Wilms' tumor

[Identification of key genes in Wilms tumor based on high-throughput RNA sequencing and their impacts on prognosis and immune responses]

OBJECTIVE

To identify the key genes differentially expressed in Wilms tumor and analyze their potential impacts on prognosis and immune responses of the patients.

METHODS

High-throughput RNA sequencing was used to identify the differentially expressed mRNAs in clinical samples of Wilms tumor and paired normal tissues, and their biological functions were analyzed using GO, KEGG and GSEA enrichment analyses. The hub genes were identified using STRING database, based on which a prognostic model was constructed using LASSO regression. The mutations of the key hub genes were analyzed and their impacts on immunotherapy efficacy was predicted using the cBioPortal platform. RT-qPCR was used to verify the differential expressions of the key hub genes in Wilms tumor.

RESULTS

Of the 1612 differentially expressed genes identified in Wilms tumor, 1030 were up-regulated and 582 were down-regulated, involving mainly cell cycle processes and immune responses. Ten hub genes were identified, among which 4 genes (TP53, MED1, CCNB1 and EGF) were closely related to the survival of children with Wilms tumor. A 3-gene prognostic signature was constructed through LASSO regression analysis, and the patients stratified into with high- and low-risk groups based on this signature had significantly different survival outcomes (HR=1.814, log-rank P=0.002). The AUCs of the 3-, 5- and 7-year survival ROC curves of this model were all greater than 0.7. The overall mutations in the key hub genes or the individual mutations in TP53/CCNB1 were strongly correlated with a lower survival rates, and a high TP53 expression was correlated with a poor immunotherapy efficacy. RT-qPCR confirmed that the key hub genes had significant differential expressions in Wilms tumor tissues and cells.

CONCLUSION

TP53 gene plays an important role in the Wilms tumor and may potentially serve as a new immunotherapeutic biomarker as well as a therapeutic target.

Race and Ethnic Group Enrollment and Outcomes for Wilms Tumor: Analysis of the Current Era Children's Oncology Group Study, AREN03B2

BACKGROUND

To review race and ethnic group enrollment and outcomes for Wilms tumor (WT) across all 4 risk-assigned therapeutic trials from the current era Children's Oncology Group Renal Tumor Biology and Risk Stratification Protocol, AREN03B2.

STUDY DESIGN

For patients with WT enrolled in AREN03B2 (2006 to 2019), disease and biologic features, therapeutic study-specific enrollment, and event-free (EFS) and overall (OS) 4-year survival were compared between institutionally reported race and ethnic groups.

RESULTS

Among 5,146 patients with WT, no statistically significant differences were detected between race and ethnic groups regarding subsequent risk-assigned therapeutic study enrollment, disease stage, histology, biologic factors, or overall EFS or OS, except the following variables: Black children were older and had larger tumors at enrollment, whereas Hispanic children had lower rates of diffuse anaplasia WT and loss of heterozygosity at 1p. The only significant difference in EFS or OS between race and ethnic groups was observed among the few children treated for diffuse anaplasia WT with regimen UH-1 and -2 on high-risk protocol, AREN0321. On this therapeutic arm only, Black children showed worse EFS (hazard ratio = 3.18) and OS (hazard ratio = 3.42). However, this finding was not replicated for patients treated with regimen UH-1 and -2 under AREN03B2 but not on AREN0321.

CONCLUSIONS

Race and ethnic group enrollment appeared constant across AREN03B2 risk-assigned therapeutic trials. EFS and OS on these therapeutic trials when analyzed together were comparable regarding race and ethnicity. Black children may have experienced worse stage-specific survival when treated with regimen UH-1 and -2 on AREN0321, but this survival gap was not confirmed when analyzing additional high-risk AREN03B2 patients.

Long-Term Outcomes After Abdominal Radiation for Wilms Tumor: A 20-Year Experience

BACKGROUND

As radiation therapy (RT) for Wilms tumor (WT) evolves with more conformal techniques, it is necessary to evaluate patterns of failure and toxicity. We sought to determine the rate of local failure (LF) after abdominal RT in WT, specifically focusing on those with contained rupture treated with whole abdominal and pelvic RT (WAPRT) vs flank RT. Secondary objectives were to determine overall survival (OS), distant failure (DF), and late toxicities.

METHODS

A single institution retrospective study of 54 pediatric patients with WT treated with abdominal RT between May 2000 and October 2022. LF and DF were calculated through cumulative incidence function and OS by Kaplan-Meier method.

RESULTS

The median age was 4.5 years and the median follow-up was 6 years. Most patients (91%) had favorable histology. Only 1 patient experienced LF, 15 months from completion of RT (cumulative incidence 2% at 5 y). All patients who received unilateral flank radiation for contained rupture/spillage (n=13) experienced long-lasting intra-abdominal tumor control. A total of 5 patients experienced a DF at a median of 7 months, all in the lung. No patient relapsed in the lungs after upfront whole lung irradiation (n=16). OS was 96% at 5 years. Among 28 patients who followed through puberty, 4 female patients with prior WAPRT experienced hormonal irregularities/infertility.

CONCLUSIONS

Unilateral flank radiation may be a viable alternative to WAPRT for contained rupture/spillage and should be further explored prospectively. Our results may also be utilized in the future for outcome and toxicity comparison as conformal radiation techniques evolve.

Immune-related gene signature associates with immune landscape and predicts prognosis accurately in patients with Wilms tumour

Wilms tumour (WT) is the most common kidney malignancy in children. Chemoresistance is the leading cause of tumour recurrence and poses a substantial therapeutic challenge. Increasing evidence has underscored the role of the tumour immune microenvironment (TIM) in cancers and the potential for immunotherapy to improve prognosis. There remain no reliable molecular markers for reflecting the immune landscape and predicting patient survival in WT. Here, we examine differences in gene expression by high-throughput RNA sequencing, focused on differentially expressed immune-related genes (IRGs) based on the ImmPort database. Via univariate Cox regression analysis and Lasso-penalized Cox regression analysis, IRGs were screened out to establish an immune signature. Kaplan-Meier curves, time-related ROC analysis, univariate and multivariate Cox regression studies, and nomograms were used to evaluate the accuracy and prognostic significance of this signature. Furthermore, we found that the immune signature could reflect the immune status and the immune cell infiltration character played in the tumour microenvironment (TME) and showed significant association with immune checkpoint molecules, suggesting that the poor outcome may be partially explained by its immunosuppressive TME. Remarkably, TIDE, a computational method to model tumour immune evasion mechanisms, showed that this signature holds great potential for predicting immunotherapy responses in the TARGET-wt cohort. To decipher the underlying mechanism, GSEA was applied to explore enriched pathways and biological processes associated with immunophenotyping and Connectivity map (CMap) along with DeSigN analysis for drug exploration. Finally, four candidate immune genes were selected, and their expression levels in WT cell lines were monitored via qRT-PCR. Meanwhile, we validated the function of a critical gene, NRP2. Taken together, we established a novel immune signature that may serve as an effective prognostic signature and predictive biomarker for immunotherapy response in WT patients. This study may give light on therapeutic strategies for WT patients from an immunological viewpoint.

Management of intravascular thrombus in cases of bilateral Wilms tumor or horseshoe kidney

PURPOSE

To describe the oncologic and surgical management of bilateral Wilms tumor or Wilms tumor arising in a horseshoe kidney with intravenous tumor thrombus to help pediatric surgeons negotiate this rare and difficult anatomic circumstance.

METHODS

A single-institution, retrospective medical record review identified 4 cases of bilateral WT and one case of WT arising in a horseshoe kidney with intravenous tumor thrombus between 2009 and 2021. The presentation, imaging, chemotherapy regimen, intraoperative approach, and surgical and oncologic outcomes were reviewed for each of these patients.

RESULTS

All patients received a total of 12 weeks of neoadjuvant chemotherapy. In two patients, a staged approach to the bilateral tumors was undertaken with the first side being operated on after six weeks of therapy and the other side undergoing surgery after an additional six weeks of therapy. Of five patients, four underwent nephron-sparing surgery of all tumors and one underwent unilateral radical nephroureterectomy with contralateral nephron-sparing surgery. Tumor thrombectomy was performed in four of five cases; one patient demonstrated a complete response of the intravenous tumor thrombus to neoadjuvant chemotherapy and did not require thrombectomy. Three patients received adjuvant flank radiotherapy. Three patients developed medically managed stage II or III chronic kidney disease and no patient required renal replacement therapy or kidney transplant to date.

