Systematic Review and Meta-analysis of Laparoscopic Versus Open Radical Nephrectomy for Paediatric Renal Tumors With Focus on Wilms' Tumor

OBJECTIVE

To summarize and evaluate the outcomes of laparoscopic radical nephrectomy (LRN) and compare its safety and efficacy with open radical nephrectomy (ORN) in pediatric renal tumors (RT) and Wilms' tumors (WT).

BACKGROUND

ORN is the gold standard treatment for pediatric RT, consisting predominantly of WT. LRN is gaining popularity but remains controversial in pediatric surgical oncology.

METHODS

A systematic search was performed for all eligible studies on LRN and comparative studies between LRN and ORN in pediatric RT and WT. Meta-analysis, subgroup analysis, and sensitivity analysis were conducted. The main endpoints were cancer-related outcomes and surgical morbidity. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.

RESULTS

No levels I to II studies were identified. LRN was feasible in nearly 1 in 5 pediatric RT and WT after neoadjuvant chemotherapy, with pooled mid-term oncological outcomes (<7% local recurrence, >90% event-free survival) comparable with those of ORN. There was no strong evidence of an increased risk of intraoperative tumor spillage, but lymph node harvest was inadequate in LRN. Large tumors crossing the ipsilateral spinal border were associated with a trend for intraoperative complications and positive margins. Pooled complications rate and hospital stay duration were similar between LRN and ORN. Long-term (>3 years) outcomes are unknown.

CONCLUSIONS

Available level III evidence indicates that LRN is a safe alternative to ORN for carefully selected cases, with similar spillage rates and mid-term oncological outcomes. However, there was no advantage in surgical morbidity and lymph node harvest was inadequate with LRN. Tumor-matched-group studies with long-term follow-up are required.

LEVEL OF EVIDENCE

Level III.

The tumor suppressor WT1 drives progenitor cell progression and epithelialization to prevent Wilms tumorigenesis in human kidney organoids

Wilms tumor is the most widespread kidney cancer in children and frequently associated with homozygous loss of the tumor suppressor WT1. Pediatric tumorigenesis is largely inaccessible in humans. Here, we develop a human kidney organoid model for Wilms tumor formation and show that deletion of WT1 during organoid development induces overgrowth of kidney progenitor cells at the expense of differentiating glomeruli and tubules. Functional and gene expression analyses demonstrate that absence of WT1 halts progenitor cell progression at a pre-epithelialized cell state and recapitulates the transcriptional changes detected in a subgroup of Wilms tumor patients with ectopic myogenesis. By "transplanting" WT1 mutant cells into wild-type kidney organoids, we find that their propagation requires an untransformed microenvironment. This work defines the role of WT1 in kidney progenitor cell progression and tumor suppression, and establishes human kidney organoids as a phenotypic model for pediatric tumorigenesis.

Nephroblastoma in a Sprague Dawley rat unrelated to titanium dioxide nanoparticle exposure in utero

Nephroblastoma is an embryonal tumour that has rarely been reported in laboratory rats. In this case report, a large nephroblastoma with peritoneal seeding was found during necropsy in an 11-month-old, female, Sprague Dawley rat. The rat had a history of indirect exposure to nano-TiO2 (titanium dioxide nanoparticles) during maternal gestation. A firm mass in the upper right abdominal quadrant was palpated. Four weeks later, the animal quickly declined. Nephroblastoma was confirmed by histopathology. Only one rat developed nephroblastoma among the ten littermates. Nephroblastomas in Sprague Dawley rats are typically spontaneous tumours with non-malignant mesenchymal elements. The capability to induce a nephroblastoma with nano-TiO2 is less likely in this case.

METTL3 polymorphisms and Wilms tumor susceptibility in Chinese children: A five-center case-control study

BACKGROUND

Wilms tumor is a common pediatric tumor worldwide. Methyltransferase like 3 (METTL3) is a core gene of the N⁶ -methyladenosine (m⁶ A) modification that widely affects the transcription of tumor-related genes in eukaryotes. METTL3 has been extensively investigated in various tumors but not Wilms tumor.

METHODS

We describe a five-center case-control study with 414 patients and 1199 controls aiming to explore the associations between METTL3 polymorphisms (rs1061026 T>G, rs1061027 C>A, rs1139130 A>G and rs1263801 G>C) and Wilms tumor susceptibility. A TaqMan real-time polymerase chain reaction was performed for genotyping. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported as evaluation indicators to determine any associations.

RESULTS

Referring to the preliminary analysis results, protective genotypes were identified as rs1061026 TG/GG, rs1061027 CA/AA, rs1139130 GG and rs1263801 GC/CC. The children with three protective genotypes were less likely to develop Wilms tumor than children without protective genotypes (adjusted OR = 0.68, 95% CI = 0.46-0.999, p = 0.0496). Similarly, stratified analysis of the subgroup aged > 18 months, carrying 3 or 4 protective genotypes, was a protective factor for Wilms tumor compared to carrying 0-2 protective genotypes (adjusted OR = 0.59 95% CI = 0.39-0.91, p = 0.016). However, we did not observe any other significant results.

CONCLUSIONS

The combined effect of METTL3 polymorphisms reduce Wilms tumor susceptibility in Chinese children. This conclusion requires further verification.

Maternal lifestyle characteristics and Wilms tumor risk in the offspring: A systematic review and meta-analysis

BACKGROUND

Little is known about the etiology of childhood Wilms tumor (WT) and potentially modifiable maternal risk factors, in particular.

METHODS

Unpublished data derived from the hospital-based, case-control study of the Greek Nationwide Registry for Childhood Hematological Malignancies and Solid Tumors (NARECHEM-ST) were included in an ad hoc conducted systematic literature review and meta-analyses examining the association between modifiable maternal lifestyle risk factors and WT. Eligible data were meta-analysed in separate strands regarding the associations of WT with (a) maternal folic acid and/or vitamins supplementation, (b) alcohol consumption and (c) smoking during pregnancy. The quality of eligible studies was evaluated using the Newcastle-Ottawa Scale.

