Twenty-five year follow-up of childhood Wilms tumor: a report from the Childhood Cancer Survivor Study

Long-term kidney outcomes in survivors of Wilms tumor: a single-center retrospective cohort study

BACKGROUND

Several studies have investigated long-term kidney outcomes in survivors of Wilms tumor (WT). However, many have small sample sizes, and there is a wide variation in reported outcomes. The aim of this study is to investigate the long-term kidney outcomes in survivors of WT (S-WT), including those patients considered to be at high risk for poor kidney outcomes, and using updated estimated glomerular filtration rate (eGFR) equations.

METHODS

This was a retrospective chart review of 64 patients treated for WT at a single pediatric center. Patients were off treatment for 5 years or more at the time of analysis and were evaluated for decreased kidney function, hypertension, proteinuria, and compensatory hypertrophy of the contralateral kidney.

RESULTS

At a median follow-up time of 11.3 years off treatment (range 5-22.6) and average age of 16.7 years (range 6.5-30), 35 patients had a decreased eGFR (< 90 mL/min/1.73 m2), and 2 patients had progressed to chronic kidney disease stage 5. Compensatory hypertrophy was observed in 67% of cases. 41% of patients had elevated clinic blood pressures, with 2 patients on an anti-hypertensive medication. Three of 9 patients had evidence of hypertension on ambulatory blood pressure monitoring. Eight of 37 patients (22%) had proteinuria.

CONCLUSIONS

Kidney dysfunction is common in S-WT at a young age. This population should be carefully monitored for the development of decreased eGFR, hypertension, and proteinuria as part of their routine survivorship care. This is particularly true for modifiable risk factors of chronic kidney disease progression, such as hypertension and proteinuria.

Actinomycin D and bortezomib disrupt protein homeostasis in Wilms tumor

Wilms tumor is the most common kidney cancer in children, and diffuse anaplastic Wilms tumor is the most chemoresistant histological subtype. Here, we explore how Wilms tumor cells evade the common chemotherapeutic drug actinomycin D, which inhibits ribosomal RNA biogenesis. Using ribosome profiling, protein arrays, and a genome-wide knockout screen, we describe how actinomycin D disrupts protein homeostasis and blocks cell cycle progression. We found that, when ribosomal capacity is limited by actinomycin D treatment, anaplastic Wilms tumor cells preferentially translate proteasome components and upregulate proteasome activity. Based on these findings, we tested whether the proteasome inhibitor bortezomib sensitizes cells to actinomycin D treatment. Indeed, we found that the combination induces apoptosis both in vitro and in vivo and prolongs survival in xenograft models. Lastly, we show that increased levels of proteasome components are associated with anaplastic histology and worse prognosis in Wilms tumor patients. In sum, maintaining protein homeostasis is critical for Wilms tumor proliferation, and it can be therapeutically disrupted by blocking protein synthesis or turnover.

Methylation changes and INS-IGF2 expression predict progression in early-stage Wilms tumor

Wilms tumor, the most common pediatric kidney cancer, accounts for 5% of childhood cancers and is classified by stage and histological subtype. Despite high survival rates (80-85%), approximately 15% of patients experience relapse, reducing survival to around 50%. Epigenetic changes, particularly DNA methylation, play a critical role in Wilms tumor pathogenesis. This study investigates the prognostic potential of DNA methylation in stage I and II patients with favorable histology, aiming to identify early relapse biomarkers. Genome-wide methylation was assessed using methylation microarrays in tumor tissues from relapsed patients (n = 9) and those with complete responses (n = 9), alongside normal tissues (n = 3 each). Differentially methylated probes and regions were analyzed, with additional ROC and survival analyses. Real-time PCR was used to measure IGF2 and INS-IGF2 gene expression. The analysis revealed hypomethylation in intergenic regions in remission patients, identifying 14 differentially methylated positions as potential biomarkers. Increased INS-IGF2 expression was associated with relapse, suggesting its role in disease progression. While the study concentrated on stages I and II patients, where relapse rates are lower, this focus inherently led to a smaller sample size. Despite this, the findings provide valuable insights into the potential role of DNA methylation markers for monitoring disease progression and guiding personalized treatment in Wilms tumor patients.

Concomitant Wilms tumor and autosomal dominant polycystic kidney disease

BACKGROUND

Concomitant Wilms tumor (WT) and autosomal dominant polycystic kidney disease (ADPKD) is exceedingly rare, presenting a diagnostic and technical challenge to pediatric surgical oncologists. The simultaneous workup and management of these disease processes are incompletely described.

PROCEDURE

We performed a retrospective analysis of patients treated at our institution with concomitant diagnoses of WT and ADPKD. We also review the literature on the underlying biology and management principles of these conditions.

RESULTS

We present three diverse cases of concomitant unilateral WT and ADPKD who underwent nephrectomy. One patient had preoperative imaging consistent with ADPKD with confirmatory testing postoperatively, one was found to have contralateral renal cysts intraoperatively with confirmatory imaging post nephrectomy, and one was diagnosed in childhood post nephrectomy. All patients are alive at last follow-up, and the patient with longest follow-up has progressed to end-stage kidney failure requiring transplantation and dialysis in adulthood. All patients underwent germline testing and were found to have no cancer predisposition syndrome or pathogenic or likely pathogenic variants for WT.

CONCLUSION

Concomitant inheritance of ADPKD and development of WT are extremely rare, and manifestations of ADPKD may not present until late childhood or adulthood. ADPKD is not a known predisposing condition for WT. When ADPKD diagnosis is made by family history, imaging, and/or genetic testing before WT diagnosis and treatment, the need for extensive preoperative characterization of cystic kidney lesions in children and increased risk of post-nephrectomy kidney failure warrant further discussion of surgical approach and perioperative management strategies.

Immune checkpoint markers and tumour mutation burden in Wilms tumour: a study of 59 cases

Wilms tumour (WT) is the most common renal tumour in children, and studies of immune checkpoint inhibitors (ICIs) treatment and markers are limited in number. In this study we investigated the ICIs' related immune landscape by examining the expression of PD-L1, PD-1, CD8 and DNA mismatch repair (MMR) proteins by immunohistochemistry (IHC), tumour mutation burden (TMB), and correlations with histology and clinical outcome. Positive PD-L1 (SP263) expression was defined as modified combined positive score (CPS) ≥1. A total of 59 WTs (from 2000 to 2017), including eight (14.0%) with anaplasia, from 46 patients were analysed (45 primary and 14 metastatic). Thirteen WTs (13/59, 22%) were positive for PD-L1 (8 primary, 5 metastatic; CPS 1.11-3.42). Positive PD-L1 expression was associated with diffuse anaplasia (p<0.05) and significantly shorter progression-free survival (p<0.05) among WTs with favourable histology (n=39). CD8+ lymphocytes were present in all analysed WTs. A subset of CD8+ cells co-expressed PD-1, which was associated with favourable histology and treatment. MMR IHC stains identified two (2/18, 11%) WTs with isolated PMS2 loss. All six WTs analysed for TMB showed low mutation burden. We found CD8+ lymphocytes in all analysed WTs and identified a fraction of WT (17.8% of primary and 35.8% of metastatic) with positive PD-L1 CPS, suggesting potential response to ICIs in some patients.

UNC13B regulates the sensitivity of Wilms' tumor cells to doxorubicin by modulating lysosomes

Wilms' tumor is a malignant neoplasm where current medical advancements have significantly improved survival rates; however, challenges persist such as the resistance of the tumor to chemotherapy drugs like doxorubicin. This necessitates higher dosages, leading to decreased sensitivity. However, using high doses of doxorubicin can have late effects on the heart. Unc-13 homolog B (UNC13B) may be involved in the drug resistance in several tumors, yet its role in modulating drug sensitivity in Wilms' tumor remains unexplored. UNC13B levels were quantified using reverse transcription-qPCR and Western blotting. The half-maximal inhibitory concentration for doxorubicin, vincristine, and actinomycin-D was determined using CCK-8 assays. Cell cycle and apoptosis were analyzed using flow cytometry, and lysosomal changes were observed using Lyso-Tracker staining. The present study initially evaluated UNC13B expression levels in the Wilms' tumor 17.94 cell line. Additionally, through short hairpin RNA-mediated knockdown, changes in doxorubicin sensitivity in 17.94 Wilms' tumor cells were assessed. Concurrently, preliminary investigations into the role of UNC13B in regulating lysosomes was performed, revealing a significant positive association between UNC13B levels and lysosome formation in the 17.94 cell line. Lysosomes likely serve a role in the sensitivity of Wilms' tumor cell lines to drugs. Elevated UNC13B expression was observed in the 17.94 Wilms' tumor cell line compared to normal kidney cells. UNC13B knockdown also resulted in increased apoptosis levels upon doxorubicin treatment. Immunofluorescence revealed UNC13B localization within cellular vesicles, and its knockdown significantly decreased lysosome levels. Overall, the findings of the present study demonstrate that UNC13B regulates the sensitivity of the Wilms' tumor 17.94 cell line to doxorubicin by modulating lysosome formation within cells. The results suggest that UNC13B is likely an enriched target involved in lysosomal regulation in certain tumors, offering a new approach for optimizing chemotherapy in Wilms' tumor and other cancers with high UNC13B expression.

