Treatment and outcome of Wilms' tumour patients: an analysis of all cases registered in the UKW3 trial

Minimally invasive and robotic-assisted approaches applied to pediatric surgical oncology

The management of pediatric tumors is complex, with surgery, chemotherapy, and radiotherapy being cornerstones in their treatment. Tumor removal is increasingly performed by a minimally invasive approach, which allows for quicker postoperative recovery and less postoperative pain. The goal of this report is to give an overview of minimally invasive surgical approaches for common pediatric tumors, with a focus on technical considerations and postoperative outcomes.

Incidence and survival for childhood cancer by endorsed non-stage prognostic indicators in Australia

BACKGROUND

An international expert panel recently recommended 15 'non-stage prognostic indicators' (NSPIs) across eight childhood cancers, classified as essential or additional, for collection in population-based cancer registries. We aimed to describe the incidence distribution and survival of each of these NSPIs.

PROCEDURES

Cases were extracted from the Australian Childhood Cancer Registry. The study cohort (n = 4187) comprised all children aged under 15 years diagnosed with an eligible cancer between 2010 and 2018, with follow-up until 31 December 2020. NSPI data were collected directly from each patient's medical records. Differences in 5-year relative survival were assessed using multivariable flexible parametric models, adjusted for sex and age group at diagnosis.

RESULTS

The availability of data varied, exceeding 85% for all essential NSPIs apart from histologic subtype for Wilms tumours (69%) and lineage for acute lymphoblastic leukaemia (78%). Information on additional NSPIs tended to be recorded less often, particularly cytogenetic subtype for non-alveolar rhabdomyosarcoma (28%) and astrocytoma (4%). Eight NSPIs exhibited a significant difference in survival, with the largest disparity occurring among children with astrocytoma according to tumour grade (5-year relative survival of 18% for grade IV disease compared with 99% for grade I disease; p < .001).

CONCLUSIONS

Our findings demonstrate that most of the recommended NSPIs can be retrieved from medical records in Australia in recent years, allowing the capability of assessing survival within patient subgroups of clinical interest. Reporting of NSPI data has the capability to inform local and global understanding of population-level disparities in childhood cancer survival.

Differentiation Potential of Hypodifferentiated Subsets of Nephrogenic Rests and Its Relationship to Prognosis in Wilms Tumor

Background Wilms tumor (WT) is highly curable, although anaplastic histology or relapse imparts a worse prognosis. Nephrogenic rests (NR) associated with a high risk of developing WT are abnormally retained embryonic kidney precursor cells. Methods After pseudo-time analysis using single-cell RNA sequencing (scRNA-seq) data, we generated and validated a WT differentiation-related gene (WTDRG) signature to predict overall survival (OS) in children with a poor OS. Results A differentiation trajectory from NR to WT was identified and showed that hypodifferentiated subsets of NR could differentiate into WT. Classification of WT children with anaplastic histology or relapse based on the expression patterns of WTDRGs suggested that patients with relatively high levels of hypodifferentiated NR presented a poorer prognosis. A WTDRG-based risk model and a clinically applicable nomogram was developed. Conclusions These findings may inform oncogenesis of WT and interventions directed toward poor prognosis in WT children of anaplastic histology or relapse.

Unusual Metastatic Patterns of Wilms Tumor: A Case Series

Wilms tumor (WT) is the most common renal malignancy of childhood. The common metastatic sites are the lungs, liver, and lymph nodes, with brain and bone metastases occurring rarely. Metastatic disease can be present at initial diagnosis or may occur with relapse or disease progression. The majority of relapses in WT occur within the first two years post-treatment. Late relapses are rare. This article describes four cases of WT, each demonstrating an unusual site or timing of metastases. Case 1 presented primarily with jaw metastases, Case 2 presented with bone (vertebrae) and spinal metastases manifesting as paraplegia, at relapse one year after completion of treatment, Case 3 presented with isolated liver metastases four years after treatment completion, and Case 4 presented with brain metastases after six weeks of treatment abandonment. This case series demonstrates the varied pattern of metastases of WT and highlights the need for a high index of suspicion for WT among patients who present with unusual sites of tumor or for metastasis in those who present with neurologic symptoms during or after treatment.

Post-operative flank irradiation using conformal versus highly conformal radiotherapy techniques for paediatric renal tumours: Results from the French registry PediaRT

PURPOSE

Three-dimensional conformal RT (3D-RT) techniques are gold standard for post-operative flank radiotherapy (RT) in paediatric renal tumours. Recently, highly conformal RT (HC-RT) techniques have been implemented without comparative clinical data. The main objective of this multicentre study was to compare locoregional control (LRC) in children treated either with HC-RT or 3D-RT techniques.

METHODS

Patients treated with post-operative flank RT for renal tumour registered in the national cohort PediaRT between March 2013 and September 2019 were included. Treatment and follow-up data, including toxicities and outcomes, were retrieved from the database. LRC was calculated, and dose reconstruction was performed in case of an event.

RESULTS

Seventy-nine patients were included. Forty patients were treated with HC-RT and 39 with 3D-RT. Median follow-up was 4.5 years. Three patients had locoregional failure (LRF; 4%). HC-RT was not associated with a higher risk of LRF. Three-year LRC were 97.4% and 94.7% in the HC-RT and 3D-RT groups, respectively. The proportion of planning target volumes receiving 95% or more of the prescribed dose did not significantly differ between both groups (HC-RT 88%; 3D-RT 69%; p = .05). HC-RT was better achieving dose constraints, and a significant mean dose reduction was observed in the peritoneal cavity and pancreas associated with lower incidence of acute gastrointestinal toxicity.

CONCLUSION

LRF after post-operative flank RT for renal tumours was rare and did not increase using HC-RT versus 3D-RT techniques. Dose to the pancreas and the peritoneal cavity, as well as acute toxicity, were reduced with HC-RT compared to 3D-RT.

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.

A higher tumor volume and undernutrition at diagnosis adversely affect the survival of children with Wilms tumor: A study of 200 patients

BACKGROUND

Distinct prognostic factors for Wilms tumor (WT) in low- and middle-income countries need identification.

METHODS

Retrospective study of patients with WT managed by the International Society of Pediatric Oncology (SIOP) approach for over 11 years (2005-2016) at a single center in Chandigarh, India.

RESULTS

The study included 200 patients (median age: 33.5 months). The tumor stage (SIOP) distribution included stage I (30%), II (36%), III (14%), IV (17%), and V (3%). The histology-risk groups were low (8%), intermediate (84%), and high risk (9%). At diagnosis, 68 out of 190 (36%) patients were underweight. The median tumor volume at diagnosis was 481 ml (interquartile ratio [IQR]: 306.9, 686.8, n = 146). Following neoadjuvant chemotherapy, it reduced to 110 ml (IQR: 151.2, 222, n = 77). Treatment was abandoned in 20.5% of the patients. Treatment-related mortality occurred in 13 of 179 (7.2%) patients. Relapse occurred in 26 of 158 (16.5%) patients. The 3-year overall survival (OS) and event-free survival (EFS) of patients who completed therapy were 78.3 and 72%, respectively. The stage (p = .013) and histology (p = .023) influenced OS. A lower OS in stage II (75.4%) versus stage III disease (83.7%) suggested understaging. Patients with a higher tumor volume at diagnosis (p = .005; odds ratio [OR]: 0.99; 95% confidence interval [CI]: 0.99-1.00) or a lower weight-for-age z-score (p = .002; OR: 1.68; 95% CI: 1.21-2.33) had an increased risk of death or relapse.

CONCLUSIONS

The 3-year OS and EFS of children who completed therapy were 78.3 and 72%, respectively. A higher tumor volume and lower weight-for-age z-score at diagnosis were identified as distinct adverse prognostic factors. A likely suboptimal lymph node assessment (intraoperative and histopathology) contributed to the understaging of stage III to II disease and reduced survival.