RESULTS

Effect estimates from 72 cases and 72 age- and sex-matched controls contributed by NARECHEM-ST were meta-analysed together with those of another 17, mainly medium size, studies of ecological, case-control and cohort design. Maternal intake of folic acid and/or other vitamins supplements during pregnancy was inversely associated with WT risk (6 studies, OR: 0.78; 95 %CI: 0.69-0.89, I2 = 5.4 %); of similar size was the association for folic acid intake alone (4 studies, OR: 0.79; 95 %CI: 0.69-0.91, I2 = 0.0 %), derived mainly from ecological studies. In the Greek study a positive association (OR: 5.31; 95 %CI: 2.00-14.10) was found for mothers who consumed alcohol only before pregnancy vs. never drinkers whereas in the meta-analysis of the four homogeneous studies examining the effect of alcohol consumption during pregnancy the respective overall result showed an OR: 1.60 (4 studies, 95 %CI: 1.28-2.01, I2 = 0.0 %). Lastly, no association was seen with maternal smoking during pregnancy (14 studies, OR: 0.93; 95 %CI: 0.80-1.09, I2 = 0.0 %).

CONCLUSIONS

In the largest to-date meta-analysis, there was an inverse association of maternal folic acid or vitamins supplementation with WT risk in the offspring, derived mainly from ecological studies. The association with maternal alcohol consumption found in our study needs to be further explored whereas no association with maternal smoking was detected. Given the proven benefits for other health conditions, recommendations regarding folic acid supplementation as well as smoking and alcohol cessation should apply. The maternal alcohol consumption associations, however, should be further explored given the inherent limitations in the assessment of exposures of the published studies.

Bilateral Wilms'Tumor in Trisomy 18 Syndrome: Case Report and Critical Review of the Literature

We present a patient with trisomy 18 syndrome and bilateral Wilms' tumor representing the second case of the literature. Physicians should remain alert to the possibility of WT in patients with trisomy 18 who may survive beyond infancy. In this event, it may be essential to consider periodic abdominal ultrasound for screening purposes. A critical review of the literature is presented.

Index analysis and human health risk model application for evaluating ambient air-heavy metal contamination in Chemical Valley Sarnia

The impacts of air emissions as a consequence of industrial activities around communities of human habitation have been extensively reported. This study is the first to assess potential adverse human health effects in the Chemical Valley Sarnia (CVS) area, around the St. Clair River, using health risk models, ecological and pollution indices. Large quantities of particulate matters (PM) are generated from anthropogenic activities, which contain several heavy metals in trace quantities with potentially adverse effects to humans and environmental health. The distribution, and human health impact assessment of trace element concentrations in PM fractions were examined. Elemental concentrations of As, Cd, Cr (VI), Cu, Fe, Mn, Pb, Ni, Zn were determined in the PM size-segregated samples collected from the CVS area between 2014 and 2017. The results showed relatively high concentration of PM_<2.5 (87.19±8.1(mgm³)) which is approximately 4 times the WHO air quality guidelines. Pb concentration (143.03 ± 46.87ηg/m³) was 3.6 times higher than the air quality standards of NAAQS. Cr (VI) showed moderate to considerable contamination ( C_f=4) in the CVS while Cr (VI), Pb, and Ni had enrichment factor E_f < 3 (minimal), signifying contributions from anthropogenic activities. Pollution load index (P_Li) value observed was 1.4 indicating human health risk from the PM, especially for the children in the area. The deposition fluxes (DΦ) showed that PM-bound metals could potentially bypass the head airways and cause damages to the tracheobronchial tree, increasing the human health risks of nephroblastomasis development. The main route of entry for the heavy metal bound PM in humans were observed as through ingestion and inhalation. The highest total excess cancer risks observed for children (6.7×10^-4) and adult (1.0×10^-4) indicating potential cancer effects. The Incremental Lifetime Cancer Risk (ILCR) increased from Pb < Ni < Cd < Cr (VI) < As. Overall, children are more likely to develop carcinogenic and non-carcinogenic health effects from exposures to elemental concentrations of airborne PM in the study area.

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.

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

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

Occurrence of Wilms' tumor in a child with hereditary spherocytosis

Hereditary spherocytosis (HS) is the most frequent cause of congenital hemolytic anemia. It is an autosomal dominant genetic disorder characterized by cell membrane abnormalities, specifically in red blood cells. Although the association between benign, borderline and malignant tumors and HS is not clear, various tumors such as splenoma, adrenal myolipoma, pancreatic schwannoma, ganglioneuroma, extramedullary hematopoiesis, myeloproliferative disorders, multiple myeloma, B-cell lymphoma and acute lymphoblastic leukemia have been presented in case reports concerning HS patients. Here we describe a 6-year-old boy with HS who presented with a mass in the left kidney. Tru-cut biopsy revealed Wilms' tumor (WT). To the best of our knowledge, this is the first case of WT associated with HS to be reported in the literature.

Results of fifteen-year follow-up from a single center: findings and risks for tumor development in isolated hemihyperplasia cases

Isolated hemihyperplasia is abnormal asymmetric growth of one or more parts of the body without any underlying disease. The risk for the development of embryonal tumor is increased in the subjects with isolated hemihyperplasia. The study presented here retrospectively evaluated the clinical data and the risk for tumor development in the cases with isolated hemihyperplasia. 24 cases with isolated hemihyperplasia were retrospectively evaluated. An extremity segment has been involved in 16.7%, an extremity has been entirely involved in 37.5%, more than one extremity have been involved on the same side in 16.7%, and definitely half of the body including the face has been involved in 25% of the patients, whereas one side of the face has been involved in only one case. Wilms tumor in the left abdomen (4.2%) was developed in one case. Isolated hemihyperplasia is a rare clinical picture that enhances the risk for the development of embryonal tumors.