DROSHA Regulates Mesenchymal Gene Expression in Wilms Tumor

Wilms tumor, the most common pediatric kidney cancer, resembles embryonic renal progenitors. Currently, there are no ways to therapeutically target Wilms tumor driver mutations, such as in the microRNA processing gene DROSHA. In this study, we used a "multiomics" approach to define the effects of DROSHA mutation in Wilms tumor. We categorized Wilms tumor mutations into four mutational subclasses with unique transcriptional effects: microRNA processing, MYCN activation, chromatin remodeling, and kidney developmental factors. In particular, we find that DROSHA mutations are correlated with de-repressing microRNA target genes that regulate differentiation and proliferation and a self-renewing, mesenchymal state. We model these findings by inhibiting DROSHA expression in a Wilms tumor cell line, which led to upregulation of the cell cycle regulator cyclin D2 (CCND2). Furthermore, we observed that DROSHA mutations in Wilms tumor and DROSHA silencing in vitro were associated with a mesenchymal state with aberrations in redox metabolism. Accordingly, we demonstrate that Wilms tumor cells lacking microRNAs are sensitized to ferroptotic cell death through inhibition of glutathione peroxidase 4, the enzyme that detoxifies lipid peroxides. Implications: This study reveals genotype-transcriptome relationships in Wilms tumor and points to ferroptosis as a potentially therapeutic vulnerability in one subset of Wilms tumor.

Dosimetric Advantage of Combined IMRT for Whole Lung and Abdomen Irradiation for Wilms Tumor

Purpose

In patients with Wilms tumor with lung metastases, a cardiac-sparing intensity modulated radiation therapy (CS-IMRT) technique is increasingly being adopted for whole lung irradiation. However, the standard technique for flank and whole abdomen radiation remains 2-dimensional anterioposterior (AP), and overlap at the junction between the whole lung CS-IMRT and abdominal AP fields can result in overdose to normal organs. Here, we compared the dosimetry of patients who received whole lung irradiation and flank or abdominal radiation therapy with CS-IMRT with AP abdominal field (IMRT-AP) versus CS-IMRT with IMRT abdominal field (combined IMRT).

Methods and Materials

We retrospectively reviewed the radiation plans of 2 patients with Wilms tumor who received CS-IMRT and flank or whole abdomen irradiation with a combined IMRT approach. Comparison IMRT-AP plans were generated with equivalent target coverage of 95% receiving the prescribed dose. Maximum doses to normal organs were compared at the junctional overlap.

Results

Overlap at the junction between CS-IMRT and abdominal fields resulted in a significantly lower dose with combined IMRT plans compared with IMRT-AP plan. Differences in maximum doses (in cGy) to normal organs between combined IMRT versus IMRT-AP plans were most significant in the vertebral body (patient 1 = 1277 vs 2065; patient 2 = 1334 vs 2287), lungs (patient 1 = 1298 vs 2081; patient 2 = 1234 vs 1820), spinal cord (patient 1 = 1235 vs 1975; patient 2 = 1345 vs 2253), stomach (patient 1 = 1264 vs 1977; patient 2 = 1118 vs 2062), and liver (patient 1 = 1297 vs 1889; patient 2 = 1334 vs 2237).

Conclusions

The combined IMRT approach for Wilms patients who require whole lung and abdomen irradiation can provide more uniform dose distribution in the junction area and significantly lower doses to normal organs at the junctional overlap.

Systematic Review and Meta-analysis of Laparoscopic Versus Open Radical Nephrectomy for Paediatric Renal Tumors With Focus on Wilms' Tumor

OBJECTIVE

To summarize and evaluate the outcomes of laparoscopic radical nephrectomy (LRN) and compare its safety and efficacy with open radical nephrectomy (ORN) in pediatric renal tumors (RT) and Wilms' tumors (WT).

BACKGROUND

ORN is the gold standard treatment for pediatric RT, consisting predominantly of WT. LRN is gaining popularity but remains controversial in pediatric surgical oncology.

METHODS

A systematic search was performed for all eligible studies on LRN and comparative studies between LRN and ORN in pediatric RT and WT. Meta-analysis, subgroup analysis, and sensitivity analysis were conducted. The main endpoints were cancer-related outcomes and surgical morbidity. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.

RESULTS

No levels I to II studies were identified. LRN was feasible in nearly 1 in 5 pediatric RT and WT after neoadjuvant chemotherapy, with pooled mid-term oncological outcomes (<7% local recurrence, >90% event-free survival) comparable with those of ORN. There was no strong evidence of an increased risk of intraoperative tumor spillage, but lymph node harvest was inadequate in LRN. Large tumors crossing the ipsilateral spinal border were associated with a trend for intraoperative complications and positive margins. Pooled complications rate and hospital stay duration were similar between LRN and ORN. Long-term (>3 years) outcomes are unknown.

CONCLUSIONS

Available level III evidence indicates that LRN is a safe alternative to ORN for carefully selected cases, with similar spillage rates and mid-term oncological outcomes. However, there was no advantage in surgical morbidity and lymph node harvest was inadequate with LRN. Tumor-matched-group studies with long-term follow-up are required.

LEVEL OF EVIDENCE

Level III.

Single-cell transcriptomes of kidneys in a 6-month-old boy with Denys-Drash syndrome reveal stromal cell heterogeneity in the tumor microenvironment

Background

Denys-Drash syndrome (DDS) is a rare disease characterized with pseudohermaphroditism, nephroblastoma (also known as Wilms tumor), and diffuse mesangial sclerosis. The therapy for DDS is largely supportive, i.e. surgery and chemotherapy for Wilms tumor and renal replacement therapy. Due to the limited understanding of the pathogenesis, precision therapy for DDS is yet to be explored. We sought to explore the cellular components and interactions in kidney tissues from an infant with DDS.

Methods

Whole-exome sequencing was performed to examine the mutations associated with DDS. Single-cell RNA sequencing (scRNA-seq) was performed to explore the heterogenicity of kidney tissue samples.

Results

A 6-month-old infant with bilateral Wilms tumors and genital ambiguity was diagnosed as having DDS. Whole exome sequencing revealed a novel de novo mutation (p.F185fs*118) in exon 1 of WT1. scRNA-seq was performed in tissue samples from bilateral Wilms tumors and the normal kidney from this infant. Fibroblasts, myocytes, epithelial cells, endothelial cells, and mononuclear phagocytes (MPs) ranked at the top of the 31 135 total cells. Fibroblasts and myocytes were dominant in the Wilms tumor samples. In contrast, most epithelial cells and endothelial cells were found in normal kidney tissues. CD44 and TUBA1A were significantly changed in myocyte subclusters, which may contribute to chemotherapy drug resistance. Macrophages intensively interacted with cancerous cells, including fibroblasts, epithelial cells, and myocytes.

Conclusions

A novel mutation (p.F185fs*118) in exon 1 of WT1 was identified in an infant with DDS. scRNA-Seq revealed the heterogenicity of cellular components in Wilms tumors and kidney tissues, shedding light on the pathogenesis of DDS.

Crafting and Authenticating Prognostic Nomograms for Overall and Cancer-specific Survival in Pediatric Small Renal Masses: A Comprehensive Two-Decade Cohort Study

BACKGROUND

The intricate task of diagnosing and managing small renal masses (SRMs) has become progressively convoluted within the realm of clinical practice. Contemporary clinical prediction instruments may succumb to a gradual decay in precision, coupled with an absence of unambiguous guidelines to navigate patient management.

METHODS

This investigation was devised to formulate and authenticate nomograms for the overall survival (OS) and cancer- specific survival (CSS) among patients afflicted with SRMs. The study encompassed a cohort of 2558 pediatric patients diagnosed with SRMs over the period of 2000 to 2019. Independent prognostic indicators for OS and CSS, encompassing historical staging, chemotherapy regimens, surgical interventions, and pathological classifications, were ascertained through the employment of multivariate Cox proportional hazards regression analysis and backward stepwise selection.

RESULTS

Through the utilization of multivariate Cox regression models, nomograms for OS and CSS were meticulously crafted, demonstrating commendable discrimination and calibration within the training set (OS C-index: 0.762, CSS C-index: 0.779). The validation set further corroborated the exemplary discrimination and calibration of the nomograms. Moreover, these nomograms adeptly differentiated between patient groups at elevated and diminished risk levels.

CONCLUSION

The nomograms delineated in this research provide propitious predictive accuracy for overall survival and cancer-specific survival in patients suffering from pediatric SRMs, thereby contributing to refined risk stratification and steering the optimal therapeutic course of action. The necessity for supplementary validation prevails before the translation of these findings into clinical practice.

