0000000000808600
AUTHOR
Peter F. Ambros
A multilocus technique for risk evaluation of patients with neuroblastoma.
Abstract Purpose: Precise and comprehensive analysis of neuroblastoma genetics is essential for accurate risk evaluation and only pangenomic/multilocus approaches fulfill the present-day requirements. We present the establishment and validation of the PCR-based multiplex ligation-dependent probe amplification (MLPA) technique for neuroblastoma. Experimental Design: A neuroblastoma-specific MLPA kit was designed by the SIOP Europe Neuroblastoma Biology Committee in cooperation with MRC-Holland. The contained target sequences cover 19 chromosomal arms and reference loci. Validation was performed by single locus and pangenomic techniques (n = 174). Dilution experiments for determination of min…
Genomic Amplifications and Distal 6q Loss: Novel Markers for Poor Survival in High-risk Neuroblastoma Patients.
Abstract Background Neuroblastoma is characterized by substantial clinical heterogeneity. Despite intensive treatment, the survival rates of high-risk neuroblastoma patients are still disappointingly low. Somatic chromosomal copy number aberrations have been shown to be associated with patient outcome, particularly in low- and intermediate-risk neuroblastoma patients. To improve outcome prediction in high-risk neuroblastoma, we aimed to design a prognostic classification method based on copy number aberrations. Methods In an international collaboration, normalized high-resolution DNA copy number data (arrayCGH and SNP arrays) from 556 high-risk neuroblastomas obtained at diagnosis were coll…
Comparative genetic study of intratumoral heterogenous MYCN amplified neuroblastoma versus aggressive genetic profile neuroblastic tumors.
Intratumoral heterogeneous MYCN amplification (hetMNA) is an unusual event in neuroblastoma with unascertained biological and clinical implications. Diagnosis is based on the detection of MYCN amplification surrounded by non-amplified tumor cells by fluorescence in situ hybridization (FISH). To better define the genetic features of hetMNA tumors, we studied the Spanish cohort of neuroblastic tumors by FISH and single nucleotide polymorphism arrays. We compared hetMNA tumors with homogeneous MNA (homMNA) and nonMNA tumors with 11q deletion (nonMNA w11q-). Of 1091 primary tumors, 28 were hetMNA by FISH. Intratumoral heterogeneity of 1p, 2p, 11q and 17q was closely associated with hetMNA tumor…
Age Dependency of the Prognostic Impact of Tumor Genomics in Localized Resectable MYCN-Nonamplified Neuroblastomas. Report From the SIOPEN Biology Group on the LNESG Trials and a COG Validation Group
Purpose: For localized, resectable neuroblastoma without MYCN amplification, surgery only is recommended even if incomplete. However, it is not known whether the genomic background of these tumors may influence outcome. Patients and methods: Diagnostic samples were obtained from 317 tumors, International Neuroblastoma Staging System stages 1/2A/2B, from 3 cohorts: Localized Neuroblastoma European Study Group I/II and Children's Oncology Group. Genomic data were analyzed using multi- and pangenomic techniques and fluorescence in-situ hybridization in 2 age groups (cutoff age, 18 months) and were quality controlled by the International Society of Pediatric Oncology European Neuroblastoma (SIO…
Segmental chromosomal alterations lead to a higher risk of relapse in infants with MYCN-non-amplified localised unresectable/disseminated neuroblastoma (a SIOPEN collaborative study)
BACKGROUND: In neuroblastoma (NB), the presence of segmental chromosome alterations (SCAs) is associated with a higher risk of relapse. METHODS: In order to analyse the role of SCAs in infants with localised unresectable/disseminated NB without MYCN amplification, we have performed an array CGH analysis of tumours from infants enrolled in the prospective European INES trials. RESULTS: Tumour samples from 218 out of 300 enroled patients could be analysed. Segmental chromosome alterations were observed in 11%, 20% and 59% of infants enroled in trials INES99.1 (localised unresectable NB), INES99.2 (stage 4s) and INES99.3 (stage 4) (P<0.0001). Progression-free survival was poorer in patients wh…
Abstract 495: Amplification of chromosomal regions 12q13-14 and 12q15 defines a distinct subgroup of high-risk neuroblastoma patients and is associated with atypical clinical features
Abstract Neuroblastoma is a pediatric cancer of the sympathetic nervous system with wide heterogeneity regarding clinobiological subtypes, ranging from patients with tumors of spontaneous regression to patients with aggressive tumors with fatal outcome despite multimodal treatment. MYCN-amplification and 11q-deletion are important, although incomplete, markers of high-risk neuroblastoma. Thus, characterization of additional genomic alterations that can be used as prognostic and/or predictive markers is of clinical importance in order to provide best possible treatment. From genomic profiles generated through high-density SNP microarrays we identified a group of neuroblastomas (14 primary tu…
Segmental chromosomal alterations have prognostic impact in neuroblastoma: a report from the INRG project
Background: In the INRG dataset, the hypothesis that any segmental chromosomal alteration might be of prognostic impact in neuroblastoma without MYCN amplification (MNA) was tested. Methods: The presence of any segmental chromosomal alteration (chromosome 1p deletion, 11q deletion and/or chromosome 17q gain) defined a segmental genomic profile. Only tumours with a confirmed unaltered status for all three chromosome arms were considered as having no segmental chromosomal alterations. Results: Among the 8800 patients in the INRG database, a genomic type could be attributed for 505 patients without MNA: 397 cases had a segmental genomic type, whereas 108 cases had an absence of any segmental a…
Changes over three decades in outcome and the prognostic influence of age-at-diagnosis in young patients with neuroblastoma: a report from the International Neuroblastoma Risk Group Project.