CONCLUSION

Nephron-sparing surgery is feasible and safe to perform in selected cases of bilateral Wilms tumor with intravascular thrombus by utilizing three-drug neoadjuvant chemotherapy, staged approaches to each kidney when appropriate, and detailed preoperative and/or intraoperative mapping of renal venous anatomy. Successful nephron-sparing surgery with tumor thrombectomy is dependent on a branched renal venous system or the presence of accessory renal veins.

LEVEL OF EVIDENCE

Level 4.

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.

Incidence and Management of Pleural Effusions in Patients with Wilms Tumor: A Pediatric Surgical Oncology Research Collaborative Study

Wilms tumor (WT) is the most common renal malignancy in children. Children with favorable histology WT achieve survival rates of over 90%. Twelve percent of patients present with metastatic disease, most commonly to the lungs. The presence of a pleural effusion at the time of diagnosis of WT may be noted on staging imaging; however, minimal data exist regarding the significance and prognostic importance of this finding. The objectives of this study are to identify the incidence of pleural effusions in patients with WT, and to determine the potential impact on oncologic outcomes. A multi-institutional retrospective review was performed from January 2009 to December 2019, including children with WT and a pleural effusion on diagnostic imaging treated at Pediatric Surgical Oncology Research Collaborative (PSORC) participating institutions. Of 1,259 children with a new WT diagnosis, 94 (7.5%) had a pleural effusion. Patients with a pleural effusion were older than those without (median 4.3 vs 3.5 years; p=0.004), and advanced stages were more common (local stage III 85.9% vs 51.9%; p<0.0001). Only 14 patients underwent a thoracentesis for fluid evaluation; 3 had cytopathologic evidence of malignant cells. Event-free and overall survival of all children with WT and pleural effusions was 86.2% and 91.5%, respectively. The rate and significance of malignant cells present in pleural fluid is unknown due to low incidence of cytopathologic analysis in our cohort; therefore, the presence of an effusion does not appear to necessitate a change in therapy. Excellent survival can be expected with current stage-specific treatment regimens.

Incidence patterns of childhood non-Wilms renal tumors: Comparing data of the Nationwide Registry of Childhood Hematological Malignancies and Solid Tumors (NARECHEM-ST), Greece, and the Surveillance, Epidemiology, and End Results Program (SEER), USA

BACKGROUND

We used, for the first time, data registered in the Nationwide Registry for Childhood Hematological Malignancies and Solid Tumors (NARECHEM-ST)-Greece to estimate incidence/time trends of the rare childhood (0-14 years) non-Wilms tumors (non-WT), and compared the results of malignant non-WT to those from the Surveillance, Epidemiology, and End Results Program (SEER)-USA.

METHODS

Fifty-five cases (n = 33 malignant-only) were extracted from NARECHEM-ST (2001-2020) and 332 malignant cases from SEER (1990-2017). To allow between-country comparisons, age-standardized incidence rates (AIR) of malignant-only non-WT were calculated, and temporal trends were evaluated using Poisson and joinpoint regressions.

RESULTS

In NARECHEM-ST, malignant and non-malignant non-WT accounted for 22.6% of all renal tumors. Among malignant tumors, the AIR was 1.0/106 children in Greece, similar to that calculated for SEER, USA (AIR=0.9/106). The proportion of infant malignant and non-malignant non-WT was 27% (20% before 6 months) in NARECHEM-ST. Most common non-WT in Greece were congenital mesoblastic nephromas (CMN) diagnosed mainly in infancy (CIR=7.2/106). The proportion of infant malignant non-WT was 20% in SEER (AIRinfancy=2.5/106), mainly attributed to rhabdoid tumors (CIR=1.6/106). The male-to-female (M:F) ratio of malignant non-WT was 0.9 in NARECHEM-ST vs. 1.2 in SEER, whereas boys outnumbered girls with clear cell sarcoma in NARECHEM-ST (M:F=4.0). Lastly, significantly increasing trends in incidence rates were noted in NARECHEM-ST [+ 6.8%, 95% confidence intervals (CI): 0.5, 13.3] and in SEER (+7.3%, 95%CI: 5.6, 9.0).

CONCLUSIONS

Observed incidence, time trends and sociodemographic variations of non-WT may reflect differential registration practices and healthcare delivery patterns including differences regarding surveillance, coding and treatment practices.

The Regulatory Network and Role of the circRNA-miRNA-mRNA ceRNA Network in the Progression and the Immune Response of Wilms Tumor Based on RNA-Seq

Circular RNA (circRNA), which is a newly discovered non-coding RNA, has been documented to play important roles in miRNA sponges, and the dysregulation of which is involved in cancer development. However, circRNA expression profiles and their role in initiation and progression of Wilms tumor (WT) remain largely unclear at present. Here, we used paired WT samples and high-throughput RNA sequencing to identify differentially expressed circRNAs (DE-circRs) and mRNAs (DE-mRs). A total of 314 DE-circRs and 1612 DE-mRs were identified. The expression of a subset of differentially expressed genes was validated by qRT–PCR. A complete circRNA-miRNA-mRNA network was then constructed based on the common miRNA targets of DE-circRs and DE-mRs identified by miRanda prediction tool. The Gene set enrichment analysis (GSEA) indicated that several signaling pathways involving targeted DE-mRs within the ceRNA network were associated with cell cycle and immune response, which implies their participation in WT development to some extent. Subsequently, these targeted DE-mRs were subjected to implement PPI analysis and to identify 10 hub genes. Four hub genes were closely related to the survival of WT patients. We then filtered prognosis-related hub genes by Cox regression and least absolute shrinkage and selection operator (LASSO) regression analysis to construct a prognosis-related risk score system based on a three-gene signature, which showed good discrimination and predictive ability for WT patient survival. Additionally, we analyzed the mutational landscape of these genes and the associations between their expression levels and those of immune checkpoint molecules and further demonstrated their potential impact on the efficacy of immunotherapy. qRT–PCR and western blotting (WB) analysis were used to validate key differentially expressed molecules at the RNA and protein levels, respectively. Besides these, we selected a key circRNA, circEYA1, for function validation. Overall, the current study presents the full-scale expression profiles of circRNAs and the circRNA-related ceRNA network in WT for the first time, deepening our understanding of the roles and downstream regulatory mechanisms of circRNAs in WT development and progression. We further constructed a useful immune-related prognostic signature, which could improve clinical outcome prediction and guide individualized treatment.

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.

Clinical significance of tumoral PD-L1 expression in Wilms tumors

BACKGROUND

Although cure rate for Wilms tumor (WT) is high recent years, there is still small fraction of patients suffering from tumor relapse or metastases. It is urgent to identify more valuable biomarkers associated with disease progression. Previous studies have shown that PD-L1 was abnormally expressed in various type of cancers and acted as predictor for poor prognosis for those cancers. PD-1/PD-L1 inhibitors have achieved great success in various malignancies with correlation between PD-L1 expression and responses. We conducted this retrospective study to better understand the role of PD-L1 in WT development.

OBJECTIVE

The aim of this study was to evaluate the expression rate of tumoral PD-L1 in WT and investigate the association of PD-L1 with tumor invasion and metastasis.

STUDY DESIGN

Seventy-seven patients with WT, including 20 cases of primary WTs with corresponding resected invasive/lymph node metastatic tumors were enrolled in the research. Immunohistochemistry was used to examine tumoral PD-L1 expression. Kaplan-Meier analysis with regard to the relationship between the expression of tumoral PD-L1 and follow-up information was performed.

RESULTS

Positive expression rate of tumoral PD-L1 was 28.6% in primary WT tissues, while 35% in associated invasive/metastatic ones. The tumoral PD-L1 expression in primary WTs were correlated with late stage and unfavorable histology (P = 0.007; P = 0.002). The expression rate of tumoral PD-L1 was higher in the progression group than that without distant metastasis or relapse (P = 0.038). The expression rate of PD-L1 between primary WTs and matched invasive/metastatic tissues was concordant (P = 0.435). Tumoral PD-L1 expression was associated with disease-free survival (DFS) and overall survival (OS) (P = 0.02; P = 0.03). Tumor PD-L1 expression was associated with DFS and OS in univariable analyses but not in multivariable Cox regression, adjusting for histology and tumor stage.

DISCUSSION

We found that PD-L1 expression was associated with the late-stage of WT and unfavorable histology, which were tightly associated with disease relapse and progression, predicting poor prognosis. The subsequent survival analysis also showed that PD-L1 expression was linked to both shorter DFS and OS. After adjustment for WT stage and histology, PD-L1 expression was no longer an independent predictor of DFS/OS. The value of PD-L1 as predictor for prognosis and potential therapeutic target in WT still need to be validated in large cohort in future.

CONCLUSION

Although PD-L1 expression correlated with established prognostic factors in our dataset, its value as a prognostic marker and therapeutic target, if any, remains to be shown in future.