Challenges in the Management of Wilms Tumor in a Developing Country: A Twenty Years' Experience From a Single Center in Pakistan

BACKGROUND

Wilms Tumor (WT) is one of the most curable childhood cancers. High cure rates seen in the developed countries are not reproduced in developing countries. Lack of access to cancer treatment facilities, financial constraints, late presentation, and abandonment have previously been described. We reviewed our data over the last 20 years to highlight some of these challenges.

METHODS

This is a retrospective chart review of children with WT at our center up to the age of 18 years between 1 November 1997 and 30 November 2017. Demographic details, presentation characteristics and treatment details were recorded. Factors associated with poor outcome were analyzed.

RESULTS

Two hundred eleven children were registered; 117(55.5%) were males. Median age at presentation was 3 (range 0 to 18) years. Presentation data were available for 184/211 patients, staging details for 159/211 and metastatic status for 178/211. Of the available dataset, 60% presented without prior treatment, whereas 40% presented atleast after primary surgical excision. High-stage (stage III or above) disease was present in 79 (49.7%) patients; 61 (34.3%) was presented with metastases or recurrence; 63 (29.8%) abandoned or refused treatment; 99/172 (57.6%) patients finished treatment, 23 (13.4%) died during treatment, and 6 died before treatment. Of the 99 patients who finished treatment 83 (83.8%) are well off therapy; 15(15.2%) relapsed; 6 (40%) are alive after salvage therapy, while 9 (60%) died.

CONCLUSIONS

Our data highlights the challenges of managing WT in resource poor environments. Prior surgery, incomplete staging work-up and abandonment are some of the most frequently encountered barriers. A multipronged approach is required to overcome these challenges.

Kidney disease in very long-term survivors of Wilms tumor: A nationwide cohort study with sibling controls

BACKGROUND

Survival after Wilms tumor has significantly increased and focus on late effects has become increasingly important. However, knowledge about long-term renal function in survivors of Wilms tumor is missing. Our aim was to investigate evidence of kidney disease in 20- or more-year survivors of Wilms tumor in a clinical setting, with siblings as comparisons.

METHODS

In this cross-sectional study, we established a cohort of Danish 20-plus-year survivors of Wilms tumor and siblings as controls. Participants answered a comprehensive health questionnaire supplemented by measurements of estimated glomerular filtration rate (eGFR), urine albumin-to-creatinine ratio, and blood pressure and were categorized according to the chronic kidney disease classification. Multiple linear regression analysis, taking family membership into account, was used to describe the differences in eGFR. Logistic regression analysis was performed to describe risk factors for the development of kidney disease.

RESULTS

We included 99 survivors of Wilms tumor and 38 sibling controls with a median of 37 years of follow-up. The eGFR of Wilms tumor survivors was 13 ml/min/1.73 m² (95% CI -20; -5) lower when compared to sibling control. Evidence of kidney disease, with risk factors as hypertension and diabetes, was found in 19% of the Wilms tumor survivors and 2% developed end-stage renal disease. Ninety-two percent of the Wilms tumor survivors had an eGFR >60 ml/min/1.73² .

CONCLUSION

Long-term Wilms tumor survivors have on average a significantly decreased renal function along with the increased prevalence of kidney disease and end-stage renal disease when compared to sibling controls. Still, most survivors had kidney function within the normal range.

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.

White paper: Onco-fertility in pediatric patients with Wilms tumor

The survival of childhood Wilms tumor is currently around 90%, with many survivors reaching reproductive age. Chemotherapy and radiotherapy are established risk factors for gonadal damage and are used in both COG and SIOP Wilms tumor treatment protocols. The risk of infertility in Wilms tumor patients is low but increases with intensification of treatment including the use of alkylating agents, whole abdominal radiation or radiotherapy to the pelvis. Both COG and SIOP protocols aim to limit the use of gonadotoxic treatment, but unfortunately this cannot be avoided in all patients. Infertility is considered one of the most important late effects of childhood cancer treatment by patients and their families. Thus, timely discussion of gonadal damage risk and fertility preservation options is important. Additionally, irrespective of the choice for preservation, consultation with a fertility preservation (FP) team is associated with decreased patient and family regret and better quality of life. Current guidelines recommend early discussion of the impact of therapy on potential fertility. Since most patients with Wilms tumors are prepubertal, potential FP methods for this group are still considered experimental. There are no proven methods for FP for prepubertal males (testicular biopsy for cryopreservation is experimental), and there is just a single option for prepubertal females (ovarian tissue cryopreservation), posing both technical and ethical challenges. Identification of genetic markers of susceptibility to gonadotoxic therapy may help to stratify patient risk of gonadal damage and identify patients most likely to benefit from FP methods.

Vascular Access in Pediatric Oncology and Hematology: State of the Art

Management and successful use of vascular access are critical issues in pediatric patients affected by malignancies. Prolonged course of disease, complex and various treatment protocols require long-lasting vascular access providing adequate tools to administrate those therapies and to collect routine blood sampling without painful and repeated venipuncture. For these reasons, central venous catheters are currently an important component in pediatric onco-hematological care, with a direct influence on outcome. Indeed, there are peculiar issues (techniques of insertion, management, complications etc.) which must be well-known in order to improve the outcome and the quality of life of children with cancer.

Characteristics of Nephroblastoma/Nephroblastomatosis in Children with a Clinically Reported Underlying Malformation or Cancer Predisposition Syndrome

Simple Summary

It is well known that different cancer predisposition syndromes are associated with characteristic WT-features. The following findings from our retrospective analysis of patients with nephroblastoma treated according to the SIOP/GPOH trials between 1989 and 2017 are relevant: (1) The outcome of patients with a cancer predisposition syndrome is not always favorable despite early diagnosis, small tumors and less metastatic disease. This finding is partly depending on complications related to the underlying syndrome. (2) Predisposition syndromes seem to be underdiagnosed as several clinical and pathological features of Wilms tumor being clearly linked to a cancer predisposition syndrome did not lead to genetic counseling before and after WT diagnosis. As a conclusion, in children with a nephroblastoma and specific clinical and pathological features that are in line with a nephroblastoma cancer predisposition syndrome such a syndrome should always be considered and ruled out if unknown at the time of tumor diagnosis.

Abstract

(1) Background: about 10% of Wilms Tumor (WT) patients have a malformation or cancer predisposition syndrome (CPS) with causative germline genetic or epigenetic variants. Knowledge on CPS is essential for genetic counselling. (2) Methods: this retrospective analysis focused on 2927 consecutive patients with WTs registered between 1989 and 2017 in the SIOP/GPOH studies. (3) Results: Genitourinary malformations (GU, N = 66, 2.3%), Beckwith-Wiedemann spectrum (BWS, N = 32, 1.1%), isolated hemihypertrophy (IHH, N = 29, 1.0%), Denys-Drash syndrome (DDS, N = 24, 0.8%) and WAGR syndrome (N = 20, 0.7%) were reported most frequently. Compared to others, these patients were younger at WT diagnosis (median age 24.5 months vs. 39.0 months), had smaller tumors (349.4 mL vs. 487.5 mL), less often metastasis (8.2% vs. 18%), but more often nephroblastomatosis (12.9% vs. 1.9%). WT with IHH was associated with blastemal WT and DDS with stromal subtype. Bilateral WTs were common in WAGR (30%), DDS (29%) and BWS (31%). Chemotherapy induced reduction in tumor volume was poor in DDS (0.4% increase) and favorable in BWS (86.9% reduction). The event-free survival (EFS) of patients with BWS was significantly (p = 0.002) worse than in others. (4) Conclusions: CPS should be considered in WTs with specific clinical features resulting in referral to a geneticist. Their outcome was not always favorable.