Phacomatosis pigmentokeratotica with nephroblastoma and juvenile hypertension

Phacomatosis pigmentokeratotica is characterized by the coexistence of an organoid epidermal naevus, follow-ing Blaschko's lines, and a large speckled lentiginous naevus, typically arranged in a chequerboard pattern. This entity has been isolated from the group of epidermal naevus syndromes and is frequently associated with extracutaneous anomalies. We report here the first observation of phacomatosis pigmentokeratotica associated with nephroblastoma. In addition to this paediatric renal tumour, the coexistence of juvenile arterial hypertension suggests an associated vascular defect. The link between the extracutaneous manifestations and cutaneous twin spot phenotype is discussed.

Exposure to pesticides and childhood cancer risk: has there been any progress in epidemiological studies?

OBJECTIVES

In Europe and the United States, cancer is a major cause of death among children aged 5-14 years. The role of environmental exposure to pesticides in carcinogenesis, although strongly postulated, is still unknown. Pesticides have been used since the early days of modern agriculture. They are biologically active compounds, which may pose health risk during or after their use.

MATERIALS AND METHODS

Epidemiological studies focused on childhood cancer and exposure to pesticides, conducted over the last seven years, were identified through searching PUBMED, MEDLINE and EBSCO literature bases. From each study, the following information was abstracted: type of cancer, type of exposure, study design, risk estimate, and study population. This review will try to answer the question on whether any further progress in epidemiology of childhood cancer due to pesticide exposure has been made.

RESULTS

Leukemia, brain cancer, non-Hodgkin's lymphoma and neuroblastoma are mentioned as potentially associated with pesticide exposure among children. Despite an increasing evidence in support of this finding, it is still limited because of the weakness of research methodology. The substantial weak points of numerous epidemiological studies of pesticide-related health effects are problems faced in exposure assessment, small numbers of exposed subjects, a limited number of studies focused on the majority of cancers, and difficulties in estimating critical windows of exposure.

CONCLUSION

In the light of existing, although still limited evidence of adverse effects of pesticide exposure, it is necessary to reduce exposure to pesticides. The literature review suggests a great need to increase awareness among people occupationally or environmentally exposed to pesticides about their potential negative influence on health of their children.

Association between the HER2 expression and histological differentiation in Wilms tumor

Human epidermal growth factor receptors (HER) play a critical role in the branching morphogenesis of renal tubules. In the current study, we analyzed the expression of HER2 in Wilms tumor and assessed the role of this gene in the tumorgenesis of Wilms tumor. During the period from 1960 to 2005, 40 patients with Wilms tumor were treated in our department. Twenty-four of those patients (except those with clear cell sarcoma of the kidney and malignant rhabdoid tumor of the kidney) were collected and assessed. The histological component of each Wilms tumor was divided into three categories (epithelial, blastemal, and mesenchymal) and the extent of HER2 protein expression was analyzed immunohistochemically. The normal kidney tissue accompanied with 12 cases of Wilms tumor was also examined. In the normal kidney, HER2 showed a strong immunoreactivity in the cell membranes of the collecting tubules and in the endothelial cells. Of 24 cases, 15 cases showed an epithelial component, while 24 cases had a blastemal component and 21 cases had a mesenchymal component, respectively. Among the 15 specimens with epithelial cell differentiation, eight (53.3%) showed HER2 immunoreactive epithelial cells. HER2 immunoreactive blastemal cells were present in 11 (45.8%) of 24 specimens with blastemal cells. On the other hand, only 3 (14.3%) of 21 specimens containing mesenchymal cells showed HER2 immunoreactivity. These results suggest that the extent of HER2 expression is associated with epithelial differentiation in Wilms tumor. These histological findings may therefore help to explain the development of Wilms tumor from the standpoint of histological differentiation.

Parental age and risk of childhood cancers: a population-based cohort study from Sweden

BACKGROUND

Frequent germ line cells mutations were previously demonstrated to be associated with aging. This suggests a higher incidence of childhood cancer among children of older parents. A population-based cohort study of parental ages and other prenatal risk factors for five main childhood cancers was performed with the use of a linkage between several national-based registries.

METHODS

In total, about 4.3 million children with their parents, born between 1961 and 2000, were included in the study. Multivariate Poisson regression was used to obtain the incidence rate ratios (IRR) and 95% confidence interval (CI). Children <5 years of age and children 5-14 years of age were analysed independently.

RESULTS

There was no significant result for children 5-14 years of age. For children <5 years of age, maternal age were associated with elevated risk of retinoblastoma (oldest age group's IRR = 2.39, 95%CI = 1.17-4.85) and leukaemia (oldest age group's IRR = 1.44, 95%CI = 1.01-2.05). Paternal age was significantly associated with leukaemia (oldest age group's IRR = 1.31, 95%CI = 1.04-1.66). For central nervous system cancer, the effect of paternal age was found to be significant (oldest age group's IRR = 1.69, 95%CI = 1.21-2.35) when maternal age was included in the analysis.

CONCLUSION

Our findings indicate that advanced parental age might be associated with an increased risk of early childhood cancers.

Comprendre le néphroblastome. informations à l'usage des parents et des proches d'un enfant malade

In response to the evolution of the information-seeking behaviour of patients and concerns from health professionals regarding cancer patient information, the French National Federation of Comprehensive Cancer Centres (FNCLCC) introduced, in 1998, an information and education program dedicated to patients and relatives, the SOR SAVOIR PATIENT program. The methodology of this program adheres to established quality criteria regarding the elaboration of patient information. Cancer patient information developed in this program is based on clinical practice guidelines produced by the FNCLCC and the twenty French regional cancer centres,the National League against Cancer, The National Cancer Institute, the French Hospital Federation, the National Oncology Federation of Regional and University Hospitals, the French Oncology Federation of General Hospitals, many learned societies, as well as an active participation of patients, former patients and caregivers. The handbook SOR SAVOIR PATIENT Understanding nephroblastoma is an adapted version of various scientific publications and international clinical practice guidelines, validated by oncology experts and by the Nephroblastoma Committee of the French Society against Cancers and Leukaemias in children and adolescents (SFCE). It was elaborated with the active participation of parents and other family members. It is meant to provide a basis for the explanation of the disease, to help parents asking questions, and to facilitate discussions with the healthcare team. It is available from the FNCLCC (101, rue de Tolbiac, 75013 PARIS, Tel. (0033)1 76 64 78 00, www.fnclcc.fr). This document was validated at the end of 2005 and published in May 2006. SOR SAVOIR PATIENT guides are systematically updated when new research becomes available. Information leaflets, extracted from the handbook SOR SAVOIR PATIENT Understanding nephroblastoma and published in this edition of the Cancer et Radiothérapie, describe the physiopathology of nephroblastoma, as well as treatments and follow-up. The guide allows parents and relatives to better understand the disease and the treatments proposed. It also offers health professionals a synthetic evidence-based patient information source which facilitates discussions with the patient.

