Wilms tumour: prognostic factors, staging, therapy and late effects

miRNAs Role in Wilms tumor pathogenesis: Signaling pathways interplay

Wilms' tumors (WTs) are the most common type of kidney tumor in children, and a negative outlook is generally associated with widespread anaplastic. MicroRNAs (miRNAs) are crucial in the development of WT by regulating the expression of specific genes. There is an increasing amount of research that connects the dysregulation of miRNAs to the development of various renal illnesses. The conditions encompassed are renal fibrosis, renal cancers, and chronic and polycystic kidney disease. Dysregulation of several important miRNAs, either oncogenic or tumor-suppressing, has been found in WT. The present state of knowledge on the involvement of dysregulated miRNAs in the progression of WT is summarized in this review.

Radiomics in differential diagnosis of Wilms tumor and neuroblastoma with adrenal location in children

OBJECTIVES

Machine learning methods can be applied successfully to various medical imaging tasks. Our aim with this study was to build a robust classifier using radiomics and clinical data for preoperative diagnosis of Wilms tumor (WT) or neuroblastoma (NB) in pediatric abdominal CT.

MATERIAL AND METHODS

This is a single-center retrospective study approved by the Institutional Ethical Board. CT scans of consecutive patients diagnosed with WT or NB admitted to our hospital from January 2005 to December 2021 were evaluated. Three distinct datasets based on clinical centers and CT machines were curated. Robust, non-redundant, high variance, and relevant radiomics features were selected using data science methods. Clinically relevant variables were integrated into the final model. Dice score for similarity of tumor ROI, Cohen's kappa for interobserver agreement among observers, and AUC for model selection were used.

RESULTS

A total of 147 patients, including 90 WT (mean age 34.78 SD: 22.06 months; 43 male) and 57 NB (mean age 23.77 SD:22.56 months; 31 male), were analyzed. After binarization at 24 months cut-off, there was no statistically significant difference between the two groups for age (p = .07) and gender (p = .54). CT clinic radiomics combined model achieved an F1 score of 0.94, 0.93 accuracy, and an AUC 0.96.

CONCLUSION

In conclusion, the CT-based clinic-radiologic-radiomics combined model could noninvasively predict WT or NB preoperatively. Notably, that model correctly predicted two patients, which none of the radiologists could correctly predict. This model may serve as a noninvasive preoperative predictor of NB/WT differentiation in CT, which should be further validated in large prospective models.

CLINICAL RELEVANCE STATEMENT

CT-based clinic-radiologic-radiomics combined model could noninvasively predict Wilms tumor or neuroblastoma preoperatively.

KEY POINTS

• CT radiomics features can predict Wilms tumor or neuroblastoma from abdominal CT preoperatively. • Integrating clinic variables may further improve the performance of the model. • The performance of the combined model is equal to or greater than human readers, depending on the lesion size.

Circulating microRNA profiles in Wilms tumour (WT): A systematic review and meta-analysis of diagnostic test accuracy

Background

Wilms tumour (WT) is caused by aberrant embryonic kidney development and associated with dysregulated expression of short, non-protein-coding RNAs termed microRNAs (miRNAs). At present, there is no reliable circulating biomarker of WT, and this remains an urgent unmet clinical need. Such biomarkers may assist diagnosis, subtyping/prognostication, and disease-monitoring. Here, we established the list of dysregulated circulating miRNAs in WT from the existing published literature.

Methods

Regardless of publication date, PubMed, Scopus, Web-of-Science, and Wiley online library databases were searched for English/French studies on WT circulating miRNAs. The PRISMA-compliant search was registered in PROSPERO. The QUADAS tool measured retained article quality. The meta-analysis assessed the sensitivity and specificity of miRNAs for WT diagnosis.

Results

Qualitative analysis included 280 samples (172 WT patients; 108 healthy controls) from five of 450 published articles. The study uncovered 301 dysregulated miRNAs (144 up-regulated, 143 down-regulated, 14 conflicting). The pooled sensitivity, specificity, and AUC of the 49 significantly dysregulated microRNAs from two studies was 0.67 [0.62; 0.73], 0.95 [0.92; 0.96] and 0.77 [0.73; 0.81] respectively, indicating a stronger diagnostic potential for WT.

Conclusions

Circulating miRNAs show promise for WT diagnosis and prognosis. More research is needed to confirm these findings and determine associations with tumour stage/subtype.

Prospero registration number

CRD42022301597.

One year overall survival of wilms tumor cases and its predictors, among children diagnosed at a teaching hospital in South Western Uganda: a retrospective cohort study

BACKGROUND

Wilms tumor (WT) is the second most common solid tumor in Africa with both low overall survival (OS) and event-free survival (EFS) rates. However, no known factors are predicting this poor overall survival.

OBJECTIVE

The study was to determine the one-year overall survival of WT cases and its predictors among children diagnosed in the pediatric oncology and surgical units of Mbarara regional referral hospital (MRRH), western Uganda.

METHODOLOGY

Children's treatment charts and files diagnosed and managed for WT were retrospectively followed up for the period between January 2017 to January 2021. Charts of children with histologically confirmed diagnoses were reviewed for demographics, clinical and histological characteristics, as well as treatment modalities.

RESULTS

One-year overall survival was found to be 59.3% (95% CI: 40.7-73.3), with tumor size greater than 15 cm (p 0.021) and unfavorable WT type (p 0.012) being the predominant predictors.

CONCLUSION

Overall survival (OS) of WT at MRRH was found to be 59.3%, and predictive factors noted were unfavorable histology and tumor size greater than 115 cm.

Biomarkers and Corresponding Biosensors for Childhood Cancer Diagnostics

Although tremendous progress has been made in treating childhood cancer, it is still one of the leading causes of death in children worldwide. Because cancer symptoms overlap with those of other diseases, it is difficult to predict a tumor early enough, which causes cancers in children to be more aggressive and progress more rapidly than in adults. Therefore, early and accurate detection methods are urgently needed to effectively treat children with cancer therapy. Identification and detection of cancer biomarkers serve as non-invasive tools for early cancer screening, prevention, and treatment. Biosensors have emerged as a potential technology for rapid, sensitive, and cost-effective biomarker detection and monitoring. In this review, we provide an overview of important biomarkers for several common childhood cancers. Accordingly, we have enumerated the developed biosensors for early detection of pediatric cancer or related biomarkers. This review offers a restructured platform for ongoing research in pediatric cancer diagnostics that can contribute to the development of rapid biosensing techniques for early-stage diagnosis, monitoring, and treatment of children with cancer and reduce the mortality rate.

