Using imaging to diagnose renal tumors beyond nephroblastoma

Wilm's tumor (WT) accounted for the vast majority of renal tumors in children (92%). However, there are many atypical or rare forms of kidney cancer, and it is certainly useful to have a diagnostic orientation in imaging to differentiate between the different diagnoses, guiding that way the therapeutic management. We report the cases of 3 patients who were initially diagnosed with nephroblastoma on the basis of radiological data (via PACS search), underwent pre-operative chemotherapy and then nephrectomy, and whose anatomopathological evidence came back in favor of benign renal tumors. Nephroblastoma is the most common renal tumor in children, but other benign tumors should not be neglected, radiological signs that may point to this entity should be taken into account, so that neoadjuvant chemotherapy with its enfeebling side effects can be avoided.

Spinal metastasis of nephroblastoma: Yes it exists

Nephroblastoma or Wilms' tumor is the most common malignant tumor of the kidney in the pediatric population. Metastasis is caused by hematogenous spread. The most common localizations in decreasing order of frequency are lymph nodes, lungs, and liver. The bone is very rarely affected. According to the literature, bone metastases have been described in the iliac bone, skull, and mandible. The vertebral localization was described in 3 cases only, the first 1 in 2009, and the 2 others in 2015 . The goal of our work is to report a very rare case of metastatic vertebral localization of a Wilms' tumor in relapse after treatment; and thus to underline the potential for vertebral and intracanal involvement in nephroblastoma.

Characteristics and Clinical Outcomes of Children With Wilms' Tumour: A 15-year Experience in a Single Centre in Nigeria

BACKGROUND

Wilms' tumor (WT) is the most common paediatric renal tumor and is one of the most treatment-responsive solid tumours. Survival from Wilms tumour (WT) in sub-Saharan Africa remains dismal as a result of late presentation, treatment abandonment and infrastructure deficit. The purpose of this study was to analyze the clinical outcome of children with Wilms tumour managed in a Nigerian referral centre over a 15-year period.

METHODS

This is a retrospective study of children with WT (nephroblastoma) who were treated at our institution between January 2006 and December 2020. Clinical characteristics, treatments, and outcomes were analyzed.

RESULTS

Thirty-five patients were identified. The median age at diagnosis was 36 months including 22 (62.9 %) females. Twenty-six (74.3 %) had advanced (stage III & IV) disease. Confirmatory histology was available for 16 patients ((45.7 %) among which 10 (62.5 %) were mixed type. The right kidney was affected in 18 patients (51.4 %), left in 15 (42.9 %) and 2 were not documented. Preoperative chemotherapy was given in 22 (62.9 %) patients and 13 (37.1) patients had primary nephrectomy. Eight (22.9 %) patients died during treatment (from disease or treatment related causes), and one abandoned treatment. A total of 26 patients completed treatment. Out of these, 8 (30.8 %) were lost to follow up, four patients died and 14 (53.8 %) patients survived at a median follow-up period of 18 months. The survival decreased with advancing stages of the disease, p = 0.002.

CONCLUSIONS

Majority of children with Wilms tumour in our practice presented with advanced disease. Death during treatment, treatment abandonment and lost to follow up were common.

LEVEL OF EVIDENCE

Level II.

TYPE OF STUDY

Retrospective Study.

Surgical Management of Wilms Tumors with Intravenous Extension: A Multicenter Analysis of Clinical Management with Technical Insights

BACKGROUND

About 5% of Wilms tumors present with vascular extension, which sometimes extends to the right atrium. Vascular extension does not affect the prognosis, but impacts the surgical strategy, which is complex and not fully standardized. Our goal is to identify elements of successful surgical management of Wilms tumors with vascular extensions.

PATIENTS AND METHODS

A retrospective study of pediatric Wilms tumors treated at three sites (January 1999-June 2019) was conducted. The inclusion criterion was the presence of a renal vein and vena cava thrombus at diagnosis. Tumor stage, pre and postoperative treatment, preoperative imaging, operative report, pathology, operative complications, and follow-up data were reviewed.

RESULTS

Of the 696 pediatric patients with Wilms tumors, 69 (9.9%) met the inclusion criterion. In total, 24 patients (37.5%) had a right atrial extension and two presented with Budd-Chiari syndrome at diagnosis. Two died at diagnosis owing to pulmonary embolism. All patients received neoadjuvant chemotherapy and thrombus regressed in 35.6% of cases. Overall, 14 patients had persistent intra-atrial thrombus extension (58%) and underwent cardiopulmonary bypass. Most thrombi (72%) were removed intact with nephrectomy. Massive intraoperative bleeding occurred during three procedures. Postoperative renal insufficiency was identified as a risk factor for patient survival (p = 0.01). With a median follow-up of 9 years (range: 0.5-20 years), overall survival was 89% and event-free survival was 78%.

CONCLUSIONS

Neoadjuvant chemotherapy with proper surgical strategy resulted in a survival rate comparable to that of children with Wilms tumors without intravascular extension. Clinicians should be aware that postoperative renal insufficiency is associated with worse survival outcomes.

The rationale for nephron-sparing surgery in unilateral non-syndromic Wilms tumour

The central question of nephron-sparing surgery in unilateral non-syndromic Wilms tumour sits at a crossroads between surgery, oncology, and nephrology. There has been a significant paradigm shift in paediatric oncology towards reducing toxicity and addressing long-term treatment-related sequalae amongst childhood cancer survivors. After paediatric nephrectomy and 30-50 years of follow-up, 40% of patients will have chronic kidney disease, including 22% with hypertension and 23% with albuminuria. It is difficult to predict which patients will progress to develop hypertension, reduced glomerular filtration rate, albuminuria, and a higher cardiovascular risk. For these reasons, nephron-sparing surgery when it is technically feasible must be considered. To decrease the incidence of positive surgical margins (viable tumour present at a resection margin), incomplete lymph node sampling, and complications, these procedures should be performed at specialist and experienced reference centres. Based on the impacts of individual treatment pathways, survivors of childhood WT need to be followed through adulthood for early detection of chronic kidney disease, hypertension, and prevention of cardiovascular events.

Hypoxia/inflammation-induced upregulation of HIF-1α and C/EBPβ promotes nephroblastoma cell EMT by improving HOXA11-AS transcription

Background

Homeobox (HOX) A11 antisense RNA (HOXA11-AS) has been identified as a cancer promoting lncRNA and is overexpressed in nephroblastoma. However, how HOXA11-AS is regulated in a hypoxic inflammatory environment has not been studied.

Methods

In this study, gene expression and epithelial-mesenchymal transition (EMT) ability were detected in the nephroblastoma cell line WiT49 under conditions of hypoxia and inflammation. Next, HOXA11-AS transcription factors were predicted by datasets and subsequently confirmed by CHIP-QPCR, EMSA, and dual-luciferase reporter assays. Moreover, the regulatory relationships of HOXA11-AS and its transcription factors were further confirmed by rescue experiments.

Results

Our results showed that a hypoxic microenvironment promoted HOXA11-AS expression and nephroblastoma progression, induced EMT, and activated the Wnt signaling pathway. Combined hypoxia and inflammation had a more substantial effect on nephroblastoma than either hypoxia or inflammation alone. HIF-1α and C/EBPβ were confirmed to be the transcription factors for HOXA11-AS. Silencing of HIF-1α or C/EBPβ downregulated HOXA11-AS expression and suppressed EMT and the Wnt signaling pathway in nephroblastoma cells exposed to a hypoxic or inflammatory microenvironment. HOXA11-AS overexpression partly reversed the effect of HIF-1α or C/EBPβ knockdown.

Conclusion

We demonstrated that hypoxia/inflammation-induced upregulation of HIF-1α and C/EBPβ promoted nephroblastoma EMT by improving HOXA11-AS transcription. HOXA11-AS might be a therapy target for nephroblastoma.