Tumour surveillance in Beckwith-Wiedemann syndrome and hemihyperplasia: a critical review of the evidence and suggested guidelines for local practice

There is strong evidence for an association between overgrowth disorders such as Beckwith-Wiedemann syndrome and the development of neoplasia. An increased cancer risk has also been observed in individuals with isolated hemihyperplasia. We critically review the evidence for tumour surveillance in Beckwith-Wiedemann syndrome and isolated hemihyperplasia and suggest local practice guidelines.

Wilms’ tumor and exposures to residential and occupational hazardous chemicals

This case-control study examines the association between residential and occupational exposures to hazardous chemicals and the risk of Wilms' tumor. The study included 303 cases recruited from six state cancer registries, who were diagnosed between January 1, 1992 and December 31, 1995. A total of 575 controls selected through random digit dialing were frequency matched to the cases. A standard questionnaire was administered to participants during a telephone interview. Parental residential addresses and locations of US Environmental Protection Agency National Priority List (NPL) sites were geocoded and analyzed, along with occupational exposure information. There were no cases of Wilms' tumor found in individuals living within one-half mile distance of a hazardous waste site. However, elevated odds ratios were found for using hairdressing chemicals, motor oil, paint, paint stripper, and pesticides during the pregnancy term and during the 2-year period prior to birth. The findings do not support the hypothesis that Wilms' tumor is associated with residing near an NPL site.

Is there a common aetiology for certain childhood malignancies? Results of cross-space-time clustering analyses

We previously demonstrated significant space-time clustering amongst cases of childhood leukaemia (in particular acute lymphoblastic leukaemia (ALL)), central nervous system (CNS) tumour (especially astrocytoma), soft tissue sarcoma and Wilms' tumour. We hypothesised that there may be common aetiological mechanisms between some of these diagnostic groups. To test this hypothesis we analysed for cross-space-time clustering between these diagnostic groups, using population-based data from north-west England. Data were examined by a second-order procedure based on K-functions. Reference points in time and space were dates and addresses at birth and diagnosis. The results showed statistically significant (P < 0.05) cross-clustering between cases of leukaemia and CNS tumour and between cases of ALL and astrocytoma. There was no statistically significant cross-clustering of Wilms' tumours and soft tissue sarcomas with any other malignancy. In conclusion, these findings are consistent with common, possibly infectious, aetiological mechanisms for childhood leukaemia (particularly ALL) and CNS tumours (particularly astrocytoma).

Risk of Wilms' tumour with multicystic kidney disease: a systematic review

BACKGROUND

Children with multicystic kidney disease (MCKD) are increasingly managed conservatively and are followed up throughout childhood because they are perceived to be at increased risk of developing Wilms' tumour. With this risk still poorly defined and somewhat controversial, the strategy and the duration of follow up do not seem to be based on evidence.

METHODS

Systematic review of the literature for all published cohort studies (prospective and retrospective) of children diagnosed to have unilateral MCKD and managed conservatively.

EXCLUSION CRITERIA

bilateral MCKD, nephrectomy (not for malignancy) during the follow up period. We estimated for children with MCKD the probability of developing Wilms' tumour during the follow up period, with 95% CI using the Poisson distribution.

RESULTS

From 26 reviewed studies, no cases of Wilms' tumour developed in 1041 eligible children. The mean probability of a child with unilateral MCKD to develop Wilms' was therefore nil, with a 97.5% upper CI estimated at 0.0035 (or 3.5 per 1000 children).

CONCLUSION

The development of a national or a European registry for children with MCKD would increase the precision of their risk estimate to develop Wilms' tumour. In the meantime, there is no evidence to support any of the different modalities for following up these children by ultrasound, if indeed such a strategy is necessary.

Epigenotyping as a tool for the prediction of tumor risk and tumor type in patients with Beckwith-Wiedemann syndrome (BWS)

OBJECTIVES

Patients with Beckwith-Wiedemann syndrome (BWS) have a risk of 7.5% to 10% of developing childhood tumors, 60% of which are Wilms' tumors. Aberrant methylation of two distinct clusters of imprinted genes on chromosome 11p15 is detected in approximately 70% of BWS cases. Our aim was to determine associations between the imprinting status of both imprinting clusters (BWSIC1/2) and the tumor incidence and type.

STUDY DESIGN

Methylation patterns of H19 and KCNQ1OT1 were collected in 114 patients with BWS with a clinical diagnosis. The patients were followed until 5 years of age, and tumor incidence and type were registered.

RESULTS

A lower risk of developing childhood tumors was found among patients with a methylation defect limited to BWSIC2 compared with other patients with BWS. No Wilms' tumors were found in this group, whereas in patients with a methylation defect limited to BWSIC1 Wilms' tumor was the most common tumor.

CONCLUSIONS

In addition to clinical factors indicative for a high tumor risk (hemihypertrophy, nephromegaly), methylation patterns discriminate between patients with BWS with a high and low tumor risk. It also is possible to predict whether they are at risk of developing a Wilms' tumor. Epigenotyping of patients is important to select the type of screening protocol to be proposed to these patients.

