Muscle-invasive bladder cancer organ-preserving therapy: systematic review and meta-analysis

To determine the effectiveness and harms of bladder-preserving trimodal therapy (TMT) as a first-line treatment versus radical cystectomy (RC) plus radical pelvic lymphadenectomy in the treatment of muscle-invasive bladder cancer in terms of overall survival.

We included parallel clinical trials and prospective and retrospective cohort studies that included patients older than 18 years old, diagnosed with muscle-invasive bladder cancer, who underwent TMT compared with RC. The planned comparison was TMT versus RC plus pelvic lymphadenectomy as first-line treatment. The primary outcome was overall survival (OS) and secondary outcomes were salvage cystectomy and cancer-specific survival and progression-free survival. A search strategy was designed for MEDLINE, CENTRAL, Embase, and LILACS. We saturated information with conference abstracts, in progress clinical trials, literature published in non-indexed journals, and other sources of gray literature. Standardized tools assessed the risk of bias independently. We performed the statistical analysis in R v3.4.1 and effect sizes were reported in terms of hazard ratios (HR) and the corresponding 95% confidence intervals (95%CI). Accordingly, we used a random effect model due to the statistical heterogeneity found in included studies.

We found 2682 records with the search strategies and, finally, 11 studies were included in the quantitative analysis. The summary HR for OS was 1.06 95%CI (0.85-1.31) I² = 77%, showing no statistical difference. Regarding cancer-specific survival, the summary HR was 1.23 95%CI (1.04-1.46) I² = 14%. On the other side, for the progression-free survival, the summary HR was 1.11 95%CI (0.63-1.95) I² = 78%. Only one study described HR for adverse events (1.37 95%CI 1.16-1.59).

We found no differences in overall survival and progression-free survival between these two interventions. Nonetheless, we found that cancer-specific survival favored patients who received radical cystectomy.