Hypertension in Wilms tumor

Wilms tumor (WT) represents over 90% of all pediatric kidney tumors. Children with WT often present acutely with hypertension which resolves in the short term after nephrectomy. However, WT survivors have increased long-term risk of hypertension, primarily due to decreased nephron mass after nephrectomy, with additional insults from possible exposure to abdominal radiation and nephrotoxic therapies. The diagnosis of hypertension may be improved by ambulatory blood pressure monitoring (ABPM), as several recent single-center studies have shown a substantial proportion of WT survivors with masked hypertension. Current gaps in knowledge include determining which WT patients may benefit from routine screening with ABPM, correlation of casual and ABPM parameters with cardiac abnormalities, and longitudinal assessment of cardiovascular and kidney parameters in relation to appropriate treatment of hypertension. This review aims to summarize the most recent literature on hypertension presentation and management at the time of WT diagnosis as well as the long-term hypertension risk and impact on kidney and cardiovascular outcomes in WT survivors.

Nephroblastoma in Older Adult: Case Report and Review of Literature

Introduction

Nephroblastoma, or Wilms' tumor, is a malignant renal neoplasm commonly found in children, is extremely rare in adults representing only 0.5% of all renal neoplasms. Adult Wilms tumor is rare, to our knowledge fewer than 300 cases have been reported in the English literature to date. However, in older adults after 60 years of age, only less than 45 cases have been reported. For this reason, treatment guidelines in adults still are lacking. Prognosis in nephroblastoma for adult patients is found to be worse than in children.

Case Presentation

We report the case of a 65-year-old female with lumbar fossa mass, flank pain and hematuria, and pathologic diagnosis of Wilms tumor. We performed nephrectomy. No adjuvant treatment was given. Our patient remains asymptomatic and without evidence of recurrence 12 months after the surgery.

Conclusion

Nephroblastoma in the elderly presents different clinical behavior and prognosis compared to nephroblastoma in children.

The association of miR-204 and mir-483 5p expression with clinicopathological features of Wilms tumor: Could this provide foresight?

BACKGROUND

Wilms tumor is the most common cancer of the kidney that occurs during childhood, and histologically, it mimics renal embryogenesis. With the development and improvement of up-to-date treatment protocols, the survival rates of Wilms tumor have increased. However, metastases or local relapses are still observed in 15% of patients. The search for reliable biomarkers to identify at-risk patients is ongoing to predict the variability in treatment success. Currently, the evaluation of clinical, histopathological and genetic features are common diagnostic methods; however, epigenetic features can be examined with microRNA expression analyses and might allow us to comment on the behavior of the tumor and treatment response.

METHODS

In this study, we aimed to evaluate the relationship between microRNA-204 and microRNA-483-5p expression with clinicopathological data and the effect on Wilms tumor survival. For this purpose, the expression levels of RNU6B, microRNA-204 and microRNA-483-5p were evaluated in tumor and normal tissue by qreal time-polymerase chain reaction. We also investigated the relationship between microRNA expression levels with the clinicopathological and histological features of Wilms tumor.

RESULTS AND CONCLUSION

The results of our study indicate that the relative expression levels of microRNA-204 in Wilms tumor tissues were significantly lower than that in adjacent normal tissues. By contrast, tumor tissue had a higher microRNA-483-5p expression than the corresponding normal tissues. A statistically significant difference between microRNA-204 expression level with age and the presence of anaplasia was observed. The upregulation of microRNA-483-5p was found to have a significant correlation with patients after preoperative chemotherapy and complete tumor necrosis. Taken together, our data suggest that microRNA-204 could play a critical role as a tumor suppressor, whereas microRNA-483-5p acts as an oncogene in Wilms tumor progression. More importantly, microRNA-204 might be a novel predictive biomarker for anaplastic histology and could be useful for developing therapeutic interventions targeting this marker.

Wilms tumor in horseshoe kidney with extensive vascular thrombosis: A case report

INTRODUCTION AND IMPORTANCE

Wilms tumor (WT), a prevalent pediatric renal malignancy (7 %), frequently intertwines with genitourinary anomalies. This unique report presents a case of WT combined with horseshoe Kidney and an extending atrial thrombus, emphasizing critical management considerations.

CASE PRESENTATION

A 3-year-old boy, experiencing flank pain and weight loss, manifested a WT linked to horseshoe Kidney, accompanied by an atrial thrombus. Neoadjuvant chemotherapy downsized the tumor and thrombus, enabling successful surgical intervention. Post-surgery, 27 weeks of adjuvant chemotherapy were administered. Over three years, follow-up exhibited renal recovery, no recurrence, and clear CT scans.

DISCUSSION

Prompt identification, precise imaging (via CT angiography), and multidisciplinary care are pivotal for managing WT in horseshoe Kidney cases. Preoperative chemotherapy notably reduced tumor and thrombus sizes, enhancing surgical feasibility. Long-term vigilance is essential for recurrence and treatment-related complications.

CONCLUSION

Effectively managing WT in horseshoe Kidneys demands timely recognition, meticulous imaging, and collaborative management. Successful outcomes highlight preoperative chemotherapy's benefits and underscore extended monitoring's significance in confirming sustained recovery.

Long-term nephrotoxicity in irradiated pediatric kidney tumor survivors: A systematic review

OBJECTIVE

Nephrotoxicity can occur as a side effect after treatment for kidney tumor in childhood. The use of radiotherapy (RT) has a potential additional effect.

METHODS

A systematic electronic literature search that combined childhood kidney cancer with different treatments and nephrotoxicity terms was performed in EMBASE. Studies were included based on the reporting of nephrotoxicity occurrence after treatment for kidney tumor during pediatric age, with 75% of participants being under the age of 25 years at the time of diagnosis, and having been treated with any type of kidney surgery, chemotherapy, and/or RT.

RESULTS

A pooled analysis did not show significant difference in estimated glomerular filtration rate between the group of patients who received RT compared with the group treated without RT (SMD -0.11 [95% CI -1.07-0.84] p = .733).

CONCLUSION

The current literature suggests that the use of RT does not have a significant impact on the decline of kidney function as independent factor.

Identification of key genes and validation of key gene aquaporin 1 on Wilms' tumor metastasis

BACKGROUND

Wilms' tumor (WT) is one of the most common solid tumors in children with unsatisfactory prognosis, but few molecular prognostic markers have been discovered for it. Many genes are associated with the occurrence and prognosis of WT. This study aimed to explore the key genes and potential molecular mechanisms through bioinformatics and to verify the effects of aquaporin 1 (AQP1) on WT metastasis.

METHODS

Differentially expressed genes (DEGs) were generated from WT gene expression data sets from the Gene Expression Omnibus (GEO) database. Gene functional enrichment analysis was carried out with the Database for Annotation, Visualization and Integrated Discovery (DAVID). A protein-protein interaction network (PPI) was constructed and visualized by the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database and Cytoscape software. Minimal Common Oncology Data Elements (MCODE) was used to detect the important modules in the PPI network, and the important nodes (genes) in the PPI module were sorted by CytoHubba. RT-qPCR was performed to validate the expression of the key genes in WT. Wound healing and Transwell assays were used to detect the cell migration and invasion abilities of AQP1-overexpressing cells. Phalloidin-iFlour 488 was used to stain the cytoskeleton to observe how AQP1 overexpression affects cytoskeletal microfilament structure.

RESULTS

A total of 73 co-expressed DEGs were chosen for further investigation. The importance of homeostasis and transmembrane transport of ions and water were highlighted by functional analysis. Gene regulatory network and PPI network were predicted. MCODE plug identified two important modules. Finally, top five key genes were identified using CytoHubba, including Renin (REN), nephrosis 2 (NPHS2), Solute Carrier Family 12 Member 3 (SLC12A3), Solute Carrier Family 12 Member 1 (SLC12A1) and AQP1. The five key genes were mainly enriched in cell volume and ion homeostasis. RT-qPCR confirmed the expression of the five key genes in WT. AQP1 was validated to be expressed at significantly lower levels in WT than in normal tissue. AQP1 overexpression significantly reduced the migratory and invasive capacity of Wit-49 cells, as evidenced by reducing the scratch healing rate and the number of perforated control cells by Wit-49 cells. AQP1 overexpression also reduced the expression of biomarkers of epithelial-mesenchymal transformation, decreased levels of vimentin and N-cadherin and increased expression of E-cadherin, resulting in decreased formation of conspicuous lamellipodial protrusions, characteristic of diminished WT cell invasion and migration.

CONCLUSION

Our study reveals the key genes of WT. These key genes may provide novel insight for the mechanism and diagnosis of WT. AQP1 overexpression inhibited invasion, migration, EMT, and cytoskeletal rearrangement of WT cells, indicating that AQP1 plays a role in the pathogenesis of WT.

RENAL nephrometry scoring system in bilateral Wilms tumor: predictive application

AIM

This study aims to explore the application of RENAL nephrometry scoring system in bilateral Wilms tumor (BWT).

METHODS

A retrospective review of patients with BWT from January 2010 to June 2022 was performed. Each kidney unit of the BWT was evaluated independently and scored according to RENAL nephrometry scoring system by 2 blinded reviewers, and reviewers were blinded to what surgery the patients ultimately had. Discrepancies were evaluated by a third reviewer to reach a consensus. Tumor anatomical characteristics were summarized and compared.

