A genome-wide association study identifies susceptibility loci for Wilms tumor.

Wilms tumor is the most common renal malignancy of childhood. To identify common variants that confer susceptibility to Wilms tumor, we conducted a genome-wide association study in 757 individuals with Wilms tumor (cases) and 1,879 controls. We evaluated ten SNPs in regions significantly associated at P < 5 × 10(-5) in two independent replication series from the UK (769 cases and 2,814 controls) and the United States (719 cases and 1,037 controls). We identified clear significant associations at 2p24 (rs3755132, P = 1.03 × 10(-14); rs807624, P = 1.32 × 10(-14)) and 11q14 (rs790356, P = 4.25 × 10(-15)). Both regions contain genes that are plausibly related to Wilms tumorigenesis. We also identified candidate association signals at 5q14, 22q12 and Xp22.

Stratification of Wilms tumor by genetic and epigenetic analysis.

Somatic defects at five loci, WT1, CTNNB1, WTX, TP53 and the imprinted 11p15 region, are implicated in Wilms tumor, the commonest childhood kidney cancer. In this study we analysed all five loci in 120 Wilms tumors. We identified epigenetic 11p15 abnormalities in 69% of tumors, 37% were H19 epimutations and 32% were paternal uniparental disomy (pUPD). We identified mutations of WTX in 32%, CTNNB1 in 15%, WT1 in 12% and TP53 in 5% of tumors. We identified several significant associations: between 11p15 and WTX (P=0.007), between WT1 and CTNNB1 (P less than 0.001), between WT1 and pUPD 11p15 (P=0.01), and a strong negative association between WT1 and H19 epimutation (P less than 0.001). We next used these data to stratify Wilms tumor into three molecular Groups, based on the status at 11p15 and WT1. Group 1 tumors (63%) were defined as 11p15-mutant and WT1-normal; a third also had WTX mutations. Group 2 tumors (13%) were WT1-mutant. They either had 11p15 pUPD or were 11p15-normal. Almost all had CTNNB1 mutations but none had H19 epimutation. Group 3 tumors (25%) were defined as 11p15-normal and WT1-normal and were typically normal at all five loci (P less than 0.001). We also identified a novel clinical association between H19 epimutation and bilateral disease (P less than 0.001). These data provide new insights into the pattern, order, interactions and clinical associations of molecular events in Wilms tumor.

Dose finding study for the use of subcutaneous recombinant interleukin-2 to augment natural killer cell numbers in an outpatient setting for stage 4 neuroblastoma after megatherapy and autologous stem-cell reinfusion.

PURPOSE: To establish a safe dose of subcutaneous (SC) recombinant interleukin 2 (rIL-2) in an outpatient setting for children with stage 4 neuroblastoma after megatherapy (MGT) and autologous stem-cell reinfusion (ASCR) that is able to sustain an increase of natural-killer cells (NKCs) above the level previously reported for immunomodulatory potency. PATIENTS AND METHODS: Between August 1997 and November 2000, 33 patients with stage 4 neuroblastoma entered the study from six countries after receiving MGT/ASCR according to national protocols. Dose levels of 3, 6, and 9 × 10(6) U rIL-2/m(2) were given SC in six 5-day cycles every 2 weeks. RESULTS: Median age at registration was 4.1 years (range, 1.8 to 7.4). Median observation time was 5 years (range, 4 to 9.8). Increase of NKCs was achieved in 89% of courses, with more than 100% increase over baseline and/or more than 1,000 NKCs/µL in 58%. On the basis of outpatient dose-limiting toxicity at dose level 3, dose level 2 was chosen for the confirmation stage. At dose level 2, the median increase in absolute NKCs was 1,180 cells/µL for all 83 cycles, corresponding to a median relative NKC increase over baseline of 711%. Fever was frequent but controllable with adequate supportive care; 6.5% of patients were hospitalized. Localized pain was moderate and acceptable. Event-free and overall survival rates at 5 years were 45% (± 9 standard deviation [SD]) and 48% (± 9 SD), respectively. CONCLUSION: The low toxicity profile and ability to sustain an increase in NKCs of IL-2 at 6 × 10(6) U/m(2) SC allows its integration in an outpatient setting.

Immunotherapy for neuroblastoma: turning promise into reality.

