The Impact of Lymph Node Ratio for Children with Wilms Tumors: A National Cancer Database Analysis.

Background: Lymph node status is a prognostic factor in Wilms tumor, and adequate lymph node sampling is strongly recommended. This study investigates the impact of lymph node ratio (LNR) (number of positive to examined lymph nodes) on overall survival in children with resected Wilms tumors. Methods: This retrospective National Cancer Database analysis included children (<18 years) who underwent resection with lymph node sampling for unilateral, non-metastatic Wilms tumor. Results: Among 2206 patients, the median age was three years, the median tumor size was 10.5 cm, and the median number of examined nodes was five. A total of 82.1% of patients had an LNR of 0, 5.4% had an LNR < 0.2, and 12.5% had an LNR ≥ 0.2. In multivariable Cox regression, LNR ≥ 0.2 was associated with worse survival (HR = 1.75, 95%CI: 1.03-2.97, p = 0.04), along with increasing age (HR = 1.11, 95%CI: 1.05-1.17, p < 0.001) and tumor size (HR = 1.03, 95%CI: 1.00-1.06, p = 0.03). Conclusions: LNR is an independent prognostic factor in Wilms tumor and may refine risk stratification and guide treatment decisions.