RESULTS

29 patients with 53 kidney units were included in the study. 53 kidney units included 12 (22.6%) low-complexity, 9 (17.0%) intermediate-complexity, and 32 (60.4%) high-complexity. 2 kidney units (3.8%) had tumor thrombus, and 14 (26.4%) had multiple lesions. A total of 42 kidney units (79.2%) underwent initial nephron-sparing surgery (NSS) and 11 (20.8%) underwent radical nephrectomy. Less complexity tumors were observed in the NSS group. Of the 42 kidney units undergoing initial NSS, 26 were performed in vivo and 16 ex vivo via autotransplantation. The latter group featured a higher complexity. During follow-up, 22 patients survived and 7 died, no statistically significant tumor complexity was observed between the two groups.

CONCLUSIONS

The anatomical characteristics of BWT are complex. Despite this study did not indicate that the complexity correlates with prognosis, low-complexity tumors were candidates for NSS, and kidney autotransplantation provided a feasible procedure for high-complexity tumors. A refined system is required due to multiple lesions and tumor thrombus.

Late Health Outcomes Among Survivors of Wilms Tumor Diagnosed Over Three Decades: A Report From the Childhood Cancer Survivor Study

PURPOSE

To evaluate long-term morbidity and mortality among unilateral, nonsyndromic Wilms tumor (WT) survivors according to conventional treatment regimens.

METHODS

Cumulative incidence of late mortality (≥ 5 years from diagnosis) and chronic health conditions (CHCs) were evaluated in WT survivors from the Childhood Cancer Survivor Study. Outcomes were evaluated by treatment, including nephrectomy combined with vincristine and actinomycin D (VA), VA + doxorubicin + abdominal radiotherapy (VAD + ART), VAD + ART + whole lung radiotherapy, or receipt of ≥ 4 chemotherapy agents.

RESULTS

Among 2,008 unilateral WT survivors, 142 deaths occurred (standardized mortality ratio, 2.9, 95% CI, 2.5 to 3.5; 35-year cumulative incidence of death, 7.8%, 95% CI, 6.3 to 9.2). The 35-year cumulative incidence of any grade 3-5 CHC was 34.1% (95% CI, 30.7 to 37.5; rate ratio [RR] compared with siblings 3.0, 95% CI, 2.6 to 3.5). Survivors treated with VA alone had comparable risk for all-cause late mortality relative to the general population (standardized mortality ratio, 1.0; 95% CI, 0.5 to 1.7) and modestly increased risk for grade 3-5 CHCs compared with siblings (RR, 1.5; 95% CI, 1.1 to 2.0), but remained at increased risk for intestinal obstruction (RR, 9.4; 95% CI, 3.9 to 22.2) and kidney failure (RR, 11.9; 95% CI, 4.2 to 33.6). Magnitudes of risk for grade 3-5 CHCs, including intestinal obstruction, kidney failure, premature ovarian insufficiency, and heart failure, increased by treatment group intensity.

CONCLUSION

With approximately 40% of patients with newly diagnosed WT currently treated with VA alone, the burden of late mortality/morbidity in future decades is projected to be lower than that for survivors from earlier eras. Nevertheless, the risk of late effects such as intestinal obstruction and kidney failure was elevated across all treatment groups, and there was a dose-dependent increase in risk for all grade 3-5 CHCs by treatment group intensity.

Stage I epithelial or stromal type Wilms tumors are low risk tumors: An analysis of patients treated on the SIOP-WT-2001 protocol in the UK-CCLG and GPOH studies (2001-2020)

BACKGROUND

Patients treated with preoperative chemotherapy with stage I intermediate-risk Wilms tumor (IR-WT) represent the largest group of patients with Wilms tumor (WT), and they have excellent outcomes.

METHODS

The authors performed a retrospective analysis of patients with stage I epithelial (ET-WT) or stromal type WT (ST-WT) treated pre- and postoperatively according to the International Society of Paediatric Oncology-WT-2001 protocol in the UK Children's Cancer and Leukaemia Group and Gesellschaft für Pädiatrische Onkologie und Hämatologie groups' participation in the relevant WT trials and studies (2001-2020).

RESULTS

There were 880 patients with stage I IR-WT, including 124 with ET-WT, 156 with ST-WT, and 600 with other IR-WT (oIR-WT). Patients with stage I ET-WT or ST-WT were significantly younger than patients with oIR-WT, represented a large proportion of stage I WTs in their groups, and tumors showed poor histologic response to preoperative chemotherapy. The 5-year event-free survival (EFS) estimates for patients with stage I ET-WT (96.8% ± 1.8 SE) or ST-WT (96.8% ± 1.6 SE) were significantly better than for patients with oIR-WT (90.3% ± 1.3 SE) (p = .014 and p = .009, respectively). A multivariate analysis showed that histologic type (ET-WT or ST-WT) remained a significant factor for EFS when adjusted for age and gender (p = .032 and p = .022, respectively). In both groups, relapses occurred in 3.2% of patients, and the overall survival was 99.2%.

CONCLUSIONS

The results suggest that stage I ET-WT or ST-WT could be regarded as low-risk WT, for which omission of postoperative chemotherapy should be considered.

PLAIN LANGUAGE SUMMARY

Patients with pretreated intermediate-risk Wilms tumor (WT) represent the largest group of patients with WT. This study reports the outcomes of patients with stage I epithelial type (ET-WT) or stromal type WT (ST-WT). These patients were significantly younger and had a larger proportion of stage I cases than patients with other intermediate-risk WT (oIR-WT). The event-free survival for patients with stage I ET-WT and ST-WT was significantly better than for patients with oIR-WT. Rare relapses were curable resulting in 99.2% overall survival.

A comparison between ultrasonography and single-phase computed tomography for preoperative assessment of solid abdominal tumors in children

OBJECTIVE

This study aimed to estimate the performance of single-phase-enhanced computed tomography and ultrasonography examinations in the preoperative evaluation of solid abdominal tumors and their relationship with relevant adjacent structures in children.

METHODS

This retrospective study included 50 pediatric patients with malignant solid abdominal tumors treated with surgical resection between 2009-2017. Preoperative computed tomography and ultrasonography were compared to operative findings (gold standard) in the diagnosis of invasion or encasement of adjacent structures. Accuracy, sensitivity, specificity, and positive and negative predictive values were evaluated.

RESULTS

Renal (20.4%) and neuroblastic (19.4%) tumors were the most common. Complete surgical resection with negative margins was achieved in 44 (88%) patients. The comparison between single-phase-enhanced computed tomography and ultrasonography findings showed the following results: sensitivity = 90.3% vs 86.6%, specificity = 86.8% vs 94.6%, negative predictive value = 95.3% vs 94.4%, positive predictive value = 75.3% vs 86.9%, and accuracy = 87.9% vs 92.2%. The correlation (kappa index) between computed tomography and ultrasonography examinations was 0.72 (p < 0.001). In 14% (7/50) of the patients, the invasion of adjacent structures was diagnosed by ultrasonography but not by computed tomography (1 patient had 2 invaded structures).

CONCLUSION

Ultrasonography can be considered a complementary method to single-phase-enhanced computed tomography in the preoperative evaluation of children with an abdominal tumor. The present study showed that ultrasonography and single-phase-enhanced computed tomography each possess a high accuracy in the preoperative planning of resection of solid abdominal tumors in children. Thus, it seems that the combination of both imaging methods would be enough for the evaluation of most abdominal tumors in the pediatric population.

Clinical Assessment of Late Health Outcomes in Survivors of Wilms Tumor

OBJECTIVES

We aimed to clinically characterize the health, neurocognitive, and physical function outcomes of curative treatment of Wilms tumor.

METHODS

Survivors of Wilms tumor (n = 280) participating in the St. Jude Lifetime Cohort, a retrospective study with prospective follow-up of individuals treated for childhood cancer at St. Jude Children's Research Hospital, were clinically evaluated and compared to age and sex-matched controls (n = 625). Health conditions were graded per a modified version of the National Cancer Institute's Common Terminology Criteria for Adverse Events. Standardized neurocognitive testing was graded by using age-adjusted z-scores. Impaired physical function was defined by age- and sex-matched z-scores >1.5 SD below controls. Modified Poisson regression was used to compare the prevalence of conditions and multivariable logistic regression to examine treatment associations.

RESULTS

Median age at evaluation was similar between survivors and controls (30.5 years [9.0-58.0] and 31.0 [12.0-70.0]). Therapies included nephrectomy (100%), vincristine (99.3%), dactinomycin (97.9%), doxorubicin (66.8%), and abdominal (59.3%) and/or chest radiation (25.0%). By age 40 years, survivors averaged 12.7 (95% confidence interval [CI] 11.7-13.8) grade 1-4 and 7.5 (CI: 6.7-8.2) grade 2 to 4 health conditions, compared to 4.2 (CI: 3.9-4.6) and 2.3 (CI: 2.1-2.5), respectively, among controls. Grade 2 to 4 endocrine (53.9%), cardiovascular (26.4%), pulmonary (18.2%), neurologic (8.6%), neoplastic (7.9%), and kidney (7.2%) conditions were most prevalent. Survivors exhibited neurocognitive and physical performance impairments.

