Characteristics and Outcome of Children with Renal Tumors in the Netherlands: First Five Year Single National Center Experience

Abstract

Background and Aims: In the Netherlands, pediatric renal tumor care has been centralized in the Princess Máxima Center since 2015. To describe epidemiology, clinical characteristics and outcome of all dutch children that presented with a renal tumor in the first 5 years of centralized care. Methods: All patients presenting with suspicion of renal cancer were included after consent for data collection and storage of biomaterials. Results: From 2015-2020, 164 patients presented with renal tumours. One family refused consent, 163 remaining cases included Wilms tumour(WT)(n=118), nephroblastomatosis/nephrogenic rests(n=6), clear cell sarcoma of the kidney(CCSK)(n=2), malignant rhabdoid tumor of the kidney(MRTK)(n=7), renal cell carcinoma(RCC)(n=8), congenital mesoblastic nephroma(CMN)(n=5), cystic nephroma(CN)(n=5), cystic partially differentiated nephroblastoma(CPDN)(n=2), angiomyolipoma(n=5) and others(n=5). It appeared, that, all malignant renal tumor cases registered in the Dutch Cancer Registry in that period, were diagnosed in Princess Máxima Center. In 149/163 children, DWI-MRI was performed at presentation, and chest-CT was performed in 121/135 children with WT, CCSK, MRTK or RCC. Central radiology(before start of treatment) and pathology review was performed respectively in 118/163 patients and 151/152 (partial-)nephrectomized cases. Treatment stratification according to SIOP-RTSG protocols was established after agreement in the multidisciplinary tumor board. 19 patients had upfront surgery and 133 patients underwent pre-operative chemotherapy. Altogether, 135 underwent unilateral tumor nephrectomy, (n=17 nephron-sparing-surgery, n=11 no surgery). Of 133/152 patients, biomaterial was stored. Three WT patients and five metastatic MRTK patients died. Conclusions: Centralization of care for children with renal tumors in the Netherlands led to centralized care of all malignant renal tumor cases, in the Netherlands. Twenty-four percent of all presenting cases included non-WT. We established a multidisciplinary approach for all renal tumor patients, which allowed best available care based on standard review based diagnostics, and enabled development of molecular and other innovation based treatment for the future, that will further enhance survival.