Comparable effect with minimal morbidity of low-dose Tokyo 172 strain compared with regular dose Connaught strain as an intravesical bacillus Calmette-Guérin prophylaxis in nonmuscle invasive bladder cancer: Results of a randomized prospective comparison

Comparative study on the efficacy of low-dose and full-dose BCG bladder perfusion therapy

BACKGROUND

Full-dose BCG bladder perfusion therapy is effective, but there are serious side effects. Whether a low dose of BCG can reduce the side effects of treatment while maintaining its efficacy is still inconclusive.

OBJECTIVE

To compare the efficacy of low-dose and full-dose BCG bladder perfusion therapy and to provide reference for individual treatment of bladder cancer.

METHODS

All relevant literature published in PubMed, Web of Science, and Embrase databases up to April 2024 was searched. The results and shortcomings of the existing literature are analyzed, the cognitive gaps between different studies are pointed out, and suggestions are made for future research.

RESULTS

A total of 32 pieces of literature were included. Twelve studies found that the efficacy of full-dose BCG perfusion was significantly better than that of low-dose BCG perfusion, and 20 studies found no statistical difference between low-dose and full-dose BCG perfusion CONCLUSION: Although there is no significant difference in the efficacy of full-dose and low-dose BCG in bladder perfusion, the trend indicates that the efficacy of full-dose BCG is still the most accurate. In cases where BCG resources are scarce or patients are intolerant, low-dose BCG bladder perfusion therapy may be an alternative to full-dose BCG bladder perfusion therapy. High-quality, large-sample prospective cohort studies (or randomized controlled studies) are still needed in the future.

Carcinoma In Situ (CIS): Is There a Difference in Efficacy between Various BCG Strains? A Comprehensive Review of the Literature

Introduction: Intravesical Bacillus Calmette-Guérin (BCG) immunotherapy is the standard of care for high-risk and intermediate-risk non-muscle-invasive bladder cancer (NMIBC) as well as for Carcinoma in situ (CIS). Evidence supports that the different BCG strains, despite genetic variability, are equally effective clinically for preventing the recurrence and progression of papillary NMIBC. The available evidence regarding possible differences in clinical efficacy between various BCG strains in CIS is lacking. Methods: We reviewed the literature on the efficacy of different BCG strains in patients with CIS (whether primary, secondary, concomitant, or unifocal/multifocal), including randomized clinical trials (RCTs), phase II/prospective trials, and retrospective studies with complete response rates (CRR), recurrence-free survival (RFS), or progression-free survival (PFS) as endpoints. Results: In most studies, being RCTs, phase II prospective trials, or retrospective studies, genetic differences between BCG strains did not translate into meaningful differences in clinical efficacy against CIS, regardless of the CIS subset (primary, secondary, or concurrent) or CIS focality (unifocal or multifocal). CRR, RFS, and PFS were not statistically different between various BCG strains. None of these trials were designed as head-to-head comparisons between BCG strains focusing specifically on CIS. Limitations include the small sample size of many studies and most comparisons between strains being indirect rather than head-to-head. Conclusions: This review suggests that the clinical efficacy of the various BCG strains appears similar, irrespective of CIS characteristics. However, based on the weak level of evidence available and underpowered studies, randomized studies in this space should be encouraged as no definitive conclusion can be drawn at this stage.

The Impact of Dose Reduction of Bacillus Calmette-Guerin on Oncological Outcomes and Toxicity in Non-Muscle Invasive Bladder Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Bacillus Calmette-Guerin (BCG) is the standard adjuvant treatment for intermediate and high-risk non-muscle invasive bladder cancer (NMIBC) following transurethral resection of the bladder (TURB). However, the optimal dose, strain, and schedule of BCG remain unclear.

OBJECTIVE

To evaluate the impact of BCG dose reduction on oncological outcomes and toxicity in patients with non-muscle invasive bladder cancer.

METHODS

We performed a systematic review of the literature in PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases. Selected studies were analyzed for Meta Analysis using PRISMA criteria. The study focused on disease recurrence, progression, and toxicity. We also compared the oncological outcomes of the different BCG strains.

