Results of the SIOP 93-01/GPOH Trial and Study for the Treatment of Patients with Unilateral Nonmetastatic Wilms Tumor

Inter-Ethnic Variations in the Clinical, Pathological, and Molecular Characteristics of Wilms Tumor

Wilms tumor is the commonest primary renal malignancy in children and demonstrates substantial inter-ethnic variation in clinical, pathological, and molecular characteristics. Wilms tumor occurs at a lower incidence and at a younger age in Asians compared to Caucasians and Africans. Asians also present at an earlier stage of disease, with a higher incidence of favorable histology tumors and a lower incidence of perilobar nephrogenic rests compared to Caucasians, while African children present with more advanced disease. Studies have implicated population differences in the incidence of WT1 mutations, loss of imprinting of the IGF2 locus, and loss of heterozygosity of 1p/16q, or 1q gain as possible bases for epidemiological differences in the disease profile of Wilms tumors in various ethnic groups. Yet, evidence to support these associations is confounded by differences in treatment protocols and inequalities in the availability of treatment resources and remains limited by the quality of population-based data, especially in resource-limited settings.

Factors Associated with Outcomes at 1 Year in Paediatric Post-nephrectomy Patients for Nephroblastoma at the University Teaching Hospital and Cancer Diseases Hospital in Lusaka, Zambia

BACKGROUND

Nephroblastoma is the most common primary malignant renal tumour of childhood. The survival rates in high-income countries are approximately 90%. However, low-income countries have low survival rates of 20%-50%. This study assessed factors associated with treatment outcomes of children post-nephrectomy for nephroblastoma at the University Teaching Hospital and Cancer Diseases Hospital in Lusaka, Zambia.

MATERIALS AND METHODS

A retrospective observational cohort study was conducted, where all children diagnosed with unilateral Wilms tumour below the age of 16 years who had nephrectomy from July 2016 to June 2019 were enrolled. Sociodemographic, clinical characteristics and treatment outcomes were noted. All data were coded and stored in a tabular format using Microsoft Excel. Statistical software STATA version 13 was used for analysis.

RESULTS

Thirty patients were enrolled. The male-to-female ratio was 1:1. The 1-year event-free survival was 46.7%. Treatment abandonment accounted for 36.6% of the participants. 16.7% of the patients had disease progression. No patient had a relapse or died during the 1-year follow-up period. 66.7% had advanced disease stages III and IV. Advancement in age (above 4.3 years), living in a rural environment more than 100 km away from Lusaka and advanced disease stage were all associated with a poor outcome.

CONCLUSIONS

Factors associated with a poor outcome in this study were advanced age and late presentation.

Prognostic role of primary tumor size in Wilms tumor

Wilms tumor (WT) is the most common childhood malignant kidney tumor. The aim of the present study was to determine the impact of primary tumor size on the survival of patients with WT. The data of 1,523 patients diagnosed with WT between 2000 and 2017 were retrieved from the Surveillance, Epidemiology, and End Results database. Receiver operating characteristic curves were plotted to determine the optimal cut-off value of primary tumor size. Overall survival (OS) and cancer-specific survival (CSS) were analyzed using the Kaplan-Meier method and the Cox proportional hazards regression model. The optimal cut-off value for primary tumor size was found to be 11.15 cm. No significant difference in the distribution of tumor size was detected between male and female patients. However, lymph node metastasis and distant metastasis were significantly more frequent in patients whose tumor was ≥11.15 cm in size compared with those with smaller tumors. In addition, patients with larger tumors exhibited significantly worse OS and CSS rates compared with those with smaller tumors. Furthermore, primary tumor size was identified as an independent prognostic factor for OS and CSS in the multivariate analyses. In summary, the present study indicates that primary tumor size is an independent prognostic factor for patients with WT, and tumors ≥11.15 cm are associated with worse OS and CSS.

Treatment of children with favorable histology Wilms tumor with extrapulmonary metastases: A report from the COG studies AREN0533 and AREN03B2 and NWTSG study NWTS-5

BACKGROUND

Patients with stage IV favorable histology Wilms tumor (FHWT) with extrapulmonary metastases (EPM) constitute a small subset of patients with FHWT. Because of their rarity and heterogeneity, optimal FHWT treatment is not well understood. Children's Oncology Group protocol AREN0533 assigned patients with FHWT and EPM to intensified chemotherapy, regimen M, after initial DD-4A chemotherapy. To improve understanding of prognostic factors and best therapies, experiences of patients with EPM on AREN0533, as well as on protocols AREN03B2 and NWTS-5, were reviewed.

METHODS

Combined outcomes for patients with EPM from NWTS-5, AREN0533, and AREN03B2 were determined. Those treated on AREN0533 were compared with those treated on NWTS-5. Prognostic factors were explored in the pooled cohort.

RESULTS

Forty-seven patients with FHWT with EPM enrolled on AREN0533, 37 enrolled on NWTS-5, and 64 were followed only on AREN03B2. The pooled cohort of all 148 patients demonstrated a 4-year event-free survival (EFS) of 77.3% (95% CI, 70.8-84.4) and 4-year overall survival of 88.9% (95% CI, 83.9-94.2). Four-year EFS of patients with EPM treated on AREN0533 was 76.0% (95% CI, 64.6-89.4) vs 64.9% (95% CI, 51.7-82.2) on NWTS-5; hazard ratio, 0.64, p = .26; no difference in overall survival was observed. Increasing linear age and slow incomplete lung response were associated with worse EFS in a pooled cohort.

CONCLUSIONS

Outcomes for patients with EPM are among the lowest for children with FHWT. Further trials with standardized surgical and radiation treatment to metastatic sites, and prospectively collected biologic and treatment details are needed.

CLINICAL TRIAL REGISTRATION

Clinical Trials.gov identifiers: NCT00379340, NCT00898365, and NCT00002611.

Hallmark discoveries in the biology of Wilms tumour

The modern study of Wilms tumour was prompted nearly 50 years ago, when Alfred Knudson proposed the 'two-hit' model of tumour development. Since then, the efforts of researchers worldwide have substantially expanded our knowledge of Wilms tumour biology, including major advances in genetics - from cloning the first Wilms tumour gene to high-throughput studies that have revealed the genetic landscape of this tumour. These discoveries improve understanding of the embryonal origin of Wilms tumour, familial occurrences and associated syndromic conditions. Many efforts have been made to find and clinically apply prognostic biomarkers to Wilms tumour, for which outcomes are generally favourable, but treatment of some affected individuals remains challenging. Challenges are also posed by the intratumoural heterogeneity of biomarkers. Furthermore, preclinical models of Wilms tumour, from cell lines to organoid cultures, have evolved. Despite these many achievements, much still remains to be discovered: further molecular understanding of relapse in Wilms tumour and of the multiple origins of bilateral Wilms tumour are two examples of areas under active investigation. International collaboration, especially when large tumour series are required to obtain robust data, will help to answer some of the remaining unresolved questions.

Critical elements of radical nephroureterectomy for pediatric unilateral renal tumor

Children with renal masses require surgical management to provide accurate surgical staging and skilled resection of the tumor. This document includes evidence-based recommendations for pediatric surgeons regarding the resection, staging, and proper nodal basin evaluation.