Comparative analysis of the clinical characteristics and outcomes of patients with Wilms tumor in the United Kingdom and Japan

BACKGROUND

Wilms tumor (WT) demonstrates epidemiological differences by world region and ethnicity. To enhance understanding of these differences, we retrospectively analyzed clinical trial data sets from the UK and Japan over a 20-year period.

PROCEDURE

We used data from three consecutive clinical trials in the UK and a single study in Japan that enrolled patients diagnosed during 1996-2015, to compare clinical characteristics and outcomes between countries.

RESULTS

During 1996-2015, 1395 patients in the UK and 537 in Japan were included. Japanese patients have a significantly younger median age at diagnosis than those in the UK (28 months vs 39 months). The proportion of patients with stage IV, large tumors, and anaplastic histology appears to be higher in the UK than in Japan (18% vs 11%, 62% vs 49%, 8% vs 3%, respectively). During 2005-2015, 77 hospitals treated WT in Japan compared with only 20 hospitals in the UK. Five-year overall survival of patients with WT was over 90% in both countries, but five-year event-free survival of patients with stage IV was significantly lower in Japan than in the UK (50.0% vs 76.2%, P = 0.001).

CONCLUSIONS

Differences in age of onset, tumor size at diagnosis, and histology may reflect differences in the genetic background of patients with WT between countries, but population-based phenotype-genotype data are lacking. The difference in survival probability for stage IV patients may be due to different diagnostic criteria or different treatment strategies. Prospective, international clinical studies including genomic analyses are needed to confirm these findings and improve clinical practice.

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.

Prognostic Factors for Wilms Tumor Recurrence: A Review of the Literature

Simple Summary

A Wilms tumor is a childhood kidney tumor. In high-income countries, 90% of patients with this tumor survive. However, the tumor recurs in 15% of patients. It is important to identify the patients at risk of recurrence in order to adjust treatment in such a way that recurrence may potentially be prevented. However, we are currently unable to determine precisely which patients are at risk of recurrence. Therefore, we present an overview of factors that influence the risk of recurrence, also known as prognostic factors. These factors range from patient-, tumor- and treatment-related characteristics to geographic and socioeconomic factors. In addition to these factors, biological markers, such as genetic alterations, should be studied more intensively as these markers may be able to better identify patients at risk of tumor recurrence.

Abstract

In high-income countries, the overall survival of children with Wilms tumors (WT) is ~90%. However, overall, 15% of patients experience tumor recurrence. The adverse prognostic factors currently used for risk stratification (advanced stage, high risk histology, and combined loss of heterozygosity at 1p and 16q in chemotherapy-naïve WTs) are present in only one third of these cases, and the significance of these factors is prone to change with advancing knowledge and improved treatment regimens. Therefore, we present a comprehensive, updated overview of the published prognostic variables for WT recurrence, ranging from patient-, tumor- and treatment-related characteristics to geographic and socioeconomic factors. Improved first-line treatment regimens based on clinicopathological characteristics and advancing knowledge on copy number variations unveil the importance of further investigating the significance of biological markers for WT recurrence in international collaborations.

Outcome of Children with Wilms' Tumor in Developing Countries

Wilms’ tumor is the most common kidney tumor of childhood. The outcome of this malignant tumor has improved due to the improvement of therapeutic strategies. The most important factor in determining the prognosis of these patients is the histopathology subtype of the tumor; unfavorable histopathology is seen in only 11.5% of the patients, which accounts for 52% of deaths. Therefore, the aim of this study was to determine the outcome of children with Wilms’ tumor referred to our hospital over a period of 10 years. This is a retrospective cohort study, and the target population included all patients with Wilms’ tumor referred to Ali Asghar Hospital and were treated according to the National Wilms tumor study 4 (NWTS-4) protocol. All patients’ data were extracted from the medical records of the department. Overall survival and event-free survival (EFS) were analyzed by the Kaplan Mayer method in the SPSS software, version 23. Fifty-two patients (24 male and 28 female patients) with Wilms’ tumor were included. The mean age of the subjects was 40 months. The most common stage among boys and girls was stage II (23.08% and 28.85%, respectively). Our findings revealed that the overall five-year survival of patients was 87±5%; this figure was determined as 100% for boys and 76.8% ± 1.6 for girls (P = 0.018). Our findings show a dramatic improvement in the outcome of children with Wilms’s tumor, and our results are comparable with other results from developed countries. Gender may be an independent prognostic factor of children with Wilms’ tumor.

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

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

An organoid biobank for childhood kidney cancers that captures disease and tissue heterogeneity

Kidney tumours are among the most common solid tumours in children, comprising distinct subtypes differing in many aspects, including cell-of-origin, genetics, and pathology. Pre-clinical cell models capturing the disease heterogeneity are currently lacking. Here, we describe the first paediatric cancer organoid biobank. It contains tumour and matching normal kidney organoids from over 50 children with different subtypes of kidney cancer, including Wilms tumours, malignant rhabdoid tumours, renal cell carcinomas, and congenital mesoblastic nephromas. Paediatric kidney tumour organoids retain key properties of native tumours, useful for revealing patient-specific drug sensitivities. Using single cell RNA-sequencing and high resolution 3D imaging, we further demonstrate that organoid cultures derived from Wilms tumours consist of multiple different cell types, including epithelial, stromal and blastemal-like cells. Our organoid biobank captures the heterogeneity of paediatric kidney tumours, providing a representative collection of well-characterised models for basic cancer research, drug-screening and personalised medicine.

Pre-clinical cell culture models capturing the heterogeneity of childhood kidney tumours are limited. Here, the authors establish and characterise an organoid biobank of tumour and matched normal organoid cultures from over 50 children with different subtypes of kidney cancer.

Is radiotherapy required in first-line treatment of stage I diffuse anaplastic Wilms tumor? A report of SIOP-RTSG, AIEOP, JWiTS, and UKCCSG

BACKGROUND

As a significant proportion of relapses occurred in the tumor bed or abdomen on patients with the fifth National Wilms Tumor Study stage I anaplastic Wilms tumor (WT), flank radiotherapy was added for stage I anaplastic WT in the subsequent study of the Children's Oncology Group (AREN0321). Preliminary results revealed reduction of relapse rate and improved survival. In cases treated with preoperative chemotherapy, such as in International Society of Pediatric Oncology (SIOP), the value of radiotherapy has never been studied. The aim of this observational study is to describe the pattern of recurrence and survival of patients with stage I diffuse anaplastic WT (DAWT) after induction chemotherapy.

METHODS

Retrospective data analysis of the pattern of relapse and survival of all patients with stage I DAWT were included in recent SIOP, L'Associazone Italiana Ematologica Oncologia Pediatrica (AIEOP), Japan Wilms Tumor Study Group (JWiTS), United Kingdom Children's Cancer Study Group (UKCCSG) renal tumor registries. Postoperative treatment consisted of actinomycin D, vincristine, and doxorubicin for 28 weeks without local irradiation.

RESULTS

One hundred nine cases with stage I DAWT were identified, of which 95 cases received preoperative chemotherapy. Of these, seven patients underwent preoperative true-cut biopsy. Sixteen of the 95 patients relapsed (17%), six locally, four at distant site, and six combined, and all treated according to SIOP 2001 relapse protocol, which resulted in a 5-year overall survival of 93%.

CONCLUSION

Despite 13% locoregional relapse rate, an excellent rescue rate was achieved after salvage treatment, in patients with stage I DAWT whose first-line treatment comprised three-drug chemotherapy (including doxorubicin), without flank irradiation. Therefore, we continue not to advocate the use of radiotherapy in first-line treatment after preoperative chemotherapy in stage I DAWT in the next SIOP protocol.

