The efficacy and safety outcomes of lower dose BCG compared to intravesical chemotherapy in non–muscle-invasive bladder cancer: A network meta-analysis

This study aimed to assess both efficacy and safety outcomes of lowering the dose of BCG compared to intravesical chemotherapies in non–muscle-invasive bladder cancer (NMIBC) patients using a systematic review, meta-analysis, and network meta-analysis approach. A comprehensive literature search was performed through Pubmed®, Web of Science™, and Scopus® in December 2022 to identify randomized controlled trials comparing the oncologic and/or safety outcomes of reduced dose intravesical BCG and/or intravesical chemotherapies according to the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) statement. The outcomes of interest were risk of recurrence, progression, treatment-related adverse events, and discontinuation. Overall, 24 studies were eligible for quantitative synthesis. Among 22 studies that adopted induction followed by maintenance intravesical therapy, with reference to the lower-dose BCG, epirubicin was associated with a significantly higher risk of recurrence (Odds ratio [OR]: 2.82, 95% CI: 1.54–5.15), but not other intravesical chemotherapies. There were no significant differences in risk of progression among the intravesical therapies. On the other hand, standard-dose BCG was associated with a higher risk of any AEs (OR: 1.91, 95% CI: 1.07–3.41) but other intravesical chemotherapies had a comparable risk of AEs compared to lower-dose BCG. The discontinuation rate did not significantly differ between lower-dose and standard-dose BCG (OR: 1.40, 95% CI: 0.81–2.43) as well as other intravesical. According to the surface under the cumulative ranking curve, gemcitabine, and standard-dose BCG were preferable to lower-dose BCG in terms of recurrence risk; gemcitabine was also preferable to lower-dose BCG in terms of risk of AEs. In patients with NMIBC, lowering the dose of BCG decreases the risks of AEs and discontinuation rate compared to standard-dose BCG, but there is no difference in these endpoints compared to other intravesical chemotherapies. Standard-dose of BCG is preferred for all intermediate and high-risk NMIBC patients based on oncologic efficacy; however, lower-dose BCG and intravesical chemotherapies, especially gemcitabine, could be considered a reasonable alternative to BCG in selected patients who suffer from significant AEs or in case standard-dose BCG is not available.