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Sökning: WFRF:(Ambros P. F.)

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1.
  • Ambros, I. M., et al. (författare)
  • 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
  • 2020
  • Ingår i: Journal of Clinical Oncology. - : American Society of Clinical Oncology (ASCO). - 0732-183X .- 1527-7755. ; 38:31
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSEFor 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 METHODSDiagnostic 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 (SIOPEN) Biology Group.RESULTSPatients with stage 1 tumors had an excellent outcome (5-year event-free survival [EFS] standard deviation [SD], 95% +/- 2%; 5-year overall survival [OS], 99% +/- 1%). In contrast, patients with stage 2 tumors had a reduced EFS in both age groups (5-year EFS +/- SD, 84% +/- 3% in patients < 18 months of age and 75% 7% in patients >= 18 months of age). However, OS was significantly decreased only in the latter group (5-year OS +/- SD in < 18months and 18months, 96% +/- 2% and 81% +/- 7%, respectively; P = .001). In < 18months, relapses occurred independent of segmental chromosome aberrations (SCAs); only 1p loss decreased EFS (5-year EFS SD in patients 1p loss and no 1p loss, 62% +/- 13% and 87% +/- 3%, respectively; P = .019) but not OS (5-year OS +/- SD, 92% +/- 8% and 97% +/- 2%, respectively). In patients >= 18 months, only SCAs led to relapse and death, with 11q loss as the strongest marker (11q loss and no 11q loss: 5-year EFS +/- SD, 48% +/- 16% and 85% +/- 7%, P = .033; 5-year OS +/- SD, 46% +/- 22% and 92% +/- 6%, P = .038).CONCLUSIONGenomic aberrations of resectable non-MYCN-amplified stage 2 neuroblastomas have a distinct age-dependent prognostic impact. Chromosome 1p loss is a risk factor for relapse but not for diminished OS in patients < 18 months, SCAs (especially 11q loss) are risk factors for reduced EFS and OS in those > 18months. In older patients with SCA, a randomized trial of postoperative chemotherapy compared with observation alone may be indicated.
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2.
  • Defferrari, R., et al. (författare)
  • Influence of segmental chromosome abnormalities on survival in children over the age of 12 months with unresectable localised peripheral neuroblastic tumours without MYCN amplification
  • 2015
  • Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 112:2, s. 290-295
  • Tidskriftsartikel (refereegranskat)abstract
    • 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 between 12 and 18 months and over 18 months of age at diagnosis, respectively (P = 0.04). A significant correlation (P = 0.03) was observed between number of SCAs per tumour and age. Event-free (EFS) and overall survival (OS) were calculated in both age groups, according to both the presence and number of SCAs. In older patients, a poorer survival was associated with the presence of SCAs (EFS = 46% vs 75%, P = 0.023; OS = 66.8% vs 100%, P = 0.003). Moreover, OS of older patients inversely correlated with number of SCAs (P = 0.002). Finally, SCAs provided additional prognostic information beyond histoprognosis, as their presence was associated with poorer OS in patients over 18 months with unfavourable International Neuroblastoma Pathology Classification (INPC) histopathology (P = 0.018). Conclusions: The presence of SCAs is a negative prognostic marker that impairs outcome of patients over the age of 18 months with localised unresectable NB without MYCN amplification, especially when more than one SCA is present. Moreover, in older patients with unfavourable INPC tumour histoprognosis, the presence of SCAs significantly affects OS.
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3.
  • Martinez-Monleon, Angela, et al. (författare)
  • Amplification of CDK4 and MDM2: a detailed study of a high-risk neuroblastoma subgroup
  • 2022
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12:1
  • Tidskriftsartikel (refereegranskat)abstract
    • In neuroblastoma, MYCN amplification and 11q-deletion are important, although incomplete, markers of high-risk disease. It is therefore relevant to characterize additional alterations that can function as prognostic and/or predictive markers. Using SNP-microarrays, a group of neuroblastoma patients showing amplification of one or multiple 12q loci was identified. Two loci containing CDK4 and MDM2 were commonly co-amplified, although amplification of either locus in the absence of the other was observed. Pharmacological inhibition of CDK4/6 with ribociclib or abemaciclib decreased proliferation in a broad set of neuroblastoma cell lines, including CDK4/MDM2-amplified, whereas MDM2 inhibition by Nutlin-3a was only effective in p53(wild-type) cells. Combined CDK4/MDM2 targeting had an additive effect in p53(wild-type) cell lines, while no or negative additive effect was observed in p53(mutated) cells. Most 12q-amplified primary tumors were of abdominal origin, including those of intrarenal origin initially suspected of being Wilms' tumor. An atypical metastatic pattern was also observed with low degree of bone marrow involvement, favoring other sites such as the lungs. Here we present detailed biological data of an aggressive neuroblastoma subgroup hallmarked by 12q amplification and atypical clinical presentation for which our in vitro studies indicate that CDK4 and/or MDM2 inhibition also could be beneficial.
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4.