Nephroblastoma-specific dysregulated gene SNHG15 with prognostic significance: scRNA-Seq with bulk RNA-Seq data and experimental validation

Wilms tumor (WT) is the most common malignancy of the genitourinary system in children. Currently, the Integration of single-cell RNA sequencing (scRNA-Seq) and Bulk RNA sequencing (RNA-Seq) analysis of heterogeneity between different cell types in pediatric WT tissues could more accurately find prognostic markers, but this is lacking. RNA-Seq and clinical data related to WT were downloaded from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. Small nucleolar RNA host gene 15 (SNHG15) was identified as a risk signature from the TARGET dataset by using weighted gene co-expression network analysis, differentially expressed analysis and univariate Cox analysis. After that, the functional mechanisms, immunological and molecular characterization of SNHG15 were investigated at the scRNA-seq, pan-cancer, and RNA-seq levels using Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), ESTIMATE, and CIBERSORT. Based on scRNA-seq data, we identified 20 clusters in WT and annotated 10 cell types. Integration of single-cell and spatial data mapped ligand-receptor networks to specific cell types, revealing M2 macrophages as hubs for intercellular communication. In addition, in vitro cellular experiments showed that siRNAs interfering with SNHG15 significantly inhibited the proliferation and migration of G401 cells and promoted the apoptosis of G401 cells compared with the control group. The effect of siRNAs interfering with SNHG15 on EMT-related protein expression was verified by Western blotting assay. Thus, our findings will improve our current understanding of the pathogenesis of WT, and they are potentially valuable in providing novel prognosis markers for the treatment of WT.

Primary testicular teratoid Wilms tumor in a 40-year-old male with retroperitoneal lymph node involvement: A case report

We report a 40-year-old male presenting with right testicular pain. Following right orchiectomy demonstrating pT1bS0N0M0 teratoma with extensive necrosis, the patient opted for surveillance. With new retroperitoneal lymphadenopathy, the patient underwent a robotic-assisted laparoscopic retroperitoneal lymph node. After final pathology demonstrated extensive necrosis, the initial orchiectomy specimen was re-reviewed which revealed 60/40 ratio of non-seminomatous teratoma to nephroblastoma. Adult presentation of testicular nephroblastoma is exceedingly rare and such reports contribute to the understanding of adult teratoid Wilms tumor pathogenesis. This case emphasizes the need for comprehensive diagnostic approaches and further research into the pathophysiology of extrarenal teratoid Wilms tumors.

Correlation of CT Scan Response to Necrosis and Volume Changes With Histopathology in Children With Wilms' Tumor

BACKGROUND

Wilms' tumor is the most common renal tumor in children.

OBJECTIVE

To correlate the percentage of necrosis and tumor volume change found in preoperative Contrast Enhance Computed Tomography (CECT) scan of the abdomen with post-operative histopathological findings of Wilms Tumor (WT).

METHODS

In this prospective study from January 2020 to December 2022, out of 33 patients, 15 patients with unilateral localized WT (stage I, II, and III) treated according to SIOP UMBRELLA protocol 2016 were included. Bilateral, syndromic, and stage IV WT were excluded. The radiological response was measured in preoperative CECT by estimating the percentage of necrosis found in static images and compared with post-operative histopathological findings. Tumor volume changes were measured by comparing CECT at diagnosis and following chemotherapy. Tumor volume change was also compared with histology.

RESULTS

There was a significant positive correlation between radiological response to necrosis with histology as per Pearson correlation. Significant positive correlation also found between volume changes on pre and post chemotherapy CECT with histology as per Spearman correlation.

CONCLUSIONS

The changes in tumors during preoperative radiological evaluation and histologically confirmed necrosis are strongly related.

Mechanism of LncRNA FTX regulates nephroblastoma progression through MiR-215-5p/PI3K/AKT axis

BACKGROUND

Nephroblastoma, also more commonly known as Wilms tumor (WT), is a common childhood malignancy that connects tumorigenesis and organ development in the kidney.

OBJECTIVE

The current study focused on the effect of lncRNA FTX in nephroblastoma.

STUDY DESIGN

Expression of lncRNA FTX in nephroblastoma tissues and cells was determined. The expression location of lncRNA FTX was detected by FISH. The binding of lncRNA FTX and miR-215-5p with Ago2 was verified by RIP. Following gain- and loss-of-function approaches, the crucial role of lncRNA FTX and miR-215-5p in nephroblastoma cell functions was measured with the involvement of the PI3K/AKT pathway.

RESULTS

LncRNA FTX was elevated and miR-215-5p was declined in nephroblastoma. Silencing of lncRNA FTX or mimic of miR-215-5p inhibited the malignant properties of nephroblastoma cells. LncRNA FTX was localized in the cytoplasm and might bind miR-215-5p. LncRNA FTX promoted the malignant features of nephroblastoma cells by inhibiting miR-215-5p through activating of the PI3K/AKT pathway.

CONCLUSIONS

LncRNA FTX is capable of accelerating nephroblastoma development in vitro by reducing miR-215-5p through activating of the PI3K/AKT pathway, indicating LncRNA FTX may possibly a future target for the diagnosis and treatment of nephroblastoma. SUMMARY FIGURE.

Robotic-assisted laparoscopic surgery for the treatment of Wilms' tumor in children: single-center experience and medium-term outcomes

To report our institutional experience and the medium-term outcomes of utilizing robotic-assisted laparoscopic surgery (RALS) in patients with Wilms' tumor (WT). The robotic surgical interventions include nephron-sparing surgery (RAL-NSS), radical nephrectomy (RAL-RN), and nephrectomy with inferior vena cava thrombectomy (RAL-N-IVCT). We retrospectively collected medical records of WT patients who underwent RALS in our center between August 2019 and February 2022. Patients' baseline demographics, preoperative parameters, and perioperative/postoperative data were recorded and analyzed. Follow-up results were collected to evaluate the oncological outcomes. A total of 12 patients (13 sides) with a median age of 30 (IQR: 19.5-45.5) months were included. All operations were successfully completed without conversion. Seven patients received preoperative chemotherapy. Distribution of surgical interventions was as follows: five patients underwent RAL-RN, five received RAL-NSS, one with bilateral WT underwent concurrent RAL-RN and RAL-NSS, and one received RAL-RN-IVCT post preoperative chemotherapy. Postoperative chemotherapy was conducted in ten patients. The estimated intraoperative blood loss was 27 ± 4.0 ml for the RAL-NSS group, 41.67 ± 12.13 ml for the RAL-RN group, and 350 ml for the RAL-RN-IVCT groups, respectively. The median perioperative serum creatinine levels were 32.5 (IQR: 30.75-39.5) μmol/l preoperatively and 35 (IQR: 31.75-38.5) μmol/l postoperatively, which showed no significant difference. No positive lymph nodes were detected. Postoperative chemotherapy was performed according to the tumor volume and pathological findings. The median follow-up time was 17.5 (15.8-22.3) months. During this interval, neither distant metastasis nor recurrence was identified. Based on our medium-term follow-up observations, RAL-NSS, RAL-RN, and RAL-RN-IVCT exhibit promising feasibility and safety profiles in the therapeutic landscape of WT.

Redo nephron-sparing surgery in stage V pediatric renal tumors - A report from the SIOP/GPOH study group for renal tumors

PURPOSE

Nephron-sparing Surgery (NSS) is the surgical treatment of choice in children with bilateral renal tumors or in syndromatic patients. With an increasing role of this surgical approach, there is also an increased number of tumor relapses after NSS. Aim of this study was to evaluate a second ("Redo-") NSS in children with relapsed renal tumors.

MATERIALS AND METHODS

We retrospectively analysed patients undergoing Redo-NSS for relapsed kidney tumors between 2009 and 2021 at our institution, which represents a national reference center of the SIOP/GPOH renal tumor study group.

RESULTS

Nine patients (5 girls, 4 boys) underwent Redo-NSS with resection of 15 lesions. Mean age at surgery was 58 months (12-137), mean operative time for Redo-NSS was 195 min (137-260). R0 resection status was achieved in all children. Two patients had second relapses, one of them was resected via NSS, the other child underwent tumor nephrectomy. Two patients with anaplastic relapses died from combined second relapses. Thus, 7/9 patients are alive without evidence of disease, an impaired renal function was observed in one child. Mean follow-up after Redo-NSS was 35 months (6-49).