Abstract Purpose Increasing age has been an adverse risk factor in children with neuroblastoma (NB) since the 1970’s, with a 12-month age-at-diagnosis cut-off for treatment stratification. Over the last 30 years, treatment intensity for children >12 months with advanced-stage disease has increased; to investigate if this strategy has improved outcome and/or reduced the prognostic influence of age, we analysed the International Neuroblastoma Risk Group (INRG) database. Patients and methods Data from 11,037 children with NB (1974–2002) from Australia, Europe, Japan, North America. Cox modelling of event-free survival (EFS) tested if the era and prognostic significance of age-of-diagnosis, adj…
High frequency of subclonal ALK mutations in high risk neuroblastoma patients. A SIOPEN study
Introduction: In neuroblastoma (NB), activating ALK receptor tyrosine kinase point mutations are detected in 8–10% at diagnosis using conventional sequencing. To determine the potential occurrence and the prognostic impact of ALK mutations in a series of high risk NB patients we studied ALK variation frequencies using targeted deep sequencing in samples of patients enrolled in the SIOPEN HR-NBL01 study
Predicting outcomes for children with neuroblastoma using a multigene-expression signature: a retrospective SIOPEN/COG/GPOH study
Summary 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, s…
Abstract 2435: Amplification of CDK4 and MDM2 is associated with atypical clinical features in high risk neuroblastoma patients
Abstract MYCN-amplification and 11q-deletion are important, although incomplete, markers of high-risk neuroblastoma. Thus, characterization of additional genomic alterations that can be used as prognostic and/or predictive markers is of clinical importance in order to provide best treatment possible. By using SNP-microarrays we identified a small group of neuroblastomas with high grade amplification of one or multiple loci on 12q, commonly involving the potential oncogenic target genes CKD4 (12q13-14) and/or MDM2 (12q15). The CDK4 and MDM2 regions were co-amplified in 13/16 samples, two tumors had CDK4-amplification in absence of MDM2-amplification while one tumor had MDM2-amplification wit…
Influence of segmental chromosome abnormalities on survival in children over the age of 12 months with unresectable localised peripheral neuroblastic tumours without MYCN amplification
Background: The prognostic impact of segmental chromosome alterations (SCAs) in children older than 1 year, diagnosed with localised unresectable neuroblastoma (NB) without MYCN amplification enrolled in the European Unresectable Neuroblastoma (EUNB) protocol is still to be clarified, while, for other group of patients, the presence of SCAs is associated with poor prognosis. Methods: To understand the role of SCAs we performed multilocus/pangenomic analysis of 98 tumour samples from patients enrolled in the EUNB protocol. Results: Age at diagnosis was categorised into two groups using 18 months as the age cutoff. Significant difference in the presence of SCAs was seen in tumours of patients…
The genetic tumor background is an important determinant for heterogeneous MYCN ‐amplified neuroblastoma
Amplification of MYCN is the signature genetic aberration of 20–25% of neuroblastoma and a stratifying marker associated with aggressive tumor behavior. The detection of heterogeneous MYCN amplification (hetMNA) poses a diagnostic dilemma due to the uncertainty of its relevance to tumor behavior. Here, we aimed to shed light on the genomic background which permits hetMNA in neuroblastoma and tied the occurrence to other stratifying markers and disease outcome. We performed SNP analysis using Affymetrix Cytoscan HD arrays on 63 samples including constitutional DNA, tumor, bone marrow and relapse samples of 26 patients with confirmed hetMNA by MYCN‐FISH. Tumors of patients ≤18m were mostly an…
Frequency and prognostic impact of ALK amplifications and mutations in the European Neuroblastoma Study Group (SIOPEN) high-risk neuroblastoma trial (HR-NBL1)
Purpose: In neuroblastoma (NB), the ALK receptor tyrosine kinase can be constitutively activated through activating point mutations or genomic amplification. We studied ALK genetic alterations in high-risk (HR) patients on the HR-NBL1/SIOPEN trial to determine their frequency, correlation with clinical parameters, and prognostic impact. Materials and methods: Diagnostic tumor samples were available from 1,092 HR-NBL1/SIOPEN patients to determine ALK amplification status (n = 330), ALK mutational profile (n = 191), or both (n = 571). Results: Genomic ALK amplification (ALKa) was detected in 4.5% of cases (41 out of 901), all except one with MYCN amplification (MNA). ALKa was associated with …