Survival in nephroblastoma treated according to the trial and study SIOP-9/GPOH with respect to relapse and morbidity

Characteristics and Clinical Outcomes of Children With Wilms' Tumour: A 15-year Experience in a Single Centre in Nigeria

BACKGROUND

Wilms' tumor (WT) is the most common paediatric renal tumor and is one of the most treatment-responsive solid tumours. Survival from Wilms tumour (WT) in sub-Saharan Africa remains dismal as a result of late presentation, treatment abandonment and infrastructure deficit. The purpose of this study was to analyze the clinical outcome of children with Wilms tumour managed in a Nigerian referral centre over a 15-year period.

METHODS

This is a retrospective study of children with WT (nephroblastoma) who were treated at our institution between January 2006 and December 2020. Clinical characteristics, treatments, and outcomes were analyzed.

RESULTS

Thirty-five patients were identified. The median age at diagnosis was 36 months including 22 (62.9 %) females. Twenty-six (74.3 %) had advanced (stage III & IV) disease. Confirmatory histology was available for 16 patients ((45.7 %) among which 10 (62.5 %) were mixed type. The right kidney was affected in 18 patients (51.4 %), left in 15 (42.9 %) and 2 were not documented. Preoperative chemotherapy was given in 22 (62.9 %) patients and 13 (37.1) patients had primary nephrectomy. Eight (22.9 %) patients died during treatment (from disease or treatment related causes), and one abandoned treatment. A total of 26 patients completed treatment. Out of these, 8 (30.8 %) were lost to follow up, four patients died and 14 (53.8 %) patients survived at a median follow-up period of 18 months. The survival decreased with advancing stages of the disease, p = 0.002.

CONCLUSIONS

Majority of children with Wilms tumour in our practice presented with advanced disease. Death during treatment, treatment abandonment and lost to follow up were common.

LEVEL OF EVIDENCE

Level II.

TYPE OF STUDY

Retrospective Study.

Impact of Time to Surgery on Outcome in Wilms Tumor Treated with Preoperative Chemotherapy

(1) Background: Wilms tumor (WT) treated preoperatively is cured in over 90% of cases. However, how long preoperative chemotherapy can be given is unknown. (2) Methods: 2561/3030 patients with WT (age < 18 years) treated between 1989 and 2022 according to SIOP-9/GPOH, SIOP-93-01/GPOH, and SIOP-2001/GPOH are retrospectively analyzed to assess the risk of time to surgery (TTS) for relapse-free survival (RFS) and overall survival (OS). (3) Results: TTS was calculated for all surgeries, with the mean being 39 days (38.5 ± 12.5) for unilateral tumors (UWT) and 70 days (69.9 ± 32.7) for bilateral disease (BWT). Relapse occurred in 347 patients, of which 63 (2.5%) were local, 199 (7.8%) were metastatic, and 85 (3.3%) were combined. Moreover, 184 patients (7.2%) died, 152 (5.9%) due to tumor progression. In UWT, recurrences and mortality are independent of TTS. For BWT without metastases at diagnosis, the incidence of recurrence is less than 18% up to 120 days and increases to 29% after 120 days, and to 60% after 150 days. The risk of relapse (Hazard Ratio) adjusted for age, local stage, and histological risk group increases to 2.87 after 120 days (CI 1.19-7.95, p = 0.022) and to 4.62 after 150 days (CI 1.17-18.26, p = 0.029). In metastatic BWT, no influence of TTS is detected. (4) Conclusions: The length of preoperative chemotherapy has no negative impact on RFS or OS in UWT. In BWT without metastatic disease, surgery should be performed before day 120, as the risk of recurrence increases significantly thereafter.

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.

Photodynamic Therapy in Complex Therapy of Retroperitoneal Tumors in Children

During the period from 2009 to 2021, 93 patients aged 0–11 years (48 boys and 45 girls) with retroperitoneal tumors were treated. There were 66 patients with nephroblastoma and 27 patients with adrenal neuroblastoma among them. As per treatment strategies, the patients were separated into two groups: the control group and the study group. The control group (comparison) received therapy according to the protocols, whereas the study group consisted of patients who received photodynamic therapy (PDT) in addition to the standard treatment. The control group consists of 47 patients with retroperitoneal tumors, including 35 patients with nephroblastoma and 12 patients with adrenal neuroblastoma. The study group included 46 children: 31 patients with nephroblastoma and 15 patients with adrenal neuroblastoma. The 5-year survival rate in the control group was 74.5%, and it was 91.3% in the study group (p = 0.030). Recurrent tumors developed in 14.9% of the patients in the control group, while in the study group, relapse occurred in 8.7% of the patients (p = 0.357). The PDT used in this study for treatment of retroperitoneal tumors improves the results of surgical treatment. It also appreciably increases the survival rate of patients with retroperitoneal tumors. Overall, PDT is a hopeful antitumor approach and can be effectively used in the complex therapy of retroperitoneal tumors in children.

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.

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.

Profile and Clinical Outcome of Children with Wilms' Tumor treated at a Tertiary Care Centre, India

Pritanjali SinghBackground  Wilms' tumor (WT) is the most common kidney tumor of the pediatric age group. The outcome of WT has improved due to the evolution of the treatment approach. A prospective observational study was conducted at All India Institute of Medical Sciences (AIIMS), Patna, to analyze the clinical profile along with the response and outcome to neoadjuvant chemotherapy according to the International Society of Pediatric Oncology (SIOP) protocol. Materials and Methods  In total, 28 patients of WT visited the radiotherapy department from January 2015 to December 2019. Results  Gender distribution showed male preponderance with a median age at diagnosis was 31 months. The abdominal lump was the dominant clinical presentation. The median volume of tumor at diagnosis was 359.48 mL (52.67-1805.76). Radiological staging workup shows that stage I, II, III, IV, and V were 7.1%, 39.3%, 39.3%, 10.7%, and 3.6% respectively. Neoadjuvant chemotherapy (NACT) was received by all patients. Also, 71.4% of patients showed > 50% of tumor volume reduction, while 28.6% of patients showed < 50% of tumor mass reduction. There was a statistically significant decrease in the tumor volume reduction following neoadjuvant chemotherapy ( p  < 0.001). There was a statistically significant stage down ( p  = 0.018) of the disease. Bivariate correlation studies showed recurrence was correlating statistically significantly with age < 24 months ( p  = 0.049), locoregional lymph nodes ( p  = 0.008), histopathological subtypes ( p  < 0.001), stage of the disease ( p  = 0.003), and risk groups ( p  < 0.001). In addition, 25% of patients developed recurrence during the median follow-up of 25 months. The median disease-free survival (DFS) and overall survival (OS) were not reached. The mean DFS and OS were 48 and 59.13 months, respectively. One- and 3-year DFS were 100% and 64.1%, respectively. One- and 3-year OS were 100% and 75% respectively. Conclusion  Our study suggests that most of the patients presented at an advanced stage, thus rendering most of the cases difficult to undergo surgery at presentation. Neoadjuvant chemotherapy followed by surgery may be considered a well-balanced approach with a comparable response and survival outcomes.