A 5-year multidisciplinary care outcomes in children with wilms' tumour managed at a tertiary centre: A retrospective observational study

BACKGROUND

Over the last two decades, there has been significant improvement in the outcomes of children with Wilms' tumour (WT) in high income countries (HICs) with approximately 85% survival rate globally. This is partly attributable to a multi-disciplinary team approach to care and the evolution of more robust treatment measures. A previous review in our centre prior to multi-disciplinary team shows a survival rate of 31.48%, However, the survival rates from low- and middle-income countries are still low when compared to HICs due to delays in access to care at all levels, poor to non-existent health insurance coverage, limited workforce resources, weak health-care systems and infrastructure. The aim of this study is to determine the impact of a multi-disciplinary team approach on the treatment outcomes of children with WT.

METHODOLOGY

This is a 5-year retrospective review of all patients managed with WT at the Lagos University Teaching Hospital, Lagos, Nigeria. Information was extracted from the patients' case notes, operation notes and ward admission records. The data were analysed with SPSS 25, and P < 0.05 was considered to be statistically significant.

RESULTS

Forty patients were included in the study; male to female ratio was 1.6:1. The disease occurred in the right kidney in 23 patients (57.5%) and on the left in 17 patients (42.5%). The average duration of symptoms before presentation was 3.6 months (range 1-7 months), majority of patients presented with abdominal masses and were assessed as per unit protocol with abdominal Computerized tomography scan, chest X-ray and abdominal ultrasound scan to assign the patient International Society of Paediatric oncology regimen. The predominant stage at surgery was Stage III 26 (65%), while Stage IV was 9 (22.5%). Morbidity after chemotherapy was 10 (25%). Twenty-five patients (63%) completed chemotherapy while 15 patients (37%) started chemotherapy but defaulted midway. The 5-year survival rate was 75%. Increasing age and male sex were associated with reduced odds of mortality; however, this was not statistically significant. Increased duration of treatment, being treated with chemotherapy alone, as well as advanced tumour stage and histology were associated with increased odds of mortality, however, this was not statistically significant.

CONCLUSION

The development of an institutional WT treatment pathway involving a multidisciplinary team has resulted in improved outcomes. There is need for increased community awareness to improve the time to presentation.

Expanding the Use of Nephron-Sparing Surgery for Wilms Tumor

Radical nephrectomy combined with contemporary chemotherapeutic and radiation therapy protocols has drastically improved outcomes for children with Wilms tumor. Patients with bilateral disease and a syndrome predisposing to tumor development have necessitated the use of nephron-sparing surgery in select cases. Success in managing these patients has increased the indication for partial nephrectomy, although current guidelines for unilateral Wilms tumor are limited. Given that children are being cured with increasing success, recent focus has shifted to long-term health outcomes in addition to tumor treatment. Specifically, renal function has an impact on long-term cardiovascular health and events. Adult outcomes with partial nephrectomy provide a guideline for a paradigm shift in the management of children with Wilms tumor, particularly with advances in imaging and adjuvant therapy. The data are limited for children undergoing partial nephrectomy for unilateral Wilms tumor and outcomes for larger tumors will need to be studied closely in future trials. Increased utilization of neoadjuvant chemotherapy could further expand the number of patients eligible for partial nephrectomy.

Nephroblastoma of the Big Child, a Rare Entity: About a Case

Nephroblastoma is a renal blast tumor, the most common malignant renal tumor in children between 1 and 5 years of age. The average age of onset is 3.5 years, rarely occurring in children over 10 years of age. Its treatment is a model of medical-surgical collaboration. The prognostic factors are mainly the stage but recent studies have also shown that the advanced age of the child is a negative prognostic factor. We report a case of a 14-year-old child who presented with pain with swelling of the right hypochondrium, ultrasound showed a heterogeneous right retroperitoneal mass, MRI showed a large retroperitoneal tumor process with a right renal origin, in heterogeneous T2 signal, in T1 hyposignal, diffusion restricted, containing necrotic areas and heterogeneously enhancing after injection, responsible for pyelocalic dilatation and right renal venous thrombosis, extended to the IVC and the right atrium, with adenopathies, suggesting first a sarcoma. The extension workup showed pulmonary nodules of secondary appearance. An echo-guided biopsy was performed and the anatomopathological study confirmed the diagnosis of nephroblastoma.

Wilms tumour

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

Expression of TCF3 in Wilms' tumor and its regulatory role in kidney tumor cell viability, migration and apoptosis in vitro

Wilms' tumor (WT) is a major type of kidney cancer in children; however, the therapeutic measures for control of tumor metastasis, recurrence and death for this type of cancer remain unsatisfactory. The present study aimed to verify the expression of T-cell factor 3 (TCF3) in WT, and to explore its role in regulating the viability, migration and apoptosis of kidney tumor cells. Tumor tissues were collected from 10 patients with WT, and adjacent tissues were collected as normal controls. The expression levels of TCF3 were detected in WT tissues and adjacent tissues by reverse transcription-quantitative PCR (RT-qPCR), western blotting and immunohistochemistry. In addition, TCF3 expression was silenced in G401 kidney tumor cells via small interfering RNA transfection. Cell viability, cell cycle progression and cell apoptosis were assessed using the MTT assay and flow cytometry; the migration and invasion of kidney tumor cells were examined using Transwell and wound-healing assays; and the expression levels of Wnt signaling pathway-related genes (Wnt1, β-catenin and c-myc) were detected by RT-qPCR and western blotting. The results revealed that the expression levels of TCF3 were high in WT tissues from patients. Silencing TCF3 expression in G401 kidney tumor cells in vitro significantly inhibited cell viability and migration, and promoted cell apoptosis. Moreover, silencing TCF3 expression in G401 cells inhibited the expression levels of Wnt signaling pathway-related genes. Overall, these data indicated that TCF3 may be involved in WT development through regulation of Wnt signaling pathways. The findings of the present study provide a novel potential marker for the treatment and prognostic evaluation of WT.

RENAL NEOPLASIA FROM A SINGLE POPULATION OF PTEROPODID BATS

Neoplastic diseases have rarely been reported in the family Pteropodidae, and primary malignant renal neoplasms are generally uncommon across animal species. This case series describes four cases of primary renal neoplasia: three renal cell carcinomas and one nephroblastoma in three species of pteropodid bats, specifically large flying foxes (Pteropus vampyrus, n = 2), straw-colored fruit bat (Eidolon helvum, n = 1), and a little golden-mantled flying fox (Pteropus pumilus, n = 1). Two of the cases were diagnosed antemortem using ultrasonography, computed tomography, and cytology; and one of these bats with a renal cell carcinoma was treated successfully with a unilateral nephrectomy. The remaining two cases were diagnosed at necropsy.