CONCLUSIONS

Wilms tumor survivors experience a threefold higher burden of chronic health conditions compared to controls and late neurocognitive and physical function deficits. Individualized clinical management, counseling, and surveillance may improve long-term health maintenance.

Identification of hub genes and construction of prognostic nomogram for patients with Wilms tumors

Background

In children, Wilms' tumors are the most common urological cancer with unsatisfactory prognosis, but few molecular prognostic markers have been discovered for it. With the rapid development of high-throughput quantitative proteomic and transcriptomic approaches, the molecular mechanisms of various cancers have been comprehensively explored. This study aimed to uncover the molecular mechanisms underlying Wilms tumor and build predictive models by use of microarray and RNA-seq data.

Methods

Gene expression datasets were downloaded from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) and Gene Expression Omnibus (GEO) databases. Bioinformatics methods wereutilized to identified hub genes, and these hub genes were validated by experiment. Nomogram predicting OS was developed using genetic risk score model and clinicopathological variables.

Results

CDC20, BUB1 and CCNB2 were highly expressed in tumor tissues and able to affect cell proliferation and the cell cycle of SK-NEP-1 cells. This may reveal molecular biology features and a new therapeutic target of Wilms tumour.7 genes were selected as prognostic genes after univariate, Lasso, and multivariate Cox regression analyses and had good accuracy, a prognostic nomogram combined gene model with clinical factors was completed with high accuracy.

Conclusions

The current study discovered CDC20,BUB1 and CCNB2 as hub-genes associated with Wilms tumor, providing references to understand the pathogenesis and be considered a novel candidate to target therapy and construct novel nomogram, incorporating both clinical risk factors and gene model, could be appropriately applied in preoperative individualized prediction of malignancy in patients with Wilms tumor.

The clinical impact of observer variability in lung nodule classification in children with Wilms tumour

OBJECTIVES

To investigate the extent to which observer variability of computed tomography (CT) lung nodule assessment may affect clinical treatment stratification in Wilms tumour (WT) patients, according to the recent Société Internationale d'Oncologie Pédiatrique Renal Tumour Study Group (SIOP-RTSG) UMBRELLA protocol.

METHODS

I: CT thoraces of children with WT submitted for central review were used to estimate size distribution of lung metastases. II: Scans were selected for blinded review by five radiologists to determine intra- and inter-observer variability. They assessed identical scans on two occasions 6 months apart. III: Monte Carlo simulation (MCMC) was used to predict the clinical impact of observer variation when applying the UMBRELLA protocol size criteria.

RESULTS

Lung nodules were found in 84 out of 360 (23%) children with WT. For 21 identified lung nodules, inter-observer limits of agreement (LOA) for the five readers were ±2.4 and ±1.4 mm (AP diameter), ±1.9 and ±1.8 mm (TS diameter) and ±2.0 and ±2.4 mm (LS diameter) at assessments 1 and 2. Intra-observer LOA across the three dimensions were ±1.5, ±2.2, ±3.5, ±3.1 and ±2.6 mm (readers 1-5). MCMC demonstrated that 17% of the patients with a 'true' nodule size of ≥3 mm will be scored as <3 mm, and 21% of the patients with a 'true' nodule size of <3 mm will be scored as being ≥3 mm.

CONCLUSION

A significant intra-inter observer variation was found when measuring lung nodules on CT for patients with WT. This may have significant implications on treatment stratification, and thereby outcome, when applying a threshold of ≥3 mm for a lung nodule to dictate metastatic status.

Case report: Important considerations for a renal mass on a solitary kidney in an adult with history of childhood wilms tumor

Adult survivors of childhood Wilms tumor are at an increased risk of secondary malignant neoplasms. The presence of a solitary kidney further complicates clinical management in this population. Herein, we present the case of a 37 year old female with a history of childhood Wilms tumor presenting with a secondary renal neoplasm. We highlight important clinical considerations for renal function preservation and present a finding of predisposition to kidney stone formation due to urinary stasis from distorted ureter architecture secondary to tumor mass effect.

Late effects of childhood cancer treatment in long-term survivors diagnosed before the age of 3 years - A multicenter, nationwide study

BACKGROUND

The effect of age on the incidence of late sequelae that occur after anticancer treatment in childhood is still not fully elucidated. In this multicenter study of long-term survivors diagnosed before age of three, we investigated the prevalence of late effects many years after treatment.

METHODS

The study group (n = 561) was selected from the Polish National Childhood Cancer Survivors Registry (n = 1761) created in 2007. A survivor was defined as an individual who has survived at least 5 years after completion of anticancer treatment. All children were diagnosed between 1991 and 2016, mean age at diagnosis was 1.82 years (range 0.03-2.99) and median follow up time - 9.85 years (range 5.0-23.6). They were treated in accordance with international protocols approved by the Polish Pediatric Leukemia and Lymphoma Group and Polish Solid Tumor Group. Chemotherapy alone was used in 192 (34.2%), chemotherapy and radiotherapy - 56 (10%), chemotherapy and surgery - 176 (31.4%), chemotherapy, radiotherapy, and surgery - 79 (14.1%), and surgery alone in 58 patients (10.3%).

RESULTS

Of all patients enrolled to the study, only 94 (16.8%) had normal function of all organs. Seventy-six (13.5%) children developed dysfunction in one organ, another 83 (14.8%) had symptoms or complaints suggestive of dysfunction in two organs or systems, 88 (15.7%) had abnormalities in three organs, and 220 (39.2%) had at least four or more dysfunctions. In the entire study group, dysfunctions most frequently (> 20% of cases) involved the following organs/systems: circulatory - 21.8%, urinary - 30.8%, gastrointestinal - 20.8%, immune - 23.5%, vision - 20.7%, hearing - 21.8%, and oral and masticatory dysfunction - 26.9%. We did not find any significant differences in organ dysfunction between children diagnosed under the age of 1 and those diagnosed at the age of 1-3, except for a lower incidence of thyroid abnormalities (p = 0.007) and the higher prevalence of liver dysfunction in youngest patients. In the subset with longer follow-up period (> 10 years) more frequent thyroid abnormalities (p = 0.019), male (p = 0.002) and female (p = 0.026) gonads dysfunction, as well as musculoskeletal problems (p < 0.001) were observed. Among subjects who received radiotherapy compared to those who did not, short stature (p = 0.001), and dysfunction of the following systems/organs - circulatory (p = 0.049), urinary (p = 0.012), thyroid gland (p < 0.0001), nervous (p = 0.007), immunological (p = 0.002), liver (p = 0.03), dental or chewing difficulties (p = 0.001), hearing (p = 0.001) and musculoskeletal (p = 0.026) were more frequently reported. When multimodal therapy was applied (chemotherapy, radiotherapy, and surgery) a higher incidence of short stature (p = 0.007), urinary system disorders (p < 0.0001), thyroid dysfunction (p < 0.0001), hearing loss (p < 0.0001), and skin problems (p = 0.031) were observed.

CONCLUSION

This study confirms that radiotherapy and some specific toxicity of cytostatics are the most important factors affecting organ function. Apart from a higher incidence of liver dysfunction in the youngest patients, there were no significant differences in organ and system toxicities between children diagnosed under the age of 1 and those diagnosed at the age of 1-3. We have shown that this group requires systematic, careful and long-term follow-up.

Kidney disease in very long-term survivors of Wilms tumor: A nationwide cohort study with sibling controls

BACKGROUND

Survival after Wilms tumor has significantly increased and focus on late effects has become increasingly important. However, knowledge about long-term renal function in survivors of Wilms tumor is missing. Our aim was to investigate evidence of kidney disease in 20- or more-year survivors of Wilms tumor in a clinical setting, with siblings as comparisons.

METHODS

In this cross-sectional study, we established a cohort of Danish 20-plus-year survivors of Wilms tumor and siblings as controls. Participants answered a comprehensive health questionnaire supplemented by measurements of estimated glomerular filtration rate (eGFR), urine albumin-to-creatinine ratio, and blood pressure and were categorized according to the chronic kidney disease classification. Multiple linear regression analysis, taking family membership into account, was used to describe the differences in eGFR. Logistic regression analysis was performed to describe risk factors for the development of kidney disease.

RESULTS

We included 99 survivors of Wilms tumor and 38 sibling controls with a median of 37 years of follow-up. The eGFR of Wilms tumor survivors was 13 ml/min/1.73 m² (95% CI -20; -5) lower when compared to sibling control. Evidence of kidney disease, with risk factors as hypertension and diabetes, was found in 19% of the Wilms tumor survivors and 2% developed end-stage renal disease. Ninety-two percent of the Wilms tumor survivors had an eGFR >60 ml/min/1.73² .

CONCLUSION

Long-term Wilms tumor survivors have on average a significantly decreased renal function along with the increased prevalence of kidney disease and end-stage renal disease when compared to sibling controls. Still, most survivors had kidney function within the normal range.