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.

Bilateral Renal Tumors in Children: The First 5 Years' Experience of National Centralization in The Netherlands and a Narrative Review of the Literature

Survival of unilateral Wilms tumors (WTs) is exceeding 90%, whereas bilateral WTs have an inferior outcome. We evaluated all Dutch patients with bilateral kidney tumors, treated in the first five years of national centralization and reviewed relevant literature. We identified 24 patients in our center (2015–2020), 23 patients had WT/nephroblastomatosis and one renal cell carcinoma. Patients were treated according to SIOP-RTSG protocols. Chemotherapy response was observed in 26/34 WTs. Nephroblastomatosis lesions were stable (n = 7) or showed response (n = 18). Nephron-sparing surgery was performed in 11/22 patients undergoing surgery (n = 2 kidneys positive margins). Local stage in 20 patients with ≥1 WT revealed stage I (n = 7), II (n = 4) and III (n = 9). Histology was intermediate risk in 15 patients and high risk in 5. Three patients developed a WT in a treated nephroblastomatosis lesion. Two of 24 patients died following toxicity and renal failure, i.e., respectively dialysis-related invasive fungal infection and septic shock. Genetic predisposition was confirmed in 18/24 patients. Our literature review revealed that knowledge is scarce on bilateral renal tumor patients with metastases and that radiotherapy seems important for local stage III patients. Bilateral renal tumors are a therapeutic challenge. We describe management and outcome in a national expert center and summarized available literature, serving as baseline for further improvement of care.

FOXO3a inhibits nephroblastoma cell proliferation, migration and invasion, and induces apoptosis through downregulating the Wnt/β‑catenin signaling pathway

Forkhead transcription factor O subfamily 3A (FOXO3a) is an important tumor suppressor gene that is expressed in renal tissue and has been reported to be downregulated in clear cell renal cell carcinoma (CCRCC). Notably, the overexpression of FOXO3a was previously discovered to inhibit the progression of CCRCC. However, the expression levels of FOXO3a in nephroblastoma cell lines remain unknown. The present study aimed to investigate the expression levels of FOXO3a in nephroblastoma cell lines and to determine the mechanism of action of the biological functions of FOXO3a. Western blotting and reverse transcription‑quantitative PCR were used to analyze the expression levels of FOXO3a in nephroblastoma cell lines. Subsequently, the effects of the overexpression of FOXO3a and the genetic knockdown of the Wnt/β‑catenin signaling protein Axin‑2 on the biological functions were determined through Cell Counting Kit‑8, cell colony formation assays, scratch and Transwell assay and flow cytometric analysis experiments. The expression levels of FOXO3a were discovered to be downregulated in nephroblastoma cell lines. The overexpression of FOXO3a inhibited the proliferation, invasion and migration of nephroblastoma cells, while inducing apoptosis. Furthermore, the overexpression of FOXO3a downregulated the expression levels of β‑catenin and Cyclin‑D1 proteins involved in the Wnt/β‑catenin signaling pathway. Cell proliferation and the migration and invasion ability of 17‑94 cells in shRNA‑Axin2‑2 group were promoted. Cell apoptosis was predominantly increased by overexpressed FOXO3a, which was reversed by shRNA‑Axin2‑1. The biological effects of overexpressing FOXO3a on nephroblastoma were reversed after activation of Wnt/β‑catenin. In conclusion, the findings of the present study suggested that FOXO3a may inhibit nephroblastoma cell proliferation, migration and invasion, while inducing apoptosis, by downregulating the Wnt/β‑catenin signaling pathway. These results may provide a novel method for the early diagnosis and precise treatment of nephroblastoma.

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.

New mutation in WT1 gene in a boy with an incomplete form of Denys-Drash syndrome: A CARE-compliant case report

RATIONALE

Pediatric patients with WTl-associated syndromes (including Wilms' tumor-aniridia syndrome and Denys-Drash syndrome), Perlman syndrome, mosaic aneuploidy, and Fanconi anemia with a biallelic breast cancer type 2 susceptibility protein mutation have the highest risk of developing Wilms' tumor.

PATIENT CONCERNS AND DIAGNOSIS

We describe a patient with bilateral metachronous Wilms' tumor, ambiguous genitalia characterized by 46, XY disorder of sexual development (DSD) with scrotal hypospadias and bilateral abdominal cryptorchidism, but without nephropathy. At the age of 7 months, the child underwent left nephrectomy with left orchiopexy. At follow-up after 8 months, a second tumor with a diameter of 10 mm was detected in abdominal CT scans at the lower pole of the right kidney.

INTERVENTION

Intra-operative macroscopic inspection of the right kidney revealed a tight attachment of the right proximal ureter to the tumor. Thus, retroperitoneoscopic resection of the lower pole of the right kidney had to be changed to an open surgical procedure with partial resection of the proximal ureter and high uretero-ureterostomy. We subsequently performed orchiopexy and two-stage correction of hypospadias using a free skin graft.

OUTCOMES

At the last follow-up at the age of 8 years, no pathology requiring treatment was noted. A pair-end-reading (2 × 125) DNA analysis with an average coverage of at least 70 to 100 × revealed a previously unknown heterozygous mutation in exon 7 of the Wilms' tumor suppressor gene 1 (WT1) gene (chr11:32417947G>A), leading to the appearance of a site of premature translation termination in codon 369 (p.Arg369Ter, NM_024426.4). This mutation had not been registered previously in the control samples "1000 genomes," Exome Sequencing Project 6500, and the Exome Aggregation Consortium. Thus, to the best of our knowledge this represents a newly identified mutation causing incomplete Denys-Drash syndrome.

