High Incidence of RAS Signalling Pathway Mutations in MLL–rearranged Acute Myeloid Leukemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 539-539
Author(s):  
Vera Grossmann ◽  
Susanne Schnittger ◽  
Alexander Kohlmann ◽  
Christiane Eder ◽  
Annette Fasan ◽  
...  

Abstract Abstract 539 Background: Chromosomal translocations of the MLL gene on chromosome 11q23 are associated with a unique subset of acute lymphoblastic or acute myeloid leukemias (AML). In adults, MLL rearrangements are detected in 3% of de novo AML and in 10% of therapy-related AML (t-AML) cases and are associated with poor prognosis. In addition to disease defining mutations recent high-throughput sequencing studies had shown that almost all myeloid malignancies accumulate a large number of cooperating gene mutations. Aim: Determination of somatic mutations occurring in cases harboring MLL rearrangements and investigation of the prognostic impact of molecular and additional chromosomal aberrations. Patients and Methods: We investigated a cohort of 110 adult AML (80 de novo, 30 t-AML) cases harboring an 11q23 translocation. The cohort was composed of 66 females and 44 males; median age: 55.8 years. MLL translocation partners were as follows: MLLT3 (n=46), MLLT4 (n=15), ELL (n=15); MLLT10 (n=8), others (n=26). Chromosome banding analysis data was available in all cases and survival data in 78 cases (median overall survival (OS) was 10.1 months). Patients were screened for mutations in ASXL1 (n=98), CBL (n=62), CEBPA (n=61), FLT3-ITD (n=103), FLT3-TKD (n=95), IDH1 (n=96), IDH2 (n=84), KRAS (n=107), NPM1 (n=101), NRAS (n=106), PTPN11 (n=99), RUNX1 (n=110), and TP53 (n=110) using amplicon deep-sequencing (454 Roche Life Sciences, Branford, CT), direct Sanger sequencing or melting curve analysis. Results: Overall, mutations were detected in 59/110 (53.6%) cases. We discovered that 42/110 (38.2%) MLL-translocated AML cases harbored mutations within the RAS signalling pathway (KRAS mut: 23/107; 21.5%; NRAS mut: 22/106; 20.8%; PTPN11 mut: 3/99, 3.0%) or alterations in the RAS regulating FLT3 gene (FLT3-ITD: 4/103, 3.9%, and FLT3-TKD: 10/95, 10.5%). Additional mutations were detected in the tumor suppressor gene TP53 (8/110; 7.3%), ASXL1 (6/98; 6.1%), RUNX1 (4/110; 3.6%), and IDH1 (1/96). No mutation was detected in IDH2, CBL, CEBPA, and NPM1. Most cases showed only one mutation (n=39, 66.1%), whereas 17 cases (28.8%) showed two and 3 cases (5.1%) three mutations in different genes. No difference of mutation distribution was seen between de novo and t-AML. In this cohort, no associations amongst gene mutations were observed, however, FLT3-ITD was associated with MLL-ELL (3/14 vs 1/89, P=0.008) and PTPN11 mutations with MLLT10-MLL (2/8 vs 1/91, P=0.017) alterations. In addition, KRAS mut and NRAS mut correlated with high WBC count (KRAS mut: 103.0±79 vs 59.2±67 x109/L, P=0.016; NRAS mut: 94.7±57 vs 60.4±72 x109/L, P=0.080). Further, we were interested in the prognostic impact of single gene mutations. NRAS mut and TP53 mut showed both a non-significant inferior impact on OS, i.e. OS after 2 years: 19.1% vs 46.4%, P=0.62; 0% vs 41.3%, P=0.114. Further, TP53 mutations were correlated with shorter event-free survival (EFS) (EFS after 2 years: 0% vs 20.0%, P=0.029). No associations with prognosis were observed for the remaining genes and translocation partners. In contrast, age was associated with OS and EFS (<60 years, n=59 vs ≥60 years, n=51: OS after 2 years: 51.4% vs 26.3%, P=0.003, EFS after 2 years: 28.0% vs 7.7%, P=0.004). Within the cohort of cases ≥60 years, TP53 mutations (n=5) were associated with worse EFS and OS in comparison to TP53 wild-type cases (n=45) (EFS after 2 years: 8.4% vs 0%, P= 0.006; OS after 2 years: 28.5% vs 0%, P=0.045). Of note, no correlations between mutation frequency and age were observed. We next focused on whether the number of mutations showed any impact on survival. This analysis revealed that cases with more than one mutation (n=20) showed shorter EFS (EFS after 2 years: 10.0% vs 27.3%, P=0.020). Finally, we concentrated on AML with t(9;11)(p22;q23)/MLLT3-MLL, recognized as a distinct WHO-entity. We neither detected an association of MLLT3-MLL (n=46) with OS (P=0.445) or EFS (P=0.644) in comparison to the remaining translocation partners nor a distinct gene mutation profile. However, NRAS mutations correlated with shorter OS and EFS in cases with MLLT3-MLL (after 2 years OS: 17.8% vs 48.3%, P=0.045; after 2 years EFS: 17.8% vs 35.2%, P=0.056). Conclusions: In patients with MLL-translocations a high number of secondary alterations (53.6%), predominantly in RAS pathway components (38.2%), were detected. This may have implication on novel therapeutic options in this unfavorable AML subset. Disclosures: Grossmann: MLL Munich Leukemia Laboratory: Employment. Schnittger:MLL Munich Leukemia Laboratory: Equity Ownership. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Eder:MLL Munich Leukemia Laboratory: Employment. Fasan:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Equity Ownership.