Multidisciplinary Treatment Strategies for Wilms Tumor: Recent Advances, Technical Innovations and Future Directions

Significant progress has been made in the management of Wilms tumor (WT) in recent years, mostly as a result of collaborative efforts and the implementation of protocol-driven, multimodal therapy. This article offers a comprehensive overview of current multidisciplinary treatment strategies for WT, whilst also addressing recent technical innovations including nephron-sparing surgery (NSS) and minimally invasive approaches. In addition, surgical concepts for the treatment of metastatic disease, advances in tumor imaging technology and potentially prognostic biomarkers will be discussed. Current evidence suggests that, in experienced hands and selected cases, laparoscopic radical nephrectomy and laparoscopic-assisted partial nephrectomy for WT may offer the same outcome as the traditional open approach. While NSS is the standard procedure for bilateral WT, NSS has evolved as an alternative technique in patients with smaller unilateral WT and in cases with imminent renal failure. Metastatic disease of the lung or liver that is associated with WT is preferably treated with a three-drug chemotherapy and local radiation therapy. However, surgical sampling of lung nodules may be advisable in persistent nodules before whole lung irradiation is commenced. Several tumor markers such as loss of heterozygosity of chromosomes 1p/16q, 11p15 and gain of function at 1q are associated with an increased risk of recurrence or a decreased risk of overall survival in patients with WT. In summary, complete resection with tumor-free margins remains the primary surgical aim in WT, while NSS and minimally invasive approaches are only suitable in a subset of patients with smaller WT and low-risk disease. In the future, advances in tumor imaging technology may assist the surgeon in defining surgical resection margins and additional biomarkers may emerge as targets for development of new diagnostic tests and potential therapies.

Genetic changes associated with relapse in favorable histology Wilms tumor: A Children's Oncology Group AREN03B2 study

Over the last decade, sequencing of primary tumors has clarified the genetic underpinnings of Wilms tumor but has not affected therapy, outcome, or toxicity. We now sharpen our focus on relapse samples from the umbrella AREN03B2 study. We show that over 40% of relapse samples contain mutations in SIX1 or genes of the MYCN network, drivers of progenitor proliferation. Not previously seen in large studies of primary Wilms tumors, DIS3 and TERT are now identified as recurrently mutated. The analysis of primary-relapse tumor pairs suggests that 11p15 loss of heterozygosity (and other copy number changes) and mutations in WT1 and MLLT1 typically occur early, but mutations in SIX1, MYCN, and WTX are late developments in some individuals. Most strikingly, 75% of relapse samples had gain of 1q, providing strong conceptual support for studying circulating tumor DNA in clinical trials to better detect 1q gain earlier and monitor response.

Recommendations for the surveillance of education and employment outcomes in survivors of childhood, adolescent, and young adult cancer: A report from the International Late Effects of Childhood Cancer Guideline Harmonization Group

Educational achievement and employment outcomes are critical indicators of quality of life in survivors of childhood, adolescent, and young adult (CAYA) cancer. This review is aimed at providing an evidence-based clinical practice guideline (CPG) with internationally harmonized recommendations for the surveillance of education and employment outcomes in survivors of CAYA cancer diagnosed before the age of 30 years. The CPG was developed by a multidisciplinary panel under the umbrella of the International Late Effects of Childhood Cancer Guideline Harmonization Group. After evaluating concordances and discordances of 4 existing CPGs, the authors performed a systematic literature search through February 2021. They screened articles for eligibility, assessed quality, and extracted and summarized the data from included articles. The authors formulated recommendations based on the evidence and clinical judgment. There were 3930 articles identified, and 83 of them, originating from 17 countries, were included. On a group level, survivors were more likely to have lower educational achievement and more likely to be unemployed than comparisons. Key risk factors for poor outcomes included receiving a primary diagnosis of a central nervous system tumor and experiencing late effects. The authors recommend that health care providers be aware of the risk of educational and employment problems, implement regular surveillance, and refer survivors to specialists if problems are identified. In conclusion, this review presents a harmonized CPG that aims to facilitate evidence-based care, positively influence education and employment outcomes, and ultimately minimize the burden of disease and treatment-related late adverse effects for survivors of CAYA cancers. LAY SUMMARY: A multidisciplinary panel has developed guidelines for the surveillance of education and employment outcomes among survivors of childhood, adolescent, and young adult cancer. On the basis of evidence showing that survivors are at risk for lower educational achievement and unemployment, it is recommended that all survivors receive regular screening for educational and employment outcomes.

A Nomogram for Predicting Cancer-Specific Survival in Children With Wilms Tumor: A Study Based on SEER Database and External Validation in China

Background

Wilms tumor (WT) is the most common tumor in children. We aim to construct a nomogram to predict the cancer-specific survival (CSS) of WT in children and externally validate in China.

Methods

We downloaded the clinicopathological data of children with WT from 2004 to 2018 in the SEER database. At the same time, we used the clinicopathological data collected previously for all children with WT between 2013 and 2018 at Children's Hospital of Chongqing Medical University (Chongqing, China). We analyzed the difference in survival between the patients in the SEER database and our hospital. Cox regression analysis was used to screen for significant risk factors. Based on these factors, a nomogram was constructed to predict the CSS of children with WT. Calibration curve, concordance index (C-index), the area under the receiver operating curve (AUC) and decision curve analysis (DCA) was used to evaluate the accuracy and reliability of the model.

Results

We included 1,045 children with WT in the SEER database. At the same time, we collected 112 children with WT in our hospital. The Kaplan-Meier curve suggested that children in China with WT had a higher mortality rate than those in the United States. Cox regression analysis revealed that age, lymph node density (LND), and tumor stage were significant prognostic factors for the patients in the SEER database. However, the patients in our hospital only confirmed that the tumor stage and the number of positive regional lymph nodes were significant factors. The prediction model established by the SEER database had been validated internally and externally to prove that it had good accuracy and reliability.

Conclusion

We have constructed a survival prognosis prediction model for children with WT, which has been validated internally and externally to prove accuracy and reliability.

Bromodomain 4 inhibition leads to MYCN downregulation in Wilms tumor

BACKGROUND

Wilms tumor is the most common childhood kidney cancer. Two distinct histological subtypes of Wilms tumor have been described: tumors lacking anaplasia (the favorable subtype) and tumors displaying anaplastic features (the unfavorable subtype). Children with favorable disease generally have a very good prognosis, whereas those with anaplasia are oftentimes refractory to standard treatments and suffer poor outcomes, leading to an unmet clinical need. MYCN dysregulation has been associated with a number of pediatric cancers including Wilms tumor.

PROCEDURES

In this context, we undertook a functional genomics approach to uncover novel therapeutic strategies for those patients with anaplastic Wilms tumor. Genomic analysis and in vitro experimentation demonstrate that cell growth can be reduced by modulating MYCN overexpression via bromodomain 4 (BRD4) inhibition in both anaplastic and nonanaplastic Wilms tumor models.

RESULTS

We observed a time-dependent reduction of MYCN and MYCC protein levels upon BRD4 inhibition in Wilms tumor cell lines, which led to cell death and proliferation suppression. BRD4 inhibition significantly reduced tumor volumes in Wilms tumor patient-derived xenograft (PDX) mouse models.

CONCLUSIONS

We suggest that AZD5153, a novel dual-BRD4 inhibitor, can reduce MYCN levels in both anaplastic and nonanaplastic Wilms tumor cell lines, reduces tumor volume in Wilms tumor PDXs, and should be further explored for its therapeutic potential.

Myelin and lymphocyte protein serves as a prognostic biomarker and is closely associated with the tumor microenvironment in the nephroblastoma

Nephroblastoma, also known as Wilms' tumor (WT), is the most common renal tumor that occurs in children. Although the efficacy of treatment has been significantly improved by a series of comprehensive treatments, some patients still have poor prognosis. Myelin and lymphocyte (MAL) protein, a highly hydrophobic integrated membrane‐bound protein, has been implicated in many tumors and is also closely linked to kidney development. However, the relationship between MAL and WT has not yet been elucidated. Therefore, we attempted to evaluate the feasibility of MAL as a promising prognosis factor for WT. The differential expression of MAL was investigated using TARGET database and was verified using the Gene Expression Omnibus database and real‐time quantitative PCR. The prognostic ability of MAL was determined using Kaplan–Meier and Cox regression analyses. Pearson correlation analysis was applied to explore the relationship between MAL expression and methylation sites. The ESTIMATE and CIBERSORT algorithms showed that MAL expression was associated with the WT tumor microenvironment. Gene Set Enrichment Analysis (GSEA) indicated that multiple signaling pathways closely associated with tumorigenesis were differentially enriched between the high‐ and low‐MAL groups. In conclusion, our study comprehensively explored the potential of MAL as a prognosis factor for WT. Meanwhile, we also demonstrated that MAL, as a prognostic factor for WT, may be closely related to the tumor microenvironment.

DNA Methylation Data-Based Classification and Identification of Prognostic Signature of Children With Wilms Tumor

Background: As an epigenetic alteration, DNA methylation plays an important role in early Wilms tumorigenesis and is possibly used as marker to improve the diagnosis and classification of tumor heterogeneity.

