Prognostic Value of TP53 Gene Mutations in Higher Risk MDS Treated with Azacitidine

Abstract Abstract 1706 Background: TP53 gene mutations in MDS and AML are, with the exception of cases of isolated del 5q, generally associated with complex karyotype, often including del (17p) (with loss of the remaining TP53 allele) and with poor overall outcome (Fenaux, BJH, 1992; Bejar, NEJM, 2011). They are, in MDS and AML, more specifically generally associated with resistance to chemotherapy, including anthracycline-Ara C combinations and low-dose AraC (Wattel, Blood, 1994), but their correlation with treatment outcome with hypomethylating agents has not been studied. Our aim was to assess the prognostic value of TP53 mutations for response to Azacitidine (AZA) in higher risk MDS, AML with 20–30% blasts or advanced CMML (corresponding to the EU label for AZA). Methods: Patients were treated with AZA (75 mg/m2/d, generally during 7 days every 4 weeks) in 2 centers of the Groupe Francophone des Myélodysplasies. TP53 mutations were detected by the functional FASAY technique, which assesses the transcriptional activity of p53 by co-transfecting an open gap repair plasmid with the product of amplification of TP53 from patients in yeasts whose growth is dependent on the functionality of p53. The detection limit of this technique is around 10–15% (Flaman et al, PNAS 1995). The presence of mutations was subsequently confirmed by direct sequencing using the Sanger method and, more recently, by a Next-Generation Sequencing (NGS) assay using pyrosequencing (GS Junior System, Roche with the IRON II plate design). Results: 72 pts treated with AZA (median n° of cycles of AZA received 4, range 1–7) were analyzed, including 34 MDS according to WHO classification (IPSS high: 9, int2: 13, int1: 6, undetermined: 6), 33 AML with 20–30% blasts and 5 advanced CMML. According to IPSS, karyotype was favorable in 27%, intermediate in 13% and unfavorable in 60% of the pts, including 47% of complex karyotypes. Response to AZA (according to IWG 2006 criteria) was observed overall in 51% of the pts, including 34% CR, 6% PR, 4% marrow CR, 7% stable disease with HI. Median overall survival (OS) from onset of AZA was 15.6 months, possibly explained by the 47% of complex karyotypes. 29 (40%) patients had a TP53 mutation, detected by FASAY technique and subsequently confirmed by Sanger sequencing or NGS (no false positive with FASAY technique was observed). 22 of the 34 (67%) patients with complex karyotype had a TP53 mutation. In the 7 patients with TP53 mutation without complex karyotype, 3 pts had isolated del(5q), 2 had del (17p) (isolated in 1 pt, with del (20q) in 1 pt), 1 had pentasomy 11 and 1 had +8, del(20q). Ten (77%) of the 13 cases with chromosome 17 rearrangement leading to del (17p) were TP53 mutated. Overall Response to AZA (41% vs 57%, p= 0.227) and CR rate (21% vs 42%, p= 0.073) did not significantly differ between TP53 mutated and wild-type patients. Nevertheless, OS was negatively influenced by the presence of TP53 mutation (median 13 vs 21 months, p= 0.0022, figure 1), complex cytogenetics (median 14 vs 18 months, p=0.0120), WHO AML diagnosis (median 13 vs 21 months for WHO-MDS or CMML, p= 0.0014). By multivariate analysis, marrow blast % (HR 1.03 (1.01–1.05) (p<10-4)) and TP53 mutational status (HR 2.29 (1.06–4.97) p=0.035) were the only 2 factors retaining statistical significance for OS. When the analysis was restricted to WHO MDS and CMML patients, only the presence of TP53 mutation was associated with worse OS in multivariate analysis (HR=4.08 (1.31– 12.7), p=0.015)). Conclusion: In higher risk MDS (and AML with 20–30% blasts and advanced CMML) patients treated with AZA, the presence of TP53 mutation appears to constitute an independent prognostic parameter of poorer survival. Disclosures: No relevant conflicts of interest to declare.