Wilms tumor screening is unnecessary in Klippel-Trenaunay syndrome

BACKGROUND

Children with hemihypertrophy are screened for Wilms tumor, because this condition is a risk factor for developing the neoplasm. Patients with Klippel-Trenaunay syndrome (KTS) are often considered potential candidates for Wilms tumor, because they have unilateral overgrowth of the lower limb. In our experience, however, an association between KTS and Wilms tumor has not been observed.

METHODS

To determine whether KTS and Wilms tumor are associated, we reviewed our institutional experience for patients with both diagnoses and searched the Klippel-Trenaunay literature for patients with Wilms tumor. The National Wilms Tumor Study Group database also was studied to identify patients with KTS. Two-sided exact binomial tests were used to evaluate whether patients with 1 condition had an increased risk for the other. Ninety-five percent confidence intervals for these 2 risks were compared with the general population risks of Wilms tumor (1 in 10 000) and KTS (1 in 47 313).

RESULTS

None of the 115 patients with KTS followed at our institution developed Wilms tumor. One case of Wilms tumor has been reported in 1363 patients with KTS in the literature, giving a confidence interval of (1/57 377) and (1/267). None of the 8614 patients in the National Wilms Tumor Study Group database had KTS, giving a confidence interval of (0, 1/2336). Because the risks of KTS and Wilms tumor in the population fall within these confidence intervals, one cannot conclude that the risks of KTS among Wilms tumor patients or Wilms tumor among KTS patients are any different from the corresponding risks in the general population.

CONCLUSIONS

Patients with KTS are not at increased risk for developing Wilms tumor and thus should not undergo routine ultrasonographic screening.

Malignancy in patients with sickle cell disease

Malignancy in patients with sickle cell disease (SCD) has been previously reported, but the types of cancer and its incidence remain undefined. With the advent of hydroxyurea therapy, there is concern about increasing the cancer risk for patients with SCD. The International Association of Sickle Cell Nurses and Physician Assistants identified 52 cases of cancer (49 patients) among 16,613 patients with SCD followed at 52 institutions. The median age at malignancy diagnosis was 34 years (range, 14 months-62 years). Twenty-one cases (40%) occurred in pediatric patients, primarily leukemia (n = 7) or Wilms' tumor (n = 5), with 15 children surviving. Most adults had solid tumors, especially carcinomas, and only nine were known to be alive. Three patients received hydroxyurea before the diagnosis of malignancy. These data provide essential baseline information for the accurate interpretation of future reports of malignancy in patients with SCD, especially those receiving hydroxyurea therapy.

Regulation of gene expression by WT1 in development and tumorigenesis

WT1 encodes a zinc finger transcription factor implicated in normal development and tumorigenesis. Germline mutation or deletion of WT1 results in a spectrum of abnormal kidney development, male-to-female intersex disorders, and predisposition to pediatric nephroblastoma, Wilms tumor. Initially thought to encode a transcriptional repressor, WT1-dependent functions are now more clearly linked to its property as a transcriptional activator of genes involved in renal development and sex determination. WT1 is expressed in 4 isoforms as a result of 2 alternative messenger RNA splicing events, the more significant of which encodes the 3 amino acids lysine, threonine, and serine (KTS) between zinc fingers 3 and 4. Although WT1 isoforms lacking KTS act as sequence-specific DNA binding factors, a large body of evidence now implicates the KTS-containing isoforms in RNA processing. In keeping with distinct biochemical mechanisms for these isoforms, genetic data from humans and mice point to separate but partially overlapping roles for WT1 (+KTS) and (-KTS) during genitourinary development. Recently, a hematopoietic model system has been used to study functional properties of WT1 in vitro. WT1 expression in primary hematopoietic cells leads to stage-specific effects that may be relevant to WT1-mediated tumor suppression.

[Risk factors for Wilms' tumor development in children]

INTRODUCTION

Wilms' tumor (WT) is the most frequent embryonic renal neoplasia in children.

OBJECTIVE

This study was carried out to investigate risk factors in the development of WT.

MATERIAL AND METHODS

A design of cases and controls, proactive, of incident cases, with four controls per case. The study population of cases were children of two oncologic reference Center of the Mexican Institute of Social Security (IMSS) in the Mexican Federal District during 5-year period. For the control group, children were frequency matched by age and sex at with cases from the same clinic. A questionnaire, previously validated, was applied to determine risk factors in both groups.

RESULTS

During the period of study, 34 cases and 136 controls were revised. Significant risk factors were: antecedent of a relative with Down syndrome (OR = 7.6, 95%CI 1.4-51.1, p = 0.008), eczema (OR = 3.7, 95%Cl 1.1-12, p = 0.01); having been conceived in autumn (OR = 5.4, 95%CI 1.3-31.6, p = 0.007) or winter (OR = 4.9, 95%Cl 1.1-29.9, p = 0.01), and beet ingestion (OR = S. 7, 95%Cl 1.7-19.4, p = 0.0007).

CONCLUSIONS

In this study, influence of prenatal factors are shown and we attempt to explain the etiology of WT, the important of beet ingestion, and conclusions suggest that that more epidemiologic studies are necessary to determine the chain of events that causes Wilms' tumor.

Does nephroblastomatosis influence the natural history and relapse rate in Wilms' tumour? A single centre experience over 11 years

The presence of multifocal or diffuse nephrogenic rests (NRs) in one or both kidneys is termed nephroblastomatosis (Nbm). Nbm may be a predisposing factor for Wilms' tumour (WT). The aim of this retrospective study was to evaluate the impact of Nbm on the outcome of WT in children. We assessed the outcome of 81 children with Wilms tumours and practical implications of Nbm in the treatment and follow-up. All the pathology slides have been reviewed in 1997. 63 had WT without Nbm (group A) and 18 had WT associated with Nbm (group B). There was no statistical difference between the two groups according to the age at diagnosis and histology. Clinical abnormalities were more frequent in group B (33 versus 8%). There was no statistical difference between the percentage of stage IV in both groups, but bilaterality (stage V) was present only in the group B. Relapse was observed in 20/81 patients (25%): 11 (17%) in group A and 9 (50%) in group B. Mean delay of relapse was longer (25 months) in group B than in group A (10 months). For the whole population, with a median follow-up of 9 years, the event-free survival (EFS) and the overall survival (OS) probabilities were respectively 74%+/-10 and 83%+/-9 at 120 months. The difference in EFS between groups A (82+/-9%) and B (38%+/-29) was significant (P=0.004). The discovery of Nbm in the non-tumoral part of the kidney with WT can be an adverse factor and in particular favours the subsequent development of a new Wilms tumour. It justifies separate follow-up guidelines.

