Prognostic Value of Pre-Treatment Systemic Inflammatory Markers in Pediatric Unilateral Wilms Tumor

Background: Systemic inflammation has been implicated in prognosis of multiple malignancies, yet evidence regarding its role in Wilms Tumor (WT) remains scarce. We investigated the prognostic significance of pre-treatment inflammatory markers in unilateral WT. Methods: We conducted a retrospective analysis of children with unilateral WT treated at our institution between November 2014 and December 2023. Clinical characteristics, treatment, and outcomes were evaluated. Inflammatory markers included a novel pan-immune-inflammation value (PIV), neutrophil-to-lymphocyte ratio (NLR), and lymphocyte-to-monocyte ratio (LMR). Optimal cut-off values for Event-Free Survival (EFS) and Overall survival (OS) were determined using data-derived optimization to maximize survival curve separation (surv_cutpoint). Cox proportional hazards models were used for survival analysis, while ROC curves were used to calculate AUC values and confirm optimal cut-off points. Results: We included 91 patients (median age: 3.6 years; 62% female), of whom 34% presented with metastasis. Higher EFS was significantly associated with low PIV (cut-off 288.9), low NLR (cut-off 1.1), and high LMR (cut-off 6.3). Similarly, OS was positively associated with lower PIV (HR 8.56 for high PIV, p = 0.038) and lower NLR (HR 4.63 for high NLR, p = 0.043). ROC analysis confirmed their discriminative ability; when evaluated at the unified survival cutpoints, LMR yielded an AUC of 0.692 for 5-year mortality (at cut-off 6.3), while NLR yielded an AUC of 0.671 for 5-year events (at cut-off 1.1). Conclusions: Pre-treatment inflammatory markers demonstrate significant prognostic value in unilateral WT. Elevated NLR and PIV, along with lower LMR, correlate with poorer survival. These accessible biomarkers provide a valuable, low-cost tool for risk assessment. Our optimal thresholds differed from Western adult cohorts, emphasizing the need for population-specific reference intervals in global pediatric oncology.