Is intravesical Bacillus Calmette-Guérin therapy superior to chemotherapy for intermediate-risk non-muscle-invasive bladder cancer? An ongoing debate

COVID-19 and Beyond: Exploring Public Health Benefits from Non-Specific Effects of BCG Vaccination

Bacille Calmette–Guérin (BCG) vaccination, widely used throughout the world to protect against infant tuberculous meningitis and miliary tuberculosis (TB), can provide broad non-specific protection against infectious respiratory diseases in certain groups. Interest in BCG has seen a resurgence within the scientific community as the mechanisms for non-specific protection have begun to be elucidated. The impact of the COVID-19 pandemic on nearly every aspect of society has profoundly illustrated the pressure that respiratory infections can place on a national healthcare system, further renewing interest in BCG vaccination as a public health policy to reduce the burden of those illnesses. However, the United States does not recommend BCG vaccination due to its variable effectiveness against adult TB, the relatively low risk of Mycobacterium tuberculosis infection in most of the United States, and the vaccine’s interference with tuberculin skin test reactivity that complicates TB screening. In this review, we explore the broad immune training effects of BCG vaccination and literature on the effects of BCG vaccination on COVID-19 spread, disease severity, and mortality. We further discuss barriers to scheduled BCG vaccination in the United States and how those barriers could potentially be overcome.

Intravesical Bacillus Calmette-Guérin versus mitomycin C for Ta and T1 bladder cancer

BACKGROUND

People with urothelial carcinoma of the bladder are at risk for recurrence and progression following transurethral resection of a bladder tumour (TURBT). Mitomycin C (MMC) and Bacillus Calmette-Guérin (BCG) are commonly used, competing forms of intravesical therapy for intermediate- or high-risk non-muscle invasive (Ta and T1) urothelial bladder cancer but their relative merits are somewhat uncertain.

OBJECTIVES

To assess the effects of BCG intravesical therapy compared to MMC intravesical therapy for treating intermediate- and high-risk Ta and T1 bladder cancer in adults.

SEARCH METHODS

We performed a systematic literature search in multiple databases (CENTRAL, MEDLINE, Embase, Web of Science, Scopus, LILACS), as well as in two clinical trial registries. We searched reference lists of relevant publications and abstract proceedings. We applied no language restrictions. The latest search was conducted in September 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared intravesical BCG with intravesical MMC therapy for non-muscle invasive urothelial bladder cancer.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the literature, extracted data, assessed risk of bias and rated the quality of evidence according to GRADE per outcome. In the meta-analyses, we used the random-effects model.

MAIN RESULTS

We identified 12 RCTs comparing BCG versus MMC in participants with intermediate- and high-risk non-muscle invasive bladder tumours (published from 1995 to 2013). In total, 2932 participants were randomised. Time to death from any cause: BCG may make little or no difference on time to death from any cause compared to MMC (hazard ratio (HR) 0.97, 95% confidence interval (CI) 0.79 to 1.20; participants = 1132, studies = 5; 567 participants in the BCG arm and 565 in the MMC arm; low-certainty evidence). This corresponds to 6 fewer deaths (40 fewer to 36 more) per 1000 participants treated with BCG at five years. We downgraded the certainty of the evidence two levels due to study limitations and imprecision. Serious adverse effects: 12/577 participants treated with BCG experienced serious non-fatal adverse effects compared to 4/447 participants in the MMC group. The pooled risk ratio (RR) is 2.31 (95% CI 0.82 to 6.52; participants = 1024, studies = 5; low-certainty evidence). Therefore, BCG may increase the risk for serious adverse effects compared to MMC. This corresponds to nine more serious adverse effects (one fewer to 37 more) with BCG. We downgraded the certainty of the evidence two levels due to study limitations and imprecision. Time to recurrence: BCG may reduce the time to recurrence compared to MMC (HR 0.88, 95% CI 0.71 to 1.09; participants = 2616, studies = 11, 1273 participants in the BCG arm and 1343 in the MMC arm; low-certainty evidence). This corresponds to 41 fewer recurrences (104 fewer to 29 more) with BCG at five years. We downgraded the certainty of the evidence two levels due to study limitations, imprecision and inconsistency. Time to progression: BCG may make little or no difference on time to progression compared to MMC (HR 0.96, 95% CI 0.73 to 1.26; participants = 1622, studies = 6; 804 participants in the BCG arm and 818 in the MMC arm; low-certainty evidence). This corresponds to four fewer progressions (29 fewer to 27 more) with BCG at five years. We downgraded the certainty of the evidence two levels due to study limitations and imprecision. Quality of life: we found very limited data for this outcomes and were unable to estimate an effect size.

AUTHORS' CONCLUSIONS

Based on our findings, BCG may reduce the risk of recurrence over time although the Confidence Intervals include the possibility of no difference. It may have no effect on either the risk of progression or risk of death from any cause over time. BCG may cause more serious adverse events although the Confidence Intervals once again include the possibility of no difference. We were unable to determine the impact on quality of life. The certainty of the evidence was consistently low, due to concerns that include possible selection bias, performance bias, given the lack of blinding in these studies, and imprecision.

Prognostic Significance of Lymphocyte Infiltration and a Stromal Immunostaining of a Bladder Cancer Associated Diagnostic Panel in Urothelial Carcinoma

We set out to expand on our previous work in which we reported the epithelial expression pattern of a urine-based bladder cancer-associated diagnostic panel (A1AT, ANG, APOE, CA9, IL8, MMP9, MMP10, PAI1, SDC1, and VEGFA). Since many of the analytes in the bladder cancer-associated diagnostic signature were chemokines, cytokines, or secreted proteins, we set out to report the stromal staining pattern of the diagnostic signature as well as CD3⁺ (T-cell) cell and CD68⁺ (macrophage) cell staining in human bladder tumors as a snapshot of the tumor immune landscape. Immunohistochemical staining was performed on 213 tumor specimens and 74 benign controls. Images were digitally captured and quantitated using Aperio (Vista, CA). The expression patterns were correlated with tumor grade, tumor stage, and outcome measures. We noted a positive correlation of seven of the 10 proteins (excluding A1AT and IL8 which had a negative association and VEGFA had no association) in bladder cancer. The overexpression of MMP10 was associated with higher grade disease, while overexpression of MMP10, PAI1, SDC1 and ANG were associated with high stage bladder cancer and CA9 was associated with low stage bladder cancer. Increased tumor infiltration of CD68⁺ cells were associated with higher stage disease. Overall survival was significantly reduced in bladder cancer patients' whose tumors expressed eight or more of the 10 proteins that comprise the bladder cancer diagnostic panel. These findings confirm that the chemokines, cytokines, and secreted proteins in a urine-based diagnostic panel are atypically expressed, not only in the epithelial component of bladder tumors, but also in the stromal component of bladder tumors and portends a worse overall survival. Thus, when assessing immunohistochemical staining, it is important to report staining patterns within the stroma as well as the entire stroma itself.