A long non-coding RNAs expression signature to improve prognostic prediction of Wilms tumor in children

BACKGROUND

Wilms tumor (WT) is the most frequent malignancy of the kidney in children, and a subset of patients remains with a poor prognosis. This study aimed to identify key long non-coding RNAs (lncRNAs) related to prognosis and establish a genomic-clinicopathologic nomogram to predict survival in children with WT.

METHODS

Clinical data of 124 WT patients and the relevant RNA sequencing data including lncRNAs expression signature of primary WT samples were obtained from the Therapeutically Applicable Research to Generate Effective Treatment (TARGET) Data Matrix. Then, lncRNAs associated with overall survival (OS) were identified through univariate Cox, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analyses. The risk scores of 124 participants were calculated, and survival analyses were performed between low- and high-risk groups. A genomic-clinicopathologic nomogram was then developed and evaluated by time-dependent receiver operating characteristic (ROC) curves, including the area under the curve (AUC), calibration curve, and decision curve analysis. Subsequently, bioinformatics analyses were performed to explore the potential molecular mechanisms that affect the prognosis of WT. The package "DESeq2" was used to identify differentially expressed protein-coding genes (DEPCGs) between groups. Gene Set Enrichment Analysis (GSEA) was applied to explore the differences in pathways enrichment. The analytical tools CIBERSORTx and ESTIMATE were used to investigate the discrepancies of the immune microenvironment.

RESULTS

A total of 10 lncRNAs were selected as independent predictors associated with OS (P<0.05). Participants in the high-risk group had a significantly worse OS and event-free survival (EFS) than those in the low-risk group (P<2E-16 and P=2.03E-04, respectively). The risk score and 3 clinicopathological features (gender, cooperative group protocol, and stage) were identified to construct the nomogram (combined model) (P=5.11E-17). The combined model (1-year AUC: 0.9272, 3-year AUC: 0.9428, 5-year AUC: 0.9259) and risk score model (1-year AUC: 0.9285, 3-year AUC: 0.9399, 5-year AUC: 0.9266) displayed higher predictive accuracy than that of the other models. Subsequently, 105 DEPCGs were identified. The GSEA revealed 4 significant pathways. Analysis with CIBERSORTx demonstrated that monocytes, macrophages M1, activated dendritic cells, and resting mast cells had significant infiltration differences between groups.

CONCLUSIONS

This study constructed a genomic-clinicopathologic nomogram, which might present a novel and efficient method for treating patients with WT.

Diagnostic Errors in Wilms' Tumors: Learning From Our Mistakes

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

3D reconstruction of Wilms' tumor and kidneys in children: Variability, usefulness and constraints

INTRODUCTION

Wilms' tumor (WT) is the most common type of malignant kidney tumor in children. Three-dimensional reconstructions can be performed pre-operatively to help surgeons in the planning phase.

OBJECTIVES

The main objective of this study was to determine the variability of WT segmentation and 3D reconstruction. The secondary objectives were to assess the usefulness of these 3D reconstructions in the surgical planning phase and in the selection of patients for nephron-sparing surgery (NSS).

METHODS

14 scans from 12 patients were manually or semi-automatically segmented by 2 teams using 3D Slicer software. Inter-individual variability of 3D reconstructions was measured based on the Dice index. The utility of 3D reconstructions for the surgical planning was evaluated by 4 pediatric surgeons using a 5-point Likert scale. The possibility of undertaking NSS was evaluated according to the criteria defined in the Umbrella SIOP-RTSG 2016 protocol.

RESULTS

Segmentation of the WT, healthy kidney, pathological kidney, arterial and venous vascularization could be performed for all of the patients in this study. Urinary cavities segmentation could only be performed for 5 out of 14 scans that had a delayed acquisition phase. The mean time required to carry out these segmentations was 8.6 h [3-15 h]. The mean Dice index for all of the scans was good (mean: 0.87; range [0.83-0.91]). Considering each anatomical structure, the Dice index was very good for the WT (mean: 0.95; range [0.91-0.97]) and the healthy kidney (mean: 0.95; range [0.93-0.96]), good for the pathological kidney (mean: 0.87; range [0.69-0.96]) and arterial vascularization (mean: 0.84; range [0.74-0.91]). The Dice index was lower than 0.8 for venous vascularization only (mean: 0.77; range [0.58-0.86]). All the surgeons who were interviewed agreed that the 3D reconstructions were realistic representations and useful for the surgical planning phase. The images reconstructed in 3D allowed most of the criteria defined by the Umbrella SIOP-RTSG 2016 protocol to be evaluated regarding the selection of patients who could benefit from NSS.

CONCLUSION

The inter-individual variability of 3D reconstructions of WT is acceptable. Three-dimensional representation appears to assist surgeons with the surgical planning phase by allowing them to better anticipate the operative risks. 3D reconstructions can also be an additional tool to better select patients for NSS. However, the manual or semi-automatic method used is very time-consuming, making it difficult for a routinely use. Developing techniques to automate this segmentation process, therefore, appears to be essential if surgeons and radiologists are to use it in daily practice.

Management of bilateral Wilms' tumour: A case report

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Wilms’ tumor is the most prevalent kidney tumor, accounting for 6% of all pediatric malignancies, 5–7% being bilateral case.

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Cases about a 19-month-old boy diagnosed as stage V Wilms tumor based on SIOP and NWTSG classification.

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Neoadjuvant chemotherapy regimen followed by the right partial, left radical nephrectomy, and adjuvant radiotherapy.

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No specific guideline on follow-up and imaging timing; we do regular follow-up every 12 months and periodic MRI imaging.

Introduction

Wilms’ tumour remains the most common renal tumour in children (6% of all pediatric malignancies) and present as one of the most challenging tasks for paediatric urologists as its management requires an advanced procedure. The ultimate goal in these cases is to preserve as much renal parenchyma as possible whilst still achieving complete tumour resection.

Presentation of case

Here we present a six year follow up report of a bilateral Wilms’ tumour case in a 19-months old boy. This patient underwent neoadjuvant chemotherapy regimen, followed by right partial nephrectomy and left radical nephrectomy. Adjuvant radiotherapy was performed following the surgery. Follow-up imaging 5 months afterward revealed a firmly heterogeneous cystic lesion consist of fat and calcification at the upper pole of the right kidney, none of which created any problem for the patient. MRI was later performed on the 19^th month after the surgery, showing marked decrease in the size of the cyst.