MYC gene associated polymorphisms and Wilms tumor risk in Chinese children: a four-center case-control study

BACKGROUND

Wilms tumor (WT) is a common embryonal malignancy in the kidney, ranking fourth in childhood cancer worldwide. MYC, a critical proto-oncogene, plays an important role in tumorigenesis. Single nucleotide polymorphisms in the MYC gene may lead to the deregulation of MYC proto-oncogene protein and thereby promote the initiation and development of tumors.

METHODS

Here, we assessed the association between MYC gene associated polymorphisms and WT susceptibility by performing a case-control study with 355 cases and 1070 controls. Two MYC gene associated polymorphisms (rs4645943 C > T, rs2070583 A > G) were genotyped by TaqMan technique. Odds ratios (ORs) and 95% confidence intervals (CIs) were used for evaluating the association between these two polymorphisms and WT susceptibility.

RESULTS

No significant association was detected between the selected polymorphisms and WT risk in the overall analysis as well as stratification analysis.

CONCLUSIONS

These results indicate that neither of two selected MYC gene associated polymorphisms might affect WT susceptibility in the Chinese population. Large well-designed studies with diverse ethnicities are warranted to verify these results.

Evaluation of needle biopsy as a potential risk factor for local recurrence of Wilms tumour in the SIOP WT 2001 trial

RATIONALE

The impact of biopsying Wilms tumour (WT) at diagnosis on assigning the tumour stage and recommended treatment remains controversial. To address this important question, we analysed the potential association of all types of biopsy with local recurrence in patients treated in the SIOP WT 2001 trial, where needle biopsy was permitted without 'upstaging' the tumour to stage III. Only open biopsy required treatment as stage III.

METHODS

Among 2971 patients with unilateral WT (stages I-IV), 420 relapsed (139 local). Risk factors for recurrence were analysed by Cox proportional hazard methods.

RESULTS

Biopsy was performed in 969 of 2971 (33%) patients (64% cutting needle, 30% fine needle aspiration [FNA] and 6% open biopsy). Biopsied patients were older, with larger tumours and a greater proportion with high-risk histology. In multivariate analysis that included all factors associated with local recurrence in univariate analysis, only high-risk histology (hazard ratio [HR] = 2.32; 95% confidence interval [CI]: 1.58-3.42, p=<0.0001), age≥2 years (HR = 2.24; 95% CI: 1.22-4.09, p = 0.01) and preoperative tumour volume (HR = 1.07 per 100 ml; 95% CI: 1.02-1.12, p = 0.01) were significant. The HR for the association of local recurrence and event-free and overall survival with biopsy was not significant (HR = 1.4; 95% CI: 0.9-2.17, p = 0.13; HR = 1.1; 95% CI: 0.85-1.42, p = 0.46 and HR = 1.13; 95% CI: 0.79-1.62, p = 0.51, respectively). These results were not materially different whether FNA or open biopsy were included in the biopsy group or not.

CONCLUSIONS

This post hoc analysis provides some reassurance that needle biopsy is not an independent adverse factor for either local recurrence or survival after adjustment for all relevant risk factors. Needle biopsy should not be an automatic criterion to 'upstage' WT.

Wilms tumour event-free and overall survival in Southern and Eastern Europe: Pooled analyses of clinical data from four childhood cancer registries (1999-2017)

BACKGROUND

Wilms tumour (WT) management represents a success story in pediatric oncology. We aimed to assess, for the first time, the event-free survival (EFS) vs. overall survival (OS) in Southern and Eastern Europe (SEE) using harmonised clinical data collected by childhood cancer registries and to identify respective prognostic factors.

METHODS

From 1999 to 2017, data for incident WT cases aged 0-14 years from 3 nationwide (Greece, Belarus and Slovenia) and one regional (Greater Poland) SEE registries were collected following common coding. Kaplan-Meier curves were constructed, and EFS vs. OS values were derived from Cox proportional hazard models by study variables.

RESULTS

A total of 338 WT cases (45.6% males; median age, 3.19 years; age<5 years, 75%) were included in the analyses. Bilateral were 21 tumours (6.2%). Among the 317 unilateral cases, the majority (93.7%) received International Society of Pediatric Oncology-based protocols; EFS_5-year was 85.1%, and OS_5-year 91.1%; both outcomes were significantly worse in stage IV patients or in those with high-risk/unfavourable histology. Relapse rate among high-risk/unfavourable histology cases was 2.3 times higher than among low-intermediate risk/favourable histology cases, with respective death rate 5.6 times higher. Both relapse and death rates increased significantly in patients with advanced anatomical stage and high-risk/unfavourable histology. Finally, significantly worse was the outcome in bilateral tumours (OS_5-year: 76.3%) vs. unilateral non-metastatic tumours (OS_5-year: 94.7%).

CONCLUSIONS

Our results delineate the potential of high-quality childhood cancer registration entailing clinical data to assess predictors of WT outcome over and beyond those derived from enrolment into clinical trials. Specifically, outcomes among children with WT residing in the four participating SEE countries were comparable with those reported by major cooperative international groups, albeit somehow inferior. Despite the excellent overall prognosis, however, subgroups of patients with advanced or bilateral disease and/or high-risk histology still suffer poor outcomes.

Comparison of 3-Dimensional and Augmented Reality Kidney Models With Conventional Imaging Data in the Preoperative Assessment of Children With Wilms Tumors

IMPORTANCE

Nephron-sparing surgery can be considered in well-defined cases of unilateral and bilateral Wilms tumors, but the surgical procedure can be very challenging for the pediatric surgeon to perform.

OBJECTIVE

To assess the added value of personalized 3-dimensional (3-D) kidney models derived from conventional imaging data to enhance preoperative surgical planning.

DESIGN, SETTING, AND PARTICIPANTS

In a survey study, the conventional imaging data of 10 Dutch children with Wilms tumors were converted to 3-D prints and augmented reality (AR) holograms and a panel of pediatric oncology surgeons (n = 7) assessed the quality of the different imaging methods during preoperative evaluation. Kidney models were created with 3-D printing and AR using a mixed reality headset for visualization.

MAIN OUTCOMES AND MEASURES

Differences in the assessment of 4 anatomical structures (tumor, arteries, veins, and urinary collecting structures) using questionnaires. A Likert scale measured differences between the imaging methods, with scores ranging from 1 (completely disagree) to 5 (completely agree).

RESULTS

Of the 10 patients, 7 were girls, and the mean (SD) age was 3.7 (1.7) years. Compared with conventional imaging, the 3-D print and the AR hologram models were evaluated by the surgeons to be superior for all anatomical structures: tumor (median scores for conventional imaging, 4.07; interquartile range [IQR], 3.62-4.15 vs 3-D print, 4.67; IQR, 4.14-4.71; P = .008 and AR hologram, 4.71; IQR, 4.26-4.75; P = .002); arteries (conventional imaging, 3.62; IQR, 3.43-3.93 vs 3-D print, 4.54; IQR, 4.32-4.71; P = .002 and AR hologram, 4.83; IQR, 4.64-4.86; P < .001), veins (conventional imaging, 3.46; IQR 3.39-3.62 vs 3-D print, 4.50; IQR, 4.39-4.68; P < .001 and AR hologram, 4.83; IQR, 4.71-4.86; P < .001), and urinary collecting structures (conventional imaging, 2.76; IQR, 2.42-3.00 vs 3-D print, 3.86; IQR, 3.64-4.39; P < .001 and AR hologram, 4.00; IQR, 3.93-4.58; P < .001). There were no differences in anatomical assessment between the two 3-D techniques (the 3-D print and AR hologram).