Diagnostic accuracy and cytomorphological spectrum of Wilms tumour in fine needle aspiration biopsy cytology samples supplemented with cell blocks

OBJECTIVE

Paediatric malignant renal neoplasms are subjected to neoadjuvant chemotherapy as per Societe Internationale d'Oncologie Pediatrique; International Society of Pediatric Oncology (SIOP) protocol. An accurate tissue diagnosis is required prior to institution of chemotherapy, and hence the aim of this study was to evaluate the diagnostic accuracy of fine needle aspiration biopsy cytology (FNABC) along with cell block histology.

MATERIALS AND METHODS

A retrospective audit of all paediatric renal neoplasms diagnosed by FNABC between 2015 and 2019 was performed. Histopathology correlation was done wherever available. WT cases were subjected to detailed cytomorphological evaluation.

RESULTS

A total of 121 cases of paediatric renal neoplasms including 109 WT, four clear cell sarcoma, one malignant rhabdoid tumour and three mesoblastic nephroma were evaluated. The age range was 4 weeks to 8 years. FNABC samples were adequate for diagnosis in 120 of 121 cases (99.18%) and a definitive cytological diagnosis was achieved in 117 cases (96.7%). The specificity and sensitivity for a cytopathological diagnosis of WT were 98.7% and 97.4%, respectively. On detailed cytomorphological analysis of 68 histopathology-proven WT, 40 (58.8%) cases were triphasic, 23 (35.3%) were biphasic and four were composed of blastema only. The corresponding cell blocks provided additional information over the conventional smears in 23 (33.8%) cases, with epithelial or mesenchymal elements recognised and evidence of rhabdomyoblastic differentiation.

CONCLUSION

FNABC along with cell block histology is highly accurate for diagnosis of WT and other malignant paediatric renal neoplasms and is recommended as the technique of choice in centres with cytopathology expertise for establishing a cellular diagnosis prior to commencement of neoadjuvant chemotherapy.

YTHDC1 gene polymorphisms and Wilms tumor susceptibility in Chinese children: A five-center case-control study

Wilms tumor is a common pediatric tumor with abundant genetic drivers. YTHDC1 is an important reader of the N⁶-methyladenosine modification that widely regulates eukaryotic transcripts. YTHDC1 has been associated with the occurrence and development of some tumors. However, this is the first study on YTHDC1 gene polymorphisms and Wilms tumor susceptibility. In brief, we conducted a five-center case-control study to explore the associations between YTHDC1 polymorphisms (rs2293596 T > C, rs2293595 T > C, and rs3813832 T > C) and Wilms tumor susceptibility in Chinese children. A total of 404 cases and 1198 controls were successfully genotyped using TaqMan real-time PCR. Odds ratios (ORs) and 95% confidence intervals (CIs) were used as the evaluation indicators. We found that children with the 2-3 risk genotypes were more likely to develop Wilms tumor than those with the 0-1 risk genotypes (adjusted OR = 1.28, 95% CI = 1.01-1.62, P = 0.042). However, no other statistically significant results were found in this research study. The combined effect of YTHDC1 polymorphisms significantly increases Wilms tumor susceptibility. Our results need to be verified in different populations after increasing the sample size and controlling for confounding factors.

A Survival-Related Competitive Endogenous RNA Network of Prognostic lncRNAs, miRNAs, and mRNAs in Wilms Tumor

Wilms tumor (WT) commonly occurs in infants and children. We evaluated clinical factors and the expression of multiple RNAs in WT samples in the TARGET database. Eight long non-coding RNAs (lncRNAs; AC079310.1, MYCNOS, LINC00271, AL445228.3, Z84485.1, AC091180.5, AP002518.2, and AC007879.3), two microRNAs (miRNAs; hsa-mir-152 andhsa-mir-181a), and nine messenger RNAs (mRNAs; TCTEX1D4, RNF133, VRK1, CCNE1, HEY1, C10orf71, SPRY1, SPAG11A, and MAGEB18) were screened from differentially expressed RNAs and used to construct predictive survival models. These models showed good prognostic ability and were highly correlated with tumor stage and histological classification. Additionally, survival-related ceRNA network was constructed using 35 RNAs (15 lncRNAs, eight miRNAs, and 12 mRNAs). KEGG pathway analysis suggested the "Wnt signaling pathway" and "Cellular senescence" as the main pathways. In conclusion, we established a multinomial predictive survival model and a survival-related ceRNA network, which provide new potential biomarkers that may improve the prognosis and treatment of WT patients.

Diagnostic Errors in Wilms' Tumors: Learning From Our Mistakes

Aim: This study aimed to analyze clinical characteristics and image findings in patients initially diagnosed with renal masses and treated on the Société Internationale d'Oncologie Pédiatrique (SIOP) 2001 protocol for Wilms tumor (WT) that eventually were diagnosed with different pathologies. Methods: We reviewed the preoperative symptoms, laboratory tests, and images of patients who were initially treated for WT and proved to have other diagnoses. Data from these patients were compared to those of the last 10 patients with WT and the last 10 patients with neuroblastoma (NBL) treated at a single institution. Results: From June 2001 to December 2020, we treated 299 patients with NBL and 194 with WT. Five patients treated with preoperative chemotherapy for WT were postoperatively diagnosed with NBL (one patient had bilateral renal masses and one with multifocal xanthogranulomatous pyelonephritis). Three underwent nephrectomy, two biopsies only, and one adrenalectomy due to intraoperative characteristics. Regarding clinical presentation, abdominal mass or swelling was very suggestive of WT (p = 0.011); pain, although very prevalent in the study group (67%), was not statistically significant, as well as intratumoral calcifications on computed tomography (CT) (67%). Urinary catecholamines were elevated in all patients mistreated for WT with the exception of the patient with pyelonephritis in which it was not collected. Conclusion: Some pathologies can be misdiagnosed as WT, especially when they present unspecified symptoms and dubious images. Diagnostic accuracy was 98.1%, which highlights the quality of the multidisciplinary team. Abdominal mass or swelling is highly suggestive of WT, especially in the absence of intratumoral calcifications on CT. If possible, urinary catecholamines should be collected at presentation as they help in the differential diagnosis of NBL.

A rare case of an isolated PAX6 mutation, aniridia, and Wilms tumor

Introduction: Wilms tumor (WT) is the most common renal malignancy of children and can be seen in WAGR syndrome (WT, aniridia, genitourinary anomalies, and intellectual disability). WAGR results from a contiguous gene deletion within the 11p13 region, encompassing the WT1 gene, often responsible for WT development, and the PAX6 gene, responsible for aniridia. Aniridia, a pan-ocular disease resulting from iris hypoplasia, is thought to increase the risk for WT development if their genetic alteration spans both the WT1 and the PAX6 genes on 11p13.Case Description: We describe a unique case of a patient with aniridia secondary to a heterozygous PAX6 nonsense mutation who developed WT despite no additional identifiable germline genetic drivers for this disease.Discussion: Isolated mutations in PAX6 previously have not been associated with increased risk of WT development case raises the question of if surveillance for WT should be continued in patients with aniridia with an isolated PAX6 mutation identified.

The Roles of Base Modifications in Kidney Cancer

Epigenetic modifications including histone modifications and DNA and RNA modifications are involved in multiple biological processes and human diseases. One disease, kidney cancer, includes a common type of tumor, accounts for about 2% of all cancers, and usually has poor prognosis. The molecular mechanisms and therapeutic strategy of kidney cancer are still under intensive study. Understanding the roles of epigenetic modifications and underlying mechanisms in kidney cancer is critical to its diagnosis and clinical therapy. Recently, the function of DNA and RNA modifications has been uncovered in kidney tumor. In the present review, we summarize recent findings about the roles of epigenetic modifications (particularly DNA and RNA modifications) in the incidence, progression, and metastasis of kidney cancer, especially the renal cell carcinomas.