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Mutational Status of the TP53 Gene As a Predictor of Response and Survival in Patients With Chronic Lymphocytic Leukemia: Results From the LRF CLL4 Trial

Journal of Clinical Oncology ◽

10.1200/jco.2010.32.0838 ◽

2011 ◽

Vol 29 (16) ◽

pp. 2223-2229 ◽

Cited By ~ 170

Author(s):

David Gonzalez ◽

Pilar Martinez ◽

Rachel Wade ◽

Sarah Hockley ◽

David Oscier ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Survival Data ◽

Prognostic Value ◽

Gene Mutations ◽

Progression Free Survival ◽

Tp53 Gene ◽

Lymphocytic Leukemia ◽

Tp53 Mutations ◽

Mutational Status ◽

Gene Tp53

Purpose TP53 mutations have been described in chronic lymphocytic leukemia (CLL) and have been associated with poor prognosis in retrospective studies. We aimed to address the frequency and prognostic value of TP53 abnormalities in patients with CLL in the context of a prospective randomized trial. Patients and Methods We analyzed 529 CLL samples from the LRF CLL4 (Leukaemia Research Foundation Chronic Lymphocytic Leukemia 4) trial (chlorambucil v fludarabine with or without cyclophosphamide) at the time of random assignment for mutations in the TP53 gene. TP53 mutation status was correlated with response and survival data. Results Mutations of TP53 were found in 40 patients (7.6%), including 25 (76%) of 33 with 17p deletion and 13 (3%) of 487 without that deletion. There was no significant correlation between TP53 mutations and age, stage, IGHV gene mutations, CD38 and ZAP-70 expression, or any other chromosomal abnormality other than 17p deletion, in which concordance was high (96%). TP53 mutations were significantly associated with poorer overall response rates (27% v 83%; P < .001) and shorter progression-free survival (PFS) and overall survival (OS; 5-year PFS: 5% v 17%; 5-year OS: 20% v 59%; P < .001 for both). Multivariate analysis that included baseline clinical variables, treatment, and known adverse genetic factors confirmed that TP53 mutations have added prognostic value. Conclusion TP53 mutations are associated with impaired response and shorter survival in patients with CLL. Analysis of TP53 mutations should be performed in patients with CLL who have progressive disease before starting first-line treatment, and those with mutations should be selected for novel experimental therapies.

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P-006 Prognostic value of TP53 gene mutations in higher-risk MDS treated with azacitidine (AZA)

Leukemia Research ◽

10.1016/s0145-2126(13)70055-9 ◽

2013 ◽

Vol 37 ◽

pp. S25

Author(s):

C. Bally ◽

L. Ades ◽

A. Renneville ◽

M.J. Mozziconacci ◽

C. Preudhomme ◽

...

Keyword(s):

Prognostic Value ◽

Gene Mutations ◽

Tp53 Gene ◽

Tp53 Gene Mutations

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Detailed Molecular Analysis of Patients with Chronic Lymphocytic Leukemia Carrying 17p Deletions Reveals Concurrent Abnormalities with Prognostic Impact

Blood ◽

10.1182/blood.v120.21.4577.4577 ◽

2012 ◽

Vol 120 (21) ◽

pp. 4577-4577

Author(s):

Julio Delgado ◽

Itziar Salaverría ◽

Eriong Lee ◽

Laura Jiménez ◽

Alba Navarro ◽

...

Keyword(s):