CONCLUSIONS AND RELEVANCE

In this study, the 3-D kidney models were associated with improved anatomical understanding among the surgeons and can be helpful in future preoperative planning of nephron-sparing surgery for Wilms tumors. These models may be considered as a supplementary visualization in clinical care.

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

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

The effect of preoperative chemotherapy on histological subtyping and staging of Wilms tumors: The United Kingdom Children's Cancer Study Group (UKCCSG) Wilms tumor trial 3 (UKW3) experience

BACKGROUND

Two principal approaches to Wilms tumor (WT) treatment are immediate surgery (IS) and preoperative chemotherapy (PCT), and both treatments use the risk-adapted approach that includes histological subclassification of the tumor, combined with additional prognostic factors. In the UKW3 trial, these two approaches were compared. The aim of the present study was to compare histological features between the two groups, to assess the impact of PCT on distribution of histological subtyping and staging and to evaluate whether PCT resulted in more staging discrepancies between local and central pathology review (CPR).

MATERIALS AND METHODS

The cases were identified from the UKW3 trial database. The criteria for inclusion in the study were unilateral, nonmetastatic, nonanaplastic WTs, and submitted for CPR with an adequate number of slides. They were subclassified according to the NWTS and later the SIOP 9301 criteria.

RESULTS

There were 244 WTs in the IS and 182 in the PCT group subclassified as follows: blastemal 86 (35%) vs 9 (5%), epithelial 34 (14%) vs 12 (7%), stromal 12 (5%) vs 25 (14%), mixed 112 (46%) vs 45 (25%), respectively, plus 40% regressive and 10% completely necrotic WTs in the PCT group. The differences between the two groups for blastemal and mixed types were statistically significant. In the PCT group, there was a significant decrease in stage III tumors. The discrepancies in staging between local and CPR were not significant.

CONCLUSION

PCT significantly altered histological features and typing of WTs. It resulted in fewer stage III tumors, and staging discrepancies were equally represented in both groups.

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

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

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

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

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

BACKGROUND AND PURPOSE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSION

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

The UMBRELLA SIOP-RTSG 2016 Wilms tumour pathology and molecular biology protocol

On the basis of the results of previous national and international trials and studies, the Renal Tumour Study Group of the International Society of Paediatric Oncology (SIOP-RTSG) has developed a new study protocol for paediatric renal tumours: the UMBRELLA SIOP-RTSG 2016 protocol (the UMBRELLA protocol). Currently, the overall outcomes of patients with Wilms tumour are excellent, but subgroups with poor prognosis and increased relapse rates still exist. The identification of these subgroups is of utmost importance to improve treatment stratification, which might lead to reduction of the direct and late effects of chemotherapy. The UMBRELLA protocol aims to validate new prognostic factors, such as blastemal tumour volume and molecular markers, to further improve outcome. To achieve this aim, large, international, high-quality databases are needed, which dictate optimization and international harmonization of specimen handling and comprehensive sampling of biological material, refine definitions and improve logistics for expert review. To promote broad implementation of the UMBRELLA protocol, the updated SIOP-RTSG pathology and molecular biology protocol for Wilms tumours has been outlined, which is a consensus from the SIOP-RTSG pathology panel.

What is the risk of local recurrence after laparoscopic transperitoneal radical nephrectomy in children with Wilms tumours? Analysis of a local series and review of the literature

BACKGROUND

To reduce long-term morbidity (adhesions-related complications and impaired quality of life due to scars), laparoscopy has been used as an alternative to open surgery in Wilms tumours (WTs). However, concerns have been raised on the risk of local recurrence after this type of resection.

OBJECTIVE

The aim was to determine the incidence of local recurrence after laparoscopic transperitoneal radical nephrectomy (LTRN).

STUDY DESIGN

We analysed 18 local cases and conducted a review of the English literature in Pubmed from 2004 to 2017 with the following keywords: (Wilms OR nephroblastoma) AND (laparoscopy OR minimally invasive surgery) AND 2004:3000. The review was conducted according to PRISMA guidelines. Data were collected independently in duplicate in a preformed Excel database. Review articles and duplicated case reports were excluded. Patients with retroperitoneoscopic or nephron-sparing surgery were also excluded.

RESULTS

One hundred and four LTRNs have been performed for WT with neoadjuvant chemotherapy in 93 cases. Tumour was ruptured preoperatively in three cases but never intraoperatively. The median volume of the tumour was 229.4 mL (3.8-776 mL). Local stage was specified in 86 cases: 49 stage I, 28 stage II, and nine stage III. Lymph nodes were sampled in 48 patients (median 2.3 [0-14] nodes). Histology was reported in 90 cases: 27 favourable and two unfavourable histology (COG); and six low, 50 intermediate, and five high-risk tumours (International Society of Paediatric Oncology). With a median follow-up of 20.5 months (1-114 months), there were four local recurrences (3.8%) at a median of 8.5 (7-9) months after surgery. Three tumours were initial local stage I (2 intermediate and 1 high risk) and one stage III. The results are presented in the Figure.

DISCUSSION

The incidence of local recurrence after LTRN is 3.8%. This is lower than previously reported after open resection. However, tumours amenable to minimally invasive surgery are smaller, with higher numbers of low stage and standard histology. Additionally, the quality of the reports is suboptimal and follow-up is relatively short.

CONCLUSION

LTRN does not seem to increase the incidence of local recurrence in WT but inclusion of patients in international protocols with prolonged and systematic follow-up is of utmost importance to carefully evaluate this risk.

Evaluation of boost irradiation in patients with intermediate-risk stage III Wilms tumour with positive lymph nodes only: Results from the SIOP-WT-2001 Registry

OBJECTIVE

To evaluate the value of radiotherapy boost omission in patients with intermediate-risk, stage III Wilms tumours (WT) with positive lymph nodes (LN).

METHODS AND MATERIALS

All patients with intermediate-risk, stage III (LN positive) WT consecutively registered in the SIOP-WT-2001 study were included in this analysis. Endpoints were 5-year event-free survival (EFS), loco-regional control (LRC) and overall survival (OS).

RESULTS

Between June 2001 and May 2015, 2,569 patients with stage I to III WT after preoperative chemotherapy were registered in the SIOP-WT-2001 study. Five hundred and twenty-three (20%) had stage III disease, of which 113 patients had stage III due to positive LN only. Of those, 101 (89%) received radiotherapy, 36 of which (36%) received, apart from flank irradiation, a boost dose to the LN positive area. Four patients (4%) did not receive any adjuvant radiotherapy. In eight patients information on radiotherapy was not available. With a median follow-up of 71 months, no difference in 5-year EFS (84% vs. 83%, P = 0.77) and LRC (96% vs. 97%, P = 0.91) was observed between patients receiving a radiotherapy boost and those without boost, respectively. Five-year OS, including salvage therapy, was excellent (boost vs. no boost: 97% vs. 95%, P = 0.58).

CONCLUSIONS

Outcome data demonstrate that omission of the radiotherapy boost to the loco-regional positive lymph nodes in patients with intermediate-risk, stage III WT who receive preoperative chemotherapy and postoperative flank irradiation (14.4 Gy) can be considered a safe approach for future SIOP protocols.

Survival and mortality rates of Wilms tumour in Southern and Eastern European countries: Socioeconomic differentials compared with the United States of America

BACKGROUND

Despite recent therapeutic advancements, Wilms tumour (WT) presents remarkable survival variations. We explored mortality and survival patterns for children (0-14 years) with WT in 12 Southern and Eastern European (SEE) countries in comparison with the United States of America (USA).