CONCLUSIONS

In renal tumor relapses, Redo-NSS can be performed with satisfactory oncological and functional results. Occurrence of diffuse anaplasia should possibly refrain from this approach. Further evaluation in international multicenter analyses are necessary for a definitive determination of Redo-NSS.

Unwrapping Nephrogenic Rests and Nephroblastomatosis for Pediatric Surgeons: A Systematic Review Utilizing the PICO Model by the APSA Cancer Committee

BACKGROUND

Nephrogenic rests (NR) may represent precursor lesions for Wilms tumor (WT), but their clinical course is not fully understood and no guidelines for treatment exist. This study sought to evaluate the outcomes of pediatric patients with NRs related to traditional chemotherapy and surgery.

METHODS

A PRISMA-P-compliant literature search was conducted in MEDLINE, Embase, CINAHL, Web of Science, COCHRANE, and SCOPUS from inception to June 2021. Clinical questions regarding the treatment of NRs, including chemotherapy and surgery, were developed in the population, intervention, comparison, and outcome format.

RESULTS

Twenty-five studies including 1445 patients met inclusion criteria for evaluating chemotherapy compared to observation for NRs. Eighteen studies including 1392 patients met inclusion criteria for evaluating the role of surgery for NRs. Patients with isolated NRs who underwent observation progressed to WT 33% of the time; chemotherapy reduced the rate of WT to 3.9%. Observation of multiple NRs and diffuse hyperplastic perilobar nephroblastomatosis (DHPLN) led to progression to WT 50% and 100% of the time, respectively. Chemotherapy reduced the rate of WT to 34% for multiple NRs and 46% for DHPLN. Surgery for isolated NRs reduced the risk of WT development from 23.7% in patients with incomplete excision to 3.3% with complete excision; however, 96% of patients with incompletely excised NRs had bilateral disease.

CONCLUSIONS

Observation with close surveillance for isolated NRs is safe. Treatment with chemotherapy is recommended for patients with multiple NRs and DHPLN. Surgical management of NRs should focus on renal function preservation.

LEVEL OF EVIDENCE

Treatment study, Level III.

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.

Wilms Tumor

Wilms tumor (WT), or nephroblastoma, is the most common primary malignant renal tumor of childhood. It is an embryonal tumor that develops from remnants of immature kidney. There are approximately 500 new WT cases diagnosed in the United States every year. Advances in multimodal therapy including surgery, chemotherapy, and radiation therapy given according to risk stratification have allowed most patients to achieve survival rates in excess of 90%.

Immunohistochemical expression of P53 protein in nephroblastoma: a predictor of unfavorable prognosis

OBJECTIVE

Immunohistochemical expression of P53 protein is so closely related to status of mutation of P53 gene which is tightly linked with pathogenesis of nephroblastoma or Wilms tumor. This study aims to determine the immunohistochemical expression of P53 protein and its predictors in formalin-fixed paraffin-embedded tissue blocks of patients with nephroblastoma.

MATERIALS AND METHODS

A series of 83 histologically diagnosed cases of nephroblastoma from formalin-fixed paraffin-embedded tissue blocks archived at the Department of Pathology, Makerere University, in Kampala, Uganda, were analyzed. Monoclonal anti-p53 antibody (DO-7, DAKO) was used to assess the expression of P53 protein expression. Multivariable logistic regression analysis was performed to determine the predictors of P53 protein immunohistochemical expression, and statistical significance was considered when p-value was less than 0.05.

RESULTS

Most (42.2%, n = 35) of the cases were in advanced tumor stages (III-V), and almost one-quarter (21.7%, n = 18) of the cases were in high-risk group. The immunohistochemical expression of P53 protein was (8.4%, n = 7), and there were more (83.3%, n = 5) positive anaplastic cases for P53 protein compared with (2.6%, n = 2) of P53 expression for non-anaplastic cases. High risk (AOR = 3.42, 95% CI = 7.91-12.55, p = 0.037) and anaplasia (AOR = 1.41, 95% CI = 13.85-4.46, p = 0.001) were potential predictors of immunohistochemical expression of P53 protein.

CONCLUSION

Most of patients with nephroblastoma in resources-limited settings are diagnosed with advanced clinical stages. Association of P53 protein with anaplasia found in this study indicates the possibility of having novel target therapy for treatment of patients with anaplastic form of nephroblastoma with a focus of identifying molecules that lead to its suppression in such subpopulations of patients with nephroblastoma.

[Correlation between 25-hydroxyvitamin D and nephroblastoma in children and its value in assessing disease prognosis]

OBJECTIVES

To study the correlation between 25-hydroxyvitamin D [25-(OH)D] and nephroblastoma in children and its value in assessing the prognosis of the disease.

METHODS

A total of 50 children with nephroblastoma who were admitted from January 2018 to December 2022 were included as the nephroblastoma group, and according to the postoperative pathological type, they were divided into a good prognosis group with 38 children and a poor prognosis group with 12 children. A total of 50 healthy children who underwent physical examination during the same period of time served as the healthy control group. The above groups were compared in terms of serum creatinine and 25-(OH)D level. A Spearman correlation analysis was used to investigate the correlation between serum 25-(OH)D level and therapeutic effect reaction. A multivariate logistic regression analysis was used to identify the risk factors affecting the prognosis of nephroblastoma in children.

RESULTS

The nephroblastoma group had significantly lower levels of serum creatinine and 25-(OH)D than the healthy control group (P<0.05). Compared with the good prognosis group, the poor prognosis group had a significantly larger tumor diameter, a significantly higher proportion of children with stage III-IV tumors, a significantly higher rate of tumor metastasis, and significantly lower serum levels of creatinine and 25-(OH)D (P<0.05). The Spearman correlation analysis showed that serum 25-(OH)D level was negatively correlated with therapeutic effect reaction (r_s=-0.685, P<0.001). The multivariate logistic regression analysis showed that tumor diameter ≥10 cm, stage III-IV tumors, presence of tumor metastasis, and 25-(OH)D <19 ng/mL were closely associated with the poor prognosis of nephroblastoma in children (P<0.05). Serum 25-(OH)D level had an area under the curve of 0.805 (95%CI: 0.706-0.903, P<0.001) in evaluating the prognosis of nephroblastoma in children, with a Youden index of 0.512, a sensitivity of 0.938, and a specificity of 0.575 at the optimal cut-off value of 1.764 ng/mL.

CONCLUSIONS

There is a significant correlation between 25-(OH)D level and the prognosis of nephroblastoma in children, and 25-(OH)D can be used for prognosis prediction.

Wilms tumor: A case report with typical clinical and radiologic features in a 3-year-old male

Wilms' tumor, also known as nephroblastoma, is a rare cancer of the kidney that occurs almost exclusively in children. In this case report, a 3-year-old male presented to the hospital with left flank swelling and recurrent fever of 4 months duration. On examination, the abdomen was distended, with associated left flank fullness and distension of the anterior abdominal wall veins. A left nontender firm flank mass was palpated. Upon extensive imaging, the mass was revealed to be a nephroblastoma. The study reviews the use of imaging as a means of achieving a diagnosis and accurately measuring the size and magnitude of the tumor in order that treatment, whether surgery or chemotherapy, be commenced.

Robot-assisted radical nephrectomy for Wilms' tumor in children

INTRODUCTION

Surgical removal of the tumor is a key step in the management of nephroblastoma. Less invasive surgical approaches such as robot-assisted radical nephrectomy (RARN) has gained momentum over the past few years. This video presents a comprehensive step-by-step video for two cases: one uncomplicated left RARN and one more challenging right RARN.

MATERIALS & METHODS

Following the UMBRELLA/SIOP protocol, both patients received neoadjuvant chemotherapy. Under general anesthesia, in a lateral decubitus position, four robotic and one assistant port are placed. After mobilization of the colon, the ureter and gonadal vessels are subsequently identified. The renal hilum is dissected, and the renal artery and vein are divided. The kidney is dissected with sparing of the adrenal gland. The ureter and gonadal vessels are divided, and the specimen is removed through a Pfannenstiel incision. Lymph node sampling is performed.

RESULTS

Patients were 4 and 5 years old. The total surgical time was 95 and 200 min, with an estimated blood loss of 5 and 10 cc. The hospital stay was limited to 3 and 4 days. Both pathological reports confirmed the diagnosis of nephroblastoma, with tumour-free resection margins. No complications were observed 2 months postoperatively.

