Wilms' tumor: An update

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.

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.

miR-590 regulates WT1 during proliferation of G401 cells

Nephroblastoma (Wilms' tumor) is frequently associated with mortality in children. MicroRNAs (miRNAs) are important for tumor development serving as oncogenes or tumor suppressors. In the present study, miRNA-590 (miR-590) was identified to be upregulated in Wilms' tumor tissues compared with the normal adjacent tissues. Additionally, the levels of miR-590 were consistent with their clinical stage. Wilms' tumor 1 (WT1) was considered to be a tumor suppressor in certain tumor types, and it has been detected at low expression levels in various types of cancer with high cell proliferation and aggressive behavior. The expression levels of miR-590 were quantified using reverse transcription-quantitative polymerase chain reaction. Cell proliferation was measured using 5-ethynyl-20-deoxyuridine assays. The protein expression levels of WT1 were investigated by western blot analysis. To the best of our knowledge, the present study was the first to determine that WT1 was a target gene of miR-590 as miR-590 was able to negatively regulate WT1 expression level by binding to the specific target site within the 3′-untranslated region (3′-UTR) of WT1 in G401 cells. Additionally, overexpression of miR-590 promoted G401 cell proliferation which was consistent with the effect of small interfering RNA-WT1. Subsequently, the present study determined that the cell phenotype altered by miR-590 overexpression may be reversed by upregulation of WT1 in G401 cells. In conclusion, the observations indicated that miR-590 may function as an oncogene via targeting WT1 to induce G401 cell proliferation. These results may contribute to current understanding of the function of miR-590 in nephroblastoma.

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.

Analyzing the gene expression profile of anaplastic histology Wilms' tumor with real-time polymerase chain reaction arrays

Background

Wilms’ tumor (WT) is one of the most common malignant neoplasms of the urinary tract in children. Anaplastic histology (unfavorable histology) accounts for about 10% of whole WTs, and it is the single most important histologic predictor of treatment response and survival in patients with WT; however, until now the molecular basis of this phenotype is not very clearly.

Methods

A real-time polymerase chain reaction (PCR) array was designed and tested. Next, the gene expression profile of pediatric anaplastic histology WT and normal adjacent tissues were analyzed. These expression data were anlyzed with Multi Experiment View (MEV) cluster software further. Datasets representing genes with altered expression profiles derived from cluster analyses were imported into the Ingenuity Pathway Analysis Tool (IPA).

Results

88 real-time PCR primer pairs for quantitative gene expression analysis of key genes involved in pediatric anaplastic histology WT were designed and tested. The gene expression profile of pediatric anaplastic histology WT is significantly different from adjacent normal controls; we identified 15 genes that are up-regulated and 16 genes that are down-regulated in the former. To investigate biological interactions of these differently regulated genes, datasets representing genes with altered expression profiles were imported into the IPA for further analysis, which revealed three significant networks: Cancer, Hematological Disease, and Gene Expression, which included 27 focus molecules and a significance score of 43. The IPA analysis also grouped the differentially expressed genes into biological mechanisms related to Cell Death and Survival 1.15E⁻¹², Cellular Development 2.84E⁻¹¹, Cellular Growth and Proliferation 2.84E^-11, Gene Expression 4.43E⁻¹⁰, and DNA Replication, Recombination, and Repair 1.39E⁻⁰⁷. The important upstream regulators of pediatric anaplastic histology WT were TP53 and TGFβ1 signaling (P = 1.15E⁻¹⁴ and 3.79E⁻¹³, respectively).

Conclusions

Our study demonstrates that the gene expression profile of pediatric anaplastic histology WT is significantly different from adjacent normal tissues with real-time PCR array. We identified some genes that are dysregulated in pediatric anaplastic histology WT for the first time, such as HDAC7, and IPA analysis showed the most important pathways for pediatric anaplastic histology WT are TP53 and TGFβ1 signaling. This work may provide new clues into the molecular mechanisms behind pediatric anaplastic histology WT.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-015-0197-x) contains supplementary material, which is available to authorized users.

Wilms' tumor: single centre retrospective study from South India

Wilms' tumor is the most common malignant renal tumor in paediatric age group, and is classically managed by multimodal treatment which involves surgery, radiotherapy and chemotherapy. The last few decades have seen a dramatic change in the prognosis of this disease, which once was a uniformly lethal malignancy. While there is plenty of data in world literature on the outcome of Wilms' tumor, there is paucity of data from India. Hence, we conducted the present study to analyze the outcome of Wilms' tumor at our institute. To study the clinicopathologic profile and outcome of Wilms' tumor with NWTS (National Wilms' Tumor Study Group) IV protocol. Sixty-one patients with histopathological proven diagnosis of Wilms' tumor and had received treatment at our institute from Jan 2003 through Dec 2010 were included for analysis. Patients received treatment based on NWTS IV protocol. Patients were analysed for overall survival and event free survival and these outcomes were correlated with age, sex, stage at presentation and histology. Favourable histology which included focal anaplasia was found in 80.3 % while unfavourable histology was elicited in 19.7 % of the cases. The estimated 5 year event-free survival was 83.3 % and overall survival was 85.2 %. Tumour histology was the single most important factor predicting the survival. Patients with childhood Wilms' still present very late in our setting, this poses management challenges as large tumor are technically difficult to deliver at surgery. Histology has a crucial role in outcome of this disease. With multidisciplinary approach, similar survival rates to National Wilms' Tumor Study Group seems to be achievable even in Indian scenario.