Discussion

According to SIOP and NWTSG classification, the patient presented as stage V of the disease. The patient was on neoadjuvant chemotherapy (Regimen I) as recommended by NWTSG. This strategy was shown to be effective, as the tumour on the left kidney was reduced to less than 70% of the initial size. A routine follow-up using chest x-ray, abdominal ultrasonography (USG), and contrast studies such as MRI and MSCT scan, was performed in our reports.

Conclusion

From our experience, the combination of neo-adjuvant chemotherapy, renal salvage surgery and adjuvant radiotherapy is a feasible, safe and effective option for bilateral Wilms’ tumour cases.

Minimally invasive surgery for pediatric renal tumors: A systematic review by the APSA Cancer Committee

Minimally invasive nephrectomy is performed routinely for adult renal tumors and for many benign pediatric conditions. Although open radical nephroureterectomy remains the standard of care for Wilms tumor and most pediatric renal malignancies, there are an increasing number of reports of minimally invasive surgery (MIS) for those operations as well. The APSA Cancer Committee performed a systematic review to better understand the risks and benefits of MIS in pediatric patients with renal tumors.

METHODS

The search focused on MIS for renal tumors in children and followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) checklist. The initial database search identified 491 published articles, and after progressive review of abstracts and full-length articles, 19 were included in this review.

RESULTS

There were two direct comparison studies where open surgery and MIS were compared. The remaining studies reported only on minimally invasive nephrectomy. Across all studies, there were a total of 151 patients, 126 of which had Wilms tumor and 10 patients had RCC. 104 patients had MIS, with 47 patients having open surgery. In the two studies in which open surgery and MIS were directly compared, more lymph nodes were harvested during open surgery (median = 2 (MIS) vs 5 (open); mean = 2.47 (MIS) vs 3.8 (open)). Many noncomparison studies reported the harvest of 2 of fewer lymph nodes for Wilms tumor. Several MIS patients were also noted to have intraoperative spill or positive margins. Survival between groups was similar.

CONCLUSIONS

There is a lack of evidence to support MIS for pediatric renal tumors. This review demonstrates that lymph node harvest has been inadequate for MIS pediatric nephrectomy and there appears to be an increased risk for intraoperative spill. Survival data are similar between groups, but follow-up times were inconsistent and patient selection was clearly biased, with only small tumors being selected for MIS.

TYPE OF STUDY

Review article.

LEVEL OF EVIDENCE

III.

Nasopharyngeal nephroblastoma in a 3-month-old Boer goat

A 3-mo-old, female Boer goat was presented because of respiratory difficulties. Tachypnea and inspiratory dyspnea were noted during physical examination. Thoracic radiographs were unremarkable; however, upper airway and nasal passage radiographs revealed a soft tissue mass within the nasal passages. The patient underwent cardiorespiratory arrest and did not respond to resuscitation efforts during endoscopy. A large, pedunculated, semi-firm mass originated from the soft palate and obstructed 90% of the nasopharynx on autopsy. Histologically, the mass was composed of primitive cells that multifocally formed tubules and glomeruloid structures intermingled with areas of fusiform and blastemal cells. The neoplastic cells were positive for cytokeratin (tubular and glomeruloid cells), vimentin (fusiform population and blastemal cells), and Wilms tumor 1 protein (glomeruloid structures) on immunohistochemistry, consistent with a triphasic nephroblastoma. To our knowledge, nasopharyngeal nephroblastoma has not been reported previously in any species.

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

Objective

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

Patients and methods

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

Results

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

Conclusion

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

Pediatric Renal Neoplasms:: MR Imaging-Based Practical Diagnostic Approach

Pediatric renal tumors may be malignant or benign. Wilms tumor, the most common malignant pediatric renal tumor, arises sporadically or with various syndromes. Renal cell carcinoma typically presents in older children. Renal clear cell sarcoma and rhabdoid tumor are typically less common, more aggressive, and present in younger children. Benign renal tumors include mesoblastic nephroma, multilocular cystic renal tumor, angiomyolipoma, and metanephric adenoma. Lymphoma and leukemia may secondarily involve the kidney. Although there is overlap in the imaging appearance of several pediatric renal tumors, magnetic resonance characteristics and clinical data narrow the differential diagnosis and suggest a specific diagnosis. This article reviews current MR techniques, as well as the common MR imaging characteristics of malignant and benign pediatric renal neoplasms.

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

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

The Iroquois homeobox proteins IRX3 and IRX5 have distinct roles in Wilms tumour development and human nephrogenesis

Wilms tumour is a paediatric malignancy with features of halted kidney development. Here, we demonstrate that the Iroquois homeobox genes IRX3 and IRX5 are essential for mammalian nephrogenesis and govern the differentiation of Wilms tumour. Knock‐out Irx3⁻/Irx5⁻ mice showed a strongly reduced embryonic nephron formation. In human foetal kidney and Wilms tumour, IRX5 expression was already activated in early proliferative blastema, whereas IRX3 protein levels peaked at tubular differentiation. Accordingly, an orthotopic xenograft mouse model of Wilms tumour showed that IRX3^−/− cells formed bulky renal tumours dominated by immature mesenchyme and active canonical WNT/β‐catenin‐signalling. In contrast, IRX5^−/− cells displayed activation of Hippo and non‐canonical WNT‐signalling and generated small tumours with abundant tubulogenesis. Our findings suggest that promotion of IRX3 signalling or inhibition of IRX5 signalling could be a route towards differentiation therapy for Wilms tumour, in which WNT5A is a candidate molecule for enforced tubular maturation. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Estimated glomerular filtration rate after nephrectomy for Wilms tumor

BACKGROUND

The aim of this study was to assess long-term residual kidney function after unilateral nephrectomy for non-syndromic Wilms tumor (NSWT).

METHODS

Of the patients who underwent one-sided NSWT at Tohoku University Hospital between 1977 and 2003, nine were followed up until age ≥18 years. For these nine patients, we retrospectively evaluated estimated glomerular filtration rate (eGFR) in childhood (3-10 years old), adolescence (11-17 years old) and adulthood (≥18 years).

RESULTS

Mean age at the last follow up was 23.0 years. Tumor classification was as follows: stage I tumor, n = 6; stage II tumor, n = 3; mixed-type nephroblastoma, n = 8; and congenital mesoblastic nephroma, n = 1. Mean eGFR was 101.3 ± 21.2 mL/min/1.73 m² in childhood, 106.0 ± 32.1 mL/min/1.73 m² in adolescence and 100.5 ± 20.7 mL/min/1.73 m² in adulthood. Therefore, no significant change in eGFR was observed over the three life stages evaluated. Further, none of the patients met the diagnostic criteria for chronic kidney disease by early adulthood.

