Adjuvant Chemotherapy in Invasive Bladder Cancer: a Systematic Review and Meta-analysis of Individual Patient Data Advanced Bladder Cancer (ABC) Meta-analysis Collaboration

Objectives: To evaluate the effect of adjuvant chemotherapy in invasive bladder cancer.

Methods: : We conducted a systematic review and meta-analysis of updated individual patient data from all available randomised controlled trials comparing local treatment plus adjuvant chemotherapy versus the same local treatment alone.

Results: Analyses were based on 491 patients from six trials, representing 90% of all patients randomised in cisplatin-based combination chemotherapy trials and 66% of patients from all eligible trials. The power of this meta-analysis is clearly limited. The overall hazard ratio for survival of 0.75 (95% CI 0.60-0.96, p = 0.019) suggests a 25% relative reduction in the risk of death for chemotherapy compared to that on control. Cox regression suggests that small imbalances in patient characteristics do not bias the results in favour of chemotherapy. However, the impact of trials that stopped early, of patients not receiving allocated treatments or not receiving salvage chemotherapy is less clear.

Conclusions: This IPD meta-analysis provides the best evidence currently available on the role of adjuvant chemotherapy for invasive bladder cancer. However, at present there is insufficient evidence on which to reliably base treatment decisions. These results highlight the urgent need for further research into the use of adjuvant chemotherapy. The results of appropriately sized randomised trials, such as the ongoing EORTC-30994 trial are needed before any definitive conclusions can be drawn.