2015 ◽  
Vol 69 (5) ◽  
pp. 409-414
Author(s):  
Benny Man Wai Lit ◽  
Yok Lam Kwong ◽  
Kit Fai Wong

AimsNucleophosmin (NPM1) gene mutations resulting in cytoplasmic delocalisation of nucleophosmin (NPMc+) are the most common genetic abnormality in acute myeloid leukaemia (AML). In this study, we tested whether immunohistochemical (IHC) detection of cytoplasmic NPM1 (cNPM1) in formalin-fixed bone marrow trephine biopsies correlated with NPM1 mutations and the prognostic impact of NPM1 and fms-related tyrosine kinase 3-internal tandem duplication (FLT3-ITD) gene mutations was also assessed.MethodsA total of 71 Chinese adult de novo AML cases were evaluated for cNPM1 by IHC where the bone marrow trephines were fixed in 10% buffered formalin and decalcified by 5% EDTA. NPM1 and FLT3-ITD gene mutations were also investigated using PCR, fragment analysis and direct DNA sequencing.ResultsIHC analysis of cNPM1 had a very good sensitivity (86.7%) and excellent specificity (96.4%) for NPM1 mutation. The positive predictive value was 86.7% and the negative predictive value was 96.4%. NPM1 mutations and FLT3-ITD were closely associated (p=0.003). Patients with mutated NPM1 and without FLT3-ITD mutation have a longer overall survival (p=0.042) than patients with both NPM1 and FLT3-ITD mutations.ConclusionsOur results showed that IHC detection of cNPM1 in formalin-fixed trephine biopsies correlated well but not entirely with NPM1 mutation. Furthermore, NPM1 mutations were significantly more frequent in FLT3-ITD than FLT3-wild-type cases.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1418-1418
Author(s):  
Satoshi Wakita ◽  
Hiroki Yamaguchi ◽  
Takeshi Ryotokuji ◽  
Tuneaki Hirakawa ◽  
Ikuko Omori ◽  
...  

