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.