Pediatric renal tumor epidemiology: Global perspectives, progress, and challenges

Pediatric renal tumors account for 3%-11% of childhood cancers, the most common of which is Wilms tumor or nephroblastoma. Epidemiology plays a key role in cancer prevention and control by describing the distribution of cancer and discovering risk factors for cancer. Large pediatric research consortium trials have led to a clearer understanding of pediatric renal tumors, identification of risk factors, and development of more risk-adapted therapies. These therapies have improved event-free and overall survival for children. However, several challenges remain and not all children have benefited from the improved outcomes. In this article, we review the global epidemiology of pediatric renal tumors, including key consortium and global studies. We identify current knowledge gaps and challenges facing both high and low middle-incomes countries.

Stage I epithelial or stromal type Wilms tumors are low risk tumors: An analysis of patients treated on the SIOP-WT-2001 protocol in the UK-CCLG and GPOH studies (2001-2020)

BACKGROUND

Patients treated with preoperative chemotherapy with stage I intermediate-risk Wilms tumor (IR-WT) represent the largest group of patients with Wilms tumor (WT), and they have excellent outcomes.

METHODS

The authors performed a retrospective analysis of patients with stage I epithelial (ET-WT) or stromal type WT (ST-WT) treated pre- and postoperatively according to the International Society of Paediatric Oncology-WT-2001 protocol in the UK Children's Cancer and Leukaemia Group and Gesellschaft für Pädiatrische Onkologie und Hämatologie groups' participation in the relevant WT trials and studies (2001-2020).

RESULTS

There were 880 patients with stage I IR-WT, including 124 with ET-WT, 156 with ST-WT, and 600 with other IR-WT (oIR-WT). Patients with stage I ET-WT or ST-WT were significantly younger than patients with oIR-WT, represented a large proportion of stage I WTs in their groups, and tumors showed poor histologic response to preoperative chemotherapy. The 5-year event-free survival (EFS) estimates for patients with stage I ET-WT (96.8% ± 1.8 SE) or ST-WT (96.8% ± 1.6 SE) were significantly better than for patients with oIR-WT (90.3% ± 1.3 SE) (p = .014 and p = .009, respectively). A multivariate analysis showed that histologic type (ET-WT or ST-WT) remained a significant factor for EFS when adjusted for age and gender (p = .032 and p = .022, respectively). In both groups, relapses occurred in 3.2% of patients, and the overall survival was 99.2%.

CONCLUSIONS

The results suggest that stage I ET-WT or ST-WT could be regarded as low-risk WT, for which omission of postoperative chemotherapy should be considered.

PLAIN LANGUAGE SUMMARY

Patients with pretreated intermediate-risk Wilms tumor (WT) represent the largest group of patients with WT. This study reports the outcomes of patients with stage I epithelial type (ET-WT) or stromal type WT (ST-WT). These patients were significantly younger and had a larger proportion of stage I cases than patients with other intermediate-risk WT (oIR-WT). The event-free survival for patients with stage I ET-WT and ST-WT was significantly better than for patients with oIR-WT. Rare relapses were curable resulting in 99.2% overall survival.

Pediatric renal tumor epidemiology: Global perspectives, progress, and challenges

Pediatric renal tumors account for 3%-11% of childhood cancers, the most common of which is Wilms tumor or nephroblastoma. Epidemiology plays a key role in cancer prevention and control by describing the distribution of cancer and discovering risk factors for cancer. Large pediatric research consortium trials have led to a clearer understanding of pediatric renal tumors, identification of risk factors, and development of more risk-adapted therapies. These therapies have improved event-free and overall survival for children. However, several challenges remain and not all children have benefited from the improved outcomes. In this article, we review the global epidemiology of pediatric renal tumors, including key consortium and global studies. We identify current knowledge gaps and challenges facing both high and low middle-incomes countries.

[Tumor predisposition syndromes and nephroblastoma : Early diagnosis with imaging]

CLINICAL/METHODICAL ISSUE

The Beckwith-Wiedemann spectrum (BWSp) as well as the WT1-related syndromes, Denys-Drash syndrome (DDS) and WAGR spectrum (Wilms tumor, Aniridia, genitourinary anomalies and a range of developmental delays) are tumor predisposition syndromes (TPS) of Wilms tumor (WT). Patients with associated TPS are at higher risk of developing chronic kidney disease and bilateral and metachronous tumors as well as nephrogenic rests.

STANDARD RADIOLOGICAL METHODS

Standard imaging diagnostics for WT include renal ultrasound and magnetic resonance imaging (MRI). In the current renal tumor studies Umbrella SIOP-RTSG 2016 and Randomet 2017, thoracic computed tomography (CT) is also recommended as standard. Positron emission tomography (PET)-CT and whole-body MRI, on the other hand, are not part of routine diagnostics.

METHODOLOGICAL INNOVATIONS

In recent publications, renal ultrasound is recommended every 3 months until the age of 7 years in cases of clinical suspicion or molecularly proven TPS.

PERFORMANCE

Patients with TPS and regular renal ultrasounds have smaller tumor volumes and lower tumor stages at WT diagnosis than patients without such a screening. This allows a reduction of therapy intensity and facilitates the performance of nephron sparing surgery, which is prognostically relevant especially in bilateral WT.

ACHIEVEMENTS

Early diagnosis of WT in the context of TPS ensures the greatest possible preservation of healthy and functional renal tissue. Standardized screening by regular renal ultrasounds should therefore be firmly established in clinical practice.

PRACTICAL RECOMMENDATIONS

The initial diagnosis of TPS is clinical and requires a skilled and attentive examiner in the presence of sometimes subtle clinical manifestations, especially in the case of BWSp. Clinical diagnosis should be followed by genetic testing, which should then be followed by sonographic screening.

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.

Outcomes based on histopathologic response to preoperative chemotherapy in children with bilateral Wilms tumor: A prospective study (COG AREN0534)

BACKGROUND

An objective of the Children's Oncology Group AREN0534 Study was to improve the survival of patients with bilateral Wilms tumors (BWT) by using preoperative chemotherapy of limited duration and tailoring postoperative therapy based on histopathologic response. The authors report outcomes based on postoperative histopathologic responses.

METHODS

Patients with BWT received treatment with vincristine, dactinomycin, and doxorubicin for 6 or 12 weeks followed by surgery. Postoperative therapy was prescribed based on the highest risk tumor according to the International Society of Pediatric Oncology classification and the Children's Oncology Group staging system.

RESULTS

Analyses were performed on data from 180 evaluable children. The 4-year event-free survival (EFS) and overall survival (OS) rates were 81% (95% CI, 74%-87%) and 95% (95% CI, 91%-99%), respectively. Seven patients who had completely necrotic tumors had a 4-year EFS rate of 100%. Of 118 patients who had tumors with intermediate-risk histopathology, the 4-year EFS and OS rates were 82% (95% CI, 74%-90%) and 97% (95% CI, 94%-100%), respectively. Fourteen patients who had blastemal-type tumors had 4-year EFS and OS rates of 79% (95% CI, 56%-100%) and 93% (95% CI, 79%-100%), respectively. Eighteen patients who had diffuse anaplasia had 4-year EFS and OS rates of 61% (95% CI, 35%-88%) and 72% (95% CI, 47%-97%), respectively; and the 4-year EFS and OS rates of 7 patients who had focal anaplasia were 71% (95% CI, 38%-100%) and 100%, respectively. There was no difference in the outcomes of patients who had different histopathologic subtypes within the intermediate-risk group (P = .54).

