Impact of intravesical chemotherapy on recurrence rate of recurrent superficial transitional cell carcinoma of the bladder: Results of a meta-analysis

Background: The impact of in travesical chemotherapy on preventing recurrence of superficial transitional cell carcinoma of the bladder is controversial. The objective of this report is to present a meta-analysis of the available clinical trial data to quantify the effect of intravesical chemotherapy on tumor recurrence following trans-urethral resection (TURB) in patients with recurrent superficial bladder cancer. Methods: A prospective study protocol outlining a meta-analysis was developed followed by a thorough search of the existing published literature using strict eligibility criteria. Eight randomized trials were found which met protocol specifications. These studies contained data on 1,609 patients which were statistically combined using a fixed effects model (Peto). The outcome of interest was the proportion of patients with tumor recurrence at one, two and three years post-TURB. Results: Combining all 8 studies using 1 year recurrence as the outcome measure yielded a Peto odds ratio (ORp) of 0.62, demonstrating a 38% reduction in one year recurrence among patients treated with intravesical chemotherapy versus TURB alone. Using 2 and 3 year recurrence as the outcome measure yielded ORp's of 0.46 and 0.35 respectively, favoring TURB + intravesical chemotherapy versus TURB alone. A statistical test for heterogeneity (Q) showed the 2 and 3 year outcome data to be heterogeneous (i.e. the studies are not measuring an effect of the same magnitude). Sensitivity analyses showed that drug type appeared to account for the observed heterogeneity with a stratified analysis demonstrating that adriamycin is less effective in reducing subsequent tumor recurrences than all other drugs studied. Conclusion: Intravesical chemotherapy appears to have a major impact on decreasing the chance of recurrence of recurrent superficial bladder cancer.