Hypertensive Cardiomyopathy with Congestive Heart Failure in an Infant with Unilateral Wilms Tumor: A Case Report

Wilms tumor (WT) is the most common malignant kidney tumor in children. High blood pressure is seen in up to 55% of children with WT. However, hypertensive cardiomyopathy with congestive heart failure due to WT is remarkably rare, with only several cases reported worldwide. In this report, a pediatric case of WT with hypertension causing hypertensive cardiomyopathy and congestive heart failure is presented. An 8-month-old male child with abdominal distension was seen by his primary physician. He was referred to our hospital for further examination and treatment. Abdominal contrast-enhanced computed tomography demonstrated a weakly enhancing, large abdominal mass, which was larger than 12 cm. Two-dimensional transthoracic echocardiography showed a diffuse hypokinetic left ventricle. The patient was diagnosed with cardiomyopathy caused by hypertension. Open surgical resection of the mass was successfully performed. His postoperative course was uncomplicated, and the patient was successfully discharged. The plasma renin activity was maintained at a high level even after left nephrectomy, suggesting that the right kidney was likely the source of renin secretion. Mechanical compression of the right renal blood vessels by a greatly enlarged left kidney can cause right renal ischemia, which activates renin excretion. Nephrectomy can be an effective treatment for a WT patient with hypertension causing hypertensive cardiomyopathy, and then cardiac function will be improved within several weeks. We recommend routine echocardiography surveillance in patients with WT. This report can help pediatric surgeons become more familiar with cardiomyopathy caused by WT.

HMGA2 gene polymorphisms and Wilms tumor susceptibility in Chinese children: a four-center case-control study

Wilms tumor is a kidney malignancy that typically occurs in children. Aberrant expression of HMGA2 gene is commonly seen in many malignant tumors. Yet, HMGA2 gene polymorphisms on Wilms tumor risk are not established. We carried out the first four-center case-control study with 355 patients and 1,070 controls to assess the association of HMGA2 polymorphisms (rs6581658 A>G, rs8756 A>C, and rs968697 T>C) with Wilms tumor risk. All of these three polymorphisms in single could not impact Wilms tumor risk. Stratified analysis revealed a contributing Wilms tumor risk role of rs968697 TC/CC in subgroup of male (TC/CC vs. TT: adjusted odds ratio [OR] = 1.46, 95% confidence interval [CI] = 1.03-2.08, P = 0.035). However, we found that presence of 1-3 protective genotypes were less likely to develop tumor in subgroup of female (adjusted OR = 0.69, 95% CI = 0.48-0.99, P = 0.045). Our findings suggest that HMGA2 gene polymorphisms might influence Wilms tumor predisposition in a weak manner, under certain circumstances.

The Potential Roles of RNA N6-Methyladenosine in Urological Tumors

N6-methyladenosine (m⁶A) is regarded as the most abundant, prevalent and conserved internal mRNA modification in mammalian cells. M⁶A can be catalyzed by m⁶A methyltransferases METTL3, METTL14 and WTAP (writers), reverted by demethylases ALKBH5 and FTO (erasers), and recognized by m⁶A -binding proteins such as YTHDF1/2/3, IGF2BP1/2/3 and HNRNPA2B1 (readers). Emerging evidence suggests that m⁶A modification is significant for regulating many biological and cellular processes and participates in the pathological development of various diseases, including tumors. This article reviews recent studies on the biological function of m⁶A modification and the methylation modification of m⁶A in urological tumors.

Predictors of treatment outcome of Wilms Tumour in low-income country; single centre experience from Pakistan

BACKGROUND

Wilms tumor (WT) represents around 85% of pediatric renal tumors. In high-income countries, 5-years survival of WT is above 90% but survival in developing countries is inferior.

OBJECTIVE

To identify the predictors of treatment outcome of WT in a developing country.

METHODS

A retrospective study conducted at the pediatric oncology department, Combined Military Hospital Rawalpindi, Pakistan. All newly diagnosed WT cases from 1st January 2012 who completed their treatment before 31st August 2019 were evaluated. Treatment was based on SIOP Wilms Tumour 2001/UK version 5. Patients presenting before nephrectomy received pre-operative chemotherapy. The postoperative chemotherapy regimen was decided according to the stage, risk stratification and metastatic status of the patient.

RESULTS

Data of 84 cases, including 40 (47.6%) males and 44 (52.4%) females was analyzed. The mean diagnostic age was 38.87 ± 28.66 months and 68 (81%) cases were less than five years of age. The commonest presenting features were abdominal mass in 75 (89.3%) cases. The right kidney was affected in 43 (51.2%) cases. Stage I disease was documented in 27 (32.1%) cases, stage II in 25 (29.8%), stage III in 13 (15.5%), and stage IV in 17 (20.2%) cases. In univariate analysis, advanced stage (P = < 0.001) and metastatic disease (P=< 0.001) adversely affected the treatment outcome. Multivariate analysis demonstrated that advanced stage WT was associated with the worst outcome (P= < 0.05). Four (4.8%) cases had treatment-related mortality (TRM). With a median follow-up time of 28.26 ± 23.03 months, OS and EFS were 66 (78.6%) and 63 (75.0%) respectively.

DISCUSSION

Delayed presentation with advanced-stage metastatic disease is quite common in the developing courtiers and is the major contributor to decreased EFS and OS. In the present study, 20.2% cases had metastatic disease, which is similar to reported from other developing countries. OS decreased from 92.6% in stage I to 47.1% in stage IV disease (P=< 0.001) and EFS decreased from 92.6% in stage I to 43.8% in stage IV disease (P=< 0.001). Very similar results are reported by a regional study [17]. Results in stage I and II disease are comparable to documented in the western world and inferior in advanced-stage disease. The strength of the present study is that multiple factors, affecting the treatment outcome of WT over almost seven years period were evaluated.

CONCLUSIONS

Stage of the disease is the most important prognostic factor. Delayed presentation with metastatic disease has a poor outcome.

ALKBH5 gene polymorphisms and Wilms tumor risk in Chinese children: A five-center case-control study

BACKGROUND

Wilms tumor is a frequently diagnosed renal cancer among children with unclear genetic causes. N6-methyladenosine (m⁶ A) modification genes play critical roles in tumorigenesis. However, whether genetic variations of m⁶ A modification genes predispose to Wilms tumor remain unclear. ALKBH5 (AlkB homolog 5), a crucial member of m⁶ A modification genes, encodes a demethylase that functions to reverse m⁶ A RNA methylation.

METHODS

Herein, we evaluated the association of single nucleotide polymorphisms (SNPs) in the m⁶ A modification gene ALKBH5 and Wilms tumor susceptibility in a large multi-center case-control study. A total of 414 Wilms tumor cases and 1199 healthy controls were genotyped for ALKBH5 rs1378602 and rs8400 polymorphisms by TaqMan.

RESULTS

No significant association was detected between these two polymorphisms and Wilms tumor risk. Moreover, 1, 2, and 1-2 protective genotypes (rs1378602 AG/AA or rs8400 GG) did not significantly reduce Wilms tumor risk, compared with risk genotypes only. Stratification analysis revealed a significant relationship between rs1378602 AG/AA genotypes and decreased Wilms tumor risk in children in clinical stage I diseases [adjusted odds ratio (OR) = 0.56, 95% confidence interval (CI) = 0.32-0.98, P = .042]. The presence of 1-2 protective genotypes was correlated with decreased Wilms tumor risk in subgroups of age > 18 months, when compared to the absence of protective genotypes (adjusted OR = 0.74, 95% CI = 0.56-0.98, P = .035).

CONCLUSION

Collectively, our results demonstrate that ALKBH5 SNPs may exert a weak influence on susceptibility to Wilms tumor. This finding increases the understanding of the role of the m⁶ A gene in tumorigenesis of Wilms tumor.

Management and outcome of pediatric metastatic Wilms' tumor at the National Cancer Institute, Egypt

BACKGROUND

Wilms' tumor (WT) is the most common renal malignant tumor of childhood. Metastatic WT has a worse prognosis than localized disease. This study aims to assess the clinical outcome and different prognostic factors that influence treatment outcome of pediatric metastatic WT cases treated at National Cancer Institute (NCI), Egypt, between January 2008 and December 2015. Medical records were retrospectively reviewed for clinical, radiological and histopathological data, treatment received, and survival outcome.

RESULTS

In the specified study period, 24/103 (23.3%) patients with WT were metastatic at presentation. The mean age was 5.25 ± 2.87 years (range 2.0-12.7). Abdominal swelling/mass was the commonest presentation (70.8%). Only 3 patients (12.5%) had combined lung and liver metastases while 21 patients (87.5%) had pulmonary-only metastases. All patients had favorable histology tumors with no anaplasia. Nine patients (37.5%) underwent upfront nephrectomy. Majority of patients (91.7%) had local stage III disease. Surgical complications were reported in 4 patients; 3 of them had up-front nephrectomy. Only 7/21 patients achieved rapid complete response of pulmonary nodules after 6 weeks of chemotherapy (CTH), and they had a better survival outcome. Patients were followed up till December 2017. Thirteen patients (54.1%) experienced events during the study period including 5 relapses, 6 cases with disease progression, and 2 patients died out of sepsis. The 3-year event-free and overall survival rates were 48.2% and 54.2%, respectively.