METHODS

A total of 3966 WT cases (0-14 years) were registered by a network of SEE childhood cancer registries (N:1723) during available registration periods circa 1990-2016 and surveillance, epidemiology, and end results program (SEER) (N:2243; 1990-2012); mortality data were provided by the respective national statistical services. Kaplan-Meier curves and Cox proportional hazards models were used to assess the role of age, sex, year of diagnosis, urbanisation and Human Development Index (HDI) on overall survival (OS).

RESULTS

Persisting regional variations shape an overall 78% 5-year OS in the participating SEE countries, lagging behind the USA figure (92%, p=0.001) and also reflected by higher SEE mortality rates. Worth mentioning is the gradually escalating OS in SEE (hazard ratio [HR]_{5-year increment}:0.67, 95% confidence interval [CI]:0.60, 0.75) vs. a non-significant 10% improvement in the SEER data, which had a high starting value. OS differentials [two-fold less favourable among children aged 10-14 years, boys and those living in rural SEE areas (HR:1.37; CI:1.10-1.71) or countries with inferior HDI (2-3-fold)] were minimal in the USA.

CONCLUSIONS

Children with WT residing in SEE countries do not equally enjoy the substantial survival gains, especially for those living in rural areas and in lower HDI countries. Noteworthy are steep and sizeable survival gains in SEE along with the newly presented Greek data pointing to achievable survival goals in SEE despite the financial crisis.

Tissue expression of retinoic acid receptor alpha and CRABP2 in metastatic nephroblastomas

Background

Nephroblastoma or Wilms tumor is the most frequent kidney cancer in children and accounts for 98% of kidney tumors in this age group. Despite favorable prognosis, a subgroup of these patients progresses to recurrence and death. The retinoic acid (RA) pathway plays a role in the chemoprevention and treatment of tumors due to its effects on cell differentiation and its antiproliferative, anti-oxidant, and pro-apoptotic activities. Reports describe abnormal cellular retinoic acid-binding protein 2 (CRABP2) expression in neoplasms and its correlation with prognostic factors and clinical and pathological characteristics. The aim of this study was to evaluate the immunohistochemical expression of retinoic acid receptor alpha (RARA) and CRABP2 in paraffin-embedded samples of nephroblastomas via semiquantitative and quantitative analyses and to correlate this expression with prognostic factors.

Methods

Seventy-seven cases of nephroblastomas were selected from pediatric oncology services. The respective medical records and surgical specimens were reviewed. Three representative tumor samples and one non-tumor renal tissue sample were selected for the preparation of tissue microarrays (TMA). The Allred scoring system was used for semiquantitative immunohistochemical analyses, whereas a morphometric analysis of the stained area was employed for quantitative evaluation. The nonparametric Mann-Whitney test was used for comparisons between two groups, while the nonparametric Kruskal-Wallis test was used to compare three or more groups.

Results

Immunopositivity for RARA and CRABP2 was observed in both the nucleus and cytoplasm. All histological components of the nephroblastoma (blastema, epithelium, and stroma) were positive for both markers. RARA, based on semiquantitative analyses, and CRABP2, bases on quantitative analyses, exhibited increased immunohistochemical expression in patients with metastasis, with p values of 0.0247 and 0.0128, respectively. These findings were similar to the results of the quantitative analysis of RARA expression, showing greater immunopositivity in tumor samples of patients subjected to pre-surgical chemotherapy. No significant correlation was found with the other variables studied, such as disease stage, anaplasia, risk group, histological type, nodal involvement, and clinical evolution.

Conclusions

Semiquantitative and quantitative analyses of the markers RARA and CRABP2 indicate their potential as biomarkers for tumor progression and their participation in nephroblastoma tumorigenesis.

Electronic supplementary material

The online version of this article (10.1186/s13000-018-0686-z) contains supplementary material, which is available to authorized users.

Position paper: Rationale for the treatment of Wilms tumour in the UMBRELLA SIOP-RTSG 2016 protocol

The Renal Tumour Study Group of the International Society of Paediatric Oncology (SIOP-RTSG) has developed a new protocol for the diagnosis and treatment of childhood renal tumours, the UMBRELLA SIOP-RTSG 2016 (the UMBRELLA protocol), to continue international collaboration in the treatment of childhood renal tumours. This protocol will support integrated biomarker and imaging research, focussing on assessing the independent prognostic value of genomic changes within the tumour and the volume of the blastemal component that survives preoperative chemotherapy. Treatment guidelines for Wilms tumours in the UMBRELLA protocol include recommendations for localized, metastatic, and bilateral disease, for all age groups, and for relapsed disease. These recommendations have been established by a multidisciplinary panel of leading experts on renal tumours within the SIOP-RTSG. The UMBRELLA protocol should promote international collaboration and research and serve as the SIOP-RTSG best available treatment standard.

Is there a socioeconomic variation in survival from renal tumours in children and young people resident in northern England (1968-2012)?

BACKGROUND

Despite strong evidence of a social gradient in cancer survival among UK adults, studies in children and young people remain inconclusive and have not included renal tumours. This study investigated the relationship between socioeconomic status and survival from renal tumours among children and young people.

PROCEDURE

Kaplan-Meier estimation and Cox regression were used to analyse survival for all 209 renal tumours in children and young people (0-24 years) diagnosed 1968-2012 and registered by a specialist population-based registry. Sociodemographic and clinicopathologic variables, including paternal occupation at birth, were also analysed.

RESULTS

No significant disparity in overall renal tumour and Wilms tumour (WT) survival was observed according to paternal social class [p=0.988 and 0.808, respectively]. The strongest predictor of survival was stage, with late stage (III-IV) disease having a 4-fold higher risk of death compared to early stage (I-II) disease [p<0.001]. Similarly, high mortality-risk was seen for late stage WT in children aged 0-14 years (Hazard Ratio=6.37; 95% CI=2.60-15.59).

CONCLUSIONS

This study did not detect a significant social gradient in renal tumour survival. The identification of tumour stage as a strong predictor of survival irrespective of age, necessitates the development of appropriate public health interventions that target early diagnosis and treatment.

Loss of heterozygosity on chromosome 16q increases relapse risk in Wilms' tumor: a meta-analysis

Wilms’ tumor (WT) is the most frequent malignant renal tumor in children. The survival rate is lower in patients with recurrence, and the factors that influence relapse in WT are not fully understood. Loss of heterozygosity on chromosome 16q (LOH 16q) has been reported to be associated with the relapse in WT, but this remains controversial. We performed a meta-analysis to clarify this. PUBMED, EMBASE, and the Cochrane Library were searched up to March 17, 2017. Ten studies involving 3385 patients were ultimately included in the meta-analysis. The meta-analysis showed that LOH 16q was significantly associated with the relapse in WT (relative risk [RR] = 1.74, 95% confidence interval [CI] = 1.43–2.13, P < 0.00001; hazard ratio [HR] = 1.76, 95% CI = 1.38–2.24, P < 0.00001). No significant heterogeneity among studies or publication bias was found. Sensitivity analysis showed omitting one study in each turn could not change the results. Subgroup analysis based on two studies indicated LOH 16q was more effective on elevated replase risk in patients with favorable-histology WT (RR = 2.52, 95% CI = 1.68–3.78, P < 0.00001; HR = 2.99, 95% CI = 1.84–4.88, P < 0.0001) but further work are needed to confirm this. These findings confirm that LOH 16q increased the relapse risk in WT, but more studies are required to further assess the association between LOH 16q and WT relapse among different subgroups.