Abstract Background Many gene mutations were detected and overlapped in de novo acute myeloid leukemia (AML), but the prognosis of complex gene mutation remains to be unclear. In this study, we analyzed the prognostic impact of complex gene mutation in de novo AML patients with the intermediate risk karyotype. Methods We analyzed 143 samples from de novo AML patients with the intermediate risk karyotype diagnosed at Nippon Medical School Hospital from 2000 to 2012. Bone marrow or peripheral blood samples containing 20% or more blast cells were used for analyses. Mutation analyses were performed using PCR method for FLT3-ITD, FLT3-TKD and MLL-PTD, and direct sequence for NPM1, C/EBPα, DNMT3a, IDH1/2, TET2 and N/K-RAS. Results The NPM1 (39.9%), DNMT3a (26.6%), FLT3-ITD (24.5%), IDH1/2 (18.9%), TET2 (17.5%), C/EBPα (14.7%), N/K-RAS (14.0%) and MLL-PTD (6.3%) mutations were detected in our cohort, respectively. When we performed prognostic analyses for mutations of these genes, DNMT3 mutation and FLT3-ITD were isolated as a poor prognostic factor in overall survival (OS) , respectively (DNMT3a mutation positive: n=39, 3yOS 17.9%. negative: n=104, 3yOS 33.2%. p=.0056) (FLT3-ITD positive: n=35, 3yOS 12.2%. negative: n=108, 3yOS 35.0%. p=.0077). Moreover, in the FLT3-ITD positive cases, OS of patients with DNMT3a R882 mutation was significantly shorter than those without R882 mutation (R882 positive: n=20, 3yOS: 0%. negative: n=15, 3yOS 25.0%. p<.0256). Interestingly, High rate of patients with FLT3-ITD (91.4%), NPM1 (89.5%), DNMT3a (92.1%), TET2 (84.0%), and IDH1/2 (88.9%) mutations were detected other overlapped mutations, respectively. The frequency of the overlapped mutations in patients with DNMT3a mutation, especially with mutations on R882, was significantly higher than those in patients without them (DNMT3a: p=.0001, R882: p<.0001). For total cohort, the rates of and OS and relapse free survival (RFS) in patients with three or more overlapping mutations (complex gene mutation: CGM) were significantly lower than those in patients without them (CGM+: n=36, 3yOS 5.6%. CGM-: n=107, 3yOS 37.7%. p<.0001) (CGM+: n=12, 3yRFS: 8.3%. CGM-: n=57, 3yRFS: 36.0%. p=.0013). Moreover, among the patients without FLT3-ITD, the rates of RFS and OS at 3 years in patients with complex gene mutation were significantly lower than those in patients without them (CGM+: n=11, 3yOS 5.6%. CGM-: n=96, 3yOS 37.7%. p<.0408) (CGM+: n=4, 3yRFS: 8.3%. CGM-: n=51, 3yRFS: 36.0%. p=.0179). Conclusions Our study revealed that the gene mutations appeared to be overlapped, and the complex gene mutation significantly affected the prognosis of de novo AML with the intermediate risk karyotype. Intriguingly the DNMT3a mutation may contribute to an occurrence of complex gene mutation by giving genetic instability to AML cells. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. SCI-13-SCI-13
Author(s):  
Scott W. Lowe

p53 action and the consequences of p53 mutation in acute myeloid leukemia TP53 mutations are common in treatment associated myeloid neoplasia (tMN) and complex karyotype acute myeloid leukemia (CK-AML), where they are associated with chemoresistance and one of the worst prognoses of any leukemia genotype. To understand the impact of TP53 mutations on AML biology, we are performing arge scale genomic analyses of p53 mutant AML and have produced a series of animal models that appear to faithfully reflect molecular and biological features of the human disease. We have gone on to explore the biology of particular TP53 mutational configurations drive AML initiation and maintenance, and to identify and understanding the events that cooperate with p53 mutations during leukemogenesis. Disclosures Lowe: Blueprint Medicines: Consultancy, Equity Ownership; ORIC pharmaceuticals: Consultancy, Equity Ownership; Mirimus: Consultancy, Equity Ownership; Constellation Pharma: Consultancy, Equity Ownership; Petra Pharmaceuticals: Consultancy, Equity Ownership; PMV Pharmaceuticals: Consultancy, Equity Ownership; Faeth Therapeutics: Consultancy, Equity Ownership.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5228-5228
Author(s):  
Genki Yamato ◽  
Hiroki Yamaguchi ◽  
Hiroshi Handa ◽  
Norio Shiba ◽  
Satoshi Wakita ◽  
...  