Multivariate Analysis ◽

Chronic Lymphocytic Leukemia ◽

Copy Number ◽

Prognostic Value ◽

De Novo ◽

Lymphocytic Leukemia ◽

Complex Karyotype ◽

Tp53 Mutations ◽

Genomic Complexity ◽

Allelic Burden

Abstract Abstract 4577 Patients with chronic lymphocytic leukemia (CLL) whose tumor cells harbor 17p deletions (17p-) by fluorescent in-situ hybridization (FISH) or chromosome banding analysis (CBA) are considered to have a poor survival. The disease is usually refractory to conventional chemotherapy and alternative therapeutic approaches are generally recommended. There is, however, a degree of clinical heterogeneity within 17p- CLL patients, as a significant proportion of them remain asymptomatic for prolonged periods of time. The aim of this study was to determine the prognostic value of concomitant molecular abnormalities in patients with 17p- CLL. Clinical and laboratory data were collected from 76 patients with 17p- CLL, detected either at diagnosis (de novo deletions, 39 patients) or over the course of the disease (acquired deletions, 37 patients). The cut-off used to define a positive FISH result was 10%, and complex karyotype was defined as the presence of 3 or more aberrations by CBA. We performed Sanger sequencing of IGHV, TP53 (exons 4–9), NOTCH1 (exon 34) and SF3B1 (exons 14–18), as well as high resolution copy number analysis using a SNP-array platform (CN-SNP). Both CBA/FISH and molecular studies were performed on samples drawn on the same date. Main biological characteristics, including CD38 and ZAP-70 expression or beta2-microglobulin (B2M), were also recorded. We evaluated the impact of these variables on time to first treatment (TTFT) and overall survival (OS) from sampling. TTFT was only evaluated in patients with de novo 17p-, and OS was evaluated in the whole cohort. Optimal cut-offs for FISH, B2M and copy number aberrations (CNAs) were calculated using maximally selected rank statistics, and were ≥25%, ≥3.5 mg/dl and ≥3, respectively (maxstat package, R, version 2.15.0). TP53 mutations were detected in 28/60 (47%) patients, and were more frequent in patients with ≥25% 17p- cells by FISH (64% vs 32%, p=0.029). CN-SNP confirmed 17p losses in only 19/68 (28%) patients and 90% of them also had concurrent TP53 mutations. 17p- by CN-SNP were mostly detected in patients with ≥25% 17p- cells by FISH [11/16 (69%)], compared to 6/49 (12%) patients with <25% cells (p<0.001). Median CNAs was 2 (range, 0–21) and was significantly higher in patients with ≥25% 17p- cells by FISH (median 3) compared to those patients with a lower allelic burden (median 1, p=0.017). Median CNAs were also higher in patients with 17p- by CN-SNP compared to those without 17p- by CN-SNP (3 vs 1, p<0.001). NOTCH1 and SF3B1 mutations were found in 8/42 (19%) and 1/20 (5%) patients, respectively. Variables predictive of a shorter TTFT in patients with de novo 17p- were unmutated IGHV genes (p=0.037), positive CD38 expression (p=0.002), positive ZAP-70 expression (p=0.010), complex karyotype by CBA (p=0.043), and ≥3 CNAs by SNP arrays (p=0.002). Multivariate analysis revealed that the presence of ≥3 CNAs was the only variable with independent prognostic value in terms of TTFT (hazard ratio [HR] 5.8, 95% confidence interval [CI] 2.0–16.7, p=0.001). Regarding OS, variables with a negative impact by univariate analysis were ≥25% 17p- cells by FISH (p=0.002), presence of TP53 mutations on the other allele (p=0.021), presence of 17p- by CN-SNP (p=0.022), unmutated IGHV genes (p=0.026), positive ZAP-70 expression (p=0.043) and elevated B2M (p=0.004). Genomic complexity was predictive of a shorter OS, but only by CBA. As such, patients with a complex karyotype had a significantly shorter OS (p=0.035), but not patients with ≥3 CNAs. Multivariate analysis revealed that ≥ 25% 17p- cells by FISH (HR 3.0, 95% CI 1.4–6.6, p=0.007) and B2M (HR 2.5, 95% CI 1.2–5.4, p=0.015) were the only variables with independent prognostic value. In conclusion, the prognosis of patients with a 17p- CLL is modulated by the allelic burden by FISH and genomic complexity. CN-SNP arrays were less sensitive than FISH in the detection of 17p losses, although the presence of ≥3 CNAs was particularly predictive of TTFT in patients with de novo 17p-. Disclosures: No relevant conflicts of interest to declare.

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In CLL with Complex Aberrant Karyotype Distinct Entities Can Be Deciphered by Molecular Genetic and Cytogenetic Parameters

Blood ◽

10.1182/blood.v112.11.3138.3138 ◽

2008 ◽

Vol 112 (11) ◽

pp. 3138-3138 ◽

Cited By ~ 1

Author(s):

Frank Dicker ◽

Susanne Schnittger ◽

Torsten Haferlach ◽

Wolfgang Kern ◽

Claudia Haferlach

Keyword(s):

