Management and outcome of pediatric Wilms tumor with malignant inferior Vena cava thrombus: largest cohort of single-center experience

Abstract

Background Wilms tumor (WT) with an inferior Vena cava (IVC) malignant thrombus comprises 4–10% of all WT cases. Methods This retrospective analysis included 51 pediatric patients presenting at Children Cancer Hospital Egypt-57357 from July 2007 to December 2016 with the diagnosis of WT with malignant IVC thrombus. Results Median age at presentation=4.4 years and 28 cases (55%) were females. Twenty-fve patients (49%) were metastatic and 4 patients (7.8%) had bilateral disease. Forty-seven cases (92.2%) had favorable histology with no evidence of anaplasia. Level of thrombus extension at presentation was classifed as infra-hepatic, retro-hepatic, supra-hepatic and intra-cardiac in 33, 9, 6 and 3 patients, respectively. Fifty patients started neoadjuvant chemotherapy (CTH) with 16 patients showing complete resolution of thrombus after 6 weeks of CTH. None of the patients developed thrombus progression after neoadjuvant CTH; one patient had stationary intra-cardiac thrombus, while remaining patients showed partial regression of their thrombus and had nephrectomy with en-bloc thrombectomy. The mean cranio-caudal dimension of IVC thrombi at initial presentation was 6.5 cm, and 3.6 cm post 6th week of CTH. The 5-year OS and EFS were 75.9% and 71.1%, respectively. There was no signifcant correlation of initial levels of thrombus extension with survival. Conclusion Neoadjuvant chemotherapy followed by radical nephrectomy with en-bloc thrombectomy and radiotherapy seems a successful approach for management of patients with WT and IVC tumor thrombus. Measurement of the cranio-caudal dimension of thrombus and its response to treatment should be considered in the surgical planning.