CONCLUSION

RARN is feasible in children.

Robotic approach with neoadjuvant chemotherapy in adult Wilms' tumor: A feasibility study report and a systematic review of the literature

Objective

The incidence of Wilms' tumor (WT) among adult individuals accounts for less than 1% of kidney cancer cases, with a prognosis usually less favorable when compared to younger individuals and an overall survival rate of 70% for the adult patients versus 90% for the pediatric cases. The diagnosis and treatment of WT are complex in the preoperative setting; neoadjuvant chemotherapy (NAC) or robotic surgery has rarely been described. This study aimed to review the literature of robotic surgery in WT and report the first adult WT management using both NAC and robotic strategy.

Methods

We reported a case of WT managed in a multidisciplinary setting. Furthermore, according to Preferred Reporting Items for Systematic reviews and Meta-Analyses recommendations, a systematic review of the literature until August 2020 of WT treated with a robotic approach was carried out.

Results

A 33-year-old female had a diagnosis of WT. She was scheduled to NAC, and according to the clinical and radiological response to a robotic radical nephrectomy with aortic lymph nodes dissection, she was managed with no intraoperative rupture, a favorable surgical outcome, and a follow-up of 25 months, which did not show any recurrence. The systematic review identified a total number of 230 cases of minimally invasive surgery reported in the literature for WT. Of these, approximately 15 patients were carried out using robotic surgery in adolescents while none in adults. Moreover, NAC has not been administered before minimally invasive surgery in adults up until now.

Conclusion

WT is a rare condition in adults with only a few cases treated with either NAC or minimally invasive approach so far. The advantage of NAC followed by the robotic approach could lead to favorable outcomes in this complex scenario. Notwithstanding, additional cases of adult WT need to be identified and investigated to improve the oncological outcome.

Wilms tumor in children: A multivariate analysis of prognostic factors, with emphasis on inferior vena cava/right atrium extension. Results from a single-center study

BACKGROUND

To identify prognostic factors for overall survival through the analysis of 132 patients with Wilms tumor followed at a single center, with emphasis on the inferior vena cava/right atrium extension.

METHODS

Retrospective analysis of overall survival using logistic regression models and including age, sex, clinical features, associated syndromes, comorbidities, tumor size before chemotherapy, stage, presence of metastatic disease and its site, invasion of adjacent structures, inferior vena cava/right atrium extension, laterality, tumor histology, chemotherapy protocol, and radiotherapy as potential risk factors.

RESULTS

From January 2000 through November 2021, 132 patients met the inclusion criteria, 64 females and 68 males; 15 (11.4%) patients presented with tumoral extension to inferior vena cava/right atrium and 44 had metastatic disease (33.3%). Based on logistic regression, the factors correlating to a fatal outcome were male sex (p = 0.046), high risk histology (p = 0.036), and the presence of metastatic disease (p = 0.003). None of the patients presenting inferior vena cava/right atrium extension died (p = 0.992). In a specific analysis of metastatic sites, hepatic metastasis alone showed correlation with a fatal outcome (p = 0.001).

CONCLUSION

These results underline the importance of identifying and treating metastatic disease and high-risk tumors. The female gender as a potential driver for a less aggressive disease is a new finding that deserves further investigation. The accurate identification of inferior vena cava/right atrium extension, subsequent preoperative chemotherapy, and resection with a skilled team promoted survival rates of all patients.

LEVEL OF EVIDENCE

II.

Direct correlation of MRI with histopathology in pediatric renal tumors through the use of a patient-specific 3-D-printed cutting guide: a feasibility study

BACKGROUND

Pediatric renal tumors are often heterogeneous lesions with variable regions of distinct histopathology. Direct comparison between in vivo imaging and ex vivo histopathology might be useful for identification of discriminating imaging features.

OBJECTIVE

This feasibility study explored the use of a patient-specific three-dimensional (3D)-printed cutting guide to ensure correct alignment (orientation and slice thickness) between magnetic resonance imaging (MRI) and histopathology.

MATERIALS AND METHODS

Before total nephrectomy, a patient-specific cutting guide based on each patient's preoperative renal MRI was generated and 3-D printed, to enable consistent transverse orientation of the histological specimen slices with MRI slices. This was expected to result in macroscopic slices of 5 mm each. The feasibility of the technique was determined qualitatively, through questionnaires administered to involved experts, and quantitatively, based on structured measurements including overlap calculation using the dice similarity coefficient.

RESULTS

The cutting guide was used in eight Wilms tumor patients receiving a total nephrectomy, after preoperative chemotherapy. The median age at diagnosis was 50 months (range: 4-100 months). The positioning and slicing of the specimens were rated overall as easy and the median macroscopic slice thickness of each specimen ranged from 5 to 6 mm. Tumor consistency strongly influenced the practical application of the cutting guide. Digital correlation of a total of 32 slices resulted in a median dice similarity coefficient of 0.912 (range: 0.530-0.960).

CONCLUSION

We report the feasibility of a patient-specific 3-D-printed MRI-based cutting guide for pediatric renal tumors, allowing improvement of the correlation of MRI and histopathology in future studies.

Sociodemographic factors associated with Wilms tumor treatment and survival: a population-based study

INTRODUCTION

Though Wilms tumor (WT) is one of the most common malignancies in children, there is a paucity of epidemiologic studies exploring sociodemographic disparities in treatment and survival. Here, we leveraged a national cancer registry to examine sociodemographic factors associated with receipt of adjuvant therapy, either chemotherapy or radiation, as well as overall survival among pediatric patients with WT.

MATERIALS AND METHODS

Within the Surveillance Epidemiology and End Results database (2000-2016), we identified 2043 patients (≤ 20 years of age) with unilateral WT. Multivariable logistic regression and Cox proportional hazard models were constructed to examine the association of sociodemographic factors with, respectively, adjuvant chemotherapy/radiotherapy and overall survival (OS).

RESULTS

Patients in the lowest SES quintile (OR 0.56, 95% CI 0.33-0.93, p = 0.03) were less likely to receive chemotherapy as compared to those in the highest SES quintile, though this association did not persist in sensitivity analyses including only patients at least 2 years of age and patients with regional/distant disease. In addition, female patients were more likely to receive chemotherapy (OR 1.46, 95% CI 1.08-1.97, p = 0.02) than male patients. Age, race, year of diagnosis, insurance status, and tumor laterality were not associated with receipt of chemotherapy. No sociodemographic variables were associated with receipt of radiotherapy. Lastly, as compared to Non-Hispanic-White patients, Hispanic patients had worse OS (HR 1.59, 95% CI 1.08-2.35, p = 0.02); no other sociodemographic variables were associated with OS.

CONCLUSIONS

This study suggests multilevel sociodemographic disparities involving ethnicity and SES in WT treatment and survival.

Surgical management and outcomes of intracranial metastatic Wilms' tumor in the pediatric population: a case series

PURPOSE

Approximately 1 to 2% of patients with Wilms' tumor (WT), or nephroblastoma, will have metastasis to the brain. Due to the rarity of intracranial metastasis, the clinical characteristics, prognosis, and a standardized treatment approach to this occurrence remain poorly understood. Here we review the surgical management and treatment outcome of WT patients with intracranial metastasis at our institution.

METHODS

A retrospective chart review of patients with WT at the Children's Hospital of Philadelphia was performed from 2007 to 2021. Clinical characteristics, operative details, radiographic studies, pathology, and patient outcomes were collected and analyzed.

RESULTS

A total of 3 patients with histologically confirmed intracranial metastatic disease from WT were identified with a mean age of 5.7 years (range 3-10 years). 2 of the 3 patients were male. The mean time from diagnosis of primary WT to development of central nervous system metastasis was 15.3 months. Both supratentorial (n = 3) and infratentorial (n = 1) sites of metastasis were observed. Surgical resection was performed, and gross total resection was achieved in all 3 patients. All cases had favorable histology with no anaplasia and received whole-brain irradiation and chemotherapy. Two of 3 patients had a good neurologic function at postoperative follow-up. One patient died from their disease 4 months after resection of the brain metastasis.

