Comparison of the combination therapy of bacillus Calmette-Guérin and mitomycin C with the monotherapy for non-muscle-invasive bladder cancer: a meta-analysis

Combination of Intravesical Bacille Calmette-Guérin and Chemotherapy vs. Bacille Calmette-Guérin Alone in Non-muscle Invasive Bladder Cancer: A Meta-Analysis

Background: About 75% of newly diagnosed bladder cancer cases suffer from non-muscle invasive bladder cancer (NMIBC), which used to recur and progress despite transurethral resection of bladder tumor (TURBT). This meta-analysis was conducted to examine if combined application of intravesical bacille Calmette-Guérin (BCG) with chemotherapy is associated with better prognosis. Methods: Systematic searches of randomized controlled trials (RCTs) concerning NMIBC were performed in PubMed, EMbase, CENTRAL, CNKI, WanFang, VIP, CBM databases, and some specialized websites. Two researchers independently implemented study selection, quality assessment and data extraction. Hazard ratios (HRs) and their 95% confidence intervals (CIs) for treatment effects on recurrence-free survival (RFS), progression-free survival (PFS), overall survival (OS) and disease-specific survival (DSS) were directly extracted, if available, or estimated using relevant data from included studies. Side effects, such as fever, gastrointestinal reaction, cystitis, irritative bladder symptoms and hematuria, were also extracted as outcome measurements, and associated relative risks (RRs) were calculated to assess treatment safety. RevMan 5.3 software was used to perform statistical analyses. Results: Thirteen RCTs containing 1,754 patients with NMIBC were included in this meta-analysis. Compared with BCG alone, the combination therapy significantly improved RFS (HR = 0.53, 95% CI: 0.43-0.66, P < 0.01), OS (HR = 0.66, 95%CI: 0.50-0.86, P = 0.002), and DSS (HR = 0.48, 95%CI: 0.29-0.80, P = 0.005). While PFS showed no obvious difference between combination therapy and BCG alone (HR = 0.65, 95%CI: 0.25-1.68, P = 0.38). The rate of fever (RR = 0.50, 95%CI: 0.27-0.91, P = 0.02), irritative bladder symptoms (RR = 0.69, 95%CI: 0.52-0.90, P = 0.007) and hematuria (RR = 0.50, 95%CI: 0.28-0.89, P = 0.02) were significantly decreased in patients treated with combination therapy compared to those with BCG alone. There were no statistically significant differences between combination therapy and BCG alone in toxicity (RR = 0.69, 95%CI: 0.34-1.40, P = 0.30), gastrointestinal reaction (RR = 2.54, 95%CI: 0.61-10.60, P = 0.20) or cystitis (RR = 0.67, 95%CI: 0.29-1.54, P = 0.34). Conclusions: Combined application of intravesical BCG and chemotherapy appears to be an effective treatment for patients with intermediate- to high-risk NMIBC, but not for those with tumor in situ alone or recurrent bladder cancer.

β-elemene induced anticancer effect in bladder cancer through upregulation of PTEN and suppression of AKT phosphorylation

Human bladder cancer is one of the most aggressive tumours known and has shown resistance to traditional chemotherapy, which depends heavily on DNA-damaging drugs. β-elemene is one of the least cytotoxic antitumor agents that are extracted from Curcuma aromatica salisb and it exhibits antitumor effects in many carcinomas. β-elemene has attracted the attention of clinicians and scientists worldwide due to its few side effects and limited effect on the bone marrow. However, the antitumor mechanism of β-elemene remains largely unstudied. In the present study, the expression of the AKT serine/threonine kinase (AKT) signaling pathway in bladder cancer and normal bladder tissue was investigated, and the influence of β-elemene on bladder cancer cells and the mechanisms involved were assessed. The results showed that phosphatase and tensin homolog deleted on chromosome ten (PTEN) was downregulated and phosphorylated-AKT (pAKT) was overexpressed in human bladder cancer. β-elemene significantly suppressed the viability of bladder cancer cells, while leaving normal bladder cells unaffected. In addition, there was an increased number of apoptotic bladder cancer cells following β-elemene treatment, and a significant reduction in cell invasion and migration. Subsequent western blot analyses revealed that bladder cancer cells treated with β-elemene had increased PTEN expression and decreased expression of pAKT. Taken together, these results suggest that β-elemene has an antitumor effect in bladder cancer cells through the upregulation of PTEN and suppression of AKT phosphorylation.

Systematic Review and Cumulative Analysis of the Combination of Mitomycin C plus Bacillus Calmette-Guérin (BCG) for Non-Muscle-Invasive Bladder Cancer

This systematic review and cumulative analysis aimed to explore the efficacy and safety of the combination of intravesical mitomycin C (MMC) plus bacillus Calmette-Guerin (BCG) for non-muscle-invasive bladder cancer (NMIBC) patients. A comprehensive literature search using Pubmed, Embase, Medline, Cochrane Library, CBM, CNKI and VIP databases was performed to identify studies applying intravesical MMC plus BCG therapy on NMIBC patients up to June 2016. Summarized unadjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the efficacy and safety of the combination therapy. A total of 25 studies containing 2749 NMIBC patients were included in this systematic review. Compared with BCG monotherapy, the combination therapy could significantly reduce the tumor recurrence rate (OR = 0.64, 95% CI: 0.44-0.94, P = 0.02) and cancer-specific mortality (OR = 0.54, 95% CI: 0.34-0.87, P = 0.01), without more toxicities (OR = 0.58, 95% CI: 0.17-1.94, P = 0.37). The combination therapy could also lead to significant lower tumor recurrence rate than MMC monotherapy (OR = 0.41, 95% CI: 0.24-0.69, P = 0.0009). Our study indicates that the combination of MMC plus BCG instillation is an effective and safe adjuvant treatment for NMIBC patients.