CONCLUSIONS

eGFR after unilateral nephrectomy in patients with NSWT remained ≥60 mL/min/1.73 m² during the transition from childhood to early adulthood, with no development of chronic kidney disease or end-stage kidney failure.

A blastema-predominant canine renal nephroblastoma with gingival metastasis: case report and literature review

Nephroblastomas are uncommon embryonal tumors in dogs. We report herein a blastema-predominant nephroblastoma with gingival metastasis in an 8-y-old Miniature Pinscher dog. Histologically, the mass was composed mainly of blastemal elements with minor epithelial and mesenchymal differentiation. Metastatic masses in the gingiva had histologic and immunohistochemical features similar to those of the primary renal nephroblastoma. Neoplastic cells were extensively positive for both vimentin and PAX8, and scattered positive for cytokeratin. Using the clinical staging of human Wilms tumor, we staged our case as stage IV with <4 mo of survival time. We summarized previous studies of canine renal and spinal nephroblastomas, and analyzed the correlations among clinical staging, histologic classification, and mean survival time of dogs with renal nephroblastomas. Clinical staging was significantly correlated with survival time, as shown in humans. In dogs, however, additional factors can potentially influence the outcome of treatment and disease development.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Outcome and Prognostic Factors in Stage III Favorable-Histology Wilms Tumor: A Report From the Children's Oncology Group Study AREN0532

Background The National Wilms Tumor Study (NWTS) approach to treating stage III favorable-histology Wilms tumor (FHWT) is Regimen DD4A (vincristine, dactinomycin, and doxorubicin) and radiation therapy. Further risk stratification is required to improve outcomes and reduce late effects. We evaluated clinical and biologic variables for patients with stage III FHWT without combined loss of heterozygosity (LOH) at chromosomes 1p and 16q treated in the Children's Oncology Group protocol AREN0532. Methods From October 2006 to August 2013, 588 prospectively treated, centrally reviewed patients with stage III FHWT were treated with Regimen DD4A and radiation therapy. Tumor LOH at 1p and 16q was determined by microsatellite analysis. Ineligible patients (n = 5) and those with combined LOH 1p/16q (n = 40) were excluded. Results A total of 535 patients with stage III disease were studied. Median follow-up was 5.2 years (range, 0.2 to 9.5). Four-year event-free survival (EFS) and overall survival estimates were 88% (95% CI, 85% to 91%) and 97% (95% CI, 95% to 99%), respectively. A total of 58 of 66 relapses occurred in the first 2 years, predominantly pulmonary (n = 36). Eighteen patients died, 14 secondary to disease. A better EFS was associated with negative lymph node status ( P < .01) and absence of LOH 1p or 16q ( P < .01), but not with gross residual disease or peritoneal implants. In contrast, the 4-year EFS was only 74% in patients with combined positive lymph node status and LOH 1p or 16q. A total of 123 patients (23%) had delayed nephrectomy. Submitted delayed nephrectomy histology showed anaplasia (n = 8; excluded from survival analysis); low risk/completely necrotic (n = 7; zero relapses), intermediate risk (n = 63; six relapses), and high-risk/blastemal type (n=7; five relapses). Conclusion Most patients with stage III FHWT had good EFS/overall survival with DD4A and radiation therapy. Combined lymph node and LOH status was highly predictive of EFS and should be considered as a potential prognostic marker for future trials.

Nutritional status of children with Wilms' tumour on admission to a South African hospital and its influence on outcome

BACKGROUND

In developing countries up to 77% of children with cancer have been shown to be malnourished on admission. High rates of malnutrition occur due to factors such as poverty and advanced disease. Weight can be an inaccurate parameter for nutritional assessment of children with solid tumours as it is influenced by tumour mass. This study aimed to assess the prevalence of malnutrition amongst children with Wilms tumour (WT), the level of nutritional support received on admission and the influence of nutritional status on outcome.

METHODS

Seventy-six children diagnosed with WT and admitted to Inkosi Albert Luthuli Central Hospital between 2004 and 2012 were studied prospectively. Nutritional assessment was conducted using weight, height, mid-upper arm circumference (MUAC) and triceps skinfold thickness (TSFT) prior to initiating treatment. Outcome was determined 2 years after admission. Time until commencement of nutritional resuscitation and nature, thereof, were recorded.

RESULTS

Stunting and wasting was evident in 12% and 15% of patients, respectively. The prevalence of malnutrition was 66% when MUAC, TSFT and albumin were used. Malnutrition was not a predictor of poor outcome and did not predict advanced disease. The majority of patients (84%) received nutritional resuscitation within 2 weeks of admission.

CONCLUSIONS

When classifying nutritional status in children with WT, the utilisation of weight and height in isolation can lead to an underestimation of the prevalence of malnutrition. Nutritional assessment of children with WT should also include MUAC and TSFT. Early aggressive nutritional resuscitation is recommended.

The predictive value of transforming growth factor-β in Wilms tumor immunopathogenesis

Wilms tumor is the most common kidney malignancy in children, especially in children aged less than 6 years. Although therapeutic approach has reached successful rates, there is still room for improvement. Considering the tumor microenvironment, cytokines represent important elements of interaction and communication between tumor cells, stroma, and immune cells. In this regard, the transforming growth factor beta (TGF-β) family members play significant functions in physiological and pathological conditions, particularly in cancer. By regulating cell growth, death, and immortalization, TGF-β signaling pathways exert tumor suppressor effects in normal and early tumor cells. Thus, it is not surprising that a high number of human tumors arise due to alterations in genes coding for various TGF-β signaling components. Understanding the ambiguous role of TGF-β in human cancer is of paramount importance for the development of new therapeutic strategies to specifically block the metastatic signaling pathway of TGF-β without affecting its tumor suppressive effect. In this context, this review attempt to summarize the involvement of TGF-β in Wilms tumor.

[Wilms' tumour: A review of 15 years recent experience]

INTRODUCTION

Wilms' tumour is the most frequent renal tumour in children. Multi-modal treatment includes chemotherapy and surgery, with or without radiotherapy. The survival is excellent, with rates exceeding 90%. A review is presented on our experience over the last 15 years of treating Wilms' tumour in Hospital Niño Jesús, Madrid.