RESULTS

A total of 2963 patients in 13 randomized controlled trials were included. In recurrence analysis, we found a non-significant difference between the full dose and any dose reduction of BCG (RR = 1.17, [1.06-1.28], I2 = 0%, p = 0.7). In terms of progression, the difference was also non-statistically significant (RR: 1.12 [0.89 - 1.41], I2 = 0%, p = 0.93). In the toxicity analysis, there were more local (RR: 0.81 [0.67-0.99] I2 = 76%; p < 0.01) and systemic (RR: 0.53 [0.34-0.82] I2 = 83%; p < 0.01) side effects in the full dose group than in the dose reduction group. There were no statistically significant differences in oncological outcomes between the analyzed BCG strains.

CONCLUSIONS

Dose reduction did not affect the oncological outcomes of patients with NMIBC who received adjuvant therapy with BCG. On the other hand, dose reduction showed a significant trend towards fewer systemic and local side effects. Further studies comparing oncological and toxicity outcomes using different strains are needed.

Efficacy of Different Bacillus of Calmette-Guérin (BCG) Strains on Recurrence Rates among Intermediate/High-Risk Non-Muscle Invasive Bladder Cancers (NMIBCs): Single-Arm Study Systematic Review, Cumulative and Network Meta-Analysis

BACKGROUND

In an era of Bacillus of Calmette-Guérin (BCG) shortages, the comparative efficacy from different adjuvant intravesical BCG strains in non-muscle invasive bladder cancer (NMIBC) has not been clearly elucidated. We aim to compare, through a systematic review and meta-analysis, the cumulative BC recurrence rates and the best efficacy profile of worldwide available BCG strains over the last forty years.

METHODS

PubMed, Scopus, Web of Science, Embase, and Cochrane databases were searched from 1982 up to 2022. A meta-analysis of pooled BC recurrence rates was stratified for studies with ≤3-y vs. >3-y recurrence-free survival (RFS) endpoints and the strain of BCG. Sensitivity analysis, sub-group analysis, and meta-regression were implemented to investigate the contribution of moderators to heterogeneity. A random-effect network meta-analysis was performed to compare BCG strains on a multi-treatment level.

RESULTS

In total, n = 62 series with n = 15,412 patients in n = 100 study arms and n = 10 different BCG strains were reviewed. BCG Tokyo 172 exhibited the lowest pooled BC recurrence rate among studies with ≤3-y RFS (0.22 (95%CI 0.16-0.28). No clinically relevant difference was noted among strains at >3-y RFS outcomes. Sub-group and meta-regression analyses highlighted the influence of NMIBC risk-group classification and previous intravesical treated categories. Out of the n = 11 studies with n = 7 BCG strains included in the network, BCG RIVM, Tice, and Tokyo 172 presented with the best-predicted probability for efficacy, yet no single strain was significantly superior to another in preventing BC recurrence risk.

CONCLUSION

We did not identify a BCG stain providing a clinically significant lower BC recurrence rate. While these findings might discourage investment in future head-to-head randomized comparison, we were, however, able to highlight some potential enhanced benefits from the genetically different BCG RIVM, Tice, and Tokyo 172. This evidence would support the use of such strains for future BCG trials in NMIBCs.

Low-dose versus standard-dose bacille Calmette–Guérin for non-muscle-invasive bladder cancer: Systematic review and meta-analysis of randomized controlled trials

Purpose

Intravesical BCG (bacille Calmette–Guérin) instillation in patients with non-muscle-invasive bladder cancer decreases the risk for tumor recurrence and progression. After one BCG product was discontinued, a chronic global BCG shortage occurred. We focused on identifying a reduced dose of BCG that could maintain efficacy and reduce adverse effects.

Materials and Methods

We conducted a comprehensive literature search of PubMed, Embase, the Cochrane Library, CINAHL, Web of Science, and Scopus to identify randomized controlled trials through April 2021. The odds ratios (ORs) and 95% confidence intervals (CIs) for the low and standard doses in nine studies were compared. A low dose was defined as a low volume of BCG compared with the standard BCG dose (Armand Frappier, 120 mg; Connaught, 81 mg; Danish 1331, 120 mg; modified Danish 1331, 120 mg; Tokyo 172, 80 mg).