  • Berbegall, A. P., et al. (författare)
  • Comparative genetic study of intratumoral heterogenous MYCN amplified neuroblastoma versus aggressive genetic profile neuroblastic tumors
  • 2016
  • Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 35:11, s. 1423-1432
  • Tidskriftsartikel (refereegranskat)abstract
    • 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 tumors when analyzing different pieces for each case. For chromosome 2, 16 cases showed 2p intact, 4 focal gain at 2p24.3 and 8 MNA. The lengths of the smallest regions of overlap (SROs) for 2p gains and 1p deletions were between the SRO lengths observed in homMNA and nonMNA w11q- tumors. Co-occurrence of 11q- and +17q was frequently found with the largest SROs for both aberrations. The evidence for and frequency of different genetic subpopulations representing a hallmark of the hetMNA subgroup of NB indicates, on one hand, the presence of a considerable genetic instability with different SRO of either gains and losses compared with those of the other NB groups and highlights and, on the other hand, the need for multiple sampling from distant and macroscopically and microscopically distinct tumor areas. Narrowing down the different SRO for both deletions and gains in NB groups would be crucial to pinpointing the candidate gene(s) and the critical gene dosage with prognostic and therapeutic significance. This complexity of segmental chromosomal aberration patterns reinforces the necessity for a larger cohort study using FISH and pangenomic techniques to develop a suitable therapeutic strategy for these patients.
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5.
  • Bogen, D., et al. (författare)
  • The genetic tumor background is an important determinant for heterogeneous MYCN-amplified neuroblastoma
  • 2016
  • Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 139:1, s. 153-163
  • Tidskriftsartikel (refereegranskat)abstract
    • 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 aneuploid with numeric chromosomal aberrations (NCAs), presented a prominent MNA subclone and carried none or a few segmental chromosomal aberrations (SCAs). In older patients, tumors were mostly di- or tetraploid, contained a lower number of MNA cells and displayed a multitude of SCAs including concomitant 11q deletions. These patients often suffered disease progression, tumor dissemination and relapse. Restricted to aneuploid tumors, we detected chromosomes with uniparental di- or trisomy (UPD/UPT) in almost every sample. UPD11 was exclusive to tumors of younger patients whereas older patients featured UPD14. In this study, the MNA subclone appears to be constraint by the tumor environment and thus less relevant for tumor behavior in aggressive tumors with a high genomic instability and many segmental aberrations. A more benign tumor background and lower tumor stage may favor an outgrowth of the MNA clone but tumors generally responded better to treatment. What's new?MYCN amplification (MNA) in neuroblastoma (NB) generally associates with an aggressive tumor behavior and detection of MNA leads to an automatic upstaging of the tumor in non-stage 1 tumors. But what if only a fraction of the tumor cells is MYCN-amplified? To investigate the diagnostic importance of heterogeneous MNA, the authors conducted a genetic analysis of samples from 26 NB patients with a particular focus on accompanying genetic aberrations. They concluded that tumor behavior is largely dependent on patient age and other chromosomal alterations in the genetic tumor background rather than the mere presence of the MNA clone.
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9.
  • Ejeskär, Katarina, 1969, et al. (författare)
  • Fine mapping of a tumour suppressor candidate gene region in 1p36.2-3, commonly deleted in neuroblastomas and germ cell tumours.
  • 2001
  • Ingår i: Medical and pediatric oncology. - 0098-1532 .- 1096-911X. ; 36:1, s. 61-6
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: A common genetic feature of neuroblastomas, which is also an important prognostic factor, is deletion of chromosome region 1p. The deletion of 1p often involves a deletion of varying size, with a consensus region within the most distal bands 1p36.2-3. The neuroblastoma SRO (shortest region of overlap of (deletions) presented earlier by our group was defined distally by the cluster of loci D1S80/ D1Z2/CDC2L1 and proximally by loci D1S244, i.e., approximately 25 cM. The 1p deletions are, however, not restricted to neuroblastoma tumours. In fact, a large spectrum of tumour types display deletions to varying degrees of 1p. PROCEDURE: We have exploited the possibility of using deletions of other tumour types, preferentially that of germ cell tumours, and combining the deletions with that of the neuroblastoma SRO. Also in germ cell tumours, distal 1p-deletions have been shown to have prognostic significance. RESULTS: We found in our germ cell tumours a SRO ranging from D1S508 to D1S200. Interestingly, this region only partially overlapped (approximately 5 cm) with our neuroblastoma SRO in region D1S508 to D1S244. We have thus focused on analysing this smaller region in the search for genes involved in the genesis of different cancers. We have performed radiation hybrid mapping of a large number of markers, STSs, ESTs, and others known to reside in 1p. We have also initiated the development of a BAC contig of the region. FISH, and fibre-FISH mapping of BACs were also performed. CONCLUSIONS: The data presented here constitute an ongoing work with the aim of identifying and cloning gene(s) important for development of germ cell tumours, neuroblastomas, and possibly other tumours.
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