CONCLUSION

In WT patients with limited systemic disease burden, the combination of surgery, chemotherapy, and radiotherapy may play a role in enhancing survival when intracranial metastasis is present, despite the perioperative risk associated with surgery.

Knockdown of lncRNA HAGLROS inhibits metastasis and promotes apoptosis in nephroblastoma cells by inhibition of autophagy

Nephroblastoma, or Wilms tumor, is a primary renal malignant tumor that easily occurs in children. Previous studies have revealed the regulatory functions of LncRNA in nephroblastoma. LncRNA HAGLROS functions as a tumor promotor in various cancers including hepatocellular carcinoma, ovarian cancer and colorectal cancer. In this study, the HAGLROS expression in nephroblastoma cells was assayed through qRT-PCR. Cell proliferation assessment employed CCK-8. Moreover, the migration and invasion of cells were examined separately through wound healing and transwell assay. Moreover, flow cytometric analysis and Western blot assay were applied to evaluate cell apoptosis. Rapamycin and 3-methyladenine were used to serve as autophagy activator or inhibitor, respectively. In addition, autophagy was identified by immunofluorescence staining and Western blot analysis. Experiment results showed that HAGLROS expressed highly in nephroblastoma cell lines. HAGLROS knockdown prevented cells from proliferating, and also showed suppressive impact on migration and invasion in HFWT cells. In addition, knockdown of HAGLROS showed a facilitative effect on apoptosis and an inhibitory effect on autophagy. Stimulation of autophagy alleviated HAGLROS silencing-induced apoptosis, while inhibition of autophagy reversed the effect in nephroblastoma cells. In summary, our results revealed that HAGLROS executed an oncogenic role in the progress of nephroblastoma, offering a new perspective on the strategy for nephroblastoma therapy.

The role of liver resection in metastatic nephroblastoma: a systematic review and Meta-regression analysis

BACKGROUND

The impact of hepatic resection for liver metastases (LM) on the survival of pediatric patients with Wilms' tumor (WT) is unclear. So far, there is a lack of studies investigating the best suited treatment for patients with WTLM, and the role of liver resection has rarely been investigated. Thus, the development of evidence-based guidelines concerning indications of liver resection for WTLM remains difficult.

AIM

To investigate the role of surgery in the therapy of WTLM. All available data on liver resections and subgroup outcomes of patients with WTLM are analyzed. Main research question is whether liver resection improves survival rates of patients with WTLM compared to non-surgical treatment.

METHODS

A systematic literature search of MEDLINE, Web of Science, and Central provided the basis for this PRISMA-compliant systematic review. For the main analysis (I), all studies reporting on surgical treatment of pediatric WTLM were included. To provide a representative overview of the general outcome of WTLM patients, in analysis II all studies with cohorts of at least five WTLM patients, regardless of the kind of treatment, were reviewed and analyzed. A Multiple meta-regression model was applied to investigate the impact liver resection on overall survival.

RESULTS

14 studies with reports of liver resection for WTLM were found (Analysis I). They included a total of 212 patients with WTLM, of which 93 underwent a liver resection. Most studies had a high risk of bias, and the quality was heterogenous. For the analysis II, eight studies with subgroups of at least five WTLM patients were found. The weighted mean overall survival (OS) of WTLM patients across the studies was 55% (SD 29). A higher rate of liver resection was a significant predictor of better OS in a multiple meta-regression model with 4 covariates (I2 29.43, coefficient 0.819, p = 0.038).

CONCLUSIONS

This is the first systematic review on WTLM. Given a lack of suited studies that specifically investigated WTLM, ecological bias was high in our analyses. Generating evidence is complicated in rare pediatric conditions and this study must be viewed in this context. Meta-regression analyses suggest that liver resection may improve survival of patients with WTLM compared to non-surgical treatment. Especially patients with persisting disease after neoadjuvant chemotherapy but also patients with metachronous LM seem to benefit from resection. Complete resection of LM is vital to achieve higher OS. Studies that prospectively investigate the impact of surgery on survival compared to non-surgical treatment for WTLM are highly needed to further close the current evidence gap.

STUDY REGISTRATION

PROSPERO 2021 CRD42021249763  https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=249763 .

Adult Wilms with Biphasic Pattern; A Case Report

Background:

Wilms' tumor, nephroblastoma, is an extremely uncommon kidney tumor of adulthood. We reported a woman with a huge kidney mass diagnosed with nephroblastoma.

Case presentation:

A 39-year-old female was assessed due to right flank pain. CT scan revealed a mass measuring 128×100 mms involving the upper portion of the right kidney. The patient underwent nephrectomy, and the diagnosis of adult Wilms' tumor was confirmed based on the morphological and immunohistochemical findings.

Conclusion:

In adult patients with flank pain and renal mass, the diagnosis of Wilms' tumor should be pronounced in the absence of histopathologic features of renal cell carcinoma.

Implications of cell division cycle associated 4 on the Wilm's tumor cells viability via AKT/mTOR signaling pathway

Objective

The aim of present report was to elucidate the effect of cell division cycle associated 4 (CDCA4) on the proliferation and apoptosis of Wilm’s tumor cells, and to further evaluate its underlying mechanism.

Methods

The expression profiles of CDCA4 and clinical information of Wilm’s tumor patients were obtained from public Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database portal. Real-time qPCR and western blot analyses were utilized to determine the expression levels of CDCA4. Gain- and loss-of-function of CDCA4 assays were conducted with transfection technology to investigate the biological role of CDCA4 in Wilm’s tumor cells. Cell counting kit 8 and flow cytometer assays were employed to examine the effect of CDCA4 on the cells proliferation and apoptosis. Protein expression levels of indicated markers in each group of Wilm’s tumor cells were measured by western blot.

Results

The transcriptional expression of CDCA4 was drastically upregulated in Wilm’s tumor tissues according to the public TARGET database and in Wilm’s tumor cells. The cells viability was remarkably reduced whereas the cells apoptosis was increased in CDCA4-knockdown group compared with negative control group. However, CDCA4-overexpression group promoted the cells proliferation and suppressed the cells apoptosis. Furthermore, the protein expression levels of p-AKT, p-mTOR, and Cyclin D1 were significantly reduced after depletion of CDCA4, whereas overexpression of CDCA4 dramatically elevated these markers’ expression levels.

Conclusions

CDCA4 is highly expressed in Wilm’s tumor and promoted the proliferation whereas inhibited the apoptosis of Wilm’s tumor cells through activating the AKT/mTOR signaling pathway.

Report of a rare testicular teratoid Wilms Tumor in an adult patient

Although primarily a pediatric disease, nephroblastomas (also known as Wilms tumor) occur in adults at a rate of less than 0.2 cases per million per year. Rarer still are teratoid Wilms tumors, which arise from teratomas and therefore can be extrarenal. We describe the sixth recorded case of a testicular teratoid Wilms tumor in an adult patient with accompanying histological images of the specimen. Following the case, there is a brief discussion of the current literature.

Duplex kidney complicated with preoperative inferior nephroblastoma rupture in children: a case report and literature review

Background

We admitted a child with a duplex kidney combined with preoperative rupture of nephroblastoma and used this case to discuss the clinical features and treatment of this disease.

Case presentation

We retrospectively analyzed the clinical data of a 5-year-old girl with preoperative duplex kidney rupture combined with inferior nephroblastoma who was admitted to the Fourth Hospital of Baotou. In addition, we reviewed the relevant literature. The patient’s details were as follows: weight, 17 kg; height, 108 cm; and body surface area, 0.7 m². Abdominal ultrasound for abdominal pain revealed the presence of a left-sided renal mass; enhanced abdominal computed tomography further confirmed it to be a left-sided duplex kidney measuring approximately 6 × 5 × 5 cm, with a rupture originating from the lower kidney. The PubMed database was searched from 2010 to 2020 for the terms “Wilms’ tumor” and “Duplex” and “Wilms’ tumor” and “Rupture.” The treatment plan was preoperative chemotherapy (vincristine/dactinomycin, VA regimen) + left kidney tumor radical surgery + postoperative chemotherapy (actinomycin-D/VCR/doxorubicin, AVD regimen). Postoperative pathology revealed an International Society of Pediatric Oncology intermediate-risk stage-3 nephroblastoma (mixed type) in the left kidney. Literature review was performed with 71 cases meeting the set criteria with an aim to analyze and summarize the clinical characteristics and treatment of patients with ruptured nephroblastoma and duplex kidney combined with nephroblastoma.