High Risk ◽

Lower Risk ◽

Tp53 Mutation ◽

Risk Group ◽

Molecular Genetic ◽

Tp53 Gene ◽

High Risk Group ◽

Complex Karyotype ◽

Tp53 Mutations ◽

The Poor

Abstract Metaphase cytogenetics have recently defined important prognostic subgroups in CLL. In addition to the poor prognosis FISH markers del(17p) and del(11q), the presence of translocations and a complex aberrant karyotype, defined by chromosome banding analyses, have been associated with shorter overall survival in a retrospective analysis. Thus far, a complex aberrant karyotype is defined by a number of three or more chromosomal aberrations, therefore, we aimed at characterizing an unselected CLL cohort of 92 patients with complex aberrant karyotype in more detail with molecular genetic, cytogenetic, and immunophenotypic parameters. Median age at diagnosis was 62.5 years (range: 33.4–83.3 years), the male/female ratio was 2.8. An unmutated IgVH status (<= 2% mutations) was detected in 51 (60.7%) of 84 analyzed samples. A positive CD38 expression (>= 30% CD38 positive cells) was detected in 55 (64%) of 86 samples and TP53 gene mutations by denaturing high performance liquid chromatography of exons 4–9 of TP53 in 29 (36.7%) of 79 samples. As the main approach for prognostication in CLL uses FISH for del(17p), del(11q), +12, del(13q) sole and normal, we related our cohort with complex aberrant karyotype into these different FISH categories. The poor prognosis markers del(17p) and del(11q) were detected with frequencies of 39.1% (n=36) and 22.8% (n=21), respectively, accounting for almost two third of all samples (n=57, 61.9%). An overlap between del(17p) and del(11q) was detected in 5 of the 36 del(17p) cases. The intermediate risk FISH marker +12 and low risk FISH markers del(13q) as sole abnormality and “normal karyotype” appeared with an incidence of 8.7% (n=8), 21.7% (n=20) and 7.6% (n=7), respectively. The high incidence of del(11q) and del(17p) in complex karyotype seems likely, as genes implicated in sensing DNA damage and in regulating apoptosis, ATM and TP53, are candidate genes in these deleted regions. As TP53 mutations have been suggested as independent poor prognostic markers, we also added TP53 gene mutation analysis to the FISH stratification. Del(17p) was associated with TP53 mutation in 26 (86.7%) of 30 analyzed cases, whereas the three residual TP53 mutations were associated with del(11q) (n=1) and del(13q) as sole abnormality (n=2). Therefore, we chose to merge samples with high risk features within the complex karyotype into one group (n=59), i.e., samples with del(17p), del(11q) or TP53 mutation, and compared these samples to the remaining samples (n=33). Effectively, the high risk group compared to the other cohort was significantly associated with an unmutated IgVH (p=0.02, Fisher’s exact test) and with an increased, median amount of cytogenetic aberrations (4.9 vs. 3.7 aberrations, p=0.005, t-test). However, no significant difference between the two groups regarding a CD38 positive status was detected (p=0.257). The prognostic impact of high risk features (del(17p), del(11q) and TP53 mutation) within the group defined above vs the lower risk group was analyzed with log-rank statistics with respect to time from diagnosis of CLL to initial treatment (TTT). 34 patients from the high risk group and 18 patients from the low risk group were available for analysis. The high risk features within the complex karyotype were significantly associated with a higher risk of early treatment in log-rank statistics with a median TTT of 12.2 month in the higher risk group compared to 70.1 month in the lower risk group (p=0.005). In conclusion, based on poor risk cytogenetic and molecular genetic features within the group of CLL with complex aberrant karyotype, we characterized patients with a higher risk of early treatment initiation. This group includes samples with del(17p), del(11q) and TP53 mutations.

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Prognostic value of TP53 gene mutations in myelodysplastic syndromes and acute myeloid leukemia treated with azacitidine

Leukemia Research ◽

10.1016/j.leukres.2014.03.012 ◽

2014 ◽

Vol 38 (7) ◽

pp. 751-755 ◽

Cited By ~ 90

Author(s):

Cecile Bally ◽

Lionel Adès ◽

Aline Renneville ◽

Marie Sebert ◽

Virginie Eclache ◽

...

Keyword(s):

Acute Myeloid Leukemia ◽

Myelodysplastic Syndromes ◽

Myeloid Leukemia ◽

Prognostic Value ◽

Gene Mutations ◽

Tp53 Gene ◽

Tp53 Gene Mutations ◽

Acute Myeloid

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TP53 Abnormality in Myelodysplastic Syndrome

Blood ◽

10.1182/blood-2019-128054 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 5410-5410

Author(s):

Fei Huang ◽

Yu Chen ◽

Yuxing Zhu ◽

Chun Qiao ◽

Sixuan Qian ◽

...