Abstract Background Acute myeloid leukemia (AML) is a complex disease caused by various genetic alterations. Some prognosis-associated cytogenetic aberrations or gene mutations such as FLT3-internal tandem duplication (ITD), t(8;21)(q22;q22)/RUNX1-RUNX1T1, and inv(16)(p13q22)/CBFB-MYH11 have been found and used to stratify the risk. Numerous gene mutations have been implicated in the pathogenesis of AML, including mutations of DNMT3A, IDH1/2, TET2 and EZH2 in addition to RAS, KIT, NPM1, CEBPA and FLT3in the recent development of massively parallel sequencing technologies. However, even after incorporating these molecular markers, the prognosis is unclear in a subset of AML patients. Recently, NUP98-NSD1 fusion gene was identified as a poor prognostic factor for AML. We have reported that all pediatric AML patients with NUP98-NSD1 fusion showed high expression of the PR domain containing 16 (PRDM16; also known as MEL1) gene, which is a zinc finger transcription factor located near the breakpoint at 1p36. PRDM16 is highly homologous to MDS1/EVI1, which is an alternatively spliced transcript of EVI1. Furthermore, PRDM16 is essential for hematopoietic stem cell maintenance and remarkable as a candidate gene to induce leukemogenesis. Recent reports revealed that high PRDM16 expression was a significant marker to predict poor prognosis in pediatric AML. However, the significance of PRDM16 expression is unclear in adult AML patients. Methods A total of 151 adult AML patients (136 patients with de novo AML and 15 patients with relapsed AML) were analyzed. They were referred to our institution between 2004 and 2015 and our collaborating center between 1996 and 2013. The median length of follow-up for censored patients was 30.6 months. Quantitative RT-PCR analysis was performed using the 7900HT Fast Real Time PCR System with TaqMan Gene Expression Master Mix and TaqMan Gene Expression Assay. In addition to PRDM16, ABL1 was also evaluated as a control gene. We investigated the correlations between PRDM16 gene expression and other genetic alterations, such as FLT3-ITD, NPM1, and DNMT3A, and clarified the prognostic impact of PRDM16 expression in adult AML patients. Mutation analyses were performed by direct sequence analysis, Mutation Biased PCR, and the next-generation sequencer Ion PGM. Results PRDM16 overexpression was identified in 29% (44/151) of adult AML patients. High PRDM16 expression correlated with higher white blood cell counts in peripheral blood and higher blast ratio in bone marrow at diagnosis; higher coincidence of mutation in NPM1 (P = 0.003) and DNMT3A (P = 0.009); and lower coincidence of t(8;21) (P = 0.010), low-risk group (P = 0.008), and mutation in BCOR (P = 0.049). Conversely, there were no significant differences in age at diagnosis and sex distribution. Patients with high PRDM16 expression tended to be low frequency in M2 (P = 0.081) subtype, and the remaining subtype had no significant differences between high and low PRDM16 expression. Remarkably, PRDM16 overexpression patients were frequently observed in non-complete remission (55.8% vs. 26.3%, P = 0.001). Patients with high PRDM16 expression tended to have a cumulative incidence of FLT3-ITD (37% vs. 21%, P = 0.089) and MLL-PTD (15% vs. 5%, P = 0.121). We analyzed the prognosis of 139 patients who were traceable. The overall survival (OS) and median survival time (MST) of patients with high PRDM16 expression were significantly worse than those of patients with low expression (5-year OS, 17% vs. 32%; MST, 287 days vs. 673 days; P = 0.004). This trend was also significant among patients aged <65 years (5-year OS, 25% vs. 48%; MST, 361 days vs. 1565 days, P = 0.013). Moreover, high PRDM16 expression was a significant prognostic factor for FLT3-ITD negative patients aged < 65 years in the intermediate cytogenetic risk group (5-year OS, 29% vs. 58%; MST, 215 days vs. undefined; P = 0.032). Conclusions We investigated the correlations among PRDM16 expression, clinical features, and other genetic alterations to reveal clinical and prognostic significance. High PRDM16 expression was independently associated with non-CR and adverse outcomes in adult AML patients, as well as pediatric AML patients. Our finding indicated that the same pathogenesis may exist in both adult and pediatric AML patients with respect to PRDM16 expression, and measuring PRDM16 expression was a powerful tool to predict the prognosis of adult AML patients. Disclosures Inokuchi: Bristol-Myers Squibb: Honoraria, Research Funding; Novartis: Honoraria; Celgene: Honoraria; Pfizer: Honoraria.