Conclusions

To our knowledge, no previous studies have reported preoperative duplex kidney combined with nephroblastoma rupture. In patients with this condition, preoperative chemotherapy is recommended when the vital signs are stable and tumor resection can be performed after the tumor has shrunk to prevent secondary spread. If the patient’s vital signs are unstable, emergency exploratory surgery is needed. If the nephroblastoma rupture is old and limited, surgery can be performed when the tumor size is small.

WT1 regulates HOXB9 gene expression in a bidirectional way

The homeoboxB9 (HOXB9) gene is necessary for specification of the anterior-posterior body axis during embryonic development and expressed in various types of cancer. Here we show that the Wilms tumor transcription factor WT1 regulates the HOXB9 gene in a bidirectional manner. Silencing of WT1 activates HOXB9 in Wt1 expressing renal cell adenocarcinoma-derived 786-0 cells, mesonephric M15 cells and ex vivo cultured murine embryonic kidneys. In contrast, HOXB9 expression in U2OS osteosarcoma and human embryonic kidney (HEK) 293 cells, which lack endogenous WT1, is enhanced by overexpression of WT1. Consistently, Hoxb9 promoter activity is stimulated by WT1 in transiently transfected U2OS and HEK293 cells, but inhibited in M15 cells with CRISPR/Cas9-mediated Wt1 deletion. Electrophoretic mobility shift assay and chromatin immunoprecipitation demonstrate binding of WT1 to the HOXB9 promoter in WT1-overexpressing U2OS cells and M15 cells. BASP1, a transcriptional co-repressor of WT1, is associated with the HOXB9 promoter in the chromatin of these cell lines. Co-transfection of U2OS and HEK293 cells with BASP1 plus WT1 prevents the stimulatory effect of WT1 on the HOXB9 promoter. Our findings identify HOXB9 as a novel downstream target gene of WT1. Depending on the endogenous expression of WT1, forced changes in WT1 can either stimulate or repress HOXB9, and the inhibitory effect of WT1 on transcription of HOXB9 involves BASP1. Consistent with inhibition of Hoxb9 expression by WT1, both transcripts are distributed in an almost non-overlapping pattern in embryonic mouse kidneys. Regulation of HOXB9 expression by WT1 might become relevant during kidney development and cancer progression.

Commentary on bilateral Wilms' tumour: An international comparison of treatments and outcomes

This is a commentary on the manuscript titled "Bilateral wilms' tumour: An international comparison of treatments and outcomes" by Drysdale H, Fawkner-Corbett D, Solomon Z, et al.

Bilateral Wilms' tumour: An international comparison of treatments and outcomes

INTRODUCTION

Wilms' tumour is the most common childhood renal malignancy, with 5-10% of cases presenting bilaterally ¹. However, there is currently no consensus between centres on optimal management of bilateral Wilms' tumours. This is an international multi-centre case series comparing management and outcomes of bilateral Wilms' tumours between low-income centres (LIC) and high-income centres (HIC).

METHODS

Patients with bilateral Wilms' tumour were identified from four tertiary referral centres internationally. Data were collected on baseline characteristics, disease status, treatment used and clinical outcomes. Results were compared between individual centres as well as between groups of low-income centres (LIC) and high-income centres (HIC).

RESULTS

Data were collected for forty patients. Most patients received preoperative chemotherapy (n = 38, 95%). The most common surgical procedures were bilateral nephron-sparing surgery (n = 10, 25%) and nephrectomy with partial nephrectomy (n = 20, 50%). Ten-year survival after treatment was as follows: LIC's n = 13 (65%); HIC's n = 20 (100%) (p = 0.01).

DISCUSSION

Ten-year survival was significantly higher in HIC's. Our results show this may be caused by patient factors such as later presentation with more advanced disease in low-income centres. This comparative case series is the first to report on a large number of cases from multiple international centres, and to compare key outcomes.

Wilms tumour surveillance in at-risk children: Literature review and recommendations from the SIOP-Europe Host Genome Working Group and SIOP Renal Tumour Study Group

Since previous consensus-based Wilms tumour (WT) surveillance guidelines were published, novel genes and syndromes associated with WT risk have been identified, and diagnostic molecular tests for previously known syndromes have improved. In view of this, the International Society of Pediatric Oncology (SIOP)-Europe Host Genome Working Group and SIOP Renal Tumour Study Group hereby present updated WT surveillance guidelines after an extensive literature review and international consensus meetings. These guidelines are for use by clinical geneticists, pediatricians, pediatric oncologists and radiologists involved in the care of children at risk of WT. Additionally, we emphasise the need to register all patients with a cancer predisposition syndrome in national or international databases, to enable the development of better tumour risk estimates and tumour surveillance programs in the future.

Wilms tumor presenting as small bowel obstruction in a neonate: A diagnostic challenge

Wilms tumor is the most common primary malignant renal tumor of childhood which usually presents between 2 and 6 years of age. Its presentation in the neonatal period is extremely rare and presenting with intestinal obstruction is perhaps unknown. We report a 2-day-old baby girl who manifested features of acute upper gastrointestinal obstruction with frequent post-feeding vomiting and abdominal distension. The initial abdominal radiograph showed abnormally displayed small bowel loops to the right hemiabdomen. Subsequent ultrasound and computed tomography scan of the abdomen detected a massive left renal mass. Left-sided nephrectomy was performed, and histopathology demonstrated left-sided Wilms tumor with favorable histology. Post-treatment yearly follow-up for 5 years recorded a disease-free, normally thriving child.

Diffusion-weighted MRI and histogram analysis: assessment of response to neoadjuvant chemotherapy in nephroblastoma

Purpose

To assess the value of diffusion-weighted MRI (DW-MRI) in the non-invasive prediction of blastemal remnant after neoadjuvant chemotherapy in nephroblastoma.

Methods

This IRB-approved study included 32 pediatric patients with 35 tumors who underwent DW-MRI prior and after completion of neoadjuvant chemotherapy and subsequent surgical resection. Two blinded radiologists volumetrically assessed each tumor on pre- and post-neoadjuvant images and the parameters mean ADC, median ADC, 12.5th/25th/75th ADC percentile, skewness, and kurtosis were calculated. Blastemal remnant was determined per the pathology report. Associations between imaging features and blastemal remnant quartiles were examined using the Kruskal–Wallis test and adjusted for false discovery rate.

Results

Inter-reader agreement was high for mean ADC, skewness, kurtosis, and volume (ICC: 0.76–0.998). Pre-therapeutic histogram parameters skewness and kurtosis were found to be higher in patients with a higher amount of blastemal remnant for reader 1 (overall p = 0.035) and for kurtosis in reader 2 (overall p = 0.032) with skewness not reaching the level of statistical significance (overall p = 0.055). Higher tumor volume on pre-treatment imaging was associated with a higher amount of blastemal remnant after therapy (overall p = 0.032 for both readers).

Conclusions

Pre-treatment skewness and kurtosis of ADC histogram analysis were significantly associated with a larger fraction of a blastemal remnant after neoadjuvant chemotherapy. These findings could be incorporated into a more personalized chemotherapeutic regime in these patients and offer prognostic information at the time of initial diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00261-021-03032-9.

[Imaging of renal tumors in children]

CLINICAL/METHODOLOGICAL ISSUE

Renal tumors in children are treated according to the guidelines of the Renal Tumor Study Group of the International Society of Pediatric Oncology (SIOP-RTSG). Nephroblastoma is the most frequent renal tumor in children.

STANDARD RADIOLOGICAL METHODS

After sonography, magnetic resonance imaging (MRI) is the preferred imaging modality. The task of imaging includes differential diagnosis with the help of morphological and epidemiological criteria. Thorax computed tomography (CT) is introduced for initial staging.

