Wilms Tumor

ImportanceNephron-sparing surgery can be considered in well-defined cases of unilateral and bilateral Wilms tumors, but the surgical procedure can be very challenging for the pediatric surgeon to perform.ObjectiveTo assess the added value of personalized 3-dimensional (3-D) kidney models derived from conventional imaging data to enhance preoperative surgical planning.Design, setting, and participantsIn a survey study, the conventional imaging data of 10 Dutch children with Wilms tumors were converted to 3-D prints and augmented reality (AR) holograms and a panel of pediatric oncology surgeons (n = 7) assessed the quality of the different imaging methods during preoperative evaluation. Kidney models were created with 3-D printing and AR using a mixed reality headset for visualization.Main outcomes and measuresDifferences in the assessment of 4 anatomical structures (tumor, arteries, veins, and urinary collecting structures) using questionnaires. A Likert scale measured differences between the imaging methods, with scores ranging from 1 (completely disagree) to 5 (completely agree).ResultsOf the 10 patients, 7 were girls, and the mean (SD) age was 3.7 (1.7) years. Compared with conventional imaging, the 3-D print and the AR hologram models were evaluated by the surgeons to be superior for all anatomical structures: tumor (median scores for conventional imaging, 4.07; interquartile range [IQR], 3.62-4.15 vs 3-D print, 4.67; IQR, 4.14-4.71; P = .008 and AR hologram, 4.71; IQR, 4.26-4.75; P = .002); arteries (conventional imaging, 3.62; IQR, 3.43-3.93 vs 3-D print, 4.54; IQR, 4.32-4.71; P = .002 and AR hologram, 4.83; IQR, 4.64-4.86; P Conclusions and relevanceIn this study, the 3-D kidney models were associated with improved anatomical understanding among the surgeons and can be helpful in future preoperative planning of nephron-sparing surgery for Wilms tumors. These models may be considered as a supplementary visualization in clinical care.

Cell-free DNA profiling using patient blood is emerging as a non-invasive complementary technique for cancer genomic characterization. Since these liquid biopsies will soon be integrated into clinical trial protocols for pediatric cancer treatment, clinicians should be informed about potential applications and advantages but also weaknesses and potential pitfalls. Small retrospective studies comparing genetic alterations detected in liquid biopsies with tumor biopsies for pediatric solid tumor types are encouraging. Molecular detection of tumor markers in cell-free DNA could be used for earlier therapy response monitoring and residual disease detection as well as enabling detection of pathognomonic and therapeutically relevant genomic alterations.Conclusion: Existing analyses of liquid biopsies from children with solid tumors increasingly suggest a potential relevance for molecular diagnostics, prognostic assessment, and therapeutic decision-making. Gaps remain in the types of tumors studied and value of detection methods applied. Here we review the current stand of liquid biopsy studies for pediatric solid tumors with a dedicated focus on cell-free DNA analysis. There is legitimate hope that integrating fully validated liquid biopsy-based innovations into the standard of care will advance patient monitoring and personalized treatment of children battling solid cancers.What is Known:• Liquid biopsies are finding their way into routine oncological screening, diagnosis, and disease monitoring in adult cancer types fast.• The most widely adopted source for liquid biopsies is blood although other easily accessible body fluids, such as saliva, pleural effusions, urine, or cerebrospinal fluid (CSF) can also serve as sources for liquid biopsiesWhat is New:• Retrospective proof-of-concept studies in small cohorts illustrate that liquid biopsies in pediatric solid tumors yield tremendous potential to be used in diagnostics, for therapy response monitoring and in residual disease detection.• Liquid biopsy diagnostics could tackle some long-standing issues in the pediatric oncology field; they can enable accurate genetic diagnostics in previously unbiopsied tumor types like renal tumors or brain stem tumors leading to better treatment strategies.

BackgroundChromosome translocations involving mixed lineage leukemia 1 (MLL1) cause acute leukemia in most infants and 5-10% children/adults with dismal clinical outcomes. Most frequent MLL1-fusion partners AF4/AFF4, AF9/ENL and ELL, together with CDK9/cyclin-T1, constitute super elongation complexes (SEC), which promote aberrant gene transcription, oncogenesis and maintenance of MLL1-rearranged (MLL1-r) leukemia. Notably, ENL, but not its paralog AF9, is essential for MLL1-r leukemia (and several other cancers) and therefore a drug target. Moreover, recurrent ENL mutations are found in Wilms tumor, the most common pediatric kidney cancer, and play critical roles in oncogenesis.MethodsProteolysis-Targeting Chimera (PROTAC) molecules were designed and synthesized to degrade ENL. Biological activities of these compounds were characterized in cell and mouse models of MLL1-r leukemia and other cancers.ResultsCompound 1 efficiently degraded ENL with DC50 of 37 nM and almost depleted it at ~ 500 nM in blood and solid tumor cells. AF9 (as well as other proteins in SEC) was not significantly decreased. Compound 1-mediated ENL reduction significantly suppressed malignant gene signatures, selectively inhibited cell proliferation of MLL1-r leukemia and Myc-driven cancer cells with EC50s as low as 320 nM, and induced cell differentiation and apoptosis. It exhibited significant antitumor activity in a mouse model of MLL1-r leukemia. Compound 1 can also degrade a mutant ENL in Wilms tumor and suppress its mediated gene transcription.ConclusionCompound 1 is a novel chemical probe for cellular and in vivo studies of ENL (including its oncogenic mutants) and a lead compound for further anticancer drug development.

Wilms tumor (WT), the most common kidney neoplasm in children, is closely associated with hereditary factors. This study included 134 WT patients (62 males, median age of 7 years, age at diagnosis of 24.9 months) with unilateral (n = 90, 67%) or bilateral WT (n = 44, 33%). Genetic testing was performed using targeted sequencing of 415 genes and multiplex ligation-dependent probe amplification (MLPA). Twenty-five mutations in eight genes were found in 17% (n = 23) of patients: WT1 (n = 10), TRIM28 (n = 4), REST (n = 3), CHEK2 (n = 3), BRCA2 (n = 2), NF1 (n = 1), RAD50 (n = 1), and CDC73 (n = 1). Large deletions of the 11p13 region were revealed in 6% (n = 5) of patients. The 11p15 locus methylation was studied in blood, tumor, and healthy kidney tissue of nine patients suspected of Beckwith-Wiedemann syndrome (BWS) using methylation-sensitive MLPA (MS-MLPA). BWS was diagnosed in 3% (n = 4) of cases (one patient had mosaic disease). Thus, genetic and epigenetic aberrations were identified in 32 WT patients (24%). These patients had a higher frequency of bilateral WT and a higher rate of abnormalities compared to patients without aberrations (56% vs. 25%, p = 0.002; and 86% vs. 25%, p < 0.0001, respectively). The detection of WT hereditary predisposing factors is crucial for treatment strategies and long-term patient surveillance.