Neuroblastoma is one of the commonest and most aggressive paediatric malignancies. The majority of children present with metastatic disease for which long-term survival remains poor despite intensive multi-modal therapies. Toxicity from current treatment regimes is already significant, and there is little room to further intensify therapy. Alternative treatment strategies are therefore needed in order to improve survival. Immunotherapy is an attractive therapeutic option for these children as it potentially offers a much more specific and less toxic treatment than conventional therapies. This review discusses the different immunotherapy strategies that may be useful in neuroblastoma, their advantages and disadvantages and the challenges that need to be overcome to successfully use them clinically.

Predicting outcomes for children with neuroblastoma using a multigene-expression signature: a retrospective SIOPEN/COG/GPOH study.

BACKGROUND: More accurate prognostic assessment of patients with neuroblastoma is required to better inform the choice of risk-related therapy. The aim of this study is to develop and validate a gene-expression signature to improve outcome prediction. METHODS: 59 genes were selected using an innovative data-mining strategy, and were profiled in the largest neuroblastoma patient series (n=579) to date using real-time quantitative PCR starting from only 20 ng of RNA. A multigene-expression signature was built using 30 training samples, tested on 313 test samples, and subsequently validated in a blind study on an independent set of 236 tumours. FINDINGS: The signature has a performance, sensitivity, and specificity of 85.4% (95% CI 77.7-93.2), 84.4% (66.5-94.1), and 86.5% (81.1-90.6), respectively, to predict patient outcome. Multivariate analysis indicates that the signature is a significant independent predictor of overall survival and progression-free survival after controlling for currently used risk factors: patients with high molecular risk have a higher risk of death from disease and higher risk of relapse or progression than patients with low molecular risk (odds ratio 19.32 [95% CI 6.50-57.43] and 3.96 [1.97-7.97] for overall survival and progression-free survival, respectively, both p<0.0001). Patients at an increased risk of an adverse outcome can also be identified in the current treatment groups, showing the potential of this signature for improved clinical management. These results were confirmed in the validation study, in which the signature was also independently statistically significant in a model adjusted for MYCN status, age, International Neuroblastoma Staging System stage, ploidy, International Neuroblastoma Pathology Classification grade of differentiation, and mitosis karyorrhexis index (odds ratios between 4.81 and 10.53 depending on the model for overall survival and 3.68 [95% CI 2.01-6.71] for progression-free survival). INTERPRETATION: The 59-gene expression signature is an accurate predictor of outcome in patients with neuroblastoma. The signature is an independent risk predictor, identifying patients with an increased risk of poor outcome in the current clinical-risk groups. The method and signature is suitable for routine laboratory testing, and should be evaluated in prospective studies. FUNDING: The Belgian Foundation Against Cancer, the Children Cancer Fund Ghent, the Belgian Society of Paediatric Haematology and Oncology, the Belgian Kid's Fund and the Fondation Nuovo-Soldati (JV), the Fund for Scientific Research Flanders (KDP, JH), the Fund for Scientific Research Flanders, the Institute for the Promotion of Innovation by Science and Technology in Flanders, Strategisch basisonderzoek, the Fondation Fournier Majoie pour l'Innovation, the Instituto Carlos III, the Italian Neuroblastoma Foundation, the European Community under the FP6, and the Belgian programme of Interuniversity Poles of Attraction.

Massive ovarian oedema: an unusual abdominal mass in infancy.

We describe a 13-month-old female who presented with vaginal bleeding, breast and pubic hair development and an abdominal mass. She underwent emergency laparotomy and left-sided salpingoophorectomy. Histological examination of the resected ovary revealed massive ovarian oedema, a rare non-neoplastic enlargement of the ovary. Consideration of this diagnosis in patients with an abdominal mass and endocrine disturbance may allow conservative surgery and preservation of fertility.

Constitutional 11p15 abnormalities, including heritable imprinting center mutations, cause nonsyndromic Wilms tumor.

Constitutional abnormalities at the imprinted 11p15 growth regulatory region cause syndromes characterized by disordered growth, some of which include a risk of Wilms tumor. We explored their possible contribution to nonsyndromic Wilms tumor and identified constitutional 11p15 abnormalities in genomic lymphocyte DNA from 13 of 437 individuals (3%) with sporadic Wilms tumor without features of growth disorders, including 12% of bilateral cases (P = 0.001) and in one familial Wilms tumor pedigree. No abnormality was detected in 220 controls (P = 0.006). Abnormalities identified included H19 DMR epimutations, uniparental disomy 11p15 and H19 DMR imprinting center mutations (one microinsertion and one microdeletion), thus identifying microinsertion as a new class of imprinting center mutation. Our data identify constitutional 11p15 defects as one of the most common known causes of Wilms tumor, provide mechanistic insights into imprinting disruption and reveal clinically important epigenotype-phenotype associations. The impact on clinical management dictates that constitutional 11p15 analysis should be considered in all individuals with Wilms tumor.