PATIENTS AND METHODS

A retrospective study was conducted on 40 consecutive paediatric patients diagnosed with nephroblastoma between 2002 and 2016 in the Hospital Niño Jesús in Madrid. The clinical characteristics, diagnostic methods, treatment, and follow-up were analysed.

RESULTS

Of the 40 patients, 23 were boys, with a median age at diagnosis of 2.5 years (range, 4 months-15 years). Three patients underwent initial nephrectomy, three received a fine needle aspiration biopsy, followed by chemotherapy, and 34 patients started pre-operative chemotherapy directly. The median follow-up of the patients was 6.75 years (range, 10 months - 13.92 years). Two patients died from disease progression. There were no treatment-related deaths. Overall survival and event-free survival at 5 years was 94.6±3.7% and 89.4±5%, respectively.

CONCLUSION

Wilms' tumour treatment is a success of modern medicine, currently achieving a survival rate of 95% in our series.

Predictive factor for intraoperative tumor rupture of Wilms tumor

PURPOSE

For Wilms tumor, intraoperative tumor rupture with wide tumor spillage during surgical manipulation raises the classification to stage 3. Then, postoperative chemotherapy must be more intensive, and abdominal radiotherapy is added. Therefore, intraoperative tumor rupture should be avoided if possible. However, predictive factors for intraoperative tumor rupture have not been sufficiently described. Here we examined the risk factors for intraoperative tumor rupture.

METHODS

Patients with Wilms tumor who underwent treatment according to the National Wilms Tumor Study or the Japanese Wilms Tumor Study protocol at our institution were reviewed retrospectively. Collected cases were categorized into two groups: the ruptured group and the non-ruptured group. Risk factors for intraoperative tumor rupture, including the ratio of the tumor area to the abdominal area in a preoperative single horizontal computed tomography slice (T/A ratio), were investigated in both groups.

RESULTS

The two groups were not different in age, body weight, tumor laterality, sex, or histological distribution. The T/A ratio in the ruptured group was significantly higher than that in the non-ruptured group. Receiver operating characteristic curve analysis identified a discriminative value for a T/A ratio >0.5.

CONCLUSION

The T/A ratio can be a predictive factor for intraoperative tumor rupture of Wilms tumor.

Residential proximity to environmental pollution sources and risk of rare tumors in children

BACKGROUND

Few epidemiologic studies have explored risk factors for rare tumors in children, and the role of environmental factors needs to be assessed.

OBJECTIVES

To ascertain the effect of residential proximity to both industrial and urban areas on childhood cancer risk, taking industrial groups into account.

METHODS

We conducted a population-based case-control study of five childhood cancers in Spain (retinoblastoma, hepatic tumors, soft tissue sarcomas, germ cell tumors, and other epithelial neoplasms/melanomas), including 557 incident cases from the Spanish Registry of Childhood Tumors (period 1996-2011), and 3342 controls individually matched by year of birth, sex, and region of residence. Distances were computed from the residences to the 1271 industries and the 30 urban areas with ≥75,000 inhabitants located in the study area. Using logistic regression, odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance to industrial and urban pollution sources were calculated, with adjustment for matching variables and socioeconomic confounders.

RESULTS

Children living near industrial and urban areas as a whole showed no excess risk for any of the tumors analyzed. However, isolated statistical associations (OR; 95%CI) were found between retinoblastoma and proximity to industries involved in glass and mineral fibers (2.49; 1.01-6.12 at 3km) and organic chemical industries (2.54; 1.10-5.90 at 2km). Moreover, soft tissue sarcomas registered the lower risks in the environs of industries as a whole (0.59; 0.38-0.93 at 4km).

CONCLUSIONS

We have found isolated statistical associations between retinoblastoma and proximity to industries involved in glass and mineral fibers and organic chemical industries.

Phenotype, cancer risk, and surveillance in Beckwith-Wiedemann syndrome depending on molecular genetic subgroups

Patients with Beckwith-Wiedemann syndrome (BWS) have an increased risk to develop cancer in childhood, especially Wilms tumor and hepatoblastoma. The risk varies depending on the cause of BWS. We obtained clinical and molecular data in our cohort of children with BWS, including tumor occurrences, and correlated phenotype and genotype. We obtained similar data from larger cohorts reported in the literature. Phenotype, genotype and tumor occurrence were available in 229 of our own patients. Minor differences in phenotype existed depending on genotype/epigenotype, similar to earlier studies. By adding patients from the literature, we obtained data on genotype and tumor occurrence of in total 1,971 BWS patients. Tumor risks were highest in the IC1 (H19/IGF2:IG-DMR) hypermethylation subgroup (28%) and pUPD subgroup (16%) and were lower in the KCNQ1OT1:TSS-DMR (IC2) subgroup (2.6%), CDKN1C (6.9%) subgroup, and the group in whom no molecular defect was detectable (6.7%). Wilms tumors (median age 24 months) were frequent in the IC1 (24%) and pUPD (7.9%) subgroups. Hepatoblastoma occurred mostly in the pUPD (3.5%) and IC2 (0.7%) subgroups, never in the IC1 and CDKN1C subgroups, and always before 30 months of age. In the CDKN1C subgroup 2.8% of patients developed neuroblastoma. We conclude tumor risks in BWS differ markedly depending on molecular background. We propose a differentiated surveillance protocol, based on tumor risks in the various molecular subgroups causing BWS. © 2016 Wiley Periodicals, Inc.

Association between residential proximity to environmental pollution sources and childhood renal tumors

BACKGROUND

Few risk factors for childhood renal tumors are well established. While a small fraction of cases might be attributable to susceptibility genes and congenital anomalies, the role of environmental factors needs to be assessed.

OBJECTIVES

To explore the possible association between residential proximity to environmental pollution sources (industrial and urban areas, and agricultural crops) and childhood renal cancer, taking into account industrial groups and toxic substances released.

METHODS

We conducted a population-based case-control study of childhood renal cancer in Spain, including 213 incident cases gathered from the Spanish Registry of Childhood Tumors (period 1996-2011), and 1278 controls individually matched by year of birth, sex, and region of residence. Distances were computed from the respective subject's residences to the 1271 industries, the 30 urban areas with ≥75,000 inhabitants, and the agricultural crops located in the study area. Using logistic regression, odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance to pollution sources were calculated, with adjustment for matching variables and socioeconomic confounders.