Clinical characteristics and outcomes of children with WAGR syndrome and Wilms tumor and/or nephroblastomatosis: The 30-year SIOP-RTSG experience

BACKGROUND

WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, and range of developmental delays) is a rare contiguous gene deletion syndrome with a 45% to 60% risk of developing Wilms tumor (WT). Currently, surveillance and treatment recommendations are based on limited evidence.

METHODS

Clinical characteristics, treatments, and outcomes were analyzed for patients with WAGR and WT/nephroblastomatosis who were identified through International Society of Pediatric Oncology Renal Tumor Study Group (SIOP-RTSG) registries and the SIOP-RTSG network (1989-2019). Events were defined as relapse, metachronous tumors, or death.

RESULTS

Forty-three patients were identified. The median age at WT/nephroblastomatosis diagnosis was 22 months (range, 6-44 months). The overall stage was available for 40 patients, including 15 (37.5%) with bilateral disease and none with metastatic disease. Histology was available for 42 patients; 6 nephroblastomatosis without further WT and 36 WT, including 19 stromal WT (52.8%), 12 mixed WT (33.3%), 1 regressive WT (2.8%) and 2 other/indeterminable WT (5.6%). Blastemal type WT occurred in 2 patients (5.6%) after prolonged treatment for nephroblastomatosis; anaplasia was not reported. Nephrogenic rests were present in 78.9%. Among patients with WT, the 5-year event-free survival rate was 84.3% (95% confidence interval, 72.4%-98.1%), and the overall survival rate was 91.2% (95% confidence interval, 82.1%-100%). Events (n = 6) did not include relapse, but contralateral tumor development (n = 3) occurred up to 7 years after the initial diagnosis, and 3 deaths were related to hepatotoxicity (n = 2) and obstructive ileus (n = 1).

CONCLUSIONS

Patients with WAGR have a high rate of bilateral disease and no metastatic or anaplastic tumors. Although they can be treated according to existing WT protocols, intensive monitoring of toxicity and surveillance of the remaining kidney(s) are advised.

LAY SUMMARY

WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, and range of developmental delays) is a rare genetic condition with an increased risk of developing Wilms tumor. In this study, 43 patients with WAGR and Wilms tumor (or Wilms tumor precursor lesions/nephroblastomatosis) were identified through the international registry of the International Society of Pediatric Oncology Renal Tumor Study Group (SIOP-RTSG) and the SIOP-RTSG network. In many patients (37.5%), both kidneys were affected. Disease spread to other organs (metastases) did not occur. Overall, this study demonstrates that patients with WAGR syndrome and Wilms tumor can be treated according to existing protocols. However, intensive monitoring of treatment complications and surveillance of the remaining kidney(s) are advised.

Minimally Invasive Approach for Wilms Tumor Treatment in a Small Child - A Case Report

Wilms tumor is the most common malignant primary tumor in children. Open traditional approach is often aggressive and offers a burden on the patient's life, imposing longer hospital stays, scarring, and higher levels of complications. Here, we present a case of a small child with Wilms tumor on the right kidney that was successfully treated with minimally invasive surgery, with no tumor spillage or rupture, hospital discharge in the next day, and good oncological outcome, with 1-year recurrence-free follow-up. We also show a comprehensive literature review of similar cases, expecting to push forward medical awareness about this approach.

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.

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.

Local Stage Dependent Necessity of Radiation Therapy in Rhabdoid Tumors of the Kidney (RTK)

PURPOSE

Rhabdoid tumor of the kidney (RTK) is one of the most aggressive childhood renal tumors. Overall survival ranges from 22% to 47%. The indication for radiation therapy (RT) in usually very young patients is an ongoing discussion. Recent protocols recommend RT independent of local stage, the latter being a good discriminator in other childhood kidney tumors. In this study, we analyze the evidence for RT in regard to risk factors, including tumor stage.

METHODS AND MATERIALS

This study analyzed 58 patients with RTK from Austria, Switzerland, and Germany treated in the framework of 4 consecutive, prospective renal/rhabdoid tumor studies from 1991 to 2014. All treatment protocols included multimodality treatment, including high-intensity chemotherapy, surgery, and RT.

RESULTS

Local stage distribution was not applicable, I, II, and III in 1, 6, 11, and 40, respectively. Twenty-nine (50%) patients had stage IV disease at diagnosis. Thirty-seven patients (64%) achieved complete remission, and 49% (18/37) relapsed. Thirty-four patients (60%) patients had progressive disease and died, 17 had local disease, 10 had combined disease, and 7 had distant disease; 2 treatment-related deaths were reported (3%). Twenty-one patients received RT during first-line treatment, 18 of them to all involved sites. Eight of the 34 cases of progressive disease occurred in irradiated patients. The local failure rate of treated patients with local stage II or III disease was 29% (6/18) in patients irradiated to all sites compared with 68% (15/22) in nonirradiated patients. One of 6 stage I patients received RT, and 1 patient experienced distant relapse (2-year progression-free and overall survival both 83% ± 15%). Progression-free survival for local stage II and III disease treated with RT, adjusted for early relapse or treatment abandonment, was 67% ± 11%, compared with 15% ± 7% without RT (P < .0001).

CONCLUSION

The 68% local failure rate in nonirradiated patients underlines the importance of local treatment. Our experience supports the use of RT for local control in higher stage disease. In contrast, no local relapse in 6 local stage I patients, including 5 nonirradiated patients, suggests omission of RT in this favorable subset of usually infant patients with RTK.

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.

Activity of Vincristine and Irinotecan in Diffuse Anaplastic Wilms Tumor and Therapy Outcomes of Stage II to IV Disease: Results of the Children's Oncology Group AREN0321 Study

PURPOSE

AREN0321 evaluated the activity of vincristine and irinotecan (VI) in patients with newly diagnosed diffuse anaplastic Wilms tumor (DAWT) and whether a regimen containing carboplatin (regimen UH1) in addition to regimen I agents used in the National Wilms Tumor Study 5 (NWTS-5; vincristine, doxorubicin, cyclophosphamide, and etoposide plus radiotherapy) would improve patient outcomes.

