedings were also reviewed. Randomized controlled trials were assessed using the Cochrane risk of bias tool. Data for single-arm trials were pooled using a random-effect meta-analysis with the proportions approach. Trials were grouped based on the minimum number of prior BCG courses required before enrollment and further stratified based on the proportion of patients with carcinoma in situ (CIS).

EVIDENCE SYNTHESIS

Thirty publications were identified with data from 23 trials for meta-analysis, of which 17 were single arm. Efficacy and safety outcomes varied widely across studies. Heterogeneity across trials was reduced in subgroup analyses. The pooled 12-mo response rates were 24% (95% confidence interval [CI]: 16-32%) for trials with two or more prior BCG courses and 36% (95% CI: 25-47%) for those with one or more prior BCG courses. In a subgroup analysis, inclusion of ≥50% of patients with CIS was associated with a lower response.

CONCLUSIONS

The variability in efficacy and safety outcomes highlights the need for consistent endpoint reporting and patient population definitions. With promising emerging treatments currently in development, efficacious and safe therapeutic options are urgently needed for this difficult-to-treat patient population.

PATIENT SUMMARY

We examined the efficacy and safety outcomes of treatments for non-muscle-invasive bladder cancer after bacillus Calmette-Guerin therapy. Outcomes varied across studies and patient populations, but emerging treatments currently in development show promising efficacy.

Red cell distribution width predicts time to recurrence in patients with primary non-muscle-invasive bladder cancer and improves the accuracy of the EORTC scoring system

PURPOSE

To investigate the clinical prognostic value of red cell distribution width (RDW) in patients with non-muscle-invasive bladder cancer (NMIBC).

MATERIALS AND METHODS

We retrospectively evaluated 582 consecutive patients with primary NMIBC. The efficacy of preoperative RDW at predicting treatment outcome was assessed. A cut-off point for predicting recurrence was also identified. Uni- and multivariable analyses of time to recurrence (TTR) and progression were conducted. Harrell's concordance index (c-index) was used to evaluate the additive value of RDW to the European Organization of Research and Treatment of Cancer (EORTC) risk scoring model for recurrence.

RESULTS

According to the receiver operating characteristic curve of RDW for recurrence, a RDW ≥ 14.5% was classified as high. In the multivariable analysis, a high RDW could independently predict shorter TTR (subdistribution hazard ratio [SHR]: 2.65, 95% confidence interval [CI]: 1.83-3.84, P < 0.001), irrespective of tumor characteristics. No significant relationship was observed between RDW and time to progression (SHR: 1.75, 95% CI: 0.76-4.08, P = 0.19). Adding binary-coded RDW to the EORTC risk scoring model significantly improved its discriminatory performance in assessing recurrence risk (c-index: 0.62, improvement: 0.052, P < 0.001). High RDW was associated with shorter TTR in patients treated with bacillus Calmette-Guerin in the multivariable analysis (SHR: 2.0, 95% CI: 1.01-3.98, P = 0.047).

CONCLUSIONS

RDW was an independent, significant prognostic factor of TTR in patients with primary NMIBC. Adding RDW to the EORTC risk model significantly improved the model's predictability for tumor recurrence.

Systematic Review of the Therapeutic Efficacy of Bladder-preserving Treatments for Non-muscle-invasive Bladder Cancer Following Intravesical Bacillus Calmette-Guérin

CONTEXT

There is a critical need for effective bladder-sparing therapies for bacillus Calmette-Guérin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC). Owing to the current lack of effective agents that can be used as a control, the US Food and Drug Administration began to accept single-arm trials for patients with carcinoma in situ (CIS), using complete response rate (CRR) and duration of response as the primary endpoints to support marketing applications. Despite the ensuing growth of clinical trials in this space, no consensus exists on a clinically relevant benchmark for CRR.

OBJECTIVE

To elucidate the CRR and recurrence-free rate (RFR) using bladder-sparing agents after BCG failure in order to provide a frame of reference for future clinical trial results.

EVIDENCE ACQUISITION

We performed a systematic review of clinical trials utilizing bladder-sparing therapeutics for NMIBC recurring after intravesical BCG (PROSPERO CRD42019130553). The search was performed in MEDLINE, EMBASE, and Cochrane Library. Relevant studies identified from bibliography search and conference abstracts were searched to complement the systematic review. A total of 42 studies utilizing 24 treatment options and consisting of 2254 patients were included for final analysis.

EVIDENCE SYNTHESIS

Median CRRs in the treatment of CIS-containing tumors were 26% at 6 mo, 17% at 12 mo, and 8% at 24 mo after treatment. In comparison, median RFRs in the papillary-only studies were 67% at 6 mo, 44% at 12 mo, and 10% at 24 mo. Specifically in the BCG-unresponsive population, 6- and 12-mo CRRs in CIS-containing patients treated with Mycobacterium phlei cell wall-nucleic acid complex were 45% and 27%, respectively, and the median 6-, 12-, and 24-mo disease-free rates in the other studies were 43%, 35%, and 18%, respectively. The median progression-free rate was 91%: 95% in the CIS-containing studies and 89% in studies restricted to papillary-only recurrences. Toxicities of intravesical agents were generally mild, with very few dose limiting toxicities.

CONCLUSIONS

We demonstrate that, to date, bladder-sparing therapies achieved modest efficacy in patients with NMIBC after BCG. Results from the current study will serve as a frame of reference for emerging trial results in the BCG-unresponsive space.

PATIENT SUMMARY

In this study, we found that bladder-sparing therapies achieved modest efficacy in patients with non-muscle-invasive bladder cancer after bacillus Calmette-Guérin (BCG). These results will serve to inform future clinical trial results for salvage agents used to treat BCG-unresponsive bladder cancer.