[Perinatal origin of malignant diseases]

In the present days the molecular genetical investigations are the mainstream of establishing the etiology of malignant diseases. Beside these surveys, prenatal, neonatal, environmental and developmental risk factors for malignancy have repeatedly been investigated during the last few years. Mounting evidences show the importance of the intrauterine and perinatal period in tumor genesis and health quality in later life. This review article summarizes the results of traditional epidemiologic studies which identified a number of risk factors for malignancy. These easily detectable anamnestic data, developmental, physical features can further support the prenatal origin of tumors and can give new directions for the modern molecular genetical investigations.

Characteristics and outcome of children with Beckwith-Wiedemann syndrome and Wilms' tumor: a report from the National Wilms Tumor Study Group

PURPOSE

Children with Beckwith-Wiedemann syndrome (BWS) are at increased risk for developing Wilms' tumor (WT). We reviewed the National Wilms Tumor Study Group (NWTSG) records to assess clinical characteristics and outcome of patients with WT and BWS.

METHODS

In the NWTSG, treating clinicians were asked to report, for each enrolled patient, whether the patient had BWS. Between 1980 and 1995, 4,669 patients were treated on two consecutive NWTSG protocols (NWTS 3 and NWTS 4). We retrospectively reviewed the clinical characteristics and treatment outcomes of BWS patients compared with patients with WT without BWS.

RESULTS

Fifty-three children enrolled onto NWTS 3 and 4 were reported to have BWS. BWS patients were more likely to present with lower-stage tumors (P =.0001), with more than half (27 of 53) presenting with stage I disease. The overall treatment outcomes for the BWS patients were nearly identical to those without BWS, with overall survival at 4 years from diagnosis at 89% and 90%, respectively. Overall, 21% of the patients with BWS had bilateral disease, either at diagnosis (nine of 53) or as metachronous contralateral recurrence (two of 53). BWS patients enrolled onto NWTS 4 had smaller tumors than those enrolled onto NWTS 3 (P =.02), a trend not seen in the non-BWS patients.

CONCLUSION

Like children without BWS, children with BWS and WT have an excellent prognosis with modern treatment regimens. There is a high risk of bilateral disease, and increasingly smaller tumors are being detected. This suggests that a national trial assessing the role of ultrasound screening followed by nephron-sparing surgery for some patients may be appropriate.

Multipoint analysis of human chromosome 11p15/mouse distal chromosome 7: inclusion of H19/IGF2 in the minimal WT2 region, gene specificity of H19 silencing in Wilms' tumorigenesis and methylation hyper-dependence of H19 imprinting

WT2 is defined by maternal-specific loss of heterozygosity (LOH) on chromosome 11p15.5 in Wilms' tumors (WTs). The imprinted H19 gene, in this region, is silenced and hypermethylated in most WTs, and this is linked to pathological biallelic expression of IGF2. However, H19 and IGF2 lie within a larger imprinted domain, and the gene specificity of H19 epimutation has been a persistent question. To address this, we assessed LOH, gene expression and DNA methylation at multiple sites in and around the imprinted domain. LOH mapping showed that the entire domain, including IGF2/H19, is within the minimal WT2 region. Genes within the domain, including IPL/TSSC3/BWR1C, IMPT1/ORCTL2/BWR1A/TSSC5, KvLQT1/KCNA9 and TAPA1/CD81, as well as the zinc finger gene ZNF195/ZNFP104 near the centromeric border, were expressed persistently in many WTs. DNA hypermethylation was not detected with 5" upstream probes for IPL, IMPT1, KvLQT1 and ZNF195 in WTs or WT-associated kidneys. Fully developed WTs showed variable hypomethylation at an imprinted CpG island in a KvLQT1 intron, but this was only complete in the cases with LOH and was not observed in pre-neoplastic WT-associated kidneys with H19 epimutation. Analysis of the corresponding region of mouse chromosome 7 using methyltransferase-hypomorphic mice showed that the H19 imprint was fully erased, but that the allelic bias at Ipl, Impt1, p57 Kip2 and, to a lesser extent, Kvlqt1, persisted. Pre-existing massive allelic asymmetry for DNA methylation and hyper-dependence of transcription on methylation status may underlie the mechanism of gene-specific silencing of H19 in Wilms' tumorigenesis.

The influence of parental age on the risk of Wilms' tumour

The Brazilian Wilms' Tumour Study Group carried out a hospital-based multicentre case-control study of potential risk factors for the disease between April 1987 and January 1989. The parents of 109 cases of Wilms' tumour (WT) were interviewed when they were admitted to hospital for diagnosis and treatment. Also interviewed were the parents of two controls per case, matched for age, sex and interviewer, who were admitted to the same or nearby hospitals for treatment of non-neoplastic conditions. Odds ratios adjusted for family income and parental education were calculated by conditional logistic regression. Among cases diagnosed before 25 months of age there was a marked gradient of increasing risk of WT with increasing maternal age at the time of the child's birth. There was no increased risk for cases diagnosed after 25 months of age. The effects of paternal age were less marked. Possible explanations for these results are discussed.

Screening for Wilms tumor in children with Beckwith-Wiedemann syndrome or idiopathic hemihypertrophy

BACKGROUND

Children with Beckwith-Wiedemann syndrome and idiopathic hemihypertrophy (BWS/HH) are at increased risk for developing Wilms tumor and screening with abdominal sonography is frequently recommended. However, there is a paucity of published data supporting this strategy. The purpose of this study was to determine whether sonographic screening at intervals of 4 months or less reduced the proportion of late-stage Wilms Tumor (WT) in children with BWS/HH.

