Comparative Effectiveness of Bacillus Calmette-Guérin and Sequential Intravesical Gemcitabine and Docetaxel for Treatment-naïve Intermediate-risk Non-muscle-invasive Bladder Cancer

Background and objective: Sequential intravesical gemcitabine/docetaxel (Gem/Doce) has emerged as a potential alternative to bacillus Calmette-Guérin (BCG) for the treatment of non-muscle-invasive bladder cancer (NMIBC). Our aim was to determine the comparative effectiveness of BCG and Gem/Doce for patients with intermediate-risk (IR) NMIBC, composed mainly of high-grade (HG) Ta disease.

Methods: Patients with IR-NMIBC who received either BCG or Gem/Doce during 2013-2023 were included. Maintenance BCG (as per the Southwest Oncology Group protocol) and monthly Gem/Doce maintenance for 1 yr were offered to patients with no evidence of recurrence after induction. Routine surveillance with cystoscopy was performed according to the American Urological Association guidelines. The Kaplan-Meier method was used to assess high-grade and any-grade recurrence-free survival (RFS). Cox regression analysis was performed to find predictors of recurrence.

Key findings and limitations: Of 483 patients, 127 had IR-NMIBC; 66 patients received BCG and 61 received Gem/Doce. Median age was 69 yr (interquartile range [IQR] 61-76) for the BCG group and 72 yr (IQR 62-76) for the Gem/Doce group. Median follow-up was 53.1 mo (IQR 25.3-71.2) for the BCG group and 20.2 mo (IQR 8.28-33.1) for the Gem/Doce group. The 2-yr high-grade RFS rates for primary high-grade tumors for BCG versus Gem/Doce groups were 81% versus 61%, with corresponding any-grade RFS rates of 60% versus 41%. Induction with Gem/Doce predicted any-grade recurrence (hazard ratio [HR] 1.87, 95% confidence interval [CI] 1.1-3.2) and high-grade recurrence for primary high-grade tumors (HR 3.4 95% CI 1.27-9.13), while receipt of maintenance therapy decreased the risk of any-grade recurrence (HR 0.4, 95% CI 0.22-0.72). This study is limited by its retrospective design.

Conclusions and clinical implications: For patients with IR-NMIBC, BCG was associated with superior any-grade RFS and high-grade RFS for primary high-grade tumors. Maintenance therapy was associated with better RFS when receiving Gem/Doce. Standardization and longer maintenance therapy protocols should be considered for Gem/Doce treatment.

Patient summary: We compared outcomes for patients who received two different in-bladder treatments for intermediate-risk bladder cancer. Bacillus Calmette-Guérin (BCG) led to better outcomes than gemcitabine + docetaxel (Gem/Doce). Monthly maintenance therapy improved recurrence-free survival for patients who received Gem/Doce. We conclude that maintenance therapy is essential for patients receiving Gem/Doce to avoid bladder cancer recurrence after treatment.