Keyword(s):

Tumor Suppressor ◽

Disease Progression ◽

Tp53 Mutation ◽

Conflicts Of Interest ◽

Multiple Time ◽

Complex Karyotype ◽

Newly Diagnosed ◽

Tp53 Mutations ◽

Molecular Abnormalities ◽

Highly Correlated

TP53 (tumor suppressor gene P53), one of the most important tumor suppressor genes, plays an important role in cell cycle arrest, cell senescence, apoptosis, differentiation and metabolism. The TP53 gene is located on 17p13.1, its encoded product is the transcription factor P53 protein, which is known as the "the guardian of the genome". Alterations of TP53 include mutations and deletions and are generally associated with advanced stages of disease, insufficient therapy-response and poor prognosis. The main purpose of our study was to comprehensively analyze the TP53 mutation and 17p deletion in MDS in our single center. To better understand the relationship between TP53 abnormality and clinical phenotype, prognosis, leukemia transformation, therapeutic response of MDS. Next generation sequencing (NGS) method combining with cytogenetics analysis were used, 36 common related AML/MDS/MPN related genes such as TP53, TET2, WT1, ASXL1, U2AF1, RUNX1, etc were covered. According to the 2016 WHO classification and prognosis score system and from June 2011 to June 2017, 88 newly diagnosed MDS patients including 17 MDS-SLD, 32 MDS-MLD,6 MDS-RS,19 MDS-EB-1,11 MDS-EB-2 and 2 MDS-U, 1 5q- syndrome were enrolled. TP53 mutation/deletions were found in twenty-two (25%) of the 88 newly diagnosed MDS patients, among them,7 MDS-SLD, 4 MDS-MLD, 2 MDS-RS, 1 5q-, 6 MDS-EB-1 and 6 MDS-EB-2. TP53 mutation/deletions cases had a higher proportion of bone marrow blasts compared with TP53 negative cases (P=0.009), At the same time, TP53 positive were highly correlated with MDS-EB-2 subtype (P=0.025), complex karyotype (P<0.001). Based on a median follow-up time of 21(1-267) months in all pts, 13 patients (14.8%) progressed to AML and pts with TP53 mutation/deletions tended to progress to AML (P=0.056) with a shorter OS (P=0.005) and PFS (P=0.001). NGS data of accompanying mutation in other classical leukemia genes shown that compound TP53 and U2AF1 mutations were significantly associated with disease progression. For TP53 mutation/deletion group (n=22), we further sequenced the TP53 status at multiple time point of pre and after DAC treatment, results shown that all patients had persistent TP53 positive status before and after treatment. In conclusion, our results indicate that in MDS TP53 mutation/deletions is highly correlated with MDS-EB-2 subtype, IPSS high-risk group, and complex karyotype. TP53 mutations that occur in the early stages of MDS may contribute to disease progression and leukemia transformation in conjunction with other molecular abnormalities. DAC improves outcomes in patients with TP53 mutation/deletion but may not clear TP53 mutations. Disclosures No relevant conflicts of interest to declare.

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Genetic Lesions in Russian CLL Patients with the Most Common Stereotyped Antigen Receptors

Blood ◽

10.1182/blood-2020-140663 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 16-17

Author(s):

Bella V. Biderman ◽

Nataliya Severina ◽

Ekaterina B Likold ◽

Tatiana N. Obukhova ◽

Andrey B. Sudarikov ◽

...

Keyword(s):