PATIENTS AND METHODS

Patients with stage II to IV DAWT without measurable disease received regimen UH1. Patients with stage IV measurable disease were eligible to receive VI (vincristine, 1.5 mg/m² per day intravenously on days 1 and 8; irinotecan, 20 mg/m² per day intravenously on days 1-5 and 8-12 of a 21-day cycle) in an upfront window; those with complete (CR) or partial response (PR) had VI incorporated into regimen UH1 (regimen UH2). The study was designed to detect improvement in outcomes of patients with stage II to IV DAWT compared with historical controls treated with regimen I.

RESULTS

Sixty-six eligible patients were enrolled. Of 14 patients with stage IV measurable disease who received VI, 11 (79%) achieved CR (n = 1) or PR (n = 10) after 2 cycles. Doses of doxorubicin, cyclophosphamide, and etoposide were reduced midstudy because of nonhematologic toxicity. Four patients (6%) died as a result of toxicity. Four-year event-free survival, relapse-free survival, and overall survival rates were 67.7% (95% CI, 55.9% to 79.4%), 72.9% (95% CI, 61.5% to 84.4%), and 73.7% (95% CI, 62.7% to 84.8%), respectively, compared with 57.5% (95% CI, 47.6% to 67.4%; P = .26), 57.5% (95% CI, 47.6% to 67.4%; P = .048), and 59.2% (95% CI, 49.4% to 69.0%; P = .08), respectively, in NWTS-5.

CONCLUSION

VI produced a high response rate in patients with metastatic DAWT. AREN0321 treatment seemed to improve outcomes for patients with stage II to IV DAWT compared with NWTS-5, but with increased toxicity. The UH2 regimen warrants further investigation with modifications to reduce toxicity.

Surgery for the complex Wilms tumour

The prognosis of children with Wilms tumour has greatly improved since the introduction of adjuvant radiotherapy and chemotherapy more than 70 years ago with a current overall long-term survival approaching 90%. Before this, surgery was the only option with around 20% survival, even in low-risk categories. The focus is now on management options for those patients in specific subgroups, who continue to have lower event-free survival and who suffer from the long-term effects of treatment. These include those with anaplastic histology, bilateral Wilms, biologically high-risk tumours and those that relapse (Aldrink et al. in J Pediatr Surg 54(3):390-397, 2019). The major advances that have already been made in risk assessment and tailoring the chemotherapy/radiotherapy to achieve maximum advantage with minimum toxicity and long-term morbidity have been predicated on safe and complete resection and staging of the tumour. There are, however, still surgical challenges faced with respect to resection of 'complex' tumours; thus, surgeons need to understand their role and advance their expertise in the overall treatment of children with Wilms tumour. These include very large tumours not responding to chemotherapy, ruptured tumours, tumours with intravascular invasion into the inferior vena cava (± 10%), heart and hepatic veins (± 4%) and Wilms tumours in horseshoe kidneys (< 1%) (Kieran and Ehrlich in Urol Oncol https://doi.org/10.1016/j.urolonc.2015.05.029, 2015). This review describes surgical strategies and techniques used in these situations, gleaned from the authors' experience in the surgical management of over 300 children with Wilms tumours in our centres over the last 30 years.

Prognostic significance of age in 5631 patients with Wilms tumour prospectively registered in International Society of Paediatric Oncology (SIOP) 93-01 and 2001

BACKGROUND

To enhance risk stratification for Wilms tumour (WT) in a pre-operative chemotherapy setting, we explored the prognostic significance and optimal age cutoffs in patients treated according to International Society of Paediatric Oncology Renal Tumour Study Group (SIOP-RTSG) protocols.

METHODS

Patients(6 months-18 years) with unilateral WT were selected from prospective SIOP 93-01 and 2001 studies(1993-2016). Martingale residual analysis was used to explore optimal age cutoffs. Outcome according to age was analyzed by uni- and multivariable analysis, adjusted for sex, biopsy(yes/no), stage, histology and tumour volume at surgery.

RESULTS

5631 patients were included; median age was 3.4 years(IQR: 2-5.1). Estimated 5-year event-free survival (EFS) and overall survival (OS) were 85%(95%CI 83.5-85.5) and 93%(95%CI 92.0-93.4). Martingale residual plots detected no optimal age cutoffs. Multivariable analysis showed lower EFS with increasing age(linear trend P<0.001). Using previously described age categories, EFS was lower for patients aged 2-4(HR 1.34, P = 0.02), 4-10(HR 1.83, P<0.0001) and 10-18 years(HR 1.74, P = 0.01) as compared to patients aged 6 months-2 years. OS was lower for patients 4-10 years(HR 1.67, P = 0.01) and 10-18 years(HR 1.87, P = 0.04), but not for 2-4 years(HR 1.29, P = 0.23). Higher stage, histological risk group and tumour volume were independent adverse prognostic factors.

CONCLUSION

Although optimal age cutoffs could not be identified, we demonstrated the prognostic significance of age as well as previously described cutoffs for EFS (2 and 4 years) and OS (4 years) in children with WT treated with pre-operative chemotherapy. These findings encourage the consideration of age in the design of future SIOP-RTSG protocols.

Blastemal NCAM+ALDH1+ Wilms' tumor cancer stem cells correlate with disease progression and poor clinical outcome: A pilot study

BACKGROUND

Cancer Stem Cells (CSCs) have been suggested as the culprit responsible for tumor resistance to treatment and disease recurrence. Wilms' tumor (WT) is a paradigm for studying the relation between development and tumorigenesis, showing three main histological elements: undifferentiated blastema, epithelia and stroma, mimicking human kidney development. NCAM + ALDH1+ cells were previously found to contain the cancer stem like-cell population in WT. Thus far, the correlation between histologic characterization of this cell population, clinicopathologic parameters and prognostic outcome has yet been investigated in WT.

PROCEDURES

Paraffin-imbedded primary WT specimens from twenty-four patients were immunostained for NCAM and ALDH1. Positivity and histologic compartment localization were determined by two independent observers, blinded to the clinical outcome. Clinicopathologic parameters and prognostic outcomes were determined based on the patients' medical records. The association of NCAM and ALDH1 co-localization with clinicopathologic characteristics was analyzed byχ²-test. Survival analysis was carried out by the log-rank test using Kaplan-Meier method.

RESULTS

Blastemal co-localization of NCAM and ALDH1 was observed in 33% of WTs. Metastases, ICE chemotherapy protocol, blastemal predominance following preoperative chemotherapy, recurrence and patient demise were found to significantly correlate with blastemal NCAM + ALDH1+ cell staining (p < 0.05). A significant inverse correlation between blastemal double positive cells, disease-free survival and overall survival was also observed.