CONCLUSION

Neo-adjuvant CTH followed by delayed nephrectomy seems more suitable approach in our institute. Pulmonary response to neo-adjuvant CTH appears to be a strong predictor for outcome.

Effects of miR-21 on proliferation and apoptosis of WT cells via PTEN/Akt pathway

Micro ribonucleic acid (miR)-21 in the proliferation and apoptosis of Wilms' tumor (WT) cells was explored. SK-NEP-1 cells were transfected with miR-21 inhibitor to silence the expression of miR-21. Then, the effects of miR-21 silencing on the proliferation and apoptosis of WT SK-NEP-1 cells were detected through cell counting kit-8 (CCK-8), colony formation assay and flow cytometry. The targets of miR-21 were analyzed via TargetScan database. Fluorescence real-time quantitative polymerase chain reaction (RT-qPCR) assay and western blot analysis were conducted to detect the changes in messenger RNA (mRNA) and protein expression levels of gene of phosphate and tension homology deleted on chromosome ten (PTEN) after silencing miR-21. Whether miR-21 directly binds to PTEN was examined by activity detection via dual luciferase reporter gene assay. Western blotting was employed to detect the correlation of miR-21 with PTEN and protein kinase B (Akt). Compared with normal control (NC) group, miR-21 inhibitor group had significantly inhibited proliferation of SK-NEP-1 cells (P<0.05), notably reduced number of clones (P<0.05) and overtly raised proportion of apoptotic cells (P<0.05). The suppression of miR-21 expression upregulated the mRNA and protein expression levels of PTEN, and the results of activity detection via dual luciferase reporter gene assay indicated that miR-21 bound to PTEN 3'-untranslated region (UTR) to repress its expression (P<0.05). PTEN silencing increased phosphorylated Akt (p-Akt) level in SK-NEP-1 cells, but there was no changes in Akt protein level. After silencing both PTEN and miR-21, the decrease in p-Akt was reversed, thereby reversing the inhibitory effect of miR-21 on the proliferation of SK-NEP-1 cells (P<0.05). miR-21 affects the proliferation and apoptosis of WT SK-NEP-1 cells via the PTEN/Akt pathway.

Surgery for the complex Wilms tumour

The prognosis of children with Wilms tumour has greatly improved since the introduction of adjuvant radiotherapy and chemotherapy more than 70 years ago with a current overall long-term survival approaching 90%. Before this, surgery was the only option with around 20% survival, even in low-risk categories. The focus is now on management options for those patients in specific subgroups, who continue to have lower event-free survival and who suffer from the long-term effects of treatment. These include those with anaplastic histology, bilateral Wilms, biologically high-risk tumours and those that relapse (Aldrink et al. in J Pediatr Surg 54(3):390-397, 2019). The major advances that have already been made in risk assessment and tailoring the chemotherapy/radiotherapy to achieve maximum advantage with minimum toxicity and long-term morbidity have been predicated on safe and complete resection and staging of the tumour. There are, however, still surgical challenges faced with respect to resection of 'complex' tumours; thus, surgeons need to understand their role and advance their expertise in the overall treatment of children with Wilms tumour. These include very large tumours not responding to chemotherapy, ruptured tumours, tumours with intravascular invasion into the inferior vena cava (± 10%), heart and hepatic veins (± 4%) and Wilms tumours in horseshoe kidneys (< 1%) (Kieran and Ehrlich in Urol Oncol https://doi.org/10.1016/j.urolonc.2015.05.029, 2015). This review describes surgical strategies and techniques used in these situations, gleaned from the authors' experience in the surgical management of over 300 children with Wilms tumours in our centres over the last 30 years.

MicroRNA Profiling in Wilms Tumor: Identification of Potential Biomarkers

Wilms tumor (WT) is the most frequently diagnosed malignant renal tumor in children. With current treatments, ~90% of children diagnosed with WT survive and generally present with tumors characterized by favorable histology (FHWT), whereas prognosis is poor for the remaining 10% of cases where the tumors are characterized by cellular diffuse anaplasia (DAWT). Relatively few studies have investigated microRNA-related epigenetic regulation and its relationship with altered gene expression in WT. Here, we aim to identify microRNAs differentially expressed in WT and describe their expression in terms of cellular anaplasia, metastasis, and association with the main genetic alterations in WT to identify potential prognostic biomarkers. Expression profiling using TaqMan low-density array was performed in a discovery cohort consisting of four DAWT and eight FHWT samples. Relative quantification resulted in the identification of 109 (48.7%) microRNAs differentially expressed in both WT types. Of these, miR-10a-5p, miR-29a-3p, miR-181a-5p, miR-200b-3p, and miR-218-5p were selected and tested by RT-qPCR on a validation cohort of 53 patient samples. MiR-29a and miR-218 showed significant differences in FHWT with low (P = 0.0018) and high (P = 0.0131) expression, respectively. To discriminate between miRNA expression FHWTs and healthy controls, the receiver operating characteristic (ROC) curves were obtained; miR-29a AUC was 0.7843. Furthermore, low expression levels of miR-29a and miR-200b (P = 0.0027 and P = 0.0248) were observed in metastatic tumors. ROC curves for miR-29a discriminated metastatic patients (AUC = 0.8529) and miR-200b (AUC = 0.7757). To confirm the differences between cases with poor prognosis, we performed in situ hybridization for three microRNAs in five DAWT and 17 FHWT samples, and only significant differences between adjacent tissues and FHWT tumors were found for miR-181a, miR-200b, and miR-218, in both total pixels and nuclear analyses. Analysis of copy number variation in genes showed that the most prevalent alterations were WTX (47%), IGF2 (21%), 1q (36%) gain, 1p36 (16%), and WTX deletion/1q duplicate (26%). The five microRNAs evaluated are involved in the Hippo signaling pathway and participate in Wilms tumor development through their effects on differentiation, proliferation, angiogenesis, and metastasis.

Prognostic Factors and Nomograms to Predict Overall and Cancer-Specific Survival for Children with Wilms' Tumor

Objective

This study is aimed at constructing and verifying nomograms that forecast overall survival (OS) and cancer-specific survival (CSS) of children with Wilms' tumor (WT).

Patients and methods

Clinical information of 1613 WT patients who were under 18 years old between 1988 and 2010 was collected from the Surveillance, Epidemiology, and End Results (SEER) database. Using these data, we performed univariate as well as multivariate Cox's regression analyses to determine independent prognostic factors for WT. Then, nomograms to predict 3- and 5-year OS and CSS rates were constructed based on the identified prognostic factors. The nomograms were validated externally and internally. The nomograms' reliability was evaluated utilizing receiver operating characteristic (ROC) curves and concordance indices (C-indices).

Results

1613 WT patients under 18 were involved in the study and randomly divided into the training (n = 1210) and validation (n = 403) cohorts. Age at diagnosis, tumor laterality, tumor size, tumor stage, and use of surgery were determined as independent prognostic factors for OS and CSS in WT and were further applied to construct prognostic nomograms. The C-index and area under the receiver operating characteristic curve (AUC) revealed the great performance of our nomograms. Internal and external calibration plots also showed excellent agreement between actual survival and nomogram prediction.

Conclusion

Precise and convenient nomograms were developed for forecasting OS and CSS of children with WT. These nomograms were able to offer accurate and individualized prognosis and assisted clinicians in performing suitable therapy.

LINC00673 rs11655237 C>T and susceptibility to Wilms tumor: A five-center case-control study

BACKGROUND

Wilms tumor, a frequently occurring pediatric renal cancer worldwide, originated from the embryonal nephric mesenchyme. However, epidemiological data on the association between LINC00673 polymorphisms and Wilms tumor risk are scant. This case-control study was conducted to investigate the potential role of the LINC00673 rs11655237 C>T polymorphism in the susceptibility to Wilms tumor.

METHODS

In the present study, we conducted a genotyping analysis of LINC00673 rs11655237 C>T in 414 cases and 1199 controls recruited from five hospitals in China. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated from multiple logistic regression models to determine the association of LINC00673 rs11655237 C>T polymorphism and Wilms tumor susceptibility.

RESULTS

No significant association between the LINC00673 rs11655237 C>T polymorphism and Wilms tumor risk was observed (CT versus CC: adjusted OR = 0.90, 95% CI = 0.71-1.15; TT versus CC: adjusted OR = 0.86, 95% CI = 0.50-1.49; TT/CT versus CC: adjusted OR = 0.90, 95% CI = 0.71-1.13; and TT versus CC/CT: adjusted OR = 0.89, 95% CI = 0.52-1.53). We also failed to make any remarkable findings for this genotype in the stratification analysis.