Gene Mutations ◽

Tp53 Gene ◽

Simultaneous Occurrence ◽

Gene Repertoire ◽

Antigen Receptors ◽

Tp53 Mutations ◽

Cytogenetic Aberrations ◽

Ighv Gene ◽

Mutation Burden ◽

Tp53 Gene Mutations

Background: The features of the IGHV gene repertoire in CLL have been widely discussed in the last 20 years. In approximately 30% of cases of CLL, highly homologous "stereotyped" antigen receptors (SARs) are expressed, representing quasi identical amino acid sequences. Associations with age, disease severity, and cytogenetic aberrations have already been reported for certain SARs. It should be noted that the predictive value of certain SARs could be higher than that of IGHV mutation status. Several SAR subgroups have already been identified as independent prognostic factors in CLL (CLL#1, CLL#2, CLL#8 demonstrate an extremely aggressive course of the disease, CLL#4 - indolent). It was also shown that SAR subgroups may associate with distinct profiles of genetic lesions. Aim: To study the frequency of cytogenetic aberrations and mutations in the TP53, NOTCH1, and SF3B1 genes in CLL patients with the most common SARs in Russia. Methods: The study included 62 patients with CLL diagnosed and followed up from 2012 to 2020. Sequencing of the IGHV gene and SAR assignment were done according to the ERIC recommendations. NOTCH1 gene mutations (exon 34) were assessed by fragment analysis or by NGS using primers described by Campregher et al. TP53 gene mutations (exons 2-11) were determined using NGS according to Pavlova et al. SF3B1 gene mutations (exons 14-16) were studied in 26 patients by NGS. 51 patients underwent a FISH study for the presence of 17p13/TP53 deletions; 29 - additionally for 11q23/ATM and 13q14 deletions (Abbott, USA). Results: CLL#1, CLL#6, and CLL#3 are the most common SAR subsets in Russian CLL patients. Here we report data for 30 patients with CLL#1, 17 with CLL#6, and 15 with CLL#3. In CLL#1 group, 10 (33.3%) patients had mutations in the TP53 gene. In 7 cases, the mutation burden exceeded 35%, in three patients it was less than 10%. In 7 (23.3%) patients, mutations in the NOTCH1 gene were detected, in 5 - c.7544_7545delCT, in 1 - c.7558_7561delCTTC and in 1 - p.Q2444X. Simultaneous mutations in the NOTCH1 and TP53 genes were found in two patients. Deletion 17p13was found in 8 patients from 25 studied (32%). In 7 patients TP53 mutation and del17p13 were observed simultaneously. Deletion 11q23 was found in 6 out of 15 patients (40%). No cases with the simultaneous occurrence of del11q23 and del17p13 or mutations in the TP53 gene were observed. SF3B1 gene mutations in this group were not investigated. In the CLL#6 group, 6 (35.3%) patients had mutations in the TP53 gene (in two of them two clones with different TP53 mutations were observed). In one case, the mutation was less than 10%. In 4 (23.5%) patients NOTCH1 gene mutations (all c.7544_7545delCT) were detected, in two cases the mutation burden was less than 5%. Simultaneous NOTCH1 and TP53 gene mutations were found in two patients. Deletion 17p13 was found in 4 patients from 14 studied (28.5%). In 3 patients TP53 mutations and del17p13 were observed simultaneously. Deletion 11q23 was found in 1 patient out of 10. No SF3B1 gene mutations were found in this group (in 11 patients tested). In CLL#3 group, only 2 (13%) patients had mutations in the TP53 gene, with one having 2 different clones and the other having 4 (this patient also had del17p13, the only one in this group). Also, only 2 (13%) patients had c.7544_7545delCT deletion in the NOTCH1 gene. SF3B1 gene mutations were found in 8 (53.3%) patients. Conclusions: Our data show that in CLL#1, CLL#6, and CLL#3 subsets genetic lesions are much more common than in CLL patients in general. This is in part consistent with earlier European studies. However, in our sample, TP53 mutations and del17p13 are much more frequent in CLL#1 and CLL#6 groups. This may be due to a more sensitive approach (NGS) for mutation detection we used. Furthermore, our cohort included patients relapsed after the FCR treatment. The discrepancy in the detection rate of del11q23 in the CLL#1 subset can be explained by the small sample. Also, population differences in the development of the disease cannot be ruled out. Further studies of genetic lesions associated with certain SAR subgroups may improve diagnostics and therapy of CLL and impact the understanding of disease pathogenesis. Disclosures No relevant conflicts of interest to declare.

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SNP Array-Based Analysis of Chromosome 17 Reveals Biallelic TP53 Mutations Due to Uniparental Disomy 17p in Advanced MDS and AML with Cooperating Deletions of Chromosomes 5 and 7

Blood ◽

10.1182/blood.v112.11.2521.2521 ◽

2008 ◽

Vol 112 (11) ◽

pp. 2521-2521 ◽

Cited By ~ 2

Author(s):

Monika Jasek ◽

Lukasz P. Gondek ◽

Nelli Bejanyan ◽

Ramon V. Tiu ◽

Jungwon Huh ◽

...