Results

The low-dose group experienced aggravated recurrence (OR, 1.45; 95% CI, 1.09–1.94; p=0.01) but similar progression (OR, 1.11; 95% CI, 0.76–1.62; p=0.59), similar cancer-specific survival (OR, 1.02; 95% CI, 0.60–1.75; p=0.93), similar overall survival (OR, 1.09; 95% CI, 0.76–1.56; p=0.65), favorable adverse effects (OR, 0.41; 95% CI, 0.28–0.62; p<0.0001), and favorable withdrawal (OR, 0.42; 95% CI, 0.25–0.71; p=0.001).

Conclusions

Low-dose BCG had more unfavorable outcomes than did standard-dose BCG in terms of recurrence. Tumor progression, cancer-specific survival, and overall survival were similar between the doses. Low-dose BCG improved adverse effects and withdrawal. In the setting of BCG shortage, low-dose BCG may have strong potential as an alternative.

Immunotherapy for non-muscle-invasive bladder cancer: from the origins of BCG to novel therapies

Supplies of intravesical Bacillus Calmette-Guérin (BCG), the first-line treatment for most intermediate- and high-risk non-muscle-invasive bladder cancers (NMIBC), have proven unreliable over the past decade. This review considers the evolution of BCG immunotherapy for NMIBC: from the discovery of the antitumour side effects of tuberculosis and subsequently the BCG vaccine, to recent advances in novel immunotherapeutic agents. We summarize the evidence for alternative options to standard intravesical BCG therapy regimens and describe the potential for immune response manipulating drugs in the treatment of NMIBC. These new agents, including immune checkpoint inhibitors, toll-like receptor agonists and recombinant viral vectors, may provide better options in the management of NMIBC in the future.

Comparative Effectiveness of Intravesical BCG-Tice and BCG-Moreau in Patients With Non-muscle-invasive Bladder Cancer

BACKGROUND

The purpose of this study was to compare the efficacy of 2 bacillus Calmette-Guérin (BCG) strains, BCG-Tice and BCG-Moreau, in the treatment of non-muscle-invasive bladder cancer (NMIBC).

MATERIALS AND METHODS

We retrospectively reviewed clinical data from patients treated with BCG for NMIBC at 3 academic centers. Inverse probability of treatment weighting (IPTW)-adjusted Kaplan-Meier curves and Cox proportional hazards regression analyses were used to compare recurrence-free (RFS) and progression-free survival (PFS) of patients in the 2 treatment groups. In addition, we performed exploratory analyses of treatment effect according to the receipt of adequate BCG treatment, high-risk disease, age, gender, smoking status, pathologic stage, and pathologic grade.

RESULTS

A total of 321 (48.6%) patients were treated with BCG-Tice and 339 (51.4%) with BCG-Moreau. IPTW-adjusted Cox proportional hazard regression analysis did not show a difference in RFS (hazard ratio, 0.88; 95% confidence interval, 0.56-1.38; P = .58) or PFS (hazard ratio, 0.55; 95% confidence interval, 0.25-1.21, P = .14) between BCG-Tice and BCG-Moreau. On subgroup analyses, we could not identify an association of BCG strain with outcomes.

CONCLUSIONS

There was no difference in RFS and PFS between BCG-Tice and BCG-Moreau strains in the adjuvant treatment of NMIBC. However, we confirmed the importance of maintenance therapy for achieving a sustainable response in patients with intermediate- and high-risk NMIBC.

Mechanisms of BCG immunotherapy and its outlook for bladder cancer

BCG immunotherapy is the gold-standard treatment for non-muscle-invasive bladder cancer at high risk of recurrence or progression. Preclinical and clinical studies have revealed that a robust inflammatory response to BCG involves several steps: attachment of BCG; internalization of BCG into resident immune cells, normal cells, and tumour urothelial cells; BCG-mediated induction of innate immunity, which is orchestrated by a cellular and cytokine milieu; and BCG-mediated initiation of tumour-specific immunity. As an added layer of complexity, variation between clinical BCG strains might influence development of tumour immunity. However, more than 40 years after the first use of BCG for bladder cancer, many questions regarding its mechanism of action remain unanswered. Clearly, a better understanding of the mechanisms underlying BCG-mediated tumour immunity could lead to improved efficacy, increased tolerance of treatment, and identification of novel immune-based therapies. Indeed, enthusiasm for bladder cancer immunotherapy, and the possibility of combining BCG with other therapies, is increasing owing to the availability of targeted immunotherapies, including checkpoint inhibitors. Understanding of the mechanism of action of BCG immunotherapy has advanced greatly, but many questions remain, and further basic and clinical research efforts are needed to develop new treatment strategies for patients with bladder cancer.

