Background: AML is a heterogeneous disease. The karyotype provides important prognostic information that influences therapy and outcome. Identification of AML patients (pts) with poor prognosis such as those with complex karyotype (CK) has great interest and impact on therapeutic strategies. TP53 is the most frequently mutated gene in human tumours. TP53 mutation rate in AML was reported to be low (2.1%), but the incidence of TP53 mutations in AML with a complex aberrant karyotype is still debated. Aims: To investigate the frequency of TP53 mutations in adult AML pts, the types of mutations, the associations with recurrent cytogenetic abnormalities and their relationship with response to therapy, clinical outcome and finally their prognostic role. To this aim, we focused on a subgroup of TOT/886 AML pts treated at the Serˆgnoli Institute of Bologna between 2002 and 2013. Patients and Methods: 886 AML patients were analysed for morphology, immunophenotype, cytogenetic and for a panel of genetic alterations (FLT3, NPM1, DNMT3A, IDH1, IDH2 mutations, WT-1 expression, CBF fusion transcripts). Of these, 172 adult AML pts were also examined for TP53 mutations using several methods, including Sanger sequencing, Next-Generation Deep-Sequencing (Roche) and HiSeq 2000 (Illumina) platform. 40 samples were genotyped with Genome-Wide Human SNP 6.0 arrays or with CytoScan HD Array (Affymetrix) and analysed by Nexus Copy Numberª v7.5 (BioDiscovery). Results: Of the 886 AML patients, 172 pts were screened for TP53 mutations. Sanger sequencing analysis detected TP53 mutations in 29/172 AML patients with 36 different types of mutations; seven pts (4%) had 2 mutations. At diagnosis, the median age of TP53 mutated and wild type patients was 68 years (range 42-86), and 65 years (range 22-97) respectively. Median WBC count was 8955/mmc (range 580-74360/mmc) and 1240/mmc (range 400-238000/mmc). Conventional cytogenetics showed that: a) 52 pts (30,2%) had 3 or more chromosome abnormalities, i.e. complex karyotype; b) 71 (41,3%) presented with one or two cytogenetic abnormalities (other-AML); c) 34 pts (19,8%) had normal karyotype. Most of the TP53 mutated pts (23/29, 79.3%) had complex karyiotype, whereas only 6/29 mutated pts had “no complex Karyotype” (21% and 3% of the entire screened population, respectively). Overall, TP53 frequency was 44.2% in the complex karyotype group, suggesting a pathogenetic role of TP53 mutations in this subgroup of leukemias. As far as the types of TP53 alterations regards, the majority of mutations (32) were deleterious.. Copy Number Alterations (CNAs) analysis performed on 40 cases by Affymetrix SNP arrays showed the presence of several CNAs in all cases: they ranged from loss or gain of the full chromosome (chr) arm to focal deletions and gains targeting one or few genes involving macroscopic (>1.5 Mbps), submicroscopic genomic intervals (50 Kbps - 1.5 Mbps) and LOH (>5 Mbps) events. Of relevance, gains located on chr 8 were statistically associated with TP53 mutations (p = 0.001). In addition to the trisomy of the chr 8, others CNAs, located on chromosomes 5q, 3, 12, 17 are significantly associated (p = 0.05) with TP53 mutations. WES analysis was performed in 37 pts: 32 TP53 were wt while 5 pts were TP53 mutated. Interestingly, TP53 mutated patients had more incidence of complex karyotype, more aneuploidy state, more number of somatic mutations (median mutation rate 30/case vs 10/case, respectively). Regarding the clinical outcome, as previously reported (Grossmann V. et Al. Blood 2013), alterations of TP53 were significantly associated with poor outcome in terms of both overall survival (median survival: 4 and 31 months in TP53 mutated and wild type patients, respectively; p<0.0001) and relapse free-survival (RFS) (p < 0.0001). (Figure 1) Figure 1: Overall Survival curve of 172 AML patients with (red) or without (blue) TP53 mutations (p< 0.0001). Conclusions: Our data demonstrated that TP53 mutations are more frequent at diagnosis in the subgroup of complex karyotype AML (16.86%) (p< 0.0001–Fisher's exact test). They are mostly deleterious mutations and are significantly correlated with worst prognosis, fail to respond to therapy and rapidly progress. We recommend TP53 mutation screening at least in AML pts carrying either complex karyotype or chr. 8 gain. Supported by: ELN, AIL, AIRC, PRIN, progetto Regione-Universitˆ 2010-12 (L. Bolondi), FP7 NGS-PTL project. Disclosures No relevant conflicts of interest to declare.
: Bone disease is the hallmark of multiple myeloma. Skeletal lesions are evaluated to establish the diagnosis, to choose the therapies and also to assess the response to treatments. Due to this, imaging procedures play a key-role in the management of multiple myeloma. For decades, conventional radiography has been the standard imaging modality. Subsequently, advances in the treatment of multiple myeloma have increased the need for accurate evaluation of skeletal disease. The introduction of new high performant imaging tools, such as whole-body low dose computed tomography, different types of magnetic resonance imaging studies, and 18F-fluorodeoxyglucose positron emission tomography, replaced conventional radiography. In this review we analyze the diagnostic potentials, indications of use, and applications of the imaging tools nowadays available. Whole body low-dose CT should be considered as the imaging modality of choice for the initial assessment of multiple myeloma lytic bone lesions. MRI is the gold-standard for detection of bone marrow involvement, while PET/CT is the preferred technique in assessment of response to therapy. Both MRI and PET/CT are able to provide prognostic information.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.