CONCLUSIONS

A risk-adapted treatment approach for BWT results in excellent outcomes. This approach was not successful in improving the outcome of patients who had diffuse anaplasia.

Postchemotherapy tumor volume as a prognostic indicator in Wilms tumor: A single-center experience from South India

BACKGROUND

Optimal risk stratification is the key to minimizing relapse and toxicity in children with Wilms tumor (WT). The study evaluated poor tumor volume response to chemotherapy as a risk factor that predicts relapse.

PROCEDURE

Children with WT who were treated between 2005 and 2020 at the center were analyzed. Tumor volumes at the time of diagnosis and after preoperative chemotherapy were calculated from cross-sectional imaging. The International Society of Paediatric Oncology (SIOP)-WT-2001 protocol was used for treatment. The area under a receiver operating characteristic curve was estimated to ascertain the ability of tumor volume to predict relapse.

RESULTS

Ninety-five patients with a median age of 40 months were included. A postchemotherapy tumor volume cutoff of 270 ml was ascertained to have the best predictive value for relapse. Patients with a tumor volume of <270 ml following preoperative chemotherapy had a better 3-year event-free survival (EFS) than those with a tumor volume of ≥270 ml (89.8% ± 4.0% vs. 57.4% ± 12.5%, p = .001). The data demonstrated that a tumor volume of ≥270 ml after chemotherapy was associated with an increased risk of relapse (hazard ratio [HR]: 5.3, p = .006). The EFS in patients with an epithelial or stromal type of histopathology was not affected by the tumor volume response (p = .437). Conversely, patients with other types of intermediate-risk histopathology who had a poor tumor volume response had an inferior survival (3-year EFS 51.4% ± 18.7%, p = .001).

CONCLUSION

A postchemotherapy tumor volume cutoff of ≥270 ml emerged as a strong predictor of relapse in a low- and middle-income country (LMIC) center study of WT treated with the SIOP protocol.

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.

Surgical Management of Wilms Tumor (Nephroblastoma) and Renal Cell Carcinoma in Children and Young Adults

This article reviews the epidemiology, pathophysiology, clinical presentation, and multimodality management of Wilms tumors and renal cell carcinoma in pediatric and young adults. Key renal Société Internationale d'Oncologie Pédiatrique and Children Oncology Group studies are presented. The article reviews the common staging systems and risk-adapted treatment strategies with particular attention to the surgical management.

The prognosis of prechemotherapy blastemal predominant histology subtype in Wilms tumor: A retrospective study in China

PURPOSE

This study aimed to retrospectively analyze survival outcomes for Chinese patients with prechemotherapy blastemal predominant histology type Wilms tumors (WTs).

METHODS

We collected and analyzed clinical data concerning patients aged <15 years with favorable histology (FH) WTs treated at the Sun Yat-Sen University Cancer Center from December 2005 to May 2016, based on the Children's Oncology Group protocol. Pathological specimens were collected through biopsy or surgical resection before initiation of chemotherapy. We analyzed survival outcomes involving different prechemotherapy histology subtypes.

RESULTS

We enrolled 97 patients with FH WTs (median follow-up, 71.5 months; range, 22.2-170.7). The total recurrence rate was 17.5%, and the subtype recurrence rates were as follows: blastemal predominant (45.5%), mixed (7.5%), epithelial (14.3%), and mesenchymal (9.5%) (P = .010). Five-year event-free survival (EFS) and overall survival (OS) rates were 84.9% and 81.4%, respectively. Respective 5-year EFS and OS rates for subtypes were as follows: blastemal predominant (54.5% and 68.2%), mixed (90.0% and 88.9%), epithelial (85.7% and 85.1%), and mesenchymal (90.5% and 94.7%). Multivariate survival analyses showed that the blastemal predominant subtype was an independent prognostic factor of EFS (P = .001) and OS (P = .017).

CONCLUSIONS

Our findings showed that prechemotherapy blastemal predominant WTs had higher recurrence and lower EFS and OS rates. Our findings suggested that, albeit with some deficiencies, blastemal predominant histology WT-diagnosed prechemotherapy may have prognostic relevance. Further research into other potential confounding variables are required to determine whether such patients warrant altered risk-stratified therapy.

Factores asociados a la sobrevida en pacientes con tumor de Wilms

Introducción. El tumor de Wilms es el segundo tumor abdominal más frecuente en la edad pediátrica y responde por más del 90 % de los tumores renales en pediatría. A pesar de que la sobrevida descrita es mayor del 90 %, en nuestro medio encontramos que solo alcanza al 70 %, por lo que deseamos evaluar cuáles son los factores asociados con dichos resultados desfavorables, con el fin de implementar medidas para mejorar la sobrevida de nuestros pacientes. Métodos. Se realizó un estudio observacional, transversal, en dos centros de alto nivel de atención, que incluyó una muestra de 84 pacientes menores de 15 años, con diagnóstico de tumor de Wilms. Resultados. Los factores que se asociaron significativamente con un aumento en la probabilidad de morir fueron: no completar el protocolo de quimioterapia, (OR 34; IC95% 3,7-312; p 0,000) y presentar recidiva tumoral (OR 35,7; IC95% 6,9-184; p 0,000). Otros factores que aumentaron esta probabilidad sin alcanzar a ser significativos, pero mostrando una evidente tendencia fueron: presentación bilateral (OR 4,1; IC95% 0,6-5,5; p 0,147), complicaciones quirúrgicas (OR 3,2; IC95% 0,7-14,6; p 0,136), compromiso de ganglios linfáticos en tomografía (OR 2,4; IC95% 0,7-8,4; p 0,139) y las metástasis a distancia (OR 2,5; IC95% 0,7-9; p 0,143). Discusión. La sobrevida de nuestros niños con tumor de Wilms es menor que la reportada en la literatura mundial, siendo la falla en terminar la quimioterapia, la recidiva y la necesidad de cirugía bilateral, los factores asociados con este desenlace.  

Liver metastasis at diagnosis in children with nephroblastoma enrolled in SIOP2001 protocol: A French multicentric study

BACKGROUND

Liver metastases are rare in children with Wilms tumor (WT), and their impact on the outcome is unclear.

PATIENTS AND METHODS

The French cohort of patients with WT presenting liver metastases at diagnosis and enrolled in the International Society of Pediatric Oncology (SIOP) 2001 study was reviewed.

RESULTS

From 2002 to 2012, 906 French patients were enrolled in the SIOP2001 trial. Among them, 131 (14%) presented with stage IV WT and 18 (1.9%) had liver metastases at diagnosis. Isolated liver metastases were displayed in four of them. After preoperative chemotherapy, persistent liver disease was reported in 14/18 patients, and 13 of them underwent metastasectomy after nephrectomy. In resected liver lesions, the same histology of the primary tumor was reported for three patients, blastemal cells without anaplasia were identified in one patient with DA-WT, and post-chemotherapy necrosis/fibrosis was identified for the other 10 patients. For the four patients who had liver and lung surgery, both sites had nonviable cells with post-chemotherapy necrosis/fibrosis. Six patients had hepatic radiotherapy. Sixteen patients achieved primary complete remission and were alive at the last follow-up (median follow-up: 6.4 years). The only two deceased patients presented diffuse anaplasia histology. The five-year EFS and OS were 83% (60%-94%) and 88% (66%-97%), respectively.

