IntroductionThe markers of inflammation such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) have been found associated with survival in cancer patients. The aim of the current study was to establish the prognostic significance of simple laboratory markers of systemic inflammation in paediatric patients diagnosed with Wilms tumour. Additionally, we aimed to compare the CBC parameters of WT patients and the non-oncological control group.Material and methodsThe study group included 83 children diagnosed with WT. Clinicopathological data, as well as complete blood count (CBC), C-reactive protein (CRP) and lactate dehydrogenase (LDH) levels at diagnosis, were obtained. Additionally, the laboratory results of healthy 63 control paediatric patients were collected. Uni- and multivariate proportional Cox’s hazard analyses were computed to create a model predicting relapse-free survival (RFS) and overall survival (OS) in the study group.ResultsHigh CRP, LDH, and NLR were associated with a higher stage of WT and shorter RFS; whereas all parameters correlated with OS. In multivariate analysis, only LDH levels had adverse significance in predicting RFS. C-reactive protein and LMR retained their prognostic value in the multivariate model predicting OS. Comparing the WT group with controls, high LDH, high CRP, high NLR, and high PLR were associated with WT presence.ConclusionsPreoperative LDH, CRP, NLR, PLR, and LMR have significant prognostic value in patients with WT independently of age and stage. Combined low CRP and high LMR identified the group of patients with excellent OS. Patients with high LDH were characterized by the highest risk of relapse.