Muscle noninvasive bladder cancer of medium risk: a review of intravesical therapy methods

Patients with muscle-noninvasive bladder cancer (MNIBC) at intermediate risk face a dilemma when planning further treatment after surgical intervention.Purpose: To conduct a systematic review and network meta-analysis to summarize the available data on oncological outcomes of intravesical therapy in patients with intermediate-risk MNIBC. Methods. MEDLINE, EMBASE, and ClinicalTrials.gov databases were used. Publication selection criteria: availability of information on the treatment of patients with intermediate-risk MNIBC who underwent transurethral resection of bladder tumor with or without intravesical chemotherapy or Bacille Calmette-Guérin (BCG) immunotherapy. Twelve studies were included in the qualitative analysis (systematic review); three were deemed eligible for quantitative analysis. A quantitative analysis of five different studies was compared in terms of 5-year risk of recurrence. Results. Chemotherapy with maintenance therapy was associated with a lower probability of 5-year recurrence than chemotherapy without maintenance therapy (probability 0.51, 95% confidence interval [CI] 0.26-1.03). Immunotherapy, regardless of full- or reduced-dose regimen, was not associated with a significantly lower probability of 5-year recurrence compared with chemotherapy without maintenance therapy (probability 0.90, 95% CI 0.39-2.11 versus probability 0.93, 95% CI 0.40-2.19). Treatment comparison analysis showed that chemotherapy with maintenance therapy was associated with the lowest 5-year risk of recurrence. Conclusion. Chemotherapy with maintenance regimen provided a better oncologic outcome relative to the 5-year risk of recurrence compared with chemotherapy without maintenance therapy in patients with intermediate-risk MNIBC. Regardless of dosing regimen, BCG immunotherapy does not appear to be superior to chemotherapy in patients with intermediate-risk MNIBC relativeto reducing the risk of disease recurrence. A maintenance schedule of chemotherapy reduces the long-term recurrence rate of bladder cancer that has not sprouted muscle tissue. Chemotherapy injected directly into the bladder as well as immunotherapy without maintenance chemotherapy appears to have less effectiveness in preventing cancer recurrence.