Radical upfront nephrectomy in children with Wilms tumors. Do tumor’s size and laterality matter? A case series

Background: Children’s Oncology Group (COG) has set one of the two internationally recognized guidelines for the treatment of children with Wilms tumors (WTs). Their guidelines recommend upfront radical nephrectomy without preoperative chemotherapy. The study assessed the risk of intraoperative tumor spillage in correlation with the tumor’s size and laterality. Patients and methods: A prospective case series study was conducted during the period from April 2018 to April 2024 and included all children with unilateral WTs who were candidate for upfront radical nephrectomy. Exclusion criteria included those patients who were not candidate for this therapeutic option as per the guidelines of COG. Recorded data included age and sex at time of presentation, tumor size and laterality, and any incident of intraoperative spillage. Patients were grouped according to tumor’s maximum diameter (TMD); into those with TMD ≥12 cm, and those with TMD <12 cm, and according to tumor laterality into those with right-sided lesions, and those with left-sided lesions. Results: A total of 17 patients were enrolled, of whom 8 (47.1%) had right-sided lesions. TMD was ≥12 cm in 14 (82.4%) patients. Radical nephrectomy with the tumor capsule intact was achieved in 16 (94.1%) patients. Intraoperative spillage, which represents rupture of the tumor capsule during resection, was reported in only 1 (5.9%) patient. There was no statistical significance correlating the risk of intraoperative spillage with the tumor size or laterality in the studied patients. Conclusion: Based on the results of this study, there is no statistical significance correlating the risk of intraoperative spillage with the tumor size or laterality. However, surgeons should be careful when resecting large tumors of ≥20 cm in their maximum diameter as the risk of spillage is more in such cases.