Primary multifocal osseous Hodgkin's lymphoma.

BACKGROUND: Hodgkin's disease (HD) most commonly presents with progressive painless enlargement of peripheral lymph nodes, especially around the cervical region. A few children have systemic symptoms and weight loss. At the time of diagnosis, osseous involvement is uncommon CASE PRESENTATION: A case is described of Primary Multifocal Osseous Hodgkin's Lymphoma in a seven-year-old boy. He presented with a painful swelling in the sternum, and further investigations revealed deposits in his L1 vertebra, the left sacro-iliac joint and the right acetabulum. CONCLUSION: The clinical, radiological and histological features of this disease can mimic other medical conditions, including Tuberculosis, making the diagnosis difficult and often leading to delays in treatment. This is a very rare condition and we believe this to be the youngest reported case in the literature.

Spectrum and significance of variants and mutations in the Fanconi anaemia group G gene in children with sporadic acute myeloid leukaemia.

Childhood acute myeloid leukaemia (AML) is uncommon. Children with Fanconi anaemia (FA), however, have a very high risk of developing AML. FA is a rare inherited disease caused by mutations in at least 12 genes, of which Fanconi anaemia group G gene (FANCG) is one of the commonest. To address to what extent FANCG variants contribute to sporadic childhood AML, we determined the spectrum of FANCG sequence variants in 107 children diagnosed with sporadic AML, using polymerase chain reaction (PCR), fluorescent single-strand conformational polymorphism (SSCP) and sequencing methodologies. The significance of variants was determined by frequency analysis and assessment of evolutionary conservation. Seven children (6.5%) carried variants in FANCG. Two of these carried two variants, including the known IVS2 + 1G>A mutation with the novel missense mutation S588F, and R513Q with the intronic deletion IVS12-38 (-28)_del11, implying that these patients might have been undiagnosed FA patients. R513Q, which affects a semi-conserved amino acid, was carried in two additional children with AML. Although not significant, the frequency of R513Q was higher in children with AML than unselected cord bloods. While FANCG mutation carrier status does not predispose to sporadic AML, the identification of unrecognised FA patients implies that FA presenting with primary AML in childhood is more common than suspected.

Lysophosphatidic acid attenuates the cytotoxic effects and degree of peroxisome proliferator-activated receptor gamma activation induced by 15-deoxyDelta12,14-prostaglandin J2 in neuroblastoma cells.

PPARgamma (peroxisome proliferator-activated receptor gamma) is a ligand-activated transcription factor that responds to 15dPGJ2 (15-deoxy-Delta12,14-prostglandin J2). 15dPGJ2, in vitro, halts neuroblastoma cell growth, but reported mechanisms vary. Here we evaluated the modulatory effects of endogenous serum lipid mitogens upon the extent of 15dPGJ2-induced growth inhibition and on the precise cellular responses of neuroblastoma cells to PPARgamma activation. We show that 15dPGJ2 specifically inhibited cell growth in both complete and delipidated media. 15dPGJ2-induced growth inhibition was accompanied by decreased cell viability, although the effect was far more marked in delipidated medium than in complete medium. Incubation with 15dPGJ2 in complete medium resulted in cytoplasmic changes characteristic of type II programmed cell death (autophagy), while prior serum lipid removal resulted in cell death via an apoptotic mechanism. These distinct, serum lipid-dependent cellular responses to 15dPGJ2 were accompanied by increases in the expression of a reporter gene construct containing a PPAR response element of 2.3-fold in complete medium, but of 4.8-fold in delipidated medium. Restoration of the serum lysolipid LPA (lysophosphatidic acid) to cells in delipidated medium reduced 15dPGJ2-mediated PPARgamma activation, growth inhibition and cell death; following addition of S1P (sphingosine 1-phosphate), decreases were apparent but more marginal. Further, while the effects of LPA in delipidated medium were mediated through a G(i)/phosphoinositide 3-kinase/MAPK (mitogen-activated protein kinase) pathway, those of S1P did not involve the MAPK component. These data suggest that the serum lysolipid LPA modulates the degree of PPARgamma activation and the precise cellular response to 15dPGJ2 via activation of a G(i)/phosphoinositide 3-kinase/MAPK pathway.