2006 ◽  
Vol 130 (7) ◽  
pp. 997-1003
Author(s):  
Randall J. Olsen ◽  
Zhouwen Tang ◽  
Daniel H. Farkas ◽  
David W. Bernard ◽  
Youli Zu ◽  
...  

Abstract Context.—A specific mutation, JAK2V617F, was recently recognized as having diagnostic value for myeloproliferative disorders. No practical assay is currently available for routine use in a clinical laboratory. Objective.—We report the development of a real-time polymerase chain reaction melting curve analysis assay that is appropriate for molecular diagnostics testing. Design.—Specific primers and fluorescence resonance energy transfer probes were designed, and patients with a previously diagnosed myeloproliferative disorder, de novo acute myeloid leukemia, or reactive condition were selected. The DNA was extracted from fresh and archived peripheral blood and bone marrow specimens, and real-time polymerase chain reaction melting curve analysis was performed on the LightCycler platform (Roche Applied Science, Indianapolis, Ind). Results.—The JAK2 region was successfully amplified, and wild-type amplicons were reproducibly discriminated from JAK2V617F amplicons. Titration studies using homozygous wild-type and mutant cell lines showed the relative areas under a melting curve were proportional to allele proportion, and the assay reliably detected one mutant in 20 total cells. JAK2V617F was identified in patients previously diagnosed with a myeloproliferative disorder or acute myeloid leukemia transformed from myeloproliferative disorder, whereas a wild-type genotype was identified in patients with reactive conditions or de novo acute myeloid leukemia. Conclusions.—These findings demonstrate the suitability of this assay for identifying JAK2V617F in a clinical laboratory setting. Furthermore, the semiquantitative detection of JAK2V617F in archived specimens provides a new tool for studying the prognostic significance of this mutation.


2011 ◽  
Vol 29 (16) ◽  
pp. 2223-2229 ◽  
Author(s):  
David Gonzalez ◽  
Pilar Martinez ◽  
Rachel Wade ◽  
Sarah Hockley ◽  
David Oscier ◽  
...  

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.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1450-1450
Author(s):  
Mariam Ibañez ◽  
Esperanza Such ◽  
Jose Cervera ◽  
Irene Luna ◽  
Sandra Dolz ◽  
...  

Abstract Abstract 1450 The clinical relevance and prognostic implications of some recently identified mutations in acute myeloid leukemia (AML) is not yet well established. Among them, we have selected to be analyzed those affecting the following genes: Additional Sex Combs-Like 1 (ASXL1), Isocitrate Dehydrogenase (IDH1 and IDH2), Casitas B-lineage Lymphoma (c-CBL), and Wilms Tumor 1 (WT1). They have been previously reported with a variable incidence: ASXL1 mutations in 10.8% patients with normal karyotype (NK), IDH1 and IDH2 mutations in 8 – 33% of de novo AML, c-CBL mutations in 2% of de novo AML, and WT1 mutations in 5–12% of de novo AML patients. In order to know the incidence and prognostic impact of these mutations and their possible cooperative role in leukemogenesis, we have screened for ASXL1, IDH1, IDH2, c-CBL, WT1, FLT3, NPM1 and CEBPa, mutations in a