CONCLUSIONS

WT blastemal NCAM + ALDH1+ CSCs significantly correlate with adverse clinicopathologic parameters and poorer prognosis. These results underscore the role of CSCs in disease progression. Additionally, this pilot study supports the addition of these markers for risk stratification of WTs.

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.

Hepatic late adverse effects after antineoplastic treatment for childhood cancer

BACKGROUND

Survival rates have greatly improved as a result of more effective treatments for childhood cancer. Unfortunately, the improved prognosis has been accompanied by the occurrence of late, treatment-related complications. Liver complications are common during and soon after treatment for childhood cancer. However, among long-term childhood cancer survivors, the risk of hepatic late adverse effects is largely unknown. To make informed decisions about future cancer treatment and follow-up policies, it is important to know the risk of, and associated risk factors for, hepatic late adverse effects. This review is an update of a previously published Cochrane review.

OBJECTIVES

To evaluate all the existing evidence on the association between antineoplastic treatment (that is, chemotherapy, radiotherapy involving the liver, surgery involving the liver and BMT) for childhood cancer and hepatic late adverse effects.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2018, Issue 1), MEDLINE (1966 to January 2018) and Embase (1980 to January 2018). In addition, we searched reference lists of relevant articles and scanned the conference proceedings of the International Society of Paediatric Oncology (SIOP) (from 2005 to 2017) and American Society of Pediatric Hematology/Oncology (ASPHO) (from 2013 to 2018) electronically.

SELECTION CRITERIA

All studies, except case reports, case series, and studies including fewer than 10 patients that examined the association between antineoplastic treatment for childhood cancer (aged 18 years or less at diagnosis) and hepatic late adverse effects (one year or more after the end of treatment).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection and 'risk of bias' assessment. The 'risk of bias' assessment was based on earlier checklists for observational studies. For the original version of the review, two review authors independently performed data extraction. For the update of the review, the data extraction was performed by one reviewer and checked by another reviewer.

MAIN RESULTS

Thirteen new studies were identified for the update of this review. In total, we included 33 cohort studies including 7876 participants investigating hepatic late adverse effects after antineoplastic treatment (especially chemotherapy and radiotherapy) for different types of childhood cancer, both haematological and solid malignancies. All studies had methodological limitations. The prevalence of hepatic late adverse effects, all defined in a biochemical way, varied widely, between 0% and 84.2%. Selecting studies where the outcome of hepatic late adverse effects was well-defined as alanine aminotransferase (ALT) above the upper limit of normal, indicating cellular liver injury, resulted in eight studies. In this subgroup, the prevalence of hepatic late adverse effects ranged from 5.8% to 52.8%, with median follow-up durations varying from three to 23 years since cancer diagnosis in studies that reported the median follow-up duration. A more stringent selection process using the outcome definition of ALT as above twice the upper limit of normal, resulted in five studies, with a prevalence ranging from 0.9% to 44.8%. One study investigated biliary tract injury, defined as gamma-glutamyltransferase (γGT) above the upper limit of normal and above twice the upper limit of normal and reported a prevalence of 5.3% and 0.9%, respectively. Three studies investigated disturbance in biliary function, defined as bilirubin above the upper limit of normal and reported prevalences ranging from 0% to 8.7%. Two studies showed that treatment with radiotherapy involving the liver (especially after a high percentage of the liver irradiated), higher BMI, and longer follow-up time or older age at evaluation increased the risk of cellular liver injury in multivariable analyses. In addition, there was some suggestion that busulfan, thioguanine, hepatic surgery, chronic viral hepatitis C, metabolic syndrome, use of statins, non-Hispanic white ethnicity, and higher alcohol intake (> 14 units per week) increase the risk of cellular liver injury in multivariable analyses. Chronic viral hepatitis was shown to increase the risk of cellular liver injury in six univariable analyses as well. Moreover, one study showed that treatment with radiotherapy involving the liver, higher BMI, higher alcohol intake (> 14 units per week), longer follow-up time, and older age at cancer diagnosis increased the risk of biliary tract injury in a multivariable analysis.

AUTHORS' CONCLUSIONS

The prevalence of hepatic late adverse effects among studies with an adequate outcome definition varied considerably from 1% to 53%. Evidence suggests that radiotherapy involving the liver, higher BMI, chronic viral hepatitis and longer follow-up time or older age at follow-up increase the risk of hepatic late adverse effects. In addition, there may be a suggestion that busulfan, thioguanine, hepatic surgery, higher alcohol intake (>14 units per week), metabolic syndrome, use of statins, non-Hispanic white ethnicity, and older age at cancer diagnosis increase the risk of hepatic late adverse effects. High-quality studies are needed to evaluate the effects of different therapy doses, time trends, and associated risk factors after antineoplastic treatment for childhood cancer.

Early and late adverse renal effects after potentially nephrotoxic treatment for childhood cancer

BACKGROUND

Improvements in diagnostics and treatment for paediatric malignancies resulted in a major increase in survival. However, childhood cancer survivors (CCS) are at risk of developing adverse effects caused by multimodal treatment for their malignancy. Nephrotoxicity is a known side effect of several treatments, including cisplatin, carboplatin, ifosfamide, radiotherapy and nephrectomy, and can cause glomerular filtration rate (GFR) impairment, proteinuria, tubulopathy, and hypertension. Evidence about the long-term effects of these treatments on renal function remains inconclusive. It is important to know the risk of, and risk factors for, early and late adverse renal effects, so that ultimately treatment and screening protocols can be adjusted. This review is an update of a previously published Cochrane Review.

OBJECTIVES

To evaluate existing evidence on the effects of potentially nephrotoxic treatment modalities on the prevalence of renal dysfunction in survivors treated for childhood cancer with a median or mean survival of at least one year after cessation of treatment, where possible in comparison with the general population or CCS treated without potentially nephrotoxic treatment. In addition, to evaluate evidence on associated risk factors, such as follow-up duration, age at time of diagnosis and treatment combinations, as well as the effect of doses.

SEARCH METHODS

On 31 March 2017 we searched the following electronic databases: CENTRAL, MEDLINE and Embase. In addition, we screened reference lists of relevant studies and we searched the congress proceedings of the International Society of Pediatric Oncology (SIOP) and The American Society of Pediatric Hematology/Oncology (ASPHO) from 2010 to 2016/2017.

