The utilization status of neoadjuvant chemotherapy in muscle-invasive bladder cancer: a systematic review and meta-analysis

Abstract

Introduction: To give a comprehensive depiction of the utilization status of neoadjuvant chemotherapy (NAC) in muscle invasive bladder cancer (MIBC) worldwide.

Evidence acquisition: Potential relevant research papers of Pubmed, Embase, Web of Science, and the Cochrane Library were reviewed to identify eligible studies. Primary outcomes of this meta-analysis were utilization rate of NAC and its utility distribution in different genders, races, ages, countries and temporal trends. The utilization rates of NAC were calculated as 'Proportion (s)' with 95% confidence intervals (CIs) and pooled estimates were calculated by using a random-effect model.

Evidence synthesis: A total of thirteen studies and 35,738 patients were included. The total proportion of NAC applied in MIBC populations prior to radical cystectomy (RC) was 17.2% (95% CI: 12.5-21.9%, I²=99.7%). The comparative analyses showed there were no significant differences existing in different genders or races on NAC utilization rates. In terms of age distribution, <60 age group conferred higher utilization rate of NAC than the older (OR=1.919, 95% CI: 1.671-2.202, P=0.0001). As for regional distribution, our meta-analysis showed that Japan (Proportion: 44.0%, 95% CI: 6.5-81.5%, I²=99.6%) and Sweden (37.9%, 95% CI: 34.9-40.8%) were the top two leading countries which contributed to the most frequent application of NAC. In respect of pathologic responses after NAC, complete, partial and down-staged pathologic responses were achieved in 16.6% (95% CI: 7.4-25.9%, I²=89.7%), 14.6% (95% CI: 0.8-28.5%, I²=89.7%) and 45.0% (95% CI: 17.8-72.2%, I²=98.8%) patients, respectively.

Conclusions: The present study shows the low utilization rate of NAC in MIBC patients. Standardization of the treatment modality of MIBC and promotion of guidelines might be necessary to expedite the adoption of NAC in near future.