CONCLUSIONS

In summary, we failed to provide any evidence in favor of the significant susceptibility of rs11655237 C>T polymorphism in LINC00673 to Wilms tumor. These data could be useful for reinforcing our understanding of the potential contribution of LINC00673 rs11655237 C>T to Wilms tumor susceptibility.

Association between PHOX2B gene rs28647582 T>C polymorphism and Wilms tumor susceptibility

Wilms tumor is one of the most common pediatric solid tumors. The pair-like homeobox 2b (PHOX2B) gene is an important transcription factor that regulates cellular proliferation and differentiation in early life. The association between PHOX2B single nucleotide polymorphisms (SNPs) and Wilms tumor risk has not been investigated. Therefore, we conducted a case-control study involving 145 Wilms tumor patients and 531 controls to explore the association between the PHOX2B rs28647582 T>C polymorphism and Wilms tumor susceptibility. The association between the PHOX2B rs28647582 T>C polymorphism and Wilms tumor susceptibility was assessed by odds ratios (ORs) and 95% confidence intervals (CIs). Our results indicated that PHOX2B rs28647582 T>C polymorphism did not significantly alter Wilms tumor susceptibility. However, in the stratified analysis, we found that TC/CC genotypes significantly increased Wilms tumor risk among children older than 18 months (adjusted OR = 1.77, 95% CI = 1.07-2.95, P=0.027) and those with clinical stages III+IV (adjusted OR = 1.75, 95% CI = 1.09-2.82, P=0.022), when compared with those with TT genotype. Our study suggested that PHOX2B rs28647582 T>C was weakly associated with Wilms tumor susceptibility. Our conclusions need further validation with a larger sample size.

LIN28A gene polymorphisms confer Wilms tumour susceptibility: A four-centre case-control study

Wilms tumour is a renal malignancy that commonly occurs in children. LIN28A gene overexpression has been reported to be involved in various human malignancies, while its roles in Wilms tumour risk are still under investigation. Here, we genotyped four LIN28A polymorphisms in 355 Wilms tumour patients and 1070 healthy controls from four hospitals in China. The genotyped single nucleotide polymorphisms (SNPs) include the following: rs3811464 G>A, rs3811463 T>C, rs34787247 G>A and rs11247957 G>A. Overall, we found that rs3811463 T>C and rs34787247 G>A were associated with increased risk of Wilms tumour. Combination analysis of risk genotypes showed that, compared to non-carriers, subjects with 1 risk genotype and 1-3 risk genotypes were more likely to develop Wilms tumour, with an adjusted odds ratio (OR) of 1.58 and 1.56, respectively. Stratified analysis further demonstrated that the risk effect remained prominent in some subgroups. We also found that presence of 1-3 risk genotypes was associated with Wilms tumour risk in subgroups > 18 months of age, females, males and those with clinical stage I + II diseases. Furthermore, expression quantitative trait locus (eQTL) analysis indicated that rs3811463 C allele was significantly associated with increased transcripts of LIN28A gene. These findings suggest that LIN28A gene polymorphisms may be associated with increased predisposition to Wilms tumour.

Development and validation of a nomogram for predicting cancer-specific survival in patients with Wilms' tumor

Purpose: The objective of this study was to develop and validate a nomogram for predicting the cancer-specific survival (CSS) in patients with Wilms' tumor (WT).

Methods: Patients with WT diagnosed between 2002 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database were divided randomly into training and validation cohorts in this study. Multivariate Cox regression analysis was used to screen variables. A Cox proportional-hazards regression model and a nomogram were constructed based on variables that significantly affected the CSS in the training cohort. The nomogram for distinguishing and predicting the CSS was evaluated using the concordance index (C-index), the area under the time-dependent receiver operating characteristic curve (AUC), and calibration plots.

Results: In total, 1631 patients from the SEER database were enrolled, with 1141 categorized into the training cohort and 490 into the validation cohort. All significant variables associated with CSS—age, the number of examined lymph nodes, SEER stage, and tumor size—were included in the nomogram. The C-index values of the nomogram in the training and validation cohorts were 0.746 and 0.703, respectively. The 3-, 5-, and 10-year AUCs were 0.755, 0.749, and 0.724, respectively, in the training cohort, and 0.718, 0.707, and 0.718 in the validation cohort. The calibration plots indicated the nomogram could accurately predict the 3-, 5-, and 10-year CSS.

Conclusions: We have developed and validated the first nomogram for predicting the survival of WT patients. The nomogram is a reliable tool for distinguishing and predicting the CSS in patients with WT. Information provided by the nomogram may help to improve the clinical practices related to WT.

Benchmarking Wilms' tumor in multisequence MRI data: why does current clinical practice fail? Which popular segmentation algorithms perform well?

Wilms' tumor is one of the most frequent malignant solid tumors in childhood. Accurate segmentation of tumor tissue is a key step during therapy and treatment planning. Since it is difficult to obtain a comprehensive set of tumor data of children, there is no benchmark so far allowing evaluation of the quality of human or computer-based segmentations. The contributions in our paper are threefold: (i) we present the first heterogeneous Wilms' tumor benchmark data set. It contains multisequence MRI data sets before and after chemotherapy, along with ground truth annotation, approximated based on the consensus of five human experts. (ii) We analyze human expert annotations and interrater variability, finding that the current clinical practice of determining tumor volume is inaccurate and that manual annotations after chemotherapy may differ substantially. (iii) We evaluate six computer-based segmentation methods, ranging from classical approaches to recent deep-learning techniques. We show that the best ones offer a quality comparable to human expert annotations.

MicroRNA-539 inhibits the progression of Wilms' Tumor through downregulation of JAG1 and Notch1/3

BACKGROUND

Previous studies demonstrated that miR-539 play an important role in the carcinogenesis of some cancers. The aim of the present study was to determine the role of miR-539 in the pathogenesis of Wilms' Tumor (WT).

METHODS

The expression level of miR-539 was measured by qRT-PCR in 42 WT tissues and SK-NEP-1 cell line. Protein expression of genes (E-cadherin, N-cadherin, Vimentin, Notch 1, Notch 3 and JAG1) was assessed by Western blot. The function of miR-539 was investigated in SK-NEP-1 cells by MTT and Transwell assays. The relationship between miR-539 and JAG1 was verified by a dual luciferase assay in SK-NEP-1 cells.

RESULTS

The expression level of miR-539 was significantly decreased in WT tissues. Downregulation of miR-539 was closely related to NWTS-5 stage, lymph node metastasis and histological type of WT patients. Furthermore, low miR-539 expression was associated with a shorter overall survival rate in WT patients. In vitro, overexpression of miR-539 suppressed proliferation, migration and invasion of SK-NEP-1 cells. In addition, JAG1 was a direct target of miR-539. MiR-539 inhibited the development of WT by inhibiting JAG1-Notch1/3 expressing and blocking EMT.

CONCLUSION

MiR-539 inhibited the progression of WT through downregulation of JAG1 and Notch1/3.

Expression of YY1 in Wilms tumors with favorable histology is a risk factor for adverse outcomes

Aim: To investigate the role of the transcription factor YY1 in Wilms tumor (WT). Patients & methods: We measured YY1 expression using tissue microarray from patients with pediatric renal tumors, mainly WT and evaluated correlations with the predicted clinical evolution. YY1 expression was measured using immunohistochemical and protein expression was determined by digital pathology. Results & conclusion: YY1 significantly increased in WT patients. In addition, an increase in YY1 expression had a greater risk of adverse outcomes in WT patients with favorable histology. YY1 expression was higher in the blastemal component of tumors, and high nuclear expression positively correlated with metastasis. YY1 may be considered as a metastasis risk factor in WT.

Association of KRAS and NRAS gene polymorphisms with Wilms tumor risk: a four-center case-control study

Wilms tumor is a type of pediatric solid tumor that arises partly due to somatic and germline mutations. Single-nucleotide polymorphisms (SNPs) in the RAS gene reportedly modify the risk for several types of human malignancies. We conducted a multicenter study to investigate whether RAS gene variants predispose individuals to Wilms tumor. Four SNPs in RAS were genotyped in 355 Wilms tumor cases and 1070 controls. The SNPs included rs12587 G>T, rs7973450 A>G and rs7312175 G>A in KRAS, and rs2273267 A>T in NRAS. Individuals harboring the rs12587 GT genotype were more likely to develop Wilms tumor than those carrying the GG genotype (adjusted odds ratio [OR]=1.30, 95% confidence interval [CI]=1.004-1.68, P=0.046). However, the other three SNPs seemed not to influence the risk for Wilms tumor. Compared to individuals without a risk genotype, those harboring one to three KRAS risk genotypes had an adjusted OR of 1.28 for developing Wilms tumor (95% CI=1.002-1.64, P=0.048). Stratification analysis revealed that rs12587 GT/TT was associated with Wilms tumor risk in children >18 months old (adjusted OR=1.39, 95% CI=1.02-1.89, P=0.037). Our findings indicate that the rs12587 G>T polymorphism in KRAS is associated with increased Wilms tumor susceptibility.

miR-140-5p alleviates the aggressive progression of Wilms' tumor through directly targeting TGFBR1 gene

Background and objective

Although many miRNAs are identified to be deregulated and play vital roles in the progression of Wilms’ tumor (WT), there are still a large number of miRNAs are waiting for us to explore. The purpose of the present study is to investigate the different expressing profiles of miRNAs in WT tissues and the adjacent normal tissues, and probe the effects and mechanism of a certain miRNA among the different expressing miRNAs.