Methods: Methylation data, RNA-sequencing (RNA-seq) data, and corresponding clinical information were downloaded from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. The prognostic values of DNA methylation subtypes in Wilms tumor were identified.

Results: Four prognostic subtypes of Wilms tumor patients were identified by consensus cluster analysis performed on 312 independent prognostic CpG sites. Cluster one showed the best prognosis, whereas Cluster two represented the worst prognosis. Unique CpG sites identified in Cluster one that were not identified in other subtypes were assessed to construct a prognostic signature. The prognostic methylation risk score was closely related to prognosis, and the area under the curve (AUC) was 0.802. Furthermore, the risk score based on prognostic signature was identified as an independent prognostic factor for Wilms tumor in univariate and multivariate Cox regression analyses. Finally, the abundance of B cell infiltration was higher in the low-risk group than in the high-risk group, based on the methylation data.

Conclusion: Collectively, we divided Wilms tumor cases into four prognostic subtypes, which could efficiently identify high-risk Wilms tumor patients. Prognostic methylation risk scores that were significantly associated with the adverse clinical outcomes were established, and this prognostic signature was able to predict the prognosis of Wilms tumor in children, which may be useful in guiding clinicians in therapeutic decision-making. Further independent studies are needed to validate and advance this hypothesis.

Wilms tumour

Wilms tumour (WT) is a childhood embryonal tumour that is paradigmatic of the intersection between disrupted organogenesis and tumorigenesis. Many WT genes play a critical (non-redundant) role in early nephrogenesis. Improving patient outcomes requires advances in understanding and targeting of the multiple genes and cellular control pathways now identified as active in WT development. Decades of clinical and basic research have helped to gradually optimize clinical care. Curative therapy is achievable in 90% of affected children, even those with disseminated disease, yet survival disparities within and between countries exist and deserve commitment to change. Updated epidemiological studies have also provided novel insights into global incidence variations. Introduction of biology-driven approaches to risk stratification and new drug development has been slower in WT than in other childhood tumours. Current prognostic classification for children with WT is grounded in clinical and pathological findings and in dedicated protocols on molecular alterations. Treatment includes conventional cytotoxic chemotherapy and surgery, and radiation therapy in some cases. Advanced imaging to capture tumour composition, optimizing irradiation techniques to reduce target volumes, and evaluation of newer surgical procedures are key areas for future research.

Systematic review of the immunological landscape of Wilms tumors

Results of immunotherapy in childhood solid cancer have been so far, with the exception of neuroblastoma, quite disappointing. Lack of knowledge of the immune contexture of these tumors may have contributed to the failure of immunotherapies so far. Here, we systematically reviewed the literature regarding the immunology of Wilms tumor (WT), one of the most frequent pediatric solid tumors of the abdomen. In Wilms tumor patients the high cure rate of >90%, achieved by the combination of surgery and radio-chemotherapy, is at the expense of a high early and late toxicity. Moreover, treatment-resistant entities, such as diffuse anaplastic tumors or recurrent disease, still pose unsolved clinical problems. Successful immunotherapy could represent a novel and possibly less-toxic treatment option. Employing the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) method of literature search, we analyzed the current knowledge of the immunological landscape of Wilms tumors in terms of tumor microenvironment, prognostic implications of single biomarkers, and immunotherapy response.

Factors influencing participation rates in clinical late-effect studies of childhood cancer survivors

To ensure external validation of a study population in clinical late-effect studies of childhood cancer, the participation rate must be high. This study investigated demographic data in Nordic late-effect studies and potential factors impacting participation rates such as cancer type, time since diagnosis, and duration of clinical examinations. We found 80 published studies originating from 16 cohorts, with median follow-up of 6.0 years (range 3-14). The overall participation rates ranged from 27% to 100%. The highest participation rates were seen in studies of survivors with solid tumors (92%) and the lowest in hematologic malignancies (67%) and central nervous system tumors (73%). The clinical examination in 10 studies (62.5%) lasted for more than 3 hours. Neither duration of the clinical examination nor time since diagnosis seemed to affect the participation rate. We encourage future studies to describe the recruitment process more thoroughly to improve understanding of the factors influencing participation rates.

Identification of CDC20 as a Novel Biomarker in Diagnosis and Treatment of Wilms Tumor

Objective: Wilms tumor (WT) is a common malignant solid tumor in children. Many tumor biomarkers have been reported; however, there are poorly targetable molecular mechanisms which have been defined in WT. This study aimed to identify the oncogene in WT and explore the potential mechanisms. Methods: Differentially expressed genes (DEGs) in three independent RNA-seq datasets were downloaded from The Cancer Genome Atlas data portal and the Gene Expression Omnibus database (GSE66405 and GSE73209). The common DEGs were then subjected to Gene Ontology enrichment analysis, protein-protein interaction (PPI) network analysis, and gene set enrichment analysis. The protein expression levels of the hub gene were analyzed by immunohistochemical analysis and Western blotting in a 60 WT sample. The univariate Kaplan-Meier analysis for overall survival was performed, and the log-rank test was utilized. A small interfering RNA targeting cell division cycle 20 (CDC20) was transfected into G401 and SK-NEP-1 cell lines. The Cell Counting Kit-8 assay and wound healing assay were used to observe the changes in cell proliferation and migration after transfection. Flow cytometry was used to detect the effect on the cell cycle. Western blot was conducted to study the changes of related functional proteins. Results: We commonly identified 44 upregulation and 272 downregulation differentially expressed genes in three independent RNA-seq datasets. Gene and pathway enrichment analyses of the regulatory networks involving hub genes suggested that cell cycle changes are crucial in WT. The top 15 highly connected genes were found by PPI network analysis. Furthermore, we demonstrated that one candidate biomarker, CDC20, for the diagnosis of WT was detected, and its high expression predicted poor prognosis of WT patients. Moreover, the area under the curve value obtained by receiver operating characteristic curve analysis from paired WT samples was 0.9181. Finally, we found that the suppression of CDC20 inhibited proliferation and migration and resulted in G2/M phase arrest in WT cells. The mechanism may be involved in increasing the protein level of securin, cyclin B1, and cyclin A Conclusion: Our results suggest that CDC20 could serve as a candidate diagnostic and prognostic biomarker for WT, and suppression of CDC20 may be a potential approach for the prevention and treatment of WT.

Wilms Tumor (Nephroblastoma), Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Wilms Tumor focus on the screening, diagnosis, staging, treatment, and management of Wilms tumor (WT, also known as nephroblastoma). WT is the most common primary renal tumor in children. Five-year survival is more than 90% for children with all stages of favorable histology WT who receive appropriate treatment. All patients with WT should be managed by a multidisciplinary team with experience in managing renal tumors; consulting a pediatric oncologist is strongly encouraged. Treatment of WT includes surgery, neoadjuvant or adjuvant chemotherapy, and radiation therapy (RT) if needed. Careful use of available therapies is necessary to maximize cure and minimize long-term toxicities. This article discusses the NCCN Guidelines recommendations for favorable histology WT.

Impact of the First Generation of Children's Oncology Group Clinical Trials on Clinical Practice for Wilms Tumor

Refinements in surgery, radiation therapy, and chemotherapy since the mid-20th century have resulted in a survival rate exceeding 90% for patients with Wilms tumor (WT). Although this figure is remarkable, a significant proportion of patients continue to have event-free survival (EFS) estimates of <75%, and nearly 25% of survivors experience severe chronic medical conditions. The first-generation Children's Oncology Group (COG) renal tumor trials (AREN '0'), which opened to enrollment in 2006, focused on augmenting treatment regimens for WT subgroups with predicted EFS <75% to 80%, including those with the adverse prognostic marker of combined loss of heterozygosity (LOH) at chromosomes 1p/16q, pulmonary metastasis with incomplete lung nodule response after 6 weeks of chemotherapy, bilateral disease, and anaplastic histology. Conversely, therapy was reduced for patient subgroups with good outcomes and potential for long-term toxicity, such as those with lung metastasis with complete lung nodule response after 6 weeks of chemotherapy. This article summarizes the key findings of the first-generation COG renal tumor studies and their implications for clinical practice.

Long-term follow-up of surgical outcomes for patients with Wilms tumor and neuroblastoma

BACKGROUND

There are minimal data on long-term surgical outcomes of patients who have undergone resection for Wilms tumor (WT) and neuroblastoma (NB).

METHODS

A retrospective review of patients in a long-term survivor clinic between the years 1967 and 2016 in a pediatric tertiary care hospital (>5 years posttreatment) was performed.

RESULTS

Eighty-six survivors of WT and 86 survivors of NB who had ongoing follow-up in the survivors' clinic were identified. The median age at diagnosis was 2.5 years (range, 0.4-15.7 years) with a mean follow-up of 22.3 years (±10.4 years) for WT. The median age at diagnosis for patients with NB was 0.9 years (range, 0.1-8.6 months); mean follow-up of 21.7 years (±7.9 years). Twelve patients with WT (14.0%) had at least 1 repeat laparotomy, 11.1% for bowel obstruction, at a median of 3 months from initial surgery. Twelve patients (14.0%) with NB required laparotomy and 8.1% for bowel obstruction, at a median of 12 years after initial surgery. The incidence of hypertension in patients with WT who had undergone nephrectomy was not outside of population norms. Patients who underwent thoracotomy for a NB have a higher incidence of scoliosis and Horner syndrome.