PROCEDURE

A case series analysis was employed to compare the proportion of late-stage (stage III or IV) Wilms tumor in patients with BWS/HH who were screened with sonography (n = 15) to the proportion of late-stage Wilms tumor in unscreened patients with BWS/HH (n = 59). Patients were identified from the BWS Registry and from previously published studies. Screened patients had sonograms at intervals of 4 months or less.

RESULTS

None of the 12 screened children with Wilms tumor had late-stage disease, whereas 25 of 59 (42%) of unscreened children had late-stage Wilms tumor, a difference that was statistically significant (P < 0.003). Three children had false positive screening studies. They were operated on for suspected Wilms tumor but the lesions proved to be complicated renal cysts (n = 2) or nephroblastomatosis (n = 1).

CONCLUSIONS

This study suggests that children with BWS/HH may benefit from screening sonograms at intervals of 4 months or less. However, false positive screening exams may result in unnecessary surgery. Given the rarity of BWS/HH, a larger, prospective international screening study is necessary to determine if the benefits of screening outweigh the risks.

[Nephroblastoma and polycystic dysplastic kidney]

The Authors pass on the case of a nephroblastoma, associated to Wilms Tumorlet and combined nephroblastomatosis, arose on a multicystic dysplastic kidney. They examine the relationships between the nephroblastoma and the kidney malformations, the possibility of malignant degeneration of a multicystic dysplastic kidney and the necessity of the nephrectomy as a prevention of the degeneration. At the moment the statistic data don't justify the nephrectomy a the birth to prevent the arising of a nephroblastoma.

Nephromegaly in infancy and early childhood: a risk factor for Wilms tumor in Beckwith-Wiedemann syndrome

OBJECTIVE

Beckwith-Wiedemann Syndrome (BWS) is an overgrowth syndrome associated with macrosomia, omphalocele, macroglossia, visceromegaly and Wilms tumor (WT). We conducted a case-control study in children with BWS to examine whether nephromegaly increases the risk of WT.

METHODS

The BWS Registry was used to identify control and case patients. Control patients were defined as children with BWS who were older than 6 years and had no imaging evidence of renal disease or previous WT and for whom complete records were available; 31 patients met these criteria. Case patients were defined as children with BWS who had WT and screening renal imaging before the diagnosis of WT; 12 of these patients had serial screening images before diagnosis of WT and comprised the study population. Only renal images obtained before the diagnosis of WT was made were used to assess renal length.

RESULTS

All 12 patients with WT had nephromegaly (> or =95th percentile of age adjusted renal length) on serial screening studies. Only four of 31 control patients (specificity = 86%) had nephromegaly resulting in an odds ratio of 72 (95% confidence interval = 13-391) for the risk of WT with nephromegaly.

CONCLUSIONS

In patients with BWS, persistent nephromegaly is a strong risk factor for the development of WT. If screening for WT is done in this population, infants with nephromegaly should be considered those at greatest risk for WT, and screening may be best targeted at this group.

Childhood cancer and paternal employment in agriculture: the role of pesticides

Previous studies have suggested that the offspring of men potentially exposed to pesticides at work may be at increased risk of kidney cancer (Wilms' tumour), brain tumours, Ewing's bone sarcoma and acute leukaemia. This paper examines the association between potential occupational exposure of fathers to pesticides and offspring's death from cancer in a large national database. Records for 167703 childhood deaths occurring during 1959-63, 1970-78 and 1979-90 in England and Wales have been analysed. Among the offspring of men with potential occupational exposure to pesticides there were 5270 deaths, of which 449 were due to cancer. Associations were assessed using proportional mortality ratios (PMRs), with adjustment for age, year of death and paternal social class. Of the childhood cancers previously linked with potential paternal occupational exposure to pesticides, the only statistically significant excess was for kidney cancer (PMR=1.59, 95% CI=1.18-2.15, based on 42 deaths). Although these results offer some support for the suggestion that paternal occupational exposure to pesticides may be related to the subsequent development of kidney cancer in offspring, other explanations cannot be excluded. In the light of the findings presented here and elsewhere, further, more detailed, research into the nature of this relationship is warranted.

Wilms tumor and multicystic dysplastic kidney disease

PURPOSE

There is ongoing controversy concerning the management of multicystic dysplastic kidney disease, particularly with regard to the potential for malignant transformation. Our report fuels the debate by adding the 2 youngest patients in whom malignancy was present from birth or developed subsequently.

MATERIALS AND METHODS

Two well documented cases of malignancy associated with multicystic dysplastic kidney disease are presented in 2 female infants (5 and 3 months old). The 5-month-old female infant was followed for multicystic dysplastic kidney disease and had no evidence of tumor either antenatally or at birth. The 3-month-old presented with hypertension and interventricular septal defect. A renal tumor was present on initial ultrasound.

RESULTS

Even though malignant degeneration is rare in multicystic dysplastic kidney disease, 9 cases have been reported in the literature so far. Of these cases 3 were Wilms tumor, 5 were renal cell carcinomas and 1 mesothelioma.

CONCLUSIONS

Our 2 cases lend support to the surgical management of multicystic dysplastic kidney disease, particularly as nephrectomy can now be performed in a day surgery setting with minimal morbidity. Only the risks of coexisting malignancy and possible malignant degeneration transformation are specifically addressed in this article. Other complications of multicystic dysplastic kidney disease such as hypertension, infection, abdominal pain, hematuria and persistent dysplastic renal tissue despite ultrasonographic resolution of multicystic dysplastic kidney disease are additional risk factors to be considered. A recommendation for nephrectomy in all cases of multicystic dysplastic kidney disease cannot be based only on these 2 cases. Several other factors must be weighed before making that decision.