SELECTION CRITERIA

Except for case reports, case series and studies including fewer than 20 participants, we included studies with all study designs that reported on renal function (one year or longer after cessation of treatment), in CCS treated before the age of 21 years with cisplatin, carboplatin, ifosfamide, radiation involving the kidney region, a nephrectomy, or a combination of two or more of these treatments. When not all treatment modalities were described or the study group of interest was unclear, a study was not eligible for the evaluation of prevalence. We still included it for the assessment of risk factors if it had performed a multivariable analysis.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment and data extraction using standardised data collection forms. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Apart from the remaining 37 studies included from the original review, the search resulted in the inclusion of 24 new studies. In total, we included 61 studies; 46 for prevalence, six for both prevalence and risk factors, and nine not meeting the inclusion criteria, but assessing risk factors. The 52 studies evaluating the prevalence of renal dysfunction included 13,327 participants of interest, of whom at least 4499 underwent renal function testing. The prevalence of adverse renal effects ranged from 0% to 84%. This variation may be due to diversity of included malignancies, received treatments, reported outcome measures, follow-up duration and the methodological quality of available evidence.Seven out of 52 studies, including 244 participants, reported the prevalence of chronic kidney disease, which ranged from 2.4% to 32%.Of these 52 studies, 36 studied a decreased (estimated) GFR, including at least 432 CCS, and found it was present in 0% to 73.7% of participants. One eligible study reported an increased risk of glomerular dysfunction after concomitant treatment with aminoglycosides and vancomycin in CCS receiving total body irradiation (TBI). Four non-eligible studies assessing a total cohort of CCS, found nephrectomy and (high-dose (HD)) ifosfamide as risk factors for decreased GFR. The majority also reported cisplatin as a risk factor. In addition, two non-eligible studies showed an association of a longer follow-up period with glomerular dysfunction.Twenty-two out of 52 studies, including 851 participants, studied proteinuria, which was present in 3.5% to 84% of participants. Risk factors, analysed by three non-eligible studies, included HD cisplatin, (HD) ifosfamide, TBI, and a combination of nephrectomy and abdominal radiotherapy. However, studies were contradictory and incomparable.Eleven out of 52 studies assessed hypophosphataemia or tubular phosphate reabsorption (TPR), or both. Prevalence ranged between 0% and 36.8% for hypophosphataemia in 287 participants, and from 0% to 62.5% for impaired TPR in 246 participants. One non-eligible study investigated risk factors for hypophosphataemia, but could not find any association.Four out of 52 studies, including 128 CCS, assessed the prevalence of hypomagnesaemia, which ranged between 13.2% and 28.6%. Both non-eligible studies investigating risk factors identified cisplatin as a risk factor. Carboplatin, nephrectomy and follow-up time were other reported risk factors.The prevalence of hypertension ranged from 0% to 50% in 2464 participants (30/52 studies). Risk factors reported by one eligible study were older age at screening and abdominal radiotherapy. A non-eligible study also found long follow-up time as risk factor. Three non-eligible studies showed that a higher body mass index increased the risk of hypertension. Treatment-related risk factors were abdominal radiotherapy and TBI, but studies were inconsistent.Because of the profound heterogeneity of the studies, it was not possible to perform meta-analyses. Risk of bias was present in all studies.

AUTHORS' CONCLUSIONS

The prevalence of adverse renal effects after treatment with cisplatin, carboplatin, ifosfamide, radiation therapy involving the kidney region, nephrectomy, or any combination of these, ranged from 0% to 84% depending on the study population, received treatment combination, reported outcome measure, follow-up duration and methodological quality. With currently available evidence, it was not possible to draw solid conclusions regarding the prevalence of, and treatment-related risk factors for, specific adverse renal effects. Future studies should focus on adequate study designs and reporting, including large prospective cohort studies with adequate control groups when possible. In addition, these studies should deploy multivariable risk factor analyses to correct for possible confounding. Next to research concerning known nephrotoxic therapies, exploring nephrotoxicity after new therapeutic agents is advised for future studies. Until more evidence becomes available, CCS should preferably be enrolled into long-term follow-up programmes to monitor their renal function and blood pressure.

Association of NEFL Gene Polymorphisms with Wilms' Tumor Susceptibility in Chinese Children

Wilms' tumor is renal tumor of childhood, characterized by the appearance of embryonic renal tissue and other kidney malformations. The genetic etiology of sporadic Wilms' tumor remains largely unknown. Neurofilament light (NEFL) is a tumor suppressor. We evaluated the association between three NEFL gene polymorphisms (rs11994014 G>A, rs2979704 T>C and rs1059111 A>T) and Wilms' tumor susceptibility in a Chinese population consisting of 145 cases and 531 controls. In the single locus analysis, rs2979704 CC variant genotype was associated with a decreased risk of Wilms' tumor [CC vs. TT: adjusted odds ratio (OR)=0.48, 95% confidence interval (CI)=0.24-0.94; CC vs. TT+CT: adjusted OR=0.51, 95% CI=0.27-0.97]. We also observed that carriers of the three protective genotypes had significantly decreased risk of Wilms' tumor when compared to those with 0-2 protective genotypes (adjusted OR=0.49, 95% CI=0.25-0.95). The association between rs11994014 G>A or rs1059111 A>T polymorphisms and Wilms' tumor susceptibility did not reach statistical significance. No significant association was detected in the stratified analyses. Our findings suggested that the NEFL rs2979704 T>C polymorphism may be associated with Wilms' tumor susceptibility in the Chinese population.

Unusual Presentation of Wilms' Tumor as Umbilical Granuloma

We report an unusual presentation of a Wilms' tumor in an 8-month-old child, incidentally detected by ultrasonography for an umbilical granuloma. A patent vitellointestinal duct anomaly required surgical excision in the same sitting as the nephroureterectomy. The case is reported for the unusual coexistence and the management implications.

Laparoscopic nephrectomy for Wilms' tumor: Can we expand on the current SIOP criteria?

INTRODUCTION

Wilms' tumor now has a good overall prognosis with open radical nephrectomy having been the mainstay of surgical treatment. Recently laparoscopic nephrectomy (LN) has been growing in popularity. The aim of our study was to review our indications and outcomes for laparoscopic resections for Wilms' tumor and compare indications with International Society of Paediatric Oncology (SIOP) criteria for LN.