Associations between LMO1 gene polymorphisms and Wilms' tumor susceptibility

Wilms' tumor is the most common childhood renal malignancy. A genome-wide association study identified LIM domain only 1 (LMO1) as having oncogenic potential. We examined the associations between LMO1 gene polymorphisms and susceptibility to Wilms' tumor. In this hospital-based, case-control study, we recruited 145 children with Wilms' tumor and 531 cancer-free children. Four polymorphisms (rs110419 A>G, rs4758051 G>A, rs10840002 A>G and rs204938 A>G) were genotyped using Taqman methodology. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to measure the associations between selected polymorphisms and Wilms' tumor susceptibility. Only rs110419 AG was found to be protective against Wilms' tumor (adjusted OR = 0.62, 95% CI = 0.41-0.94, P = 0.024) when compared to rs110419 AA. Wilms' tumor risk was markedly greater in children with 1-4 risk genotypes (nucleotide alterations) than in those with no risk genotypes (adjusted OR = 1.84, 95% CI = 1.25-2.69, P = 0.002). In a stratified analysis, the protective effect of rs110419 AG/GG was predominant in males. The association of 1-4 risk genotypes with Wilms' tumor risk was limited to subgroups of children who were >18 months old, female, and in clinical stages III+IV. Thus, LMO1 gene polymorphisms may contribute to Wilms' tumor risk, but this conclusion should be validated in other populations and larger studies.

Results of the Third AIEOP Cooperative Protocol on Wilms Tumor (TW2003) and Related Considerations

PURPOSE

TW2003, the third Italian prospective study on Wilms tumor, aimed to improve survival in patients with stage III-IV tumors, de-escalate therapy for stage I-II nonanaplastic tumors, refine the risk stratification of therapy, and develop a national infrastructure for biobanking and central pathology review.

MATERIALS AND METHODS

TW2003 recruited children 18 years old or younger with primary intrarenal tumors. Local physicians chose nephrectomy with or without preoperative chemotherapy as the initial treatment based on the risk of unsafe and/or incomplete immediate surgery. The main drivers for adjuvant therapy were tumor stage and diffuse anaplasia. A new risk stratification schema was investigated, incorporating patient age, reason for stage III designation and completeness of lung nodule response in stage IV disease.

RESULTS

We report on 453 patients with unilateral Wilms tumor. Preoperative chemotherapy was administered to 42% of patients. The 5-year event-free survival and overall survival rates were 89.1% (95% CI 83.6-94.9) and 97.0% (93.7-100) for stage I; 85.1% (79.6-91.1) and 94.0% (90.1-98.1) for stage II (160); 82.7% (75.3-90.8) and 90.9% (85.0-97.1) for stage III (101); and 72.1% (61.9-84.0) and 82.5% (73.1-93.1) for stage IV (69), respectively. On multivariable analysis only anaplasia was significant for event-free survival (HR 2.68, 95% CI 1.48-4.86, p=0.001; bias corrected c-index 0.580) and overall survival (HR 5.29, 95% CI 2.52-11.12, p <0.001; bias corrected c-index 0.697).

CONCLUSIONS

The survival rates achieved and the proposed risk stratification schema provide a basis for future comparisons of Wilms tumor treatment burden and patient outcome.

Renal Tumors in Children Younger Than 12 Months of Age: A 65-Year Single Institution Review

Wilms tumor (WT) is the most prevalent pediatric renal tumor and most commonly occurs between ages 1 and 5 years. Data are lacking on children younger than 12 months with renal tumors. The cancer registry at the authors' institution was queried to identify patients 12 months and younger with renal masses. Demographics, clinical presentation, histopathology, stage, and survival outcomes were reviewed. The most common presenting symptoms included an asymptomatic abdominal mass (73%) and hematuria (9%). Histopathology revealed WT in 73% of patients, mesoblastic nephroma in 20%. Of those infants younger than 1 month of age, mesoblastic nephroma was the most common histopathology (68%). The 5-year overall survival (OS) was 93%, and 5-year event-free survival (EFS) was 93% for the entire group. For patients with WT, 5-year OS was 88% and 5-year EFS was 83%. Outcomes for congenital mesoblastic nephroma were excellent with 5-year OS and EFS of 100%. Reasons for good prognosis may be multifactorial and may include frequent well child checks in the first year of life and favorable histology. Patients in this age group are more likely to be classified as very low risk and may be treated with surgical resection alone.

Wilms Tumor Treatment Outcomes: Perspectives From a Low-Income Setting

Purpose

Wilms tumor is the commonest renal malignancy in childhood. Survival in high-income countries is approximately 90%, whereas in low-income countries, it is less than 50%. This study assessed treatment outcomes of patients with Wilms tumor at a Kenyan academic hospital.

Patients and Methods

We conducted a retrospective medical record review of all children diagnosed with Wilms tumor between 2010 and 2012. Data on treatment outcomes and various sociodemographic and clinical characteristics were collected.

Results

Of the 39 patients with Wilms tumor, 41% had event-free survival, 31% abandoned treatment, 23% died, and 5% had progressive or relapsed disease. Most patients presented at an advanced stage: stage I (0%), II (7%), III (43%), IV (40%), or V (10%). The most likely treatment outcome in patients with low-stage (I to III) disease was event-free survival (67%), whereas in those with high-stage (IV to V) disease, it was death (40%). No deaths or instances of progressive or relapsed disease were recorded among patients with low-stage disease; their only reason for treatment failure was abandonment of treatment. Stage of disease significantly affected treatment outcomes (P = .014) and event-free survival estimates (P < .001). Age at diagnosis, sex, duration of symptoms, distance to hospital, and health insurance status did not statistically significantly influence treatment outcomes or event-free survival estimates.

Conclusion

Survival of patients with Wilms tumor in Kenya is lower compared with that in high-income countries. Treatment abandonment is the most common cause of treatment failure. Stage of disease at diagnosis statistically significantly affects treatment outcomes and survival.

Significance of TP53 Mutation in Wilms Tumors with Diffuse Anaplasia: A Report from the Children's Oncology Group

PURPOSE

To investigate the role and significance of TP53 mutation in diffusely anaplastic Wilms tumors (DAWTs).

EXPERIMENTAL DESIGN

All DAWTs registered on National Wilms Tumor Study-5 (n = 118) with available samples were analyzed for TP53 mutations and copy loss. Integrative genomic analysis was performed on 39 selected DAWTs.

RESULTS

Following analysis of a single random sample, 57 DAWTs (48%) demonstrated TP53 mutations, 13 (11%) copy loss without mutation, and 48 (41%) lacked both [defined as TP53-wild-type (wt)]. Patients with stage III/IV TP53-wt DAWTs (but not those with stage I/II disease) had significantly lower relapse and death rates than those with TP53 abnormalities. In-depth analysis of a subset of 39 DAWTs showed seven (18%) to be TP53-wt: These demonstrated gene expression evidence of an active p53 pathway. Retrospective pathology review of TP53-wt DAWT revealed no or very low volume of anaplasia in six of seven tumors. When samples from TP53-wt tumors known to contain anaplasia histologically were available, abnormal p53 protein accumulation was observed by immunohistochemistry.

CONCLUSIONS

These data support the key role of TP53 loss in the development of anaplasia in WT, and support its significant clinical impact in patients with residual anaplastic tumor following surgery. These data also suggest that most DAWTs will show evidence of TP53 mutation when samples selected for the presence of anaplasia are analyzed. This suggests that modifications of the current criteria to also consider volume of anaplasia and documentation of TP53 aberrations may better reflect the risk of relapse and death and enable optimization of therapeutic stratification. Clin Cancer Res; 22(22); 5582-91. ©2016 AACR.

Clinicoepidemiological Profile and Outcome of Children With Wilms Tumor in a Developing Country

BACKGROUND

Outcome of children with Wilms tumor (WT) has improved remarkably because of the advancements in Pediatric Oncology. However, in most developing countries survival rates are still poor. There is a paucity of data regarding the clinical profile and outcome of children with WT in India.

METHODS

Children with WT who were treated at our center between 2005 and 2014 were retrospectively analyzed.