CONCLUSIONS

Small bowel obstruction requiring laparotomy is significantly higher than the literature norms for both tumor patient populations and typically occurs in the early postoperative period for patients with WT and remotely in patients with NB. The long-term surgical complications of patients who underwent resection for NB and WT clearly merit follow-up and patient education within multidisciplinary long-term survivorship clinics.

Estimated clinical benefit of combining highly conformal target volumes with Volumetric-Modulated Arc Therapy (VMAT) versus conventional flank irradiation in pediatric renal tumors

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Recently, flank target volumes adjusted for organ shift/motion have been defined.

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Highly conformal volumes with VMAT were compared to conventional volumes/beams.

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The new approach prevented a dose constraint violation of ≥ 1 OARs in 60% of cases.

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VMAT reduced the irradiated Total Body Volume receiving > 10% of the prescribed dose.

Background

For decades, Anterior-Posterior/Posterior-Anterior (AP/PA) photon beams were standard-of-care for flank irradiation in children with renal cancer. Recently, highly conformal flank target volumes were defined correcting for postoperative organ shift and intra-fraction motion.

By radiotherapy treatment plan comparison, this study aims to estimate the clinical benefits and potential risks of combining highly conformal target volumes with Volumetric-Modulated Arc Therapy (VMAT) versus conventional target volumes with AP/PA beams for flank irradiation.

Materials and Methods

Twenty consecutive renal tumor cases (left/right-sided:10/10; median age:3.2 years) were selected. Highly conformal flank target volumes were generated for VMAT, while conventional target volumes were used for AP/PA. For each case, the dose to the organs at risk (OARs) and Total Body Volume (TBV) was calculated to compare VMAT with AP/PA treatment plans for a prescribed dose (PD) of 14.4/1.8 Gy. Dose constraint violation of the tail of the pancreas and spleen (D_mean < 10 Gy), heart (D₅₀ < 5 Gy) or mammary buds (D_mean < 10 Gy) were prioritized as potentially beneficial for clinics.

Results

Highly conformal Planning Target Volumes (PTV) were smaller than conventional volumes (mean ΔPTV_AP/PA-PTV_VMAT: 555 mL, Δ60%, p=<0.01). A mean dose reduction favoring VMAT was observed for almost all OARs. Dose constraints to the tail of the pancreas, spleen, heart and mammary buds were fulfilled in 8/20, 12/20, 16/20 and 19/20 cases with AP/PA, versus 14/20, 17/20, 20/20 and 20/20 cases with VMAT, respectively. In 12/20 cases, VMAT prevented the dose constraint violation of one or more OARs otherwise exceeded by AP/PA. VMAT increased the TBV receiving 10% of the PD, but reduced the amount of irradiated TBV for all higher doses.

Conclusion

Compared to 14.4 Gy flank irradiation using conventional AP/PA photon beams, an estimated clinical benefit by dose reduction to the OARs can be expected in 60% of the pediatric renal tumor cases using highly conformal flank target volumes combined with VMAT.

Disease-specific hospitalizations among 5-year survivors of Wilms tumor: A Nordic population-based cohort study

BACKGROUND

With modern therapy, over 90% of Wilms tumor patients can expect to become long-term survivors, and focus on morbidity and late effects become increasingly important. We provide a novel evaluation and insight to subsequent hospitalizations in 5-year survivors of Wilms tumor.

METHODS

As part of the Adult Life after Childhood Cancer in Scandinavia (ALiCCS) study, we identified 5-year survivors of Wilms tumor. Based on stratified random sampling, we constructed a population comparison cohort. Outcomes of interest were overall hospitalizations; hospitalizations for specific organ systems and disease-specific categories. Standardized hospitalization rate ratios (SHRR) and absolute excess risks (AER) were calculated.

RESULTS

We included 913, 5-year survivors of Wilms tumor and 152 231 population comparisons. Survivors of Wilms tumor had an increased overall risk of being hospitalized (SHRR 1.8; 95% confidence interval (CI) 1.7-2.0). The hospitalization risk was increased within all major organ systems: urinary and genital organs (SHRR 2.5; 95% CI 2.1-3.0), endocrine (SHRR 2.5; 95% CI 1.9-3.3), cardiovascular (SHRR 2.2; 95% CI 1.7-2.9), and gastrointestinal (SHRR 1.5; 95% CI 1.3-1.8). Risks for specific diseases are reported in the study.

CONCLUSIONS

Survivors of Wilms tumor had higher risks than population comparisons for a wide range of diseases, with the highest risks seen for urinary, endocrine, and cardiovascular disorders. Five to 20 years after the Wilms tumor diagnosis, 43% of survivors had been hospitalized at least once versus 29% of population comparisons. The overall AER was 2.3, which translates into 0.2 extra hospitalizations in 10 years for every Wilms tumor survivor.

Locoregional control using highly conformal flank target volumes and volumetric-modulated arc therapy in pediatric renal tumors: Results from the Dutch national cohort

BACKGROUND AND PURPOSE

In pediatric renal tumors, conventional two opposing photon beams have been used to cover the postoperative flank target volume for decades. This single center study describes the locoregional outcome using highly conformal flank target volumes adjusted for postoperative changes and intra-fraction motion combined with Volumetric-Modulated Arc Therapy (VMAT).

MATERIALS AND METHODS

Between 01-2015 and 12-2019, 36/161 newly diagnosed patients with renal tumors underwent flank only irradiation (n = 30) or flank + whole lung irradiation (n = 6) using highly conformal target volumes in line with the SIOP-RTSG consensus statement. VMAT consisted of full-arc 10MV photon beams optimized for constraints of the organs at risk. In case of locoregional relapses, image co-registration and dose reconstruction was performed. Each relapse was classified as either 'infield' (V95%_relapse: ≥99.0%), 'marginal' (V95%_relapse: 20.0-98.9%) or 'outfield' (V95%_relapse: 0-19.9%).

RESULTS

At a median follow-up from diagnosis of 3.1 years (range:0.4-5.7), the estimated 2-year Locoregional Control Rate, Disease-Free Interval and Overall Survival were 94%, 91% and 94%, respectively. Locoregional relapse was observed in two patients. One patient had a combined tumor bed and regional recurrence, classified as infield (V95%_relapse: 100%) and outfield (V95%_relapse: 1.2%). The second patient had a regional relapse in the inferior vena cava classified as marginal recurrence (V95%_relapse: 93%). Relapses would not have been adequately covered by conventional beams.

CONCLUSIONS

This single center analysis provides encouraging evidence that excellent locoregional control can be obtained by using highly conformal flank target volumes with VMAT in pediatric renal tumors. The safety of this approach will be validated in a prospective multicenter study.

Cardiac-Sparing and Breast-Sparing Whole Lung Irradiation Using Intensity-Modulated Proton Therapy

PURPOSE

Whole lung irradiation (WLI) is indicated for certain pediatric patients with lung metastases. This study investigated whether WLI delivered as intensity-modulated proton therapy (IMPT) could significantly spare the heart and breasts when compared with conventional WLI delivered with anteroposterior/posteroanterior photon fields and with intensity-modulated photon therapy (IMRT) WLI.

MATERIALS AND METHODS

Conventional, IMRT, and IMPT plans were generated for 5 patients (aged 5-22 years). The prescription dose was 16.5 GyRBE in 1.5-GyRBE fractions. Conventional plans used 6-MV photons prescribed to the midline and a field-in-field technique to cover the planning target volume (the internal target volume [ITV] + 1 cm). IMRT plans used 6-MV photons with a 7-beam arrangement with dose prescribed to the planning target volume. IMPT plans used scenario-based optimization with 5% range uncertainty and 5-mm positional uncertainty to cover the ITV robustly. Monte Carlo dose calculation was used for all IMPT plans. Doses were compared with paired Student t test.

RESULTS

The ITV Dmean was similar for the IMPT, conventional, and IMRT plans, but the IMPT plans had a lower Dmin and a higher Dmax at tissue interfaces than conventional plans (Dmean ratio: 0.96, P > .05; Dmin ratio: 0.9, P < .001; Dmax ratio: 1.1, P = .014). Dmeans for breast and heart substructures were lower with IMPT plans than with conventional/IMRT plans (heart ratios, 0.63:0.73; left ventricle ratios, 0.61:0.72; right ventricle ratios, 0.45:0.57; left atrium ratios, 0.79:0.85; right atrium ratios, 0.81:0.86; left breast ratios, 0.40:0.51; right breast ratio, 0.46:0.52; all P < .05).

CONCLUSIONS

IMPT resulted in comparable ITV coverage and lower mean doses to the heart and breasts when compared with other techniques. Whole lung irradiation delivered as IMPT warrants prospective evaluation in pediatric patients.