RESULTS

Excess risk (OR; 95%CI) of childhood renal tumors was observed for children living near (≤2.5km) industrial installations as a whole (1.97; 1.13-3.42) - particularly glass and mineral fibers (2.69; 1.19-6.08), galvanization (2.66; 1.14-6.22), hazardous waste (2.59; 1.25-5.37), ceramic (2.35; 1.06-5.21), surface treatment of metals (2.25; 1.24-4.08), organic chemical industry (2.22; 1.15-4.26), food and beverage sector (2.19; 1.18-4.07), urban and waste-water treatment plants (2.14; 1.07-4.30), and production and processing of metals (1.98; 1.03-3.82) -, and in the proximity of agricultural crops (3.16; 1.54-8.89 for children with percentage of crop surface ≥24.35% in a 1-km buffer around their residences).

CONCLUSIONS

Our study provides some epidemiological evidence that living near certain industrial areas and agricultural crops may be a risk factor for childhood renal cancer.

Next-generation sequencing reveals germline mutations in an infant with synchronous occurrence of nephro- and neuroblastoma

Although neuro- and nephroblastoma are common solid tumors in children, the simultaneous occurrence is very rare and is often associated with syndromes. Here, we present a unique case of synchronous occurrence of neuro- and nephroblastoma in an infant with no signs of congenital anomalies or a syndrome. We performed genetic testing for possible candidate genes as underlying mutation using the next-generation sequencing (NGS) approach to target 94 genes and 284 single-nucleotide polymorphisms (SNPs) involved in cancer. We uncovered a novel heterozygous germline missense mutation p.F58L (c.172T→C) in the anaplastic lymphoma kinase (ALK) gene and one novel heterozygous rearrangement Q418Hfs(*)11 (c.1254_1264delins TTACTTAGTACAAGAACTG) in the Fanconi anemia gene FANCD2 leading to a truncated protein. Besides, several SNPs associated with the occurrence of neuroblastoma and/or nephroblastoma or multiple primary tumors were identified. The next-generation sequencing approach might in the future be useful not only in understanding tumor etiology but also in recognizing new genetic markers and targets for future personalized therapy.

Initial Surgery in Tailoring Treatment for Children With Stage II and III Wilms' Tumor: An Experience From Resource Challenged Settings

BACKGROUND

Although Wilms' tumor (WT) is ranked first among primary childhood's renal neoplasm, controversy still exists regarding the best approach for its management. The study aimed at evaluating the role of initial surgery in treatment of stage II and III pediatric WT as a part of the short administration schedule as in National Wilms' Tumor Study (NWTS)-4 and evaluating its effectiveness compared to the long administration schedule.

METHODS

The study included 30 children who were primarily diagnosed as stage II and III WT. They were divided into two equal groups. Group I (n = 15) included those children who had undergone neoadjuvant chemotherapy followed by surgery and postoperative chemotherapy, while group II (n = 15) included those children who had undergone primary surgery as an initial management followed by chemotherapy. After a mean postoperative follow-up period of 14 ± 5 months, clinical and radiological evaluation was performed to all patients.

RESULTS

In group I, 10 patients were preoperatively diagnosed as stage II and five patients as stage III while in group II, 11 patients were proved to be stage II and four patients were stage III. After a follow-up period, clinical and radiological evaluation using CT was performed to all patients. In patients with stage II, evidence of recurrence was noted in three patients of group I whereas no patient showed any evidence of recurrence in group II. In patients with stage III, rebound increase in size was seen in two patients in group I and only one patient in group II.

CONCLUSIONS

Initial surgical intervention with appropriate adjuvant therapy has better outcomes than the neoadjuvant chemotherapy and delayed surgery for children primarily diagnosed as stage II and III WT. Moreover, it may act as a short administration schedule for the treatment as it is not less effective than the long administration schedule and can be administered at a substantially lower total treatment cost.

Treating childhood cancer in Rwanda: the nephroblastoma example

Introduction

Wilms tumor (WT) or nephroblastoma is the commonest childhood cancer in Rwanda. Nephroblastoma is regarded as one of the successes of pediatric oncology with long-term survival approaching 90%. The Objectives to evaluate the feasibilityof treating childhood cancer using the nephroblastoma example and to calculate its cost of treatment in Rwanda.

Methods

Prospective study over a 2 year period: 01 Jan 2010- 31 December 2011. A questionnaire was completed by all participants in the study and the following variables were collected at Kigali University Teaching Hospital: age at diagnosis, gender, transport cost, cost of investigations, staging, treatment and outcome, cost of hospitalization, type of medical, surgical, radiological interventions and their costs, number of admissions per patient and factors related to non compliance to treatment. All patients had a confirmed diagnosis on histopathology examination. The cost for treatment was calculated for early and late stage and was expressed in USA dollars. Analysis was done with SPSS 16.0.

Results

There were 25 patients diagnosed and treated for WT during the study period. Almost half of the patients 14/25 (56%) had advanced disease, seven children (28%) had stage IV, seven children stage III, six patients (24%) with stage II, while the remaining five (20%) had stage I with high risk tumor. The direct cost of management ranged from1,831.2 USD for early disease to 2,418.7 USD for advanced disease. The cost of transport, investigations and drugs were recorded as main contributing factors to the feasibility and cost of the treatment in 80% of the responses, followed by late presentation (56%) and poor compliance to treatment.

Conclusion

Most challenges are related to unaffordable treatment and late presentation. The management of WT is feasible in Rwandan setting but efforts should be made in order to improve awareness of childhood cancer, early diagnosis and access to care. The government of Rwanda is committed to improve cancer care in the country and organized the first pediatric international oncology conference in Kigali, in March 2012 to develop National protocols for the top five most common cancers in children.

The impact of ethnicity on wilms tumor: characteristics and outcome of a South african cohort

Background. Nephroblastoma is the commonest renal tumour seen in children. It has a good prognosis in developed countries with survival rates estimated to be between 80% and 90%, while in Africa it remains low. Method. Retrospective study of patients diagnosed with nephroblastoma who are seen at 4 paediatric oncology units, representing 58.5% of all South African children with nephroblastoma and treated following SIOP protocol between January 2000 and December 2010. Results. A total of 416 patients were seen at the 4 units. Over 80% of our patients were African and almost 10% of mixed ethnicity. The most common stage was stage 4. The median survival was 28 months after diagnosis with the mixed ethnicity patients recording the longest duration (39 months) and the white patients had the shortest median survival. The overall 5-year survival rate was estimated to be 66%. Stage 2 patients did significantly better (85%). Conclusions. Our patients are similar with regard to gender ratio, median age, and age distribution as described in the literature, but in South Africa the more advanced stage disease seen than in other developed countries is translated into low overall survival rate.