RESULTS

Over the 10-year study period, 108 children with WT were treated in our unit. The median age at presentation was 30 months (male:female ratio of 4:1). Abdominal mass was the most common presenting feature (91%). The majority of children had stage 2 (30%) or stage 3 (35%) disease. Fifty-nine children had large or bilateral tumors requiring preoperative chemotherapy. Of the total 108 children, 11 died during primary treatment and 14 relapsed after completion of treatment. The projected 5-year overall survival is 74%, whereas the event-free survival is 73%.

CONCLUSIONS

Children with WT in our setting present late with advanced disease and large tumors, which are technically difficult to deliver at surgery. With a multidisciplinary approach, reasonably good survival rates were achieved even in the resource-limited Indian scenario.

Wilms tumor: "State-of-the-art" update, 2016

Despite an impressive increase in survival rate over the past decades, there is still a need to improve the survival of specific subgroups of Wilms tumor (anaplastic, metastatic, and bilateral) and to decrease the late effects of treatment in terms of renal function and heart toxicity. We aim to explore new areas of improvement, from diagnosis to treatment: in the field of radiology the increased use of MRI and exploration of its diffusion-weighted imaging capabilities to predict WT histology at diagnosis and for preoperative assessment; in biology the emergence of new biomarkers that could be integrated into the decision-making process; and surgical techniques with more accurate indication of nephron-sparing surgery that is no longer reserved for bilateral WT and the minimally invasive approach. The long-term outcome of patients with WT should thus be a strong indicator of the improvement in adapting and personalizing the treatment to each individual.

Profiling Loss of Heterozygosity Patterns in a Cohort of Favorable Histology Nephroblastoma Egyptian Patients: What is Consistent With the Rest of the World

According to the Fifth National Wilms Tumor Study (NWTS-5), tumor-specific loss of heterozygosity (LOH) for chromosomes 1p and 16q identifies a subset of patients with Wilms tumor (WT) who despite having favorable histology (FH) have a significantly increased risk of relapse and death. We aimed to find out 1p and 16q LOH frequencies in patients with FH-WT as well as its correlation to survival outcome and epidemiologic and clinical characteristics. Data of patients with FH-WT presenting to the National Cancer Institute, Egypt, were retrospectively analyzed. Paraffin blocks were tested for 1p and 16q LOH using polymorphic loci that span the minimal regions of LOH at this area. The study included 100 patients with a median age of 5 years. Thirty-nine patients (39%) showed LOH at 1p (n = 14), 16q (n = 13), or both (n = 12). LOH was most frequently encountered in patients above 10 years (5/5), advanced stages disease (80% of stage V and 50% of stages IV and III each). The 3-year overall survival (OS) and event-free survival (EFS) were significantly lower in patients with double LOH (75% and 50%, respectively), followed by 16q (92% and 54%), in comparison with 1p (93% each) and negative LOH (97% and 100%) cases, respectively (p = 0.001). Combined LOH (1p+16q), followed by 16q LOH alone, was predictive of poorer outcome and was associated with lower OS and EFS in patients with FH-WT. Our results showed a higher-risk disease that would suggest the need for an intensified upfront therapy in this group of patients.

Gain of 1q As a Prognostic Biomarker in Wilms Tumors (WTs) Treated With Preoperative Chemotherapy in the International Society of Paediatric Oncology (SIOP) WT 2001 Trial: A SIOP Renal Tumours Biology Consortium Study

PURPOSE

Wilms tumor (WT) is the most common pediatric renal tumor. Treatment planning under International Society of Paediatric Oncology (SIOP) protocols is based on staging and histologic assessment of response to preoperative chemotherapy. Despite high overall survival (OS), many relapses occur in patients without specific risk factors, and many successfully treated patients are exposed to treatments with significant risks of late effects. To investigate whether molecular biomarkers could improve risk stratification, we assessed 1q status and other potential copy number biomarkers in a large WT series.

MATERIALS AND METHODS

WT nephrectomy samples from 586 SIOP WT 2001 patients were analyzed using a multiplex ligation-dependent probe amplification (MLPA) assay that measured the copy number of 1q and other regions of interest.

RESULTS

One hundred sixty-seven (28%) of 586 WTs had 1q gain. Five-year event-free survival (EFS) was 75.0% in patients with 1q gain (95% CI, 68.5% to 82.0%) and 88.2% in patients without gain (95% CI, 85.0% to 91.4%). OS was 88.4% with gain (95% CI, 83.5% to 93.6%) and 94.4% without gain (95% CI, 92.1% to 96.7%). In univariable analysis, 1q gain was associated with poorer EFS (P < .001; hazard ratio, 2.33) and OS (P = .01; hazard ratio, 2.16). The association of 1q gain with poorer EFS retained significance in multivariable analysis adjusted for 1p and 16q loss, sex, stage, age, and histologic risk group. Gain of 1q remained associated with poorer EFS in tumor subsets limited to either intermediate-risk localized disease or nonanaplastic localized disease. Other notable aberrations associated with poorer EFS included MYCN gain and TP53 loss.

CONCLUSION

Gain of 1q is a potentially valuable prognostic biomarker in WT, in addition to histologic response to preoperative chemotherapy and tumor stage.

Risk of Adverse Health and Social Outcomes Up to 50 Years After Wilms Tumor: The British Childhood Cancer Survivor Study

Purpose

Survivors of Wilms tumor (WT) are at risk for adverse health and social outcomes but risks beyond 30 years from diagnosis remain uncertain. We investigated the risks of adverse outcomes among 5-year survivors of WT, in particular, those between 30 and 50 years from diagnosis.

Patients and Methods

The British Childhood Cancer Survivor Study includes 1,441 5-year survivors of WT. We investigated cause-specific mortality, risk of subsequent primary neoplasms (SPNs), and, for those who completed a questionnaire, the extent of smoking and drinking, educational achievement, health status, and health service use compared with the general population.

Results

Cumulative risk of death from all causes, excluding recurrence, increased substantially from 5.4% to 22.7% at 30 years and 50 years, respectively, after WT diagnosis—75% of excess deaths beyond 30 years from diagnosis were attributable to SPNs (50%) and cardiac diseases (25%). Digestive cancer, most frequently bowel, accounted for 41% of excess cancers beyond 30 years.

Conclusion

Between 30 and 50 years from diagnosis, survivors of WT are at a substantially increased risk of premature mortality, and 75% of excess deaths were accounted for by SPNs and cardiac diseases. Radiotherapy exposure was a risk factor for both outcomes. The proportion of patients with WT who are exposed to radiotherapy has reduced substantially in recent decades because of initiatives such as the SIOP WT 2001 clinical trial, which sought to reduce late effects; however, the majority of current survivors, who are at least 30 years from diagnosis, received radiotherapy. Surveillance of this group should focus on SPNs, in particular, bowel and breast cancers, and cardiac conditions.

Evidence for a delay in diagnosis of Wilms' tumour in the UK compared with Germany: implications for primary care for children

The UK has a longstanding system of general practice which provides the vast majority of primary care, including that for children. It acts as a 'gatekeeper' to more specialist care. Parents may also use accident and emergency departments as their first point of medical contact for their children. Outcomes in the UK for many conditions in children appear to be worse than in comparable European countries where there is direct access to care by paediatricians. We have therefore looked at pathways to diagnosis and compared outcomes in the childhood kidney cancer, Wilms' tumour, which has been treated in the UK and Germany within the same clinical trial for over a decade. We find that Wilms' tumours are significantly larger in volume and have a more advanced tumour stage at diagnosis in the UK compared to Germany. There is a small (∼3%) difference in event free and overall survival between the two countries. Our data suggest that the system of primary care for children in the UK is less likely to result in the incidental finding of an abdominal mass in a child with no or vague symptoms. This may be a reason for the poorer outcome.