MATERIAL AND METHODS

Patient demographics, preoperative management, surgical data, respect of SIOP criteria, complications, disease outcome, and follow-up were recorded on consecutive children who underwent nephrectomy for Wilms' tumor.

RESULTS AND DISCUSSION

Fifty-four consecutive children with Wilms' tumor underwent a nephrectomy; 20 had a LN (Table). Nine of 20 (45%) patients who had LN did not meet SIOP criteria for LN. No patients had an intraoperative tumor rupture and one patient had positive margins because of preoperative rupture. There were two conversions: one caused by difficulty accessing the renal hilum and the other caused by difficulty maintaining oxygen saturations. There was one local recurrence.

CONCLUSION

SIOP criteria are conservative and safe. Indications can be extended for teams experienced in surgical oncology and laparoscopy after agreement at a multidisciplinary meeting (MDM).

Familial synchronous bilateral teratoid Wilms tumor with elevated alpha-fetoprotein level

Familial Wilms tumor is a rare entity that accounts for only 1–2% of all Wilms tumor cases, with an earlier age of onset and an increased frequency of bilateral tumors. Teratoid Wilms tumor is a variant of nephroblastoma with a predominance of heterologous tissues comprising more than 50% of the tumor volume. Wilms tumor does not usually secrete any specific tumor marker and all teratoid Wilms tumor cases previously reported were sporadic non-secreting neoplasms. Here we describe an infant with familial synchronous bilateral teratoid Wilms tumor whose serum alpha-fetoprotein level was elevated. To our knowledge, this extremely rare type of case is reported for the first time 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.

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.

Association Between HACE1 Gene Polymorphisms and Wilms' Tumor Risk in a Chinese Population

Wilms' tumor is one of the most common solid tumors of childhood; however, the genetic basis underlying the majority of cases remains largely unknown. HACE1 is a putative Wilms' tumor susceptibility gene. We investigated the association between five HACE1 gene polymorphisms and Wilms' tumor susceptibility in a Chinese population consisting of 145 patients and 531 controls. We found a significant association between HACE1 rs9404576 polymorphism and decreased Wilms' tumor risk. No significant association was detected for other polymorphisms in the overall analysis. Our results indicated that HACE1 rs9404576 polymorphism may be associated with Wilms' tumor susceptibility in the Chinese population.

Results of the First Prospective Multi-institutional Treatment Study in Children With Bilateral Wilms Tumor (AREN0534): A Report From the Children's Oncology Group

OBJECTIVE

The Children's Oncology Group study AREN0534 aimed to improve event-free survival (EFS) and overall survival (OS) while preserving renal tissue by intensifying preoperative chemotherapy, completing definitive surgery by 12 weeks from diagnosis, and modifying postoperative chemotherapy based on histologic response.

BACKGROUND

No prospective therapeutic clinic trials in children with bilateral Wilms tumors (BWT) exist. Historical outcomes for this group were poor and often involved prolonged chemotherapy; on NWTS-5, 4-year EFS for all children with BWT was 56%.

METHODS

Patients were enrolled and imaging studies were centrally reviewed to assess for bilateral renal lesions. They were treated with 3-drug induction chemotherapy (vincristine, dactinomycin, and doxorubicin) for 6 or 12 weeks based on radiographic response followed by surgery and further chemotherapy determined by histology. Radiation therapy was provided for postchemotherapy stage III and IV disease.

RESULTS

One hundred eighty-nine of 208 patients were evaluable. Four-year EFS and OS were 82.1% (95% CI: 73.5%-90.8%) and 94.9% (95% CI: 90.1%-99.7%. Twenty-three patients relapsed and 7 had disease progression. After induction chemotherapy 163 of 189 (84.0%) underwent definitive surgical treatment in at least 1 kidney by 12 weeks and 39% retained parts of both kidneys. Surgical approaches included: unilateral total nephrectomy with contralateral partial nephrectomy (48%), bilateral partial nephrectomy (35%), unilateral total nephrectomy (10.5%), unilateral partial nephrectomy (4%), and bilateral total nephrectomies (2.5%).

CONCLUSION

This treatment approach including standardized 3-drug preoperative chemotherapy, surgical resection within 12 weeks of diagnosis and response and histology-based postoperative therapy improved EFS and OS and preservation of renal parenchyma compared with historical outcomes for children with BWT.

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.

Bilateral Wilms tumour: a review of clinical and molecular features

Wilms tumour (WT) is the most common paediatric kidney cancer and affects approximately one in 10 000 children. The tumour is associated with undifferentiated embryonic lesions called nephrogenic rests (NRs) or, when diffuse, nephroblastomatosis. WT or NRs can occur in both kidneys, termed bilateral disease, found in only 5-8% of cases. Management of bilateral WT presents a major clinical challenge in terms of maximising survival, preserving renal function and understanding underlying genetic risk. In this review, we compile clinical data from 545 published cases of bilateral WT and discuss recent progress in understanding the molecular basis of bilateral WT and its associated precursor NRs in the context of the latest radiological, surgical and epidemiological features.

Management of bilateral Wilms tumours

Wilms tumour is named after Max Wilms. It is an embryonal tumour derived from the metanephros. It is the commonest childhood renal tumour and the third commonest paediatric malignancy. Synchronous bilateral Wilms tumours (BWT) represent 4-7% of all Wilms tumours (WT) and present at a younger age than unilateral Wilms tumours. At least 10% of synchronous BWTs have unfavourable histology, and up to 22% are associated with genitourinary abnormalities, aniridia, WAGR syndrome, Denys-Drash syndrome, hemihypertrophy, or one of the other overgrowth syndromes. The long-term disease-free survival rate for patients with unilateral WT is approaching 90%, and is around 70% for those with metastatic disease. For both synchronous and metachronous Wilms tumours the prognosis is less favourable with reported cure rates approaching 80% in the best centres and lower in resource poor settings. There is potential for a reduced quality of life due to renal insufficiency and the possible need for renal transplantation. The major clinical challenge in BWTs is preservation of functioning renal tissue using nephron-sparing surgical techniques, while achieving cure with minimum therapy-related morbidity. Mortality is generally associated with progressive disease of anaplastic tumours. Chemotherapy followed by nephron-sparing surgery has been able, in most cases, to eradicate the tumour while preserving renal function. Radiotherapy has largely been avoided because of fears of long-term radiation injury to the residual functioning renal mass. Patient selection, appropriate pre- and post-operative chemotherapy and skilled surgical techniques all contribute to excellent outcomes where these are achievable.

