Optimal schedule of bacillus calmette-guerin for non-muscle-invasive bladder cancer: a meta-analysis of comparative studies

Background: To explore the necessity of maintenance, efficacy of low-dose and superiority of various combination therapies of Bacillus Calmette-Guerin (BCG) in treatment of superficial bladder cancer (BCa). Methods: Comprehensive searches of electronic databases (PubMed, Embase, and the Cochrane Library) were performed, then a systematic review and cumulative meta-analysis of 21 randomized controlled trials (RCTs) and 9 retrospective comparative studies were carried out according to predefined inclusion criteria. Results: Significantly better recurrence-free survivals (RFS) were observed respectively in patients who received BCG maintenance, standard-dose and BCG plus epirubicin therapy comparing to those received induction, low-dose and BCG alone. BCG maintenance therapy was also associated with significantly better progression-free survival (PFS), but there were more incidences of adverse events. Pooled results showed no remarkable advantage of BCG combined with Mitomycin C or with interferon alpha-2b in improving oncologic outcomes. Sensitivity-analyses stratified by study-design and tumor stage led to very similar overall results and often to a decrease of the between-study heterogeneity. Our data confirmed that non-RCT only affected strength rather than direction of the overall results. Conclusions: All patients with superficial BCa should be encouraged to accept BCG maintenance therapy with standard-dose if well tolerated. Patients can benefit from BCG combined with epirubicin but not from BCG combined with Mitomycin C or interferon alpha-2b.