Prognostic Value of Lymph Node Ratio in Children with Wilms Tumor: A Systematic Review and Meta-Analysis

Abstract

Background: Lymph node (LN) involvement is a critical determinant of staging and prognosis in Wilms tumor (WT). However, conventional binary nodal staging (positive vs. negative) is often compromised by significant variability in surgical lymph node sampling. The lymph node ratio (LNR), which integrates metastatic burden and sampling adequacy, has emerged as a potential prognostic alternative. This systematic review and meta-analysis evaluated whether LNR serves as an independent predictor of survival outcomes in children with WT. Methods: A systematic query of PubMed, MEDLINE, Embase, Web of Science, the Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov was executed, covering the period from their earliest records through May 10, 2026. Retrospective cohort studies reporting hazard ratios (HRs) or risk ratios (RRs) for survival outcomes based on LNR in children with WT were included. Overall survival (OS) was the primary outcome; 5-year, 10-year, and 20-year OS were secondary outcomes. Prespecified subgroup analyses were performed by LNR cutoff (≥0.40 vs. <0.40). Results: Six retrospective cohort studies involving 4,190 patients met the inclusion criteria. High LNR was significantly associated with poorer overall survival (HR = 2.10; 95% CI: 1.67–2.64). This prognostic significance persisted across secondary outcomes, including 5-year OS (RR = 1.14; 95% CI: 1.11–1.17), 10-year OS (RR = 1.19; 95% CI: 1.15–1.23), and 20-year OS (RR = 1.14; 95% CI: 1.10–1.19).