METHODOLOGICAL INNOVATIONS

Current studies of diffusion-weighted imaging (DWI)-MRI with analysis of the apparent diffusion coefficient (ADC) histogram indicate the potential to differentiate blastemal or anaplastic high-risk histology nephroblatoma subtypes. Imaging criteria for nephron-sparing surgery are defined and allow an individual therapy option in unilateral and especially in bilateral renal nephroblastoma.

PERFORMANCE

In addition to nephroblastoma, the differential diagnosis includes congenital mesoblastic nephroma, malignant rhabdoid tumor of the kidney, clear cell sarcoma and renal cell carcinoma. The diagnosis of nephrogenic rests and nephroblastomatosis is challenging.

ACHIEVEMENTS

Diagnostic standardization improves diagnosis and therapy of renal childhood tumors, and new prognostic markers may be introduced in the near future.

Recombinant Chinese Hu191 measles virus exhibits a significant antitumor activity against nephroblastoma mediated by immunogenic form of apoptosis

In previous studies oncolytic measles viruses (MVs) have shown significant antitumor activity against various tumors. In our research recombinant MV-Hu191 (rMV-Hu191), established via reverse genetics technology and expressing enhanced green fluorescent protein (EGFP), was evaluated for its therapeutic effects and related mechanisms against nephroblastoma cell lines. We built three different constructs based on rMV-Hu191 to express EGFP effectively. Our experiments showed that rMV-Hu191 expressing EGFP could efficiently infect and replicate in nephroblastoma cell lines. Caspase-induced apoptosis exerted a significant impact on MV-induced cell death, which was accompanied by emission of cellular ATP and high-mobility group protein 1 (HMGB1) and by translocation of calreticulin (CRT). Intratumoral injection of rMV-Hu191-EGFP resulted in significant regression of tumors in a G401 xenograft model. Our results indicate that the MV-Hu191 strain, which is widely used in China, is an appropriate vector for expression of foreign genes and could serve as a potentially good candidate for nephroblastoma therapy mediated by induction of apoptosis-associated immunogenic cell death (ICD).

Many faces of Wilms Tumor: Recent advances and future directions

Background

Wilms’ tumor (WT) is the most frequently occurring paediatric renal tumor and is one of the most treatment-responsive tumors. A tumor-suppressor gene and other genetic abnormalities have been implicated in its etiology. In addition, patients with many congenital anomalies, such as Beckwith-Wiedemann syndrome, WAGR syndrome and Denys-Drash syndrome, have an increased risk of WT.

Methods and results

Two large collaborative groups – National Wilms Tumor Study Group (NWTSG)/Children's Oncology Group (COG) and The International Society of Paediatric Oncology (SIOP) have laid down the guidelines for standardized treatment of WT, though differing in the diagnostic and therapeutic approach. The major difference in the two guidelines is the timing of surgery: SIOP recommends using preoperative chemotherapy and NWTSG/COG prefers primary surgery before any adjuvant treatments. Both these groups currently aim at intensifying treatment for patients with poor prognosticators while appropriating the therapy to reduce long-term complications for those with favourable prognostic features. As the survival rate has now reached 90%, the primary objectives of the physician are to perform nephron-sparing surgery in selected cases and to reduce the dosage and duration of chemotherapy and radiotherapy in appropriate cases. The purpose of this review is to present current standards of diagnosis and treatment of WT around the world.

Conclusion

Further studies in future should be done to highlight the use of chemotherapy and radiotherapy under risk-stratified strategies. Further improvement in survival of these children can only be achieved by increasing awareness, early recognition, appropriate referral, and a multidisciplinary approach.

•

o Most of the patients with WT have good prognosis.

•

o Multimodality treatment and multidisciplinary care are the major contributors for an improved prognosis.

•

o Further studies should be done on usage of chemotherapy and radiotherapy under more accurate risk-stratified strategies and to decrease the late effects of surgery.

Methods of spatial cluster detection in rare childhood cancers: Benchmarking data and results from a simulation study on nephroblastoma

The potential existence of spatial clusters in childhood cancer incidence is a debated topic. Identification of rare disease clusters in general may help to better understand disease etiology and develop preventive strategies against such entities.

The incidence of newly diagnosed childhood malignancies under 15 years of age is 140/1,000,000. In this context, the subgroup of nephroblastoma represents an extremely rare entity with an annual incidence of 7/1,000,000. We evaluated widely used statistical approaches for spatial cluster detection in childhood cancer (Ref. Schündeln et al., 2021, Cancer Epidemiology). For the simulation study, random high risk clusters of 1 to 50 adjacent districts (NUTS-level 3, nomenclature des unités territoriales statistiques) were generated on the basis of the 402 German administrative districts. Each cluster was simulated with different relative risk levels (1 to 100). For each combination of cluster size and risk level 2000 iterations were performed. Simulated data was then analyzed by three local clustering tests: Besag-Newell method, spatial scan statistic and the Bayesian Besag-York-Mollié approach (fit by Integrated Nested Laplace Approximation). The performance characteristics of all three methods were systematically documented (sensitivity, specificity, positive/negative predictive values, exact- and minimum power, correct classification, positive/negative diagnostic likelihood and false positive/negative rate).

This data article links to a Mendeley online repository which includes the raw data of simulated high-risk clusters and simulated cases on the district level for an all-childhood-malignancy scenario as well as for cases of nephroblastoma. These data was used for the evaluation of the three cluster detection methods. The R code for simulation and analysis are available from GitHub.

The article also includes analyzed data summarizing the performance of the cluster detection tests in very rare disease entities, using the example of simulated nephroblastoma cases.

The raw data from the study can be used for benchmarking analyses applying different spatial statistical methods systematically and evaluating their performance characteristics comparatively. The analyzed data from the nephroblastoma example can be useful to interpret the performance of the three applied local cluster detection tests in the setting of extremely rare disease entities. As a practical application, data and R code can be used for performance analyses when planning to establish surveillance systems for rare disease entities.

[Deleted in lymphocytic leukemia 1 promoted proliferation and apoptosis of nephroblastoma cells through regulating miR-513a-5p and RANBP2 pathway]

Objective: To study the regulatory effects and mechanisms of deleted in lymphocytic leukemia 1 (DLEU1), microRNA-513a-5p (miR-513a-5p), and RAN binding protein 2 (RANBP2) in nephroblastoma. Methods: The GHINK-1 cells were transfected with pcDNA (pcDNA group), pcDNA-DLEU1 (pcDNA-DLEU1 group), miR-NC (miR-NC group), miR-513a-5p mimics (miR-513a-5p group), pcDNA-RANBP2 (pcDNA-RANBP2 group), pcDNA-DLEU1 and miR-NC (pcDNA-DLEU1+ miR-NC group), pcDNA-DLEU1 and miR-513a-5p mimics (pcDNA-DLEU1+ miR-513a-5p group), miR-513a-5p mimics and pcDNA (miR-513a-5p+ pcDNA group), miR-513a-5p mimics and pcDNA-RANBP2 (miR-513a-5p + pcDNA-RANBP2 group). Real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to detect the expressions of DLEU1, miR-513a-5p, RANBP2 in nephroblastoma tissues, normal adjacent tissues, normal kidney cell HK2, and hemangioblastoma cell GHINK-1. Western blot was used to detect the expressions of proliferating cell nuclear antigen (PCNA), B cell lymphoma/leukemia-2 (Bcl-2) and Bcl-2 related X (Bax). Cell counting kit 8 (CCK-8) was used to detect the cell survival rate. Flow cytometry was used to detect the apoptosis rate. Dual luciferase report test was used to detect the luciferase activity of cells. Results: The expression levels of DLEU1, miR-513a-5p and RANBP2 in adjacent tissues were 1.02±0.08, 1.01±0.06, 1.00±0.05, respectively, significantly lower than 5.16±0.24, 0.23±0.02, 1.67±0.09 in nephroblasts tumor tissues (P<0.05). Their expression levels in HK2 cells were 1.00±0.06, 1.00±0.08, 1.02±0.09, respectively, significantly lower than 3.15±0.21, 0.18±0.01, 1.54±0.10 in GHINK-1 cells (P<0.05). Overexpression of DLEU1 significantly reduced the apoptosis rate (7.35±0.41 vs 12.35±1.12, P<0.05). Overexpression of RANBP2 significantly reduced the apoptosis rate (8.89±0.48 vs 12.64±1.12, P<0.05). Compared with the miR-NC group (1.01±0.06, 0.99±0.06), the luciferase activity of DLEU1-WT (0.43±0.04) and RANBP2-WT (0.61±0.07) in miR-513a-5p group were significantly reduced (P<0.05). Compared with anti-miR-NC group (0.99±0.07, 0.98±0.05), the luciferase activity of DLEU1-WT (1.34±0.11) and RANBP2-WT (1.39 ±0.13) in anti-miR-513a-5p group was significantly increased (P<0.05). Simultaneous overexpression of pcDNA-DLEU1 and miR-513a-5p in GHINK-1 cells significantly reduced the apoptosis rate (11.34±1.03 vs 8.51±0.69, P<0.05). Simultaneous overexpression of miR-513a-5p and RANBP2 in GHINK-1 cells significantly reduced the apoptosis rate (9.96±0.72 vs 15.94±1.00, P<0.05). Conclusions: The long-chain non-coding RNA (lncRNA) DLEU1 can promote the proliferation and inhibit the apoptosis of nephroblastoma cells. The mechanism is related to the targeted regulation of miR-513a-5p and RANBP2 function, which will provide theoretical support for the nephroblastoma treatment.

