Efficacy of Preoperative Chemotherapy in Treatment of Children With Wilms’ Tumor: A Meta-Analysis

CONTEXT: To assess the efficacy of preoperative chemotherapy in Wilms’ tumor patients and explore its true value for specific subgroups. OBJECTIVES: In the presence of these controversies, a meta-analysis that examines the efficacy of preoperative chemotherapy in Wilms’ tumor patients and specific subgroups is needed to clarify these issues. The objective of this meta-analysis is to assess the efficacy of preoperative chemotherapy in Wilms’ tumor patients and explore its true value for specific subgroups. DATA SOURCES: Computer-based systematic search with “preoperative chemotherapy”, “Neoadjuvant Therapy” and “Wilms’ tumor” as search terms till January 2013 was performed. STUDY SELECTION: No language restrictions were applied. Searches were limited to randomized clinical trials (RCTs) or retrospective studies in human participants under 18 years. A manual examination of references in selected articles was also performed. DATA EXTRACTION: Relative Risk (RR) and their 95% Confidence Interval (CI) for Tumor Shrinkage (TS), total Tumor Resection (TR), Event-Free Survival (EFS) and details of subgroup analysis were extracted. Meta-analysis was carried out with the help of the software STATA 11.0. Finally, four original Randomized Clinical Trials (RCTs) and 28 retrospective studies with 2375 patients were included. RESULTS: For preoperative chemotherapy vs. up-front surgery (PC vs. SU) group, the pooled RR was 9.109 for TS (95% CI: 5.109 - 16.241; P < 0.001), 1.291 for TR (95% CI: 1.124 - 1.483; P < 0.001) and 1.101 for EFS (95% CI: 0.980 - 1.238; P = 0.106). For subgroup short course vs. long course (SC vs. LC), the pooled RR was 1.097 for TS (95% CI: 0.784 - 1.563; P = 0.587), 1.197 for TR (95% CI: 0.960 - 1.493; P = 0.110) and 1.006 for EFS (95% CI: 0.910 - 1.250; P = 0.430). CONCLUSIONS: Short course preoperative chemotherapy is as effective as long course and preoperative chemotherapy only benefits Wilms’ tumor patients in tumor shrinkage and resection but not event-free survival.