Methods

miRNA microarray was recruited to assess the differently expressed miRNAs in WT tissues and normal tissues, which was further verified by RT-PCR. Receiver operating characteristic curves were performed to calculate the specificity and sensitivity of miRNAs in the diagnose of WT. CCK-8, flow cytometry, wound healing, transwell chamber and tumor-burdened assays were used to assess cell growth, apoptosis, migration, invasion and tumorigenesis. Luciferase report assay was used to evaluate the interaction between miR-140-5p and TGFBR1.

Results

A total of 34 miRNAs were abnormally expressed in the WT tissues, among which, miR-140-5p was identified to be obviously down-regulated in WT tissues, and the AUC of it was 0.961. Besides, we found that patients with miR-140-5p low expression always had a shorter overall survival and more aggressive clinical features, such as bigger tumor size (P=0.002), higher pathological stage (P=0.003) and higher occurrence rate of lymph node metastasis (P=0.009) than those in patients with miR-140-5p high expression. Moreover, luciferase reporter assay showed that TGFBR1 was the direct target of miR-140-5p, which was negatively regulated by miR-140-5p and was highly expressed in WT tissues. Furthermore, knockdown of miR-140-5p obviously enhanced the proliferation and tumorigenesis and repressed the apoptosis of G401 cells, and these effects were all abolished when TGFBR1 was down-regulated.

Conclusion

The present study illustrates that miR-140-5p functions as a tumor suppressor in the occurrence and development of WT via targeting TGFBR1, which provides theoretical foundation for serving miR-140-5p as a new diagnosis marker even a therapeutic target for WT.

TP53 rs1042522 C>G polymorphism and Wilms tumor susceptibility in Chinese children: a four-center case-control study

Wilms tumor is the most common renal malignancy that occurs in children. TP53 gene is considered as a tumor-suppressing gene through controlling cell growth. TP53 gene rs1042522 C>G (Arg72Pro) polymorphism is widely investigated in various types of cancers. However, it is not established if TP53 rs1042522 C>G polymorphism is a candidate variant for Wilms tumor risk. The aim of the study was to determine whether TP53 rs1042522 C>G polymorphism is responsible for the risk of Wilms tumor in Chinese children. All subjects (355 cases and 1070 controls) from four centers of China were genotyped for rs1042522 C>G polymorphism. The effect of rs1042522 C>G polymorphism on Wilms tumor prevalence was analyzed using logistic regression models. We failed to detect a significant relationship between rs1042522 C>G polymorphism and Wilms tumor risk. Further stratification analysis also could not detect a significant relationship. We conclude that TP53 rs1042522 C>G polymorphism might not have enough impact on the risk of Wilms tumor. More validation study with larger sample size will be required to better define the role of TP53 rs1042522 C>G polymorphism in Wilms tumor risk.

Determining the optimal cutoff point for lymph node density and its impact on overall survival in children with Wilms' tumor

Objective

Previous studies showed that the lymph node density (LND) was a predictor of survival in Wilms’ tumor (WT). However, the optimal LND cutoff point is controversial due to methodological shortcomings of previous studies, and no studies have shown the effect of LND on survival in children with WT. The purpose of this study was to remedy this situation.

Methods

We identified 376 children with WT. LND cutoff point was determined using the median value, the X-tile program, the survival-tree algorithm, and the time-dependent ROC curve analysis. Survival functions were estimated by the Kaplan–Meier method. We used Cox regression analysis to determine the impact of LND on survival. Smooth curve fitting between relative mortality risk and LND was performed.

Results

The LND cutoff point was 0.44, 0.65, 0.65, and 0.64 according to the median value, the X-tile program, the survival-tree algorithm, and the time-dependent ROC curve analysis, respectively. The 5-, 10-, and 20-year overall survival rates were 86.9%, 86.9%, and 84.7%, respectively, in the <0.44 group and 81.3%, 80.3%, and 80.3%, respectively, in the ≥0.44 group. Survival did not differ significantly between the two groups (P=0.185). The 5-, 10-, and 20-year overall survival rates were 87.8%, 87.8%, and 86.0%, respectively, in the < 0.65 or < 0.64 group and 76.5%, 75.1%, and 75.1%, respectively, in the ≥ 0.65 or ≥ 0.64 group. Children with the high LND had a significantly worse survival (P=0.011) if 0.64 or 0.65 was used for the stratification. LND was a significant predictor for overall survival in the multivariate Cox regression analysis (HR =1.797; 95% CI, 1.043–3.097; P=0.035). Smooth curve fitting suggested that the risk of mortality tended to be ascending with the increase in LND in general.

Conclusion

The three methods including the X-tile program, the survival-tree algorithm, and the time-dependent receiver operating characteristic (ROC) curve analysis are equivalent in their ability to stratify patients and clearly better than the median method. The results showed that the optimal LND cutoff point was around 0.65 and the LND was a reliable predictor of overall survival in children with WT.

AURKA rs8173 G>C Polymorphism Decreases Wilms Tumor Risk in Chinese Children

Wilms tumor is the most common type of renal malignancy in children. Previous studies have demonstrated that single nucleotide polymorphisms (SNPs) in the AURKA gene could predispose to several human malignancies. We recruited 145 cases and 531 cancer-free controls to investigate whether AURKA gene variants modify Wilms tumor susceptibility. Three AURKA SNPs (rs1047972 C>T, rs2273535 T>A, and rs8173 G>C) were genotyped by the Taqman methodology. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of association between AURKA SNPs and Wilms tumor risk. We found that only the rs8173 G>C polymorphism was significantly associated with Wilms tumor risk (GC vs. GG: adjusted OR (AOR) = 0.50, 95% CI = 0.35-0.73, P=0.0002; GC/CC vs. GG: AOR = 0.60, 95% CI = 0.42-0.88, P=0.008). Stratification analysis revealed that rs8173 GC/CC genotypes were associated with Wilms tumor risk among children aged >18 months (AOR = 0.56, 95% CI = 0.34-0.93, P=0.024), male children (AOR = 0.54, 95% CI = 0.33-0.90, P=0.017), and children with clinical stage III + IV diseases (AOR = 0.56, 95% CI = 0.35-0.90, P=0.017). Haplotype analysis indicated that the CAG haplotype was significantly associated with increased Wilms tumor risk. In conclusion, our findings indicated that the AURKA rs8173 G>C polymorphism was associated with decreased Wilms tumor risk in Chinese children.

Outcomes of non-anaplastic stage III and 'inoperable' Wilms tumour treated in the UKW3 trial

BACKGROUND AND PURPOSE

To describe the outcome of patients with stage III Wilms tumours (WT) treated in the UKW3 trial.

MATERIAL AND METHODS

Patients with a pathologically confirmed stage III non-anaplastic WT at nephrectomy (Group A) or with an 'inoperable' tumour at diagnosis managed by biopsy and pre-operative chemotherapy (Actinomycin D-Vincristine-Doxorubicin) but stage I or II at subsequent nephrectomy (Group B) were included.

RESULTS

The 4-year overall (OS)/event free survival (EFS) for Group A (n = 117) patients was 90%(95%CI:83-94)/81%(CI:73-87) and for Group B (n = 32) 94%(CI:77-98)/88%(CI:70-95). The 4-year OS/EFS of patients with pathological stage III WT according to whether they received flank/abdominal radiotherapy (95 patients) or not (37 patients, 22 from UKW3 pooled with 17 patients from UKW2) were 91%(CI:83-95)/82%(CI:73-89), and 84%(CI:67-92)/78%(CI:61-89), respectively. The 4-year OS/EFS for patients having one reason to be stage III versus two or three was 92%(CI:84-96)/83%(CI:73-90) and 85%(CI:70-93)/78%(CI:61-88), respectively.