[Immunotherapy and bladder cancer]

Immunotherapy as a treatment of solid malignancy is based on the activation of the immune system against tumor cells. Since 1976, intravesical instillation of Bacillus Calmette-Guérin (BCG) has been used widely for the treatment of non muscle invasive bladder cancer and is nowadays recommended by all scientific guidelines. New targeted systemic immunotherapies and particularly checkpoints inhibitors are now widely used in several different cancers and notably in onco-urology. Immune checkpoint molecule inhibitors have opened the possibility of treatments for cancers and there are already phase 2 and 3 trials running with or without BCG in localized, muscle invasive and metastatic bladder cancer.

Intravesical bacillus Calmette-Guérin for bladder cancer: are all the strains equal?

Intravesical immunotherapy with bacillus Calmette-Guérin (BCG) is the standard of care for high-risk and intermediate-risk non-muscle-invasive bladder cancer (NMIBC). Several BCG strains are available. Despite originating all from subcultures of the same Mycobacterium, strains are genetically different which may lead to differences in treatment efficacy and adverse events. Identification of a more efficient strain and assessing its optimal administration schedule may improve oncological outcomes in NMIBC, specifically because of the worldwide shortage in BCG availability. This review focused on the antitumor effect of different BCG strains with a particular emphasis on the evidence underlying BCG dose and treatment schedules.

Safety and efficacy of various strains of bacille Calmette-Guérin in the treatment of bladder tumours in standard clinical practice

BACKGROUND

The natural progression of bladder tumours (nonmuscle-invasive bladder cancer [NMIBC]) is recurrence with a high rate of progression. Bacille Calmette-Guérin (BCG) has been shown effective in reducing these rates, but there are few comparative studies between strains.

MATERIAL AND METHODS

An observational, prospective and multicentre registry studied 433 patients with a 12-month follow-up visit from 961 registered patients, assessing disease-free survival (DFS), progression-free survival (PFS) cancer-specific survival (CSS) and adverse effects. We studied the Tice, Russian, Tokyo, Connaught and RIVM strains.

RESULTS

The sociodemographic data, NMIBC history, comorbidities, size, number, stage, grade, associated carcinoma in situ and transurethral resection were well balanced. DFS: There were 85 relapses (19.6%). The median DFS time was 20months. When comparing the various strains, we detected no statistically significant differences (log-rank test; P=.93). LPS: There were 33 cases of progression (7.62%). When comparing the various strains, we detected no statistically significant differences (log-rank test; P=.69). CSS: Seven patients died (1.68%). When comparing the various strains, we detected no statistically significant differences (log-rank test; P=.93). In terms of safety, 33.3% of the patients presented some type of adverse effect, mostly lower urinary symptoms (no urinary tract infections) <48h, >48h and haematuria. According to the Common Toxicity Criteria of the European Organisation for Research and Treatment of Cancer, 92.7% of the patients were grade1. There were no statistically significant differences between the strains.

CONCLUSIONS

In this intermediate analysis, the risk of recurrence, progression, specific death and safety were independent of the BCG strain employed.

Low-Dose Versus Standard Dose of Bacillus Calmette-Guerin in the Treatment of Nonmuscle Invasive Bladder Cancer: A Systematic Review and Meta-Analysis