Keyword(s):

Median Survival ◽

Tp53 Mutation ◽

Clinical Phenotype ◽

Snp Array ◽

Uniparental Disomy ◽

Chromosome 17 ◽

Missense Mutations ◽

Complex Karyotype ◽

Tp53 Mutations ◽

Myeloid Malignancies

Abstract Areas of loss of heterozygosity (LOH) can be precisely delineated using single nucleotide polymorphism arrays (SNP-A) allowing for detection of submicroscopic chromosomal defects and segmental somatic uniparental disomy (UPD) not revealed by metaphase cytogenetic analysis (MC). This study focused on aberration of chromosome 17. We analyzed marrow specimens in 1162 MDS/AML by MC and found 39 patients whose karyotype involved monosomy 17. All had a complex karyotype, aggressive histomorphologic features (1/39 low risk, 26/39 advanced MDS/sAML, 2/39 MDS/MPD, and 10/39 pAML) with a median survival of 3 months. In addition to loss of chromosome 17, 35/39 patients also showed either −5/del(5q) (N=10), −7/del(7q) (N=2), or both (N=23). To better delineate the boundaries of LOH on 17th chromosome, we analyzed a subset of 532 patients by SNP-A and identified 43/532 samples with an abnormal chromosome 17; 28 had interstitial deletions and 15 had somatic UPD. In 17/19 samples with monosomy 17 by MC, SNP-A revealed a deletion in 17p or 17q, indicating incomplete loss of chromosome 17 material. SNP-A yielded a total of 11 additional lesions on 17q not detected by MC. We were able to define two commonly deleted regions (CDR1 and CDR2). CDR1 (bp 6,828,482 to 8,075,871; 1.25 Mb) encompassed around 90 genes, including TP53, and was present in 11/14 samples with del17p. CDR2 (bp 25,320,435 to 27,355,332; 2Mb) was detected in 7/14 patients and encompassed approximately 33 genes, including NF1. Overall, the frequency of UPD17 was high: 17p UPD was detected in 7 and 17q in 8 samples analyzed. In all cases with 17p UPD, the region of UPD overlapped with CDR1. CDR2 overlapped with the region of 17q UPD in 4/8 samples. In analogy to monosomy 17, 18/21patients with LOH 17p (7 UPD, 14 losses) had a complex karyotype, 21/21 had aggressive histomorphologic features (1/21 RCMD, 3/21 RCMD-RS, 6/21 RAEB-1/2, 3/21 pAML, 8/21sAML) and a poor prognosis with a median survival of 2.6 months. Moreover, in 13/14 patients with del(17p) by SNP-A, −5/del(5q) (N=1) or both −5/del(5q) and −7/del(7q) (N=12) were present. One patient did not show deletions of chromosomes 5 or 7, but had del (4)(q26) and del(6)(q23.2). No patient had del(17p) as the sole abnormality. Strong association between 17p UPD and abnormalities of chromosomes 5 and/or 7 was also noted: of 7 patients with 17p UPD, 3 had 5/del(5q), 1 showed −7/del(7q), and 3 had −5/del(5q) and −7/del(7q). We hypothesized that LOH within the 17p CDR1 that includes TP53 might be associated with a distinct clinical phenotype and point toward pathogenic TP53 mutations. Overall, 18 instances of 17p LOH included the TP53 locus. When TP53 exons 5–9 were screened for mutations in patients with 17p LOH, we found biallelic TP53 mutations in 5/6 patients with somatic 17p UPD and in 6/8 patients with 17p deletions. We detected 10 missense mutations and 1 insertion. All missense mutations were located in the DNA-binding domain of TP53 (4/10 in exon 5: C141Y, V172F, C176Y, H179Q; 2/10 exon 6: H193N, H193R; 1/10 exon 7: R249G and 3/10 exon 8: V272L, V272M, R273H). Our study demonstrates that LOH of 17p in myeloid malignancies should prompt consideration of TP53 mutation. TP53 mutation is linked with an aggressive clinical phenotype and is highly associated with partial or complete loss of chromosomes 5 and/or 7. To our knowledge this is the first report of biallelic TP53 mutations due to UPD17p in myeloid malignancies, and indicates that both heterozygous and homozygous mutations can be encountered and comprise part of the pathologic continuum of the selection process of malignant myeloid clones.

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Incidence and Prognostic Value of TP53 Mutations in Lower Risk MDS with Del 5q.

Blood ◽

10.1182/blood.v120.21.2809.2809 ◽

2012 ◽

Vol 120 (21) ◽

pp. 2809-2809

Author(s):

Cecile Bally ◽

Lionel Ades ◽

Aline Renneville ◽

Sophie Raynaud ◽

Virginie Eclache ◽

...