CONCLUSION

Liver involvement does not appear to be an adverse prognostic factor in metastatic WT. The role of hepatic surgery and radiotherapy remains unclear, and should be carefully considered in case of persistent liver metastases, according to histology and radiological response to other metastatic sites.

Outcome analysis of stage I epithelial-predominant favorable-histology Wilms tumors: A report from Children's Oncology Group study AREN03B2

BACKGROUND

Stage I epithelial-predominant favorable-histology Wilms tumors (EFHWTs) have long been suspected to have an excellent outcome. This study investigates the clinical and pathologic features of patients with stage I EFHWTs to better evaluate the potential for a reduction of chemotherapy and its associated toxicity.

METHODS

All patients registered in the Children's Oncology Group (COG) AREN03B2 study between 2006 and 2017 with stage I EFHWTs were identified. EFHWTs were defined as tumors with at least 66% epithelial differentiation, regardless of the degree of differentiation. Clinical information was abstracted from COG records. Event-free survival (EFS) and overall survival (OS) were calculated and compared between groups based on age and therapy.

RESULTS

The 4-year EFS rate was 96.2% (95% confidence interval, 92%-100%), and the OS rate was 100%; EFS and OS did not statistically significantly differ with the age at diagnosis (<48 vs ≥48 months; P = .37) or treatment (EE4A vs observation only; P = .55). Six events were reported. Three patients developed contralateral tumors and did not otherwise relapse; none of these had nephrogenic rests or a recognized predisposition syndrome. Three patients developed metastatic recurrence; all 3 had received EE4A as their primary therapy after nephrectomy.

CONCLUSIONS

These findings demonstrate an excellent outcome for stage I EFHWTs with >95% EFS and OS. These data support the utility of investigating the treatment of stage I EFHWTs with observation alone after nephrectomy.

Outcome of patients with stage IV high-risk Wilms tumour treated according to the SIOP2001 protocol: A report of the SIOP Renal Tumour Study Group

INTRODUCTION

High-risk (HR) metastatic (stage IV) Wilms tumours (WTs) have a particular poor outcome.

METHODS

Here, we report the results of HR (diffuse anaplastic [DA] or blastemal type [BT]) stage IV WT treated patients according to the HR arm in the SIOP2001 prospective study.

RESULTS

From January 2002 to August 2014, 3559 patients with WT were included in the SIOP2001 trial. Among the 525 patients (15%) with metastatic WT, 74 (14%) had stage IV HR-WT. The median age at diagnosis was 5.5 years (range: 1.4-18.3). Thirty-four patients (47%) had BT-WT and 40 (53%) had DA-WT. Five-year event-free survival rates were 44 ± 17% and 28 ± 15% for BT-WT and DA-WT, respectively (p = 0.09). Five-year overall survival rates were 53 ± 17% and 29 ± 16% for BT-WT and DA-WT, respectively (p = 0.03). Metastatic complete response after preoperative treatment was significantly associated with outcome in univariate and multivariate analyses (hazards ratio = 0.3; p = 0.01). Postoperative radiotherapy of metastatic sites might also be beneficial. Forty-three of 74 patients experienced a relapse or progression predominantly in the lungs (80%). The median time to relapse/progression after diagnosis was 7.3 months (range: 1.6-33.3) and 4.9 months (range: 0.7-28.4) for BT-WT and DA-WT, respectively (p = 0.67). This is the first prospective evidence of inferior survival of stage IV BT-WT as compared with historical intermediate-risk WT. Survival of patients with stage IV DA-WT has not improved compared to the previous SIOP93-01 study.

CONCLUSION

These results call for new treatment approaches for patients with HR stage IV WT.

Optimal neoadjuvant chemotherapy duration in Wilms tumour with intravascular thrombus: A literature review and evidence from SIOP WT 2001 trial

INTRODUCTION

Preoperative chemotherapy is recommended for children with Wilms tumour with intravascular extension. Extended chemotherapy may improve resectability, but increase tumour adherence to vascular endothelium, precluding complete resection. To evaluate the optimal length of preoperative treatment, we report a two-part review comprising systematic review of the literature and investigation of patients treated in the International Society of Paediatric Oncology (SIOP) WT 2001 trial.

METHODS

Studies were identified using Medline and Embase databases from 1996 to present. English language titles reporting management of intravascular Wilms tumour were analysed. Patients with Wilms tumour and thrombus were identified from the SIOP WT 2001 trial. Overall survival (OS) and event-free survival (EFS), tumour regression, completeness of resection and cavectomy were investigated.

RESULTS

The search retrieved 43 articles documenting 498 children. Note that 72% of the patients received neoadjuvant chemotherapy: 101 received standard course (4-6 weeks, standard course neoadjuvant chemotherapy [StC]) and 62 extended course (> 6 weeks, extended course neoadjuvant chemotherapy [EC]). There was no significant difference between the groups in terms of thrombus regression or completeness of resection. EFS was greater in the StC group (78 vs 54%; P = .04). Of 4511 patients registered in the SIOP WT 2001 trial, 166 had thrombus. Note that 97% of the patients received neoadjuvant chemotherapy: 63 StC and 67 EC. There was no significant difference between the groups with regard to tumour regression, complete resection, or cavectomy. Survival was significantly higher in those receiving StC than EC (OS: 95% vs 82%, P = .025; EFS: 88% vs 72%, P = .047).

CONCLUSION

There is no evidence that prolonged courses of neoadjuvant chemotherapy beyond the recommended protocols confer any additional benefit in treating intravascular extension of Wilms tumour.

[Rare childhood kidney tumors]

Pediatric kidney tumors are rare and account for about 6% of all childhood malignancies. By far the most common tumors are nephroblastomas. This review presents rare childhood renal tumors. Mesoblastic nephroma, as tumors of the low risk group, as well as the clear-cell sarcomas of the kidney and malignant rhabdoid tumors, as tumors of the high-risk group, and the so-called anaplastic sarcomas of the kidney will be discussed.Due to the significantly divergent therapy, a correct diagnosis is important. Due to the often overlapping morphology, pathologic diagnosis is often difficult. In addition to the typical morphologic features, the specific immunohistochemical aspects as well as the known molecular changes will be presented.

Agreement between clinicoradiological signs at diagnosis and radiohistological analysis after neoadjuvant chemotherapy of suspected Wilms tumor rupture: Consequences on therapeutic choices

INTRODUCTION

According to SIOP criteria, every patient presenting with preoperative Wilms tumor (WT) rupture must receive abdominal radiotherapy. Neoadjuvant chemotherapy reduces tumor volume and is responsible for the development of peritumoral capsule formation, which can mask tumor rupture on histological analysis, while it was clinically or radiologically obvious at diagnosis. Yet, there are no protocol recommendations for this particular presentation.

OBJECTIVES

Study the agreement between clinicoradiological signs and histological confirmation after neoadjuvant chemotherapy of suspected WT rupture and describe the therapeutic choices arising in consequence.

METHODS

Descriptive retrospective study on a monocentric series of patients with WT between June 1991 and August 2017.