Management of bilateral Wilms tumours

Wilms tumour is named after Max Wilms. It is an embryonal tumour derived from the metanephros. It is the commonest childhood renal tumour and the third commonest paediatric malignancy. Synchronous bilateral Wilms tumours (BWT) represent 4-7% of all Wilms tumours (WT) and present at a younger age than unilateral Wilms tumours. At least 10% of synchronous BWTs have unfavourable histology, and up to 22% are associated with genitourinary abnormalities, aniridia, WAGR syndrome, Denys-Drash Syndrome, hemihypertrophy, or one of the other overgrowth syndromes. The long-term disease-free survival (DFS) rate for patients with unilateral Wilms' tumours is approaching 90%, and is around 70% for those with metastatic disease. For both synchronous and metachronous Wilms tumours the prognosis is less favourable with reported cure rates approaching 80% in the best centres and lower in resource poor settings. There is potential for a reduced quality of life due to renal insufficiency and the possible need for renal transplantation. The major clinical challenge in BWTs is preservation of functioning renal tissue using nephron sparing surgical techniques, while achieving cure with minimum therapy-related morbidity. Mortality is generally associated with progressive disease of anaplastic tumours. Chemotherapy followed by nephron sparing surgery has been able, in most cases, to eradicate the tumour while preserving renal function. Radiotherapy has largely been avoided because of fears of long term radiation injury to the residual functioning renal mass. Patient selection, appropriate pre- and post-operative chemotherapy and skilled surgical techniques all contribute to excellent outcomes where these are achievable.

Mutations in the SIX1/2 pathway and the DROSHA/DGCR8 miRNA microprocessor complex underlie high-risk blastemal type Wilms tumors

Blastemal histology in chemotherapy-treated pediatric Wilms tumors (nephroblastoma) is associated with adverse prognosis. To uncover the underlying tumor biology and find therapeutic leads for this subgroup, we analyzed 58 blastemal type Wilms tumors by exome and transcriptome sequencing and validated our findings in a large replication cohort. Recurrent mutations included a hotspot mutation (Q177R) in the homeo-domain of SIX1 and SIX2 in tumors with high proliferative potential (18.1% of blastemal cases); mutations in the DROSHA/DGCR8 microprocessor genes (18.2% of blastemal cases); mutations in DICER1 and DIS3L2; and alterations in IGF2, MYCN, and TP53, the latter being strongly associated with dismal outcome. DROSHA and DGCR8 mutations strongly altered miRNA expression patterns in tumors, which was functionally validated in cell lines expressing mutant DROSHA.

[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.

Pathological Features of the Unilateral Favorable Histology Nephroblastoma with Relapse

PURPOSE

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Risk factors for local recurrence in Wilms tumour and the potential influence of biopsy - the United Kingdom experience

RATIONALE

The UKW3 trial compared biopsy/pre-operative chemotherapy versus immediate nephrectomy and afforded the opportunity to examine the influence of percutaneous retroperitoneal biopsy and other factors on local and distant relapse of Wilms tumour (WT).

METHODS

Patients with unilateral WT (stages I-IV) excluding metachronous relapse or early progressive disease were eligible. Metastatic and 'inoperable' tumours were biopsied electively. 'Local' was defined as relapse within the abdomen, except for liver metastases considered as 'distant' relapse, together with other haematogenous routes. Uni- and multivariable analyses estimated the risk factors for relapse.

RESULTS

Overall, 285/635 (44.9%) patients had a biopsy. With a median follow-up of 10.1 years, 35 (5.5%) patients experienced a 'local', 15 a combined (2.4%) and 60 (9.4%) a 'distant' relapse. On univariate analysis, biopsy, anaplasia and tumour size were associated with an increased risk of local relapse. On multivariable analysis, anaplasia and tumour size remained significant for local relapse whereas the elevated risk of biopsy (hazards ratio (HR) = 1.80: 95% confidence interval (CI) 0.97-3.32, p = 0.060) was marginal. Age, anaplasia, tumour size, lymph nodes metastases and stage, but not biopsy, were individually associated with increased risk of distant relapse but only age and anaplasia remained significant following multivariable analysis.

CONCLUSIONS

The UKW3 trial provides some reassurance that biopsy should not automatically lead to 'upstaging' of WT. Further assessment of this controversial area is required. Comparison of local relapse rates in a multinational trial in which the United Kingdom (UK) continued the practice of routinely biopsying all patients in contrast to the standard European approach will afford this opportunity and is planned.

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.

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.

Malformations, genetic abnormalities, and Wilms tumor

BACKGROUND

Wilms Tumor (WT) can occur in association with tumor predisposition syndromes and/or with clinical malformations. These associations have not been fully characterized at a clinical and molecular genetic level. This study aims to describe clinical malformations, genetic abnormalities, and tumor predisposition syndromes in patients with WT and to propose guidelines regarding indications for clinical and molecular genetic explorations.

PROCEDURE

This retrospective study analyzed clinical abnormalities and predisposition syndromes among 295 patients treated for WT between 1986 and 2009 in a single pediatric oncological center.

RESULTS

Clinically identified malformations and predisposition syndromes were observed in 52/295 patients (17.6%). Genetically proven tumor predisposition syndromes (n = 14) frequently observed were syndromes associated with alterations of the chromosome WT1 region such as WAGR (n = 6) and Denys-Drash syndromes (n = 3), syndromes associated with alterations of the WT2 region (Beckwith-Wiedeman syndrome, n = 3), and Fanconi anemia (n = 2). Hemihypertrophy and genito-urinary malformations (n = 12 and n = 16, respectively) were the most frequently identified malformations. Other different syndromes or malformations (n = 10) were less frequent. Median age of WT diagnosis was significantly earlier for children with malformations than those without (27 months vs. 37 months, P = 0.0009). There was no significant difference in terms of 5-year EFS and OS between WT patients without or with malformations.

CONCLUSIONS

The frequency of malformations observed in patients with WT underline the need of genetic counseling and molecular genetic explorations for a better follow-up of these patients, with a frequently good outcome. A decisional tree, based on clinical observations of patients with WT, is proposed to guide clinicians for further molecular genetic explorations.