Extrarenal Wilms tumor in children: A retrospective observational case series

INTRODUCTION

Pediatric extrarenal Wilms tumor (ERWT) is rare. The diversity of clinical characteristics makes diagnosis, treatment and judging the prognosis difficult. Long-term follow-up outcomes and the possible prognostic factors of ERWT are still insufficient.

OBJECTIVE

To identify the characteristics, therapeutic strategies and long-term results of pediatric ERWT.

PATIENTS AND METHODS

All children with ERWT in our institution were retrospectively reviewed. The National Wilms Tumor Study (NWTS) system was used to evaluate tumor grade.

RESULTS

Among the 876 patients with Wilms tumor in our institution between January 1986 and July 2018, 5 (0.57%) patients had ERWT. Of the 5 children with ERWT, the locations were the retroperitoneum in 3 patients (including 1 presacral) and the gubernaculum testis of an undescended testis and a duplicate sigmoid colon in 1 patient each. Two patients were stage II, and 3 patients were stage III. The three patients with larger tumor sizes had preoperative tumor rupture. In the long-term follow-up, ranging from 1.0 to 10.8 years, 3 patients had disease-free survival, and 2 patients with older age, a larger tumor size and preoperative tumor rupture had recurrence with metastasis, including 1 death.

DISCUSSION

Wilms tumor extremely rarely originates outside the kidney. The current case series represents the first report of ERWT accompanied by a duplicate sigmoid colon. ERWT can coassociate with congenital gastrointestinal and genitourinary system anomalies, such as undescended testis and duplicate sigmoid colon, which provide clues to the preoperative diagnosis of ERWT. Deep and not easily palpated locations for the ERWT and older ages were associated with diagnosis delay, which can lead to enlargement of the tumor, an increased risk of preoperative tumor rupture and advancement of the tumor stage. Although only 3% of ERWT cases were metastatic according to previous reports, 2 of 5 patients (patients 1 and 4) with older age, larger tumor size and preoperative tumor rupture had recurrence and metastases in the current study. Thus, patients with poor prognoses often require aggressive combination treatments, and more attention is needed in terms of the recurrence, metastases and fatality of ERWT.

CONCLUSION

ERWTs are rare tumors and can coassociate with congenital gastrointestinal and genitourinary system anomalies. The prognosis of ERWT is comparable to that of Wilms tumor located at normal anatomical sites.

Diffusion-weighted MRI in the assessment of nephroblastoma: results of a multi-center trial

PURPOSE

To assess the value of diffusion-weighted MRI in the pre-therapeutic evaluation of pediatric renal cortical tumors.

METHODS

This IRB-approved, retrospective multi-center study included 122 pediatric patients with 130 renal tumors, who underwent MRI including DWI before neoadjuvant chemotherapy and nephrectomy. Two radiologists independently assessed each tumor volumetrically, and apparent diffusion coefficient (ADC) values were calculated on a voxel-wise basis, including parameters derived from histogram and texture analysis.

RESULTS

Inter-reader agreement was excellent (ICC 0.717-0.975). For both readers, patients with locally aggressive tumor growth (SIOP 3 stage) or with metastases (M1) had significantly lower 12.5th-percentile ADC values (p ≤ 0.028) compared to those with lower-stage tumors, and the parameter energy differed significantly between patients with M1 and those with M0 status (p ≤ 0.028). Contrast and homogeneity differed significantly between benign nephroblastomatosis and malignant nephroblastoma (p ≤ 0.045, both readers). As compared to all other subtypes, the blastemal subtype demonstrated significantly higher skewness (p ≤ 0.022, both readers) and the diffuse anaplastic subtype demonstrated significantly higher 75th-percentile ADC values (p ≤ 0.042, both readers).

CONCLUSIONS

Diffusion-weighted MRI may be of value in identifying benign nephroblastomatosis and assessing nephroblastoma subtypes. Therefore, further research is warranted to assess its value in risk stratification for pediatric patients with renal tumors in the future.

Cervical Spine Chondrosarcoma in an Adult with a History of Wilms Tumor

INTRODUCTION

We report the first case of cervical spine chondrosarcoma in a Wilms tumor survivor.

CASE DESCRIPTION

A 52-year-old female patient presented with myelopathic symptoms including poor balance, difficulty walking, and numbness of both feet. A magnetic resonance imaging of the spine showed a mass at the right C7-T1 foramen causing significant cord compression. The patient's symptoms improved after posterior decompression and fusion with excision of the tumor.

CONCLUSION

Through our experience with this case, we would like to suggest a possible unknown genetic syndrome predisposing patients with Wilms tumor to chondrosarcoma as secondary neoplasms. We would also like to re-emphasize the need for vigilance when assessing patients with a history of Wilms tumor.

From Wilms to kidney tumors: which ones require a biopsy?

Ninety percent of childhood renal tumors are Wilms tumors (nephroblastoma). While the Children's Oncology Group (COG) recommends primary surgery, the International Society of Paediatric Oncology (SIOP) recommends neoadjuvant chemotherapy, which can be initiated without histological confirmation if the presentation is typical for Wilms tumor. This review article describes the clinical, biological and radiologic criteria used by the SIOP community to consider diagnostic biopsy, i.e. when the renal origin is doubtful, when a pseudotumor is suspected or when a non-Wilms histology may be anticipated.

Health disparities among tennessee pediatric renal tumor patients

BACKGROUND/PURPOSE

Wilms tumor (WT) poses a cancer health disparity to black children globally, which has not been evaluated thoroughly for other pediatric renal cancers. We aimed to characterize health disparities among Tennessee children treated for any renal cancer.

METHODS

The Tennessee Cancer Registry (TCR) was queried for patients ≤18 years having any renal cancer (n = 160). To clarify treatment and outcomes, we performed a retrospective cohort study of pediatric renal cancer patients in our institutional cancer registry (ICR; n = 121). Diagnoses in both registries included WT, Sarcoma/Other, and Renal Cell Carcinoma. Wilcoxon/Pearson, Kaplan-Meier, and logistic regression were completed.

RESULTS

In both registries, WT comprised the most common renal cancer and youngest median age. Sarcoma was intermediate in frequency and age, and RCC was least common, having the oldest age (p < 0.001). In the TCR, black patients comprised 26% of all patients, presented more commonly with distant disease than white patients (37% v. 16%; p = 0.021), and showed worse overall survival (73% v. 89%; p = 0.018), while the ICR showed similar survival between race groups (92% v. 93%, p = 0.868). Sarcoma and metastases were independent predictors of death in both registries (p ≤ 0.002).

CONCLUSIONS

Black children in Tennessee presented with more advanced disease and experienced worse survival when combining all renal cancer types, particularly RCC and Sarcoma. When treated at a comprehensive pediatric cancer center, these survival disparities appear diminished.

TYPE OF STUDY

Prognostic study.

LEVEL OF EVIDENCE

Level II (retrospective cohort).

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.