RESULTS

Out of 71 patients, 28 presented with suspected tumor rupture. We observed good agreement between clinical and radiological signs of suspected rupture (κ coefficient: 0.67). However, we assessed poor agreement between these signs and histological conclusions after neoadjuvant chemotherapy (κ coefficient: 0.27). Only five patients with clinicoradiological signs were overtreated with radiotherapy while tumor rupture had been refuted after histological review. The notion of abdominal trauma and the presence of intraperitoneal effusion seemed to guide collegial decision to overtreat these patients. No statistical difference in survival between patients with and without suspicion of tumor rupture at diagnosis was observed.

CONCLUSION

This study highlights the need for recommendations in case of discrepancy between radiological and histological signs of rupture at diagnosis and after neoadjuvant chemotherapy. A study with stronger statistical power is necessary to define criteria that would lead to optimization of treatment in this context.

Indications and results of diagnostic biopsy in pediatric renal tumors: A retrospective analysis of 317 patients with critical review of SIOP guidelines

OBJECTIVES

According to the Renal Tumor Study Group (RTSG) of the International Society of Paediatric Oncology (SIOP), diagnostic biopsy of renal tumors prior to neoadjuvant chemotherapy is not mandatory unless the presentation is atypical for a Wilms tumor (WT). This study addresses the relevance of this strategy as well as the accuracy and safety of image-guided needle biopsy.

METHODS

Clinical, radiological, and pathological data from 317 children (141 males/176 females, mean age: 4 years, range, 0-17.6) consecutively treated in one SIOP-affiliated institution were retrospectively analyzed.

RESULTS

Presumptive chemotherapy for WT was decided for 182 patients (57% of the cohort), 24 (8%) were operated upfront, and 111 (35%) were biopsied at diagnosis. A non-WT was confirmed after surgery in 5/182 (3%), 11/24 (46%), and 28/111 (25%), respectively. Age at diagnosis was the most commonly (46%) used criterion to go for biopsy but a nine-year threshold should be retrospectively considered more relevant. Tumor volumes of clear cell sarcoma of the kidney and WT were significantly higher than those of other tumors (P = 0.002). The agreement between core-needle biopsy (CNB) and final histology was 99%. No significant morbidity was associated with CNB.

CONCLUSION

The use of SIOP criteria to identify patients eligible for presumptive WT neoadjuvant chemotherapy or upfront surgery avoided biopsy in 65% of children and led to a 97% rate of appropriate preoperative chemotherapy. Image-guided CNB is a safe and accurate diagnostic procedure. The relevance of SIOP biopsy criteria might be improved by using an older age threshold (9 years instead of 6 years) and by adding initial tumor volume.

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.

Synchronous Bilateral Wilms Tumor: Five-Year Single-Center Experience with Assessment of Quality of Life

Context:

Synchronous Bilateral Wilms tumor (sBWT).

Aims:

This study aimed to assess the outcome of patients with sBWT treated on SIOP protocol.

Settings and Design:

Retrospective and prospective randomized study.

Subjects and Methods:

SIOP 93-01 protocol was used to study nine patients of sBWT in a single center and followed up over a period from 2 to 5 years.

Statistical Analysis Used:

Unpaired t-test and Mann–Whitney U-test were used for analysis.

Results:

Of nine patients, six were included in the study as three patients lost to follow-up. Among the six patients, there were four girls and two boys with a median age of 2 years. Mean regression in the size of tumor was 87% in four out of six patients. Tumor with unfavorable histology showed 32% response (ratio of favorable: unfavorable histology 2:1). Event-free survival rate was 81.3% and overall survival was 90% over 2–5 years. Recurrence was seen in two patients of whom one had Denys–Drash syndrome. Mean DTPA glomerular filtration rate was 91.4/ml/min/1.73 m² preoperatively and that of 3 months after completion of treatment was 84/ml/min/1.73 m². Health-related quality of life (HRQOL) using Pediatric Quality of Life Inventory and Lansky Play Performance Scale revealed significant improvement results of all functioning domains such as physical, social, emotional, and school subscales with P < 0.05 and performance scale (P < 0.04).

Conclusions:

We suggest SIOP protocol for sBWT and bilateral nephron-sparing surgery in two stages. However, long-term follow-up is required to assess the ultimate renal function outcome. HRQOL is an essential guide in improving the conditions of pediatric cancer survivors.

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.

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.

Anterior Unilateral Plagiocephaly in Patient with Alagille Syndrome: Case Report

BACKGROUND

The polymalformative syndromes and craniofacial anomalies association is a well-known phenomenon in patients with Crouzon, Pfeiffer, Apert, or Muenke disease. Recently, other less frequent pathologies, such as Alagille syndrome, have shown an association with alterations in the development of cranial sutures, resulting in serious cosmetic defects and neurologic disorders.

CASE DESCRIPTION

We report an exceptional case of a 30-month-old girl, a nephroblastoma survivor diagnosed with Alagille syndrome, who was referred to our department with progressive anterior plagiocephaly and premature left coronal suture closure associated with a large compensating right bossing. Despite the patient's age, we offered aggressive surgical treatment performing a new forehead harvested from the skull vertex with orbital rim reconstruction.

CONCLUSIONS

Alagille syndrome is a complex multisystem pathology with a poor craniosynostosis association and only 3 cases have been described in the literature.

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

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

TP53 alterations in Wilms tumour represent progression events with strong intratumour heterogeneity that are closely linked but not limited to anaplasia

TP53 mutations have been associated with anaplasia in Wilms tumour, which conveys a high risk for relapse and fatal outcome. Nevertheless, TP53 alterations have been reported in no more than 60% of anaplastic tumours, and recent data have suggested their presence in tumours that do not fulfil the criteria for anaplasia, questioning the clinical utility of TP53 analysis. Therefore, we characterized the TP53 status in 84 fatal cases of Wilms tumour, irrespective of histological subtype. We identified TP53 alterations in at least 90% of fatal cases of anaplastic Wilms tumour, and even more when diffuse anaplasia was present, indicating a very strong if not absolute coupling between anaplasia and deregulation of p53 function. Unfortunately, TP53 mutations do not provide additional predictive value in anaplastic tumours since the same mutation rate was found in a cohort of non-fatal anaplastic tumours. When classified according to tumour stage, patients with stage I diffuse anaplastic tumours still had a high chance of survival (87%), but this rate dropped to 26% for stages II-IV. Thus, volume of anaplasia or possible spread may turn out to be critical parameters. Importantly, among non-anaplastic fatal tumours, 26% had TP53 alterations, indicating that TP53 screening may identify additional cases at risk. Several of these non-anaplastic tumours fulfilled some criteria for anaplasia, for example nuclear unrest, suggesting that such partial phenotypes should be under special scrutiny to enhance detection of high-risk tumours via TP53 screening. A major drawback is that these alterations are secondary changes that occur only later in tumour development, leading to striking intratumour heterogeneity that requires multiple biopsies and analysis guided by histological criteria. In conclusion, we found a very close correlation between histological signs of anaplasia and TP53 alterations. The latter may precede development of anaplasia and thereby provide diagnostic value pointing towards aggressive disease.