Whether low-dose Bacillus Calmette-Guerin (BCG) treatment can reduce the side effects while maintaining efficacy for patients with nonmuscle invasive bladder cancer (NMIBC) is controversial.To investigate whether low-dose BCG treatment can reduce the side effects while maintaining efficacy for patients with NMIBC when compared with standard-dose BCG treatment.A comprehensive literature search of PubMed, EMBASE, CINAHL, LILACS, and CENTRAL databases was conducted to identify relevant randomized controlled trials (RCT) or quasi-randomized controlled trials (qRCT) that have assessed the efficacy of low- and standard-dose BCG therapy for patients with NMIBC. Systematic review and meta-analysis were performed according to Preferred Reporting Items for Systematic Reviews and Meta-analysis Criteria.Six RCTs and 2 qRCTs were eligible for meta-analysis. Low-dose BCG instillation was not inferior to reduce the risk of bladder tumor recurrence (hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.00-1.31; P = 0.05), meanwhile no difference was found regarding tumor progression (HR = 1.08; 95%CI, 0.83-1.42; P = 0.57). However, low-dose BCG provided a significantly lower incidence of overall side effects (RR = 0.75; 95%CI, 0.60-0.94; P = 0.01), systemic side effects (RR = 0.57; 95%CI, 0.34-0.97; P = 0.04), severe side effects (RR = 0.52; 95%CI, 0.36-0.74; P = 0.0003), and withdrawal due to BCG toxicity (RR = 0.49; 95%CI, 0.26-0.91; P = 0.02). In contrast, local side effects were comparable between low- and standard-dose arms (RR = 0.89; 95%CI, 0.73-1.08; P = 0.24).Low-dose BCG instillation significantly reduces the incidence of overall side effects, especially severe and systemic symptoms in patients with NMIBC, while the oncological control efficacy of low-dose BCG is not inferior to standard-dose BCG. Further studies with stratification using different risk factors at randomization are required to assess whether the efficacy of low-dose BCG is comparable to standard dose BCG for different risk of patients.PROSPERO registration No CRD42014014871 (http://www.crd.york.ac.uk/prospero/).

Clinical characteristics and needle aspiration management of Bacillus Calmette-Guérin lymphadenitis in children

OBJECTIVES

To describe characteristics of children developing Bacillus Calmette-Guérin (BCG) lymphadenitis, and to evaluate needle aspiration treatment.

METHODS

Children developing BCG lymphadenitis following BCG vaccination in Al-Rass General Hospital, Al-Rass, Saudi Arabia were prospectively studied from October 2008 to September 2013. Non-suppurative BCG lymphadenitis was conservatively managed, while suppurative lymphadenitis was treated by needle aspiration.

RESULTS

The mean (SD) age of children (n=23) was 4.1 (1.4) months, and symptoms duration was 2.08 (1.38) months. Fifteen (65.2%) children had suppurative, whereas 8 (34.8%) had non-suppurative lymphadenitis. Age, gender, birth weight, and duration of symptoms were not significantly different between children with suppurative and non-suppurative lymphadenitis (p>0.05). Children with suppurative adenitis had higher weight, and larger size of the involved lymph nodes compared with those with non-suppurative nodes (p=0.001). Most (91.3%) had axillary lesions; with a mean lymph node size of 3.2 cm. Abscesses were detected by ultrasound in 8 (80%). Non-suppurative lymphadenitis was conservatively managed, while suppurative was aspirated. The mean duration for resolution was 3.25 months. Lymph nodes aspirate were positive for acid and alcohol fast bacilli in 10 patients (66.6%), and 3 of them grew Staphylococcus aureus.

CONCLUSION

Bacillus Calmette-Guérin adenitis occurs in young children, mainly as unilocular suppurative left axillary group with a mean size of 3.2 cm. Needle aspiration is safe in treatment of suppurative lymphadenitis. Mycobacteria stained positive in most of the suppurative lesions. Excision is not needed.

Applications of bacillus Calmette-Guerin and recombinant bacillus Calmette-Guerin in vaccine development and tumor immunotherapy

Bacillus Calmette-Guerin (BCG) vaccines are attenuated live strains of Mycobacterium bovis and are among the most widely used vaccines in the world. BCG is proven to be effective in preventing severe infant meningitis and miliary tuberculosis. Intravesical instillation of BCG is also a standard treatment for non-muscle invasive bladder cancer. In the past few decades, recombinant BCG (rBCG) technology had been extensively applied to develop vaccine candidates for a variety of infectious diseases, including bacterial, viral, and parasite infections, and to improve the efficacy of BCG in bladder cancer therapy. This review is intended to show the vast applications of BCG and recombinant BCG (rBCG) in the prevention of infectious diseases and cancer immunotherapy, with a special emphasis on recent approaches and trends on both pre-clinical and clinical levels.