Keyword(s):

Early Phase ◽

Lower Risk ◽

Prognostic Value ◽

Tp53 Mutation ◽

Cytogenetic Response ◽

Complex Karyotype ◽

Early Disease ◽

Tp53 Mutations ◽

Erythroid Response ◽

Significant Difference

Abstract Abstract 2809 Background: TP53 gene mutations, frequent in AML and MDS with complex karyotype, have recently been found in about 20% of lower risk MDS with del 5q, where they possibly conferred resistance to lenalidomide (LEN), and a higher risk of AML progression (Jadersten, JCO, 2011). We assessed the incidence and prognostic value of TP53 mutations in 79 lower risk MDS with del 5q, treated or not with LEN, and analysed in early disease phase or after progression to higher risk MDS or AML. Methods: IPSS low and int 1 (Lower) risk MDS with del 5q were analysed at diagnosis or onset of LEN (“early phase”) and/or after progression to IPSS high or int 2 (higher) risk MDS or AML. LEN was administered at 5 or 10 mg/d during 16 weeks, and continued in erythroid responders until relapse or disease progression. TP53 mutations were detected by the functional FASAY technique, assessing the transcriptional activity of p53 by co-transfecting an open gap repair plasmid with the product of amplification of TP53 from patients in yeasts whose growth is dependent on p53 functionality. The detection limit of this technique is around 10–15% (Flaman, PNAS 1995). Mutations found by FASAY were confirmed by direct sequencing, using Sanger method and /or (more recently) high sensitivity (1%) Next Generation Sequencing (NGS) by pyrosequencing (GS Junior System-Roche, with the IRON II plate design). Results: 79 lower risk MDS with del 5q from 6 French centers of the GFM were analyzed, including 62 at diagnosis or onset of LEN (“early phase”), and 17 after progression to higher risk MDS or AML (5 of the latter were also retrospectively analysed on early phase samples). Overall, 28 (35%) of the 79 patients had TP53 mutation, including 16 (26%) of the 62 pts analyzed at early phase and 12 (70%) of the 17 evaluated after higher risk MDS or AML progression (p= 0.001). The 62 early phase pts had marrow blasts <5% and 5–9% in 91 and 9% of the cases, isolated del 5q, del 5q+1 and del5q+>1 (complex karyotype) in 84, 14 and 2% of the cases, and IPSS low and int 1 in 80 and 20% of the cases, respectively. No significant difference was found between mutated and non mutated cases for baseline characteristics including gender, age, WHO classification, cytogenetic complexity and IPSS. In the 5 pts analysed after progression where early phase samples were available, who all had received LEN, 4 had TP53 mutation at progression. In all of them, TP53 mutation was already detectable during early phase. However, the percentage of mutated colonies found by FASAY increased with progression, from 18 to 75%, 26 to 55%, 12 to 87% and 13 to 23%, respectively, showing an increase of the size of the mutated clone at progression. Among the 43 pts analyzed in early phase who received LEN (we excluded the 5 pts analysed after progression where early phase samples were available, to avoid bias), 36 (84 %) had isolated del 5q, 6 (14%) del 5q+1, and 1 (2%) had complex karyotype. IPSS was low in 73% and int-1 in 27%. 12/43 (28%) had TP53 mutation. 63% of the 43 pts achieved erythroid response, and 9 (47%) of the 19 pts evaluable at erythroid response achieved cytogenetic response. Erythroid response was seen in 45% mutated vs 71% non mutated cases (p= 0.258). Cytogenetic response was seen in 1/8(12%) mutated vs 8/11 (73%) non mutated cases (p=0.020). In those 43 pts who received LEN, the cumulative incidence (CI) of AML evolution, with death as a competitive event, did not significantly differ between patients with or without TP53 mutation (3 year CI of 35% vs 30%, p=0.33). Finally, in those pts, TP53 mutational status had no significant impact on OS (median 49 months in mutated pts vs not reached in non mutated pts, p=0.48, figure 1). Conclusion: We confirm the presence of TP53 mutations in about 25 % of lower risk MDS with del 5q analysed in early disease phase. TP53 mutations, in those patients, were not correlated with other baseline parameters. When treated with LEN, mutated cases had similar hematological response, lower cytogenetic response but no significant difference in progression to higher risk MDS or AML and survival compared to non mutated cases. The high incidence of TP 53 mutations at progression to higher risk MDS/AML (70%), and the increase in the TP53 mutated clone size observed during progression in pts with a baseline mutation support the pathophysiological importance of TP53 mutations in disease progression in lower risk MDS with del 5q. Disclosures: No relevant conflicts of interest to declare.

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