Pediatric Surgery remains the only true General Surgery

This article states that Pediatric Surgery remains probably the only remaining General Surgery because it is not about organs and systems but rather the whole Surgery from fetal life until completion of growth and maturation. Pediatric surgeons are currently involved in prenatal treatments for fetal diseases, they take in charge the surgery of congenital malformations, acquired neonatal diseases, common conditions like hernias, undescended testes and appendicitis, but also of the more complex gastrointestinal, broncho-pulmonary or genitourinary conditions, tumors, trauma and solid organ transplantation. For this, like other surgical specialists, they use open, endoscopic and minimally invasive techniques. The broad spectrum of diseases, many of them scarcely prevalent, makes training long and hard, but this challenge accounts for the greatness of this specialty. Pediatric surgeons also carry out research work in their field because they are aware that understanding of why the conditions treated by them occur is mandatory. In summary, Pediatric Surgery is a lively, exciting, difficult specialty that offers an attractive alternative to young doctors interested in surgery.

Large Multicystic Dysplastic Kidney Mimicking a Large Cystic Renal Neoplasm

Multicystic Dysplastic Kidney (MCDK) is one of the most common renal conditions seen in paediatric population. The natural history typically involves involution and many of the patients with unilateral disease may actually never become symptomatic. The initial evaluation is usually done on Ultrasonography (USG) while cross-sectional imaging and nuclear scan are reserved for diagnostic dilemmas. Management is conservative and surgery is done for selected patients with symptomatic cysts or suspicion of neoplasm. We present an interesting case of MCDK in a nine-month-old female hypertensive child presenting with a large abdominal mass increasing in size with imaging features similar to cystic neoplasm and managed with nephrectomy.

Outcome of Nephroblastoma Treatment According to the SIOP-2001 Strategy at a Single Institution in Argentina

OBJECTIVE

Wilms tumor (WT) is a disease with a good prognosis. The aim of this study was to evaluate the outcome of patients with WT, treated according to the SIOP-2001 strategy.

METHODS

A retrospective analysis of 141 consecutive patients with WT diagnosed at our institution between December 2001 and 2013 was performed.

RESULTS

A total of 114 patients, median age 38.8 months (3 to 155 mo), were assessable for analysis. Fine-needle aspiration was initially performed in 88 patients (84.6%). Stage distribution was: I: 33%, II: 9.6%, III: 28%, IV: 14%, V: 14.9%. Six patients were stage III because of tumor spillage. The remaining patients received preoperative chemotherapy. Adjuvant chemotherapy was given without randomization, using vincristine-actinomycin for stage II and vincristine-doxorubicin-actinomycin plus radiotherapy for stage III. After a median follow-up of 52 months, 5-year overall survival and event-free survival were 91% and 85%, respectively. Overall survival according to stage was: I: 96%, II: 99%, III: 88%, IV: 78%, V: 90% (P=0.16). There was no significant difference in event-free survival (P=0.7). Seventy-eight (85.7%) were intermediate-risk and 11 (12%) were high-risk patients. Seventeen patients (14.9%) relapsed within 2 to 99 months (median 29.9 mo). Eight patients (7%) died of progressive disease. There were no treatment-related deaths.

CONCLUSIONS

The SIOP-01 protocol proposes a treatment strategy that is feasible in our institution, achieving good results.

Wilms tumor: Successes and challenges in management outside of cooperative clinical trials

OBJECTIVE/BACKGROUND

Management of Wilms tumor (WT) in children depends on a multidisciplinary approach to treatment, and outcomes have significantly improved as reported by cooperative group clinical trials. Here, we review the clinical outcomes of patients with WT and identify challenges and barriers encountered in multidisciplinary management outside of cooperative clinical trials.

METHODS

We retrospectively reviewed the clinical records of 35 children with WT treated between April 2002 and June 2013 at the Children's Cancer Institute in Lebanon.

RESULTS

Upfront resection was performed in 23 cases. Biopsies were performed for Stage V tumors (n=4), those with unresectable tumors or inferior vena caval thrombus (n=5), and patients who had partial surgery performed elsewhere prior to presentation (n=2). One patient died due to toxicity prior to surgery. The tumor was Stage I in eight patients, Stage II in five patients, Stages III and IV in nine patients each, and bilateral (Stage V) in four patients. Adherence to The National Wilms Tumor Study-5 recommendations was adequate. At the time of analysis, 30 patients were free of disease and four patients had relapse-all having metastatic disease initially.

CONCLUSION

The National Wilms Tumor Study-5 therapy resulted in favorable outcomes in children with nonmetastatic Wilms tumor in the setting of a multidisciplinary approach to therapy and resolution of financial barriers to medical care. Upstaging due to prior intervention and lung radiation therapy to all those with computed tomography-detected lung nodules may both have resulted in overtreatment of a subset of patients. Finally, the relatively high incidence of bilateral tumors suggests the need for further genetic and molecular studies in this patient population.

Omission of doxorubicin from the treatment of stage II-III, intermediate-risk Wilms' tumour (SIOP WT 2001): an open-label, non-inferiority, randomised controlled trial

BACKGROUND

Before this study started, the standard postoperative chemotherapy regimen for stage II-III Wilms' tumour pretreated with chemotherapy was to include doxorubicin. However, avoidance of doxorubicin-related cardiotoxicity effects is important to improve long-term outcomes for childhood cancers that have excellent prognosis. We aimed to assess whether doxorubicin can be omitted safely from chemotherapy for stage II-III, histological intermediate-risk Wilms' tumour when a newly defined high-risk blastemal subtype was excluded from randomisation.

METHODS

For this international, multicentre, open-label, non-inferiority, phase 3, randomised SIOP WT 2001 trial, we recruited children aged 6 months to 18 years at the time of diagnosis of a primary renal tumour from 251 hospitals in 26 countries who had received 4 weeks of preoperative chemotherapy with vincristine and actinomycin D. Children with stage II-III intermediate-risk Wilms' tumours assessed after delayed nephrectomy were randomly assigned (1:1) by a minimisation technique to receive vincristine 1·5 mg/m(2) at weeks 1-8, 11, 12, 14, 15, 17, 18, 20, 21, 23, 24, 26, and 27, plus actinomycin D 45 μg/kg every 3 weeks from week 2, either with five doses of doxorubicin 50 mg/m(2) given every 6 weeks from week 2 (standard treatment) or without doxorubicin (experimental treatment). The primary endpoint was non-inferiority of event-free survival at 2 years, analysed by intention to treat and a margin of 10%. Assessment of safety and adverse events included systematic monitoring of hepatic toxicity and cardiotoxicity. This trial is registered with EudraCT, number 2007-004591-39, and is closed to new participants.

FINDINGS

Between Nov 1, 2001, and Dec 16, 2009, we recruited 583 patients, 341 with stage II and 242 with stage III tumours, and randomly assigned 291 children to treatment including doxorubicin, and 292 children to treatment excluding doxorubicin. Median follow-up was 60·8 months (IQR 40·8-79·8). 2 year event-free survival was 92·6% (95% CI 89·6-95·7) for treatment including doxorubicin and 88·2% (84·5-92·1) for treatment excluding doxorubicin, a difference of 4·4% (95% CI 0·4-9·3) that did not exceed the predefined 10% margin. 5 year overall survival was 96·5% (94·3-98·8) for treatment including doxorubicin and 95·8% (93·3-98·4) for treatment excluding doxorubicin. Four children died from a treatment-related toxic effect; one (<1%) of 291 receiving treatment including doxorubicin died of sepsis, three (1%) of 292 receiving treatment excluding doxorubicin died of varicella, metabolic seizure, and sepsis during treatment for relapse. 17 patients (3%) had hepatic veno-occlusive disease. Cardiotoxic effects were reported in 15 (5%) of 291 children receiving treatment including doxorubicin. 12 children receiving treatment including doxorubicin, and ten children receiving treatment excluding doxorubicin, died, with the remaining deaths from tumour recurrence.