Beck-Wiedemann syndrome and Wilms' tumour

Patients with rare overgrowth disorders, such as Beck-Wiedemann syndrome and Simpson-Golabi-Behmel syndrome, are predisposed to embryonal tumours, including Wilms' tumour of the kidney. Therefore, these disorders offer a link between hyperplastic growth and cancer. Genetic lesions at chromosome 11p15 have been associated with Beck-Wiedemann syndrome and Wilms' tumour for several years and the presence of the gene encoding insulin-like growth factor-II (IGF-II) in this region has given rise to much speculation over the involvement of this factor in these growth defects. This speculation was heightened by genetic evidence for the involvement of genomic imprinting in Beck-Wiedemann syndrome and Wilms' tumour, combined with the discovery that the IGF-II gene is imprinted. Although there is a wealth of evidence linking the IGF signalling pathway with overgrowth and cancer, recent progress in the study of 11p15 and developments in our understanding of the mechanism of genomic imprinting indicate that additional imprinted genes located in this region also contribute to these growth disorders.

Birth characteristics and risk of Wilms' tumour: a nationwide prospective study in Norway

Relationships between incidence of Wilms' tumour and information recorded at birth were investigated in a prospective study of the 1,489,297 children born in Norway between 1967 and 1992. A total of 119 individuals were diagnosed with Wilms' tumour in the age interval 0-14 years. A high length at birth was significantly associated with a high risk (incidence rate ratio 1.8 for length > or = 53 cm vs < or = 49 cm, 95% CI 1.0-3.2). A low Apgar score at 1 min was also associated with an increased risk (incidence rate ratio 2.2 for Apgar score < or = 8 vs a score > or = 9, 95% CI 1.2-3.9). For all variables for which an association was indicated, the association seemed to be restricted mainly to children aged less than 2 years. This suggests that Wilms' tumour diagnosed early in life may differ aetiologically from that of cases diagnosed later.

Vitamin K and childhood cancer: a population based case-control study in Lower Saxony, Germany

OBJECTIVE

To confirm or refute a possible association of parenteral vitamin K prophylaxis and childhood cancer.

DESIGN

Population based case-control study. Comparison of vitamin K exposure in children with leukaemia or other common tumours with two control groups.

SETTING

State of Lower Saxony (north western part of Germany); case recruitment from the German childhood cancer registry.

SUBJECTS

272 children with leukaemia, nephroblastoma, neuroblastoma, rhabdomyosarcoma, and tumours of the central nervous system diagnosed between 1 July 1988 and 30 June 1993; children were aged between 30 days and 15 years at diagnosis. 334 population based controls without diagnoses of cancer matched to the leukaemia cases for age and sex.

MAIN EXPOSURE MEASURES

Parenteral vitamin K prophylaxis (intramuscular and subcutaneous) versus oral and no vitamin K prophylaxis.

RESULTS

An association between parenteral vitamin K exposure and childhood cancer (leukaemias and other tumours combined) could not be confirmed (odds ratio 1.04, 95% confidence interval 0.74 to 1.48). For leukaemias the observed odds ratio was only 0.98 (0.64 to 1.50) (comparison of leukaemia cases with local controls 1.24 (0.68 to 2.25); state controls 0.82 (0.50 to 1.36)). These odds ratios remained almost unchanged when several potential confounders were considered in the logistic regression model.

CONCLUSIONS

This population based study adds substantial evidence that there is no association between parenteral vitamin K and childhood cancer.

Immunohistochemical detection of p53 in Wilms' tumors correlates with unfavorable outcome

The role of p53 in the pathogenesis and progression of Wilms' tumors is only partly understood. Although p53 mutations were initially reported only in anaplastic Wilms' tumors, we had reported that, of two of twenty-one cases that had a p53 mutation, one tumor showed no evidence of anaplasia. To determine the significance of p53 expression in all clinical stages of Wilms' tumor, twenty-eight cases were analyzed for p53 immunoreactivity. Paraffin sections were immunolabeled with two different monoclonal antibodies, recognizing both mutant and wild-type p53. Fifteen of sixteen tumors in the recurrent/metastatic group and three of twelve tumors in the nonmetastatic/nonrecurrent group showed p53 immunopositivity. Only one of three positive tumors in the latter group showed moderate to strong positivity, whereas twelve of sixteen metastatic/recurrent tumors revealed a similar degree of p53 positivity. The positivity was stronger in the metastasis/recurrences as compared with the corresponding primary tumor. Western blot analysis revealed p53 expression in all of the Wilms' tumors tested, suggesting its involvement in the development of Wilms' tumors. Single-strand conformation polymorphism analysis performed on twenty-three of these tumors revealed p53 mutations in four of fourteen recurrent/metastatic tumors and none in the nonmetastatic/nonrecurrent group. Our results show that, whereas 60% of cases were immunopositive for p53 protein, mutations were detected in only 16% of tumors, indicating that wild-type p53 protein is retained in the other tumors. We conclude that p53 immunopositivity strongly correlates with recurrence/metastasis in Wilms' tumors. Furthermore, the accumulation of p53 in these tumors is not only due to mutations but may also involve stabilization of normal p53 with other proteins.

Somatic overgrowth associated with overexpression of insulin-like growth factor II

Overexpression of the normally imprinted fetal insulin-like growth factor II (IGF2) has been implicated in the pathogenesis of the cancer-predisposing Beckwith-Wiedemann syndrome (BWS). We have detected constitutional relaxation of imprinting of IGF2 in four children with somatic overgrowth who do not show diagnostic features of BWS. Three children showed constitutional abnormalities of H19 methylation. All four children showed nephromegaly and two developed Wilms' tumors. Gene methylation is known to be associated with gene silencing, and three children showed constitutional abnormalities of H19 gene methylation. Disruption of H19 methylation, and concomitant relaxation of IGF2 imprinting, provides another mechanism that can increase IGF2 expression in children with overgrowth. The accumulated data on normal and pathologic IGF2 expression are now sufficient to define an entity, "IGF2 overgrowth disorder," of which BWS may be one extreme manifestation. These findings have broad implications for the characterization of idiopathic overgrowth.