Comparison of diagnostic performance of CT and MRI for abdominal staging of pediatric renal tumors: a report from the Children's Oncology Group

BACKGROUND

CT and MRI are both used for abdominal staging of pediatric renal tumors. The diagnostic performance of the two modalities for local and regional staging of renal tumors has not been systematically evaluated.

OBJECTIVE

To compare the diagnostic performance of CT and MRI for local staging of pediatric renal tumors.

MATERIALS AND METHODS

The study population was derived from the AREN03B2 study of the Children's Oncology Group. Baseline abdominal imaging performed with both CT and MRI within 30 days of nephrectomy was available for retrospective review in 82 renal tumor cases. Each case was evaluated for capsular penetration, lymph node metastasis, tumor thrombus, preoperative tumor rupture, and synchronous contralateral lesions. The surgical and pathological findings at central review were the reference standard.

RESULTS

The sensitivity of CT and MRI for detecting capsular penetration was 68.6% and 62.9%, respectively (P = 0.73), while specificity was 86.5% and 83.8% (P = 1.0). The sensitivity of CT and MRI for detecting lymph node metastasis was 76.5% and 52.9% (P = 0.22), and specificity was 90.4% and 92.3% (P = 1.0). Synchronous contralateral lesions were identified by CT in 4/9 cases and by MRI in 7/9 cases.

CONCLUSION

CT and MRI have similar diagnostic performance for detection of lymph node metastasis and capsular penetration. MR detected more contralateral synchronous lesions; however these were present in a very small number of cases. Either modality can be used for initial loco-regional staging of pediatric renal tumors.

Pathological Features of the Unilateral Favorable Histology Nephroblastoma with Relapse

PURPOSE

To evaluate the pathological features of the primary lesion in patients with relapse of unilateral favorable histology nephroblastoma.

MATERIAL AND METHODS

Fifty-eight patients with unilateral favorable histology nephroblastoma who underwent initial nephrectomy before chemotherapy were categorized into one of two groups: the nonrelapsed group (n = 52) and the relapsed group (n = 6). The histological subtypes of both groups and pathological features of the relapsed group were re-evaluated retrospectively.

RESULTS

The histological subtypes of all relapsed cases were classified as blastemal predominant. In three of six cases with relapse, sheets of spindle-shaped blastemal cells that were histologically reminiscent of synovial sarcoma were predominant (massive sarcomatoid pattern).

CONCLUSIONS

The histological blastemal predominant subtype of nephroblastoma is a strong indicator of relapse. In particular, the blastemal predominant subtype with massive sarcomatoid pattern may have a higher risk of relapse.

Impact of nephrectomy on long-term renal function in non-syndromic children treated for unifocal Wilms tumor

OBJECTIVE

The present study is designed to assess the long-term renal function of children who underwent radical nephrectomy for unifocal Wilms tumor.

METHODS

A single institution retrospective cohort study of non-syndromic children treated with radical nephrectomy for unifocal Wilms tumor between 1995 and 2011 was performed to identify risk factors for decreased glomerular filtration rate (GFR). The primary endpoint was decrease in age-adjusted GFR below normal published ranges. The secondary endpoint was progression to chronic renal insufficiency (CRI).

RESULTS

A total of 55 patients were identified in the cohort. Eight (15%) patients exhibited decreased age-adjusted GFR during the follow-up period, with 2 (4%) progressing to CRI. Increasing time between surgery and the last known GFR follow-up was associated with decreased GFR, with the normal GFR group having median follow-up of 7.32 years versus 11.47 years (p = 0.019) in the decreased GFR group.

CONCLUSIONS

A trend toward decline in GFR was detected with longer follow-up. Longer follow-up may reveal that clinically significant decline in renal function occurs years following nephrectomy among a subset of Wilms tumor survivors, even among those who do not progress to end stage renal disease.

The initial experience with RENAL Nephrometry in children, adolescents, and young adults with renal tumors

BACKGROUND

No standardized manner exits to objectively compare renal tumor complexity in children and adolescents. However, the RENAL Nephrometry scoring system has been recently developed in adults and shown to predict tumor complexity and correlate with clinical outcomes. Thus, the study objective was to evaluate RENAL Nephrometry tumor score in a population of children, adolescents, and young adults and correlate it with tumor features and pathology.

METHODS

Patients at the study institution who underwent attempted renal tumor resection from 2002 to 2012, and had pre-operative imaging available for scoring were retrospectively reviewed. A Nephrometry score for each affected kidney was calculated separately by two blinded reviewers and the final score was based on consensus review. Tumor characteristics and oncologic outcomes were compared between the low-, moderate-, and high-complexity masses.

RESULTS

Sixty-five patients and 67 kidneys met study criteria. This included: 5 (7.5%) low-complexity, 11 (16.4%) moderate-complexity, and 51 (76.1%) high-complexity lesions. In comparing the clinical and pathologic features between groups, it was observed that less complex masses were observed in older patients, were more commonly managed with nephron-sparing surgery, and more often represented renal cell carcinoma (RCC) and other non-Wilms tumor pathology. No statistically significant correlation was observed between tumor complexity score and blood loss, operative time, transfusion requirement, positive margins or tumor rupture.

CONCLUSION

In general, renal lesions in this population are highly complex. In its current form, RENAL Nephrometry appears most useful in evaluating tumor complexity in RCC and masses in older children and adolescents.

Malignant renal tumors in childhood: report of 54 cases treated at a single institution

BACKGROUND

Wilms tumor is the most common primary renal malignancy occurring in childhood. Significant improvement has been made in the treatment of children with Wilms tumor. However, the treatment of patients with non-Wilms renal tumors remains challenging.

METHODS

Between 1991 and 2010, 70 children with renal tumors were diagnosed at a single institution. Fifty-four patients were histologically confirmed and divided into three groups, including 42 Wilms tumors, seven clear cell sarcomas of kidney, and five malignant rhabdoid tumors. Most patients underwent unilateral nephrectomy and lymph node sampling followed by adjuvant chemotherapy. Twenty-one of these patients subsequently received radiotherapy.

RESULTS

During follow-up, 12 patients died of progressive disease and one died of operative mortality. One patient with unilateral pleural metastases subsequently underwent hematopoietic stem cell transplantation. The median survival time of all patients was 88 months. Children under 2 years of age at diagnosis with Wilms tumor or clear cell sarcoma of kidney had an excellent survival rate of 100% compared to the 0% survival rate of MRT.

CONCLUSION

Younger age at diagnosis bore a better prognosis than did older age, whereas a diagnosis of malignant rhabdoid tumor portended a worse prognosis. Younger patients and appropriate treatment may have contributed to the improved prognosis of clear cell sarcoma of kidney.