INTERPRETATION

Doxorubicin does not need to be included in treatment of stage II-III intermediate risk Wilms' tumour when the histological response to preoperative chemotherapy is incorporated into the risk stratification.

FUNDING

See Acknowledgments for funders.

Use of 18F-FDG-PET-CT for Assessment of Response to Neoadjuvant Chemotherapy in Children With Wilms Tumor

PURPOSE

The aim of this study was to evaluate the predictive value of fluorine-18-fluorodeoxyglucose positron emission tomography with computed tomography (F-FDG-PET-CT) in the assessment of histologic response to neoadjuvant chemotherapy in children with Wilms tumors (WTs).

MATERIALS AND METHODS

We prospectively registered 12 patients with WTs who were treated with 2 cycles of neoadjuvant chemotherapy and surgery. All patients underwent sequential F-FDG-PET-CT before (PET-CT1) and after (PET-CT2) neoadjuvant chemotherapy. Maximum standardized uptake value (SUVmax) was measured on PET-CT1 (SUV1) and PET-CT2 (SUV2). The percentage change in SUVmax (SUVmax reduction) was calculated. After surgery the effects of neoadjuvant chemotherapy were graded histopathologically: ≥90% necrosis indicated a good response and <90% necrosis was considered a poor response. The correlation between SUVmax reduction and histologic response was estimated using the Spearman correlation coefficient.

RESULTS

Among the 12 patients who underwent PET-CT before and after chemotherapy, SUVmax reduction was significantly different between the good response group and the poor response group (P=0.035). A significant, in terms of P value, correlation was found between pathologic response and SUVmax reduction (r=0.700; 95% confidence interval, 0.060-0.935; P=0.011). A threshold of 66% reduction in SUVmax was identified, with which partition, there were 8 good histologic responders (≥66% decrease in SUVmax) and 4 poor responders. The histologic complete response rate of the good responders was 87.5%, whereas that of poor responders was 0%. SUV1≥7 and SUV2≥2.4 were both considered to be with high risk of recurrence. In patients with SUV1≥7, 4/5 cases relapsed and 4/6 patients with SUV2≥2.4 relapsed.

CONCLUSIONS

As there seems to be a good correlation of changes in SUVmax and histologic response, PET-CT has the potential of predicting the response to neoadjuvant chemotherapy in children with WT. SUV1 and SUV2 by themselves might be a good prognosticator of the clinical outcome of WT pediatric patients treated with International Society of Pediatric Oncology protocols, although the reduction rate of SUVmax is much less powerful for prognosis.

Outcome of localised blastemal-type Wilms tumour patients treated according to intensified treatment in the SIOP WT 2001 protocol, a report of the SIOP Renal Tumour Study Group (SIOP-RTSG)

Blastemal-type Wilms tumour (BT-WT) has been identified as a high risk histological subgroup in WT assessed after pre-nephrectomy chemotherapy in trials of the International Society of Paediatric Oncology (SIOP) Renal Tumour Study Group. Therefore, in SIOPWT2001, post-operative chemotherapy for BT-WT was intensified aiming to improve survival. Survival analysis of all unilateral BT-WT patients (SIOPWT2001) (n=238), was compared with historical BT-WT controls (SIOP93-01) (n=113). 351/4061 (8.6%) unilateral non-metastatic BT-WT patients (SIOP93-01/SIOPWT2001) were studied. Median age at diagnosis was 43 months (Inter Quartile Range (IQR) 24-68 months), stages: I (n=140, 40%), II (n=106, 30%), III (n=105, 30%). BT-WTs were higher staged, showed greater volume decrease after pre-operative chemotherapy and were diagnosed at an older median age compared to other WT patients. Patient characteristics did not differ substantially between SIOP93-01 and SIOPWT2001. Univariate analysis showed a 5-year event-free survival (EFS) of 80% (95% confidence interval (CI): 75-86%) (SIOPWT2001) compared to 67% in SIOP93-01 (95% CI: 59-76%; p=0.006) and overall survival (OS) of 88% (95% CI: 83-93%) (SIOPWT2001) compared to 84% (95% CI: 77-91%; p=0.4) in SIOP93-01. 95% of relapses were distant metastases (SIOP93-01/SIOPWT2001). Treatment protocol, age at diagnosis, tumour stage (III versus I/II) and volume (at surgery), were prognostic variables for EFS (uni- and multivariate Cox regression analysis). Independent prognosticators for OS were age at diagnosis, tumour stage and volume (at surgery). The most significant survival benefit of intensified treatment, was observed in Stage I (EFS 96% in SIOPWT2001 (OS 100%), 71% in SIOP93-01 (OS 90%)). BT-WT derived benefits from more intensive chemotherapy as reflected by a reduction in relapse risk. However, the benefit of the more intensive chemotherapy to improve OS was only observed in stage I BT-WTs, by adding doxorubicin.

[Tumor size and prognosis in patients with Wilms tumor]

OBJECTIVE

Investigate the relationship of the tumor volume after preoperative chemotherapy (TVAPQ) and before preoperative chemotherapy (TVBPQ) with overall survival at two and at five years, and lifetime.

METHODS

Our sample consisted of consecutive patients evaluated in the period from 1989 to 2009 in an Onco-Hematology Service. Clinical, histological and volumetric data were collected from the medical records. For analysis, chi-square, Kaplan-Meier, log-rank and Cox regression tests were used.

RESULTS

The sample consisted of 32 patients, 53.1% were male with a median age at diagnosis of 43 months. There was a significant association between TVAPQ >500 mL and the difference between the TVBPQ and TVAPQ (p=0.015) and histologic types of risk (p=0.008). It was also verified an association between the difference between the TVBPQ and TVAPQ and the predominant stromal tumor (p=0.037). When assessing the TVAPQ of all patients, without a cutoff, there was an association of the variable with lifetime (p=0.013), i.e., for each increase of 10 mL in TVAPQ there was an average increase of 2% in the risk of death.

CONCLUSIONS

Although our results indicate that the TVAPQ could be considered alone as a predictor of poor prognosis regardless of the cutoff suggested in the literature, more studies are needed to replace the histology and staging by tumor size as best prognostic variable.

Wilms tumor: experience of a hospital in southern Brazil

BACKGROUND

Wilms tumor (WT) is the most common renal malignancy of childhood. The aim of this study was to verify the epidemiological profile and prognosis of a sample of patients from Brazil and compare them to similar data from other Latin American studies.

METHOD

The sample consisted of consecutive patients diagnosed with WT in an oncohematology service of a referral hospital in Southern Brazil, between 1989 and 2009. Clinical, radiological, pathological and survival data were collected from the medical records. Analysis was done using Excel and SPSS version 18.0. The significance level was set at P < 0.05.