CONCLUSION

Our findings question the inclusion of biopsy or pre-operative chemotherapy as sole criterion for assigning a tumour stage III. Selected patients with pathological stage III WT can survive without radiotherapy. Whilst cautious interpretation is needed due to the post hoc nature of these analyses, further biological studies may better characterise those who could benefit from reduced therapy.

Clinical outcomes of children with Wilms tumor treated on a SIOP WT 2001 protocol in a tertiary care hospital in south India

INTRODUCTION

Wilms tumor is the most common pediatric renal malignancy. While developed countries have had excellent survival, it remains poorer by comparison in developing countries. The aim was to analyze the clinical outcome of children with Wilms tumor managed in a developing country from 2004 to 2014 by the SIOP WT 2001 protocol.

METHODS

Fifty-nine children with Wilms tumor managed by a SIOP WT 2001 regimen from 2004 to 2014 were analyzed.

RESULTS

The median age at presentation was 36 months, and 59% were boys. The average size of the tumor at presentation was 523 mL. Inferior vena cava thrombus was present in 11, distant metastases in 18, and bilateral tumors in six. Preoperative chemotherapy was given to all children after a diagnostic core needle biopsy. Preoperative chemotherapy reduced the tumor size to a mean of 208 mL and resolved venacaval thrombus in eight. Fifty-five children underwent definitive surgery while two children died during preoperative chemotherapy and two remained inoperable. All surviving children received adjuvant chemotherapy with 17 receiving radiotherapy as well. The overall survival (OS) was 80% and the event-free survival (EFS) was 73% after a mean follow up of 42 months after completion of therapy.

DISCUSSION

The tumor volumes at presentation and the incidence of venous tumor thrombosis in our cohort were much higher than those reported from developed countries. The incidence of metastatic disease at diagnosis (30.5%) was significantly higher than the 10-12% reported in Western data, but similar to that reported from various developing countries (14.1-31%). The OS in our cohort was 80% and the EFS was 73% with there being no events after 28 months. Although the survival rate for localized disease is similar to that in developed countries, the OS for metastatic disease was significantly less (50% vs. 75%). We also found that using an upfront posterior flank core biopsy was safe and beneficial for differentiating Wilms tumor from other pediatric renal tumors that are less chemosensitive.

CONCLUSION

In a resource-restricted environment such as ours, the SIOP WT 2001 protocol has been found to show excellent results.

Abscessing Infection by Streptococcus mitis Mimicking Metastatic Lesions in a 5-Year-Old Girl With Nephroblastoma: A Case Report

Streptococcus mitis is a common pathogen causing infections in oncological patients. However, cases of abscesses caused by Streptococcus mitis in oncological patients have not been reported so far. We report on 5-year-old child with nephroblastoma and pulmonary and hepatic metastases at diagnosis who went into complete remission undergoing chemotherapy and nephrectomy, and who developed new round lesions in liver and lungs under continuous chemotherapy suggestive of new metastases. Biopsy of the lesions revealed abscesses with detection of Streptococcus mitis. The child was successfully treated with antibiotics, finished chemotherapy per protocol and has been in complete remission for 14 months. Infectious lesions involving organs of typical metastatic dissemination can easily be misdiagnosed as metastases, especially in the absence of symptoms. Histologic proof of lesions suspicious of metastases is mandatory if it leads to a change of prognosis and therapy. Streptococcus mitis can be a causative organism of pulmonary and hepatic abscesses in oncological patients.

Wilms Tumor After Orthotopic Liver Transplant in a Patient With Alagille Syndrome

We present a case of Wilms Tumor in a patient with Alagille syndrome 10 months after liver transplant. We explore a suggested genetic connection between these 2 diseases. In children with Wilms Tumor, we propose a pathoembryologic explanation for not just the tumor, but also for the cause of associated benign ureteral and renal parenchymal aberrancies that are commonly seen in the Alagille population. We also discuss the diagnostic and therapeutic challenges that can arise in a liver transplant patient with Alagille syndrome who subsequently develops a renal mass.

MiR-1180-5p regulates apoptosis of Wilms' tumor by targeting p73

Introduction

Wilms’ tumor (WT), the most common childhood tumor, occurs in sporadic or familial forms. Recent findings reported that abnormal expression in microRNA (miRNA) suggests an important role of miRNAs during WT progress. MiRNAs are endogenous short-chain noncoding RNAs, which have been reported as key biomarkers for detecting tumor onset and progression. However, the functional role of miR-1180 in WT has remained unknown.

Materials and methods

MTT and clonogenic survival assays were used to detect WT cell proliferation. Flow cytometry Annexin V-FITC was used to measure apoptosis. In addition, proteins expressions in the cells were determined by Western blotting.

Results

In the present study, we demonstrated that miR-1180 is upregulated in WT when compared with adjacent tissues by quantitative reverse-transcription polymerase chain reaction. In addition, the inhibition of miR-1180 induced apoptosis in SK-NEP-1 cell line in vitro. Moreover, luciferase reporter assay showed that p73 protein was the target of miR-1180, which was confirmed by the results of Western blotting. Finally, in vivo data indicated that the tumor growth in mice was significantly inhibited by miR-1180 inhibitor.

Conclusion

Our results indicate that miR-1180 might serve as a therapeutic target for future WT therapy.

Surgical management and outcomes of 12 cases of Wilms tumour with intracardiac extension from a single centre

PURPOSE

To review demographics, effect of preoperative chemotherapy on tumour thrombus, imaging, operative strategy, and outcomes of 12 patients presenting with intracardiac extension of Wilms tumour thrombus.

METHODS

A retrospective audit was undertaken on patients with intracardiac extension of Wilms tumour. Patients were identified from the oncology database and information obtained on clinical presentation, stage, preoperative treatment, surgical procedures and complications, histology, and survival status. Ethics approval was obtained from the University of Cape Town Human Research Ethics Committee.

RESULTS

From 1984 to 2016, 337 children with Wilms tumour were treated. Twelve (3.6%) had intracardiac extension of tumour thrombus, nine into the right atrium, and three into the right ventricle. Ultrasound, computerized tomography, magnetic resonance imaging, and echocardiograms were used to assess thrombus level. Patients were staged as stage III(8) and IV(4). All patients received preoperative chemotherapy. Thrombus retracted from the heart in two cases. One patient died preoperatively. Eleven underwent laparotomy, median sternotomy, and cardiopulmonary bypass (CPB). Four underwent cavectomy. Five required cavoatrial patches. Thrombus extending into the hepatic veins was extracted in five patients. There was one intraoperative complication and one perioperative death. Thrombus histology showed viable tumour in 9 of 11 patients. Three patients died of progressive disease. Seven patients are currently disease free.

CONCLUSION

A combination of imaging is required to determine thrombus extent, and this facilitates surgical planning. Preoperative chemotherapy may cause thrombus regression, thus avoiding CPB. CPB offers appropriate conditions for safe tumour thrombus excision. Full management in centres with appropriately experienced staff and facilities for CPB is recommended.

LINC00473 antagonizes the tumour suppressor miR-195 to mediate the pathogenesis of Wilms tumour via IKKα

OBJECTIVES

Although dramatic improvements of overall survival has achieved in patients with favourable histology Wilms tumour, disease recurrence is still the main cause of cancer-related death in childhood. Long non-coding RNAs (lncRNAs) as oncogenes or tumour suppressors are dysregulated during carcinogenesis. However, the role of lncRNAs in the pathogenesis of Wilms tumour is unknown. Here, an lncRNA LINC00473 signature that functioned as oncogene was identified in Wilms tumour.

METHODS

Wilms tumour (n = 15) and relative normal tissues were collected. The LINC00473 expression and function in Wilms tumour was determined. The LncRNA-miRNA network of LINC00473 was analysed in vitro and vivo.

RESULTS

We uncovered that the expression of LINC00473 was elevated in tumour tissues than that in relative normal tissues. Higher LINC00473 levels correlated to higher stage and unfavourable histology Wilms tumour. Mechanistically, knockdown of LINC00473 inhibited cell vitality and induced Bcl-2-dependent apoptosis and G1/S arrest via CDK2 and cyclin D1. Moreover, LINC00473 harboured binding sites for miR-195 and limited miR-195 availability in a dose-dependent manner. Forced expression of miR-195 impaired tumour survival and metastasis, which, however, could be restored by LINC00473. Furthermore, IKKα was the downstream of LINC00473/miR-195 signals and could be directly targeted by miR-195 to participate LINC00473-induced tumour progression. Loss-of-function of LINC00473 in vivo effectively promoted the regression of Wilms tumour via miR-195/IKKα-mediated growth inhibition.

CONCLUSION

LINC00473 as an oncogene is up-regulated to participate into the molecular pathogenesis of Wilms tumour via miR-195/IKKα.