RESULTS

The final sample consisted of 45 patients. The male/female ratio was 1.25:1. Mean age at diagnosis was 43.9 months and all patients were of European descent. Thirty-three patients (73.3%) had both signs/symptoms of abdominal mass and hypertension. Malformation was observed in nine patients (20%) and there was one case of Fanconi's anemia (2.2%). Three patients had bilateral disease (6.7%). The majority of patients had stage III and IV (62.2%). Patients with malformation had an earlier age at diagnosis (P = 0.018) and a higher prevalence of bilateral disease (P = 0.044). Overall survival was 75%. Age at diagnosis was the only significant independent predictor associated with death.

CONCLUSION

Death is closely related to late diagnosis in WT. Oncologic services should also be concerned about morbidity caused by therapeutic options in cases of late diagnosis, and the consequences for quality of life.

Malignant rhabdoid tumor of the kidney: significantly improved response to pre-operative treatment intensified with doxorubicin

Case reports and in vitro testing suggest sensitivity of malignant rhabdoid tumor of the kidney (MRTK) to anthracyclines. Prospective study data supporting doxorubicin's efficacy is lacking. We compared the change of tumor volume in the kidney to upfront treatment with either actinomycin D and vincristine (AV) or doxorubicin-intensified AV (AVD) in all patients with MRTK, who had been treated from 1991-2013 in Austria, Switzerland, and Germany in the framework of three prospective Société International d'Oncologie Pédiatrique/Gesellschaft für Pädiatrische Onkologie und Hämatologie nephroblastoma studies. A total of 37 patients with MRTK received pre-operative chemotherapy (AV, n = 19; AVD, n = 18). Initial and tumor volume after pre-operative treatment was reported in all patients who received AV and 15 of 18 (83%) patients who received AVD. Mean tumor volume at diagnosis was 247 (±48) mL in the AV cohort and 345 (±47) mL in the AVD cohort. Mean volume at surgery was 249 (±46) mL and 137 (±27) mL, respectively. Relative change in tumor volume was +19 (±16)% in patients who received AV and -63 (±26)% in patients who received AVD (P < 0.001). Change in volume to AV ranged from -60 to +224%, whereas the change to AVD ranged from -9 to -92%. We provide good evidence of doxorubicin's activity in MRTK in vivo by demonstrating a significantly better response to neoadjuvant AVD compared with AV alone.

Preoperative chemotherapy and local stage III in nephroblastoma

The evolution of Nephroblastoma (WT) treatment over the last decades has been one major success around the world. Despite pursuing different upfront treatment approaches the Children's Oncology Group (COG, former National Wilms Tumor Study Group, NWTSG) and the International Society of Paediatric Oncology's Renal Tumor Study Group (SIOP-RTSG) show the same outcome. Treatment starts with preoperative chemotherapy in SIOP-RTSG compared to initial surgery in COG. Response to chemotherapy can be used as a stratification parameter. This allows treating patients with blastemal subtype more aggressively resulting in a better event free survival (EFS). Moreover the percentage of patients with local stage III is less in SIOP-RTSG than in COG studies. Lymph node involvement, in NWTS 5 together with residual microscopic disease, results in a lower EFS in both study groups. But overall survival (OS) is not different comparing patients with or without positive lymph nodes (LN). No other reason for stage III has a significant impact on outcome. The role of radiotherapy for local tumor control in stage III is important, but the radiation dose needs to be questioned as 10.8 Gy used in COG is as efficient as 15 Gy in SIOP-RTSG protocols. In addition in part of low income countries radiotherapy can not be given due to a lack of radiation facilities. Nevertheless some patients are cured without irradiation. The analysis of local stage III patients underlines the importance of preoperative chemotherapy and the need for molecular studies to better stratify patients according to their individual risk.

Repeat nephron-sparing surgery for children with bilateral Wilms tumor

BACKGROUND

Renal insufficiency is a significant complication of Wilms tumor treatment in the 5% with bilateral disease. Nephron-sparing surgery (NSS) is recommended after neoadjuvant chemotherapy initially. However, the role of NSS in recurrent disease is unknown. We reviewed our experience to assess the feasibility and oncologic and functional outcomes of repeat NSS for children with recurrent disease.

METHODS

A retrospective review was performed of all children treated at our institution for bilateral, favorable histology (FH) Wilms tumor. Patients undergoing repeat NSS for locally recurrent disease were identified. The outcomes evaluated included tumor recurrence, renal function, and patient survival.

RESULTS

Since 2001, 36 children with bilateral FH Wilms tumor have been treated at our institution. Eight patients (22%) underwent repeat NSS for locally recurrent disease. Two patients had a second local recurrence and underwent a third NSS. Six patients are alive without disease (75%) with an average follow-up of 4.5years. Two patients have died, each with blastemal-predominant histology at repeat NSS. The surviving patients have normal renal function, although two patients require medical management of hypertension.

CONCLUSIONS

Our experience suggests that repeat NSS for local recurrence of FH bilateral Wilms tumor is feasible and affords acceptable oncologic outcome with preservation of renal function. However, more aggressive therapy may be required for patients whose recurrence has blastemal-predominant histology, given the poor outcome for these patients in our series.

Image based feasibility of renal sparing surgery for very low risk unilateral Wilms tumors: a report from the Children's Oncology Group

PURPOSE

Nephrectomy with lymph node sampling is the recommended treatment for children with unilateral Wilms tumor under the Children's Oncology Group protocols. Using radiological assessment, we determined the feasibility of performing partial nephrectomy in a select group of patients with very low risk unilateral Wilms tumor.

MATERIALS AND METHODS

We reviewed imaging studies of 60 patients with a mean age of less than 2 years with very low risk unilateral Wilms tumor (mean weight less than 550 gm) to assess the feasibility of partial nephrectomy. We evaluated percentage of salvageable parenchyma, tumor location and anatomical features preventing a nephron sparing approach.

RESULTS

A linear relationship exists between tumor weight and computerized tomography estimated tumor volume. Mean tumor weight in the study population was 315 gm. Partial nephrectomy was deemed feasible in only 5 of 60 patients (8%).

CONCLUSIONS

When considering a select population with very low risk unilateral Wilms tumor (lower volume tumor), only a small percentage of nonpretreated patients are candidates for nephron sparing surgery.

Oncology: the role of partial nephrectomy in Wilms tumor

Wilms tumor represents the most common pediatric renal malignancy and the fourth most common childhood cancer overall. Overall survival from Wilms tumor has increased to over 90 % secondary to multidisciplinary therapy and multi-institutional cooperative group trials. Recent therapeutic focus has shifted to reduction in treatment morbidity and renal preservation while maintaining the high survival rates. Partial nephrectomy is an integral component of the multimodal treatment protocols for Wilms tumor patients with bilateral disease, solitary kidney, or predisposing syndromes. Recent consideration has been given to utilization of nephron sparing surgery (NSS) in carefully selected patients with nonsyndromic unilateral Wilms tumor. While long-term, prospective data in this subgroup of patients is not yet available, case series demonstrate comparable oncologic outcomes after partial versus radical nephrectomy. The relative rarity of Wilms tumor, especially those amenable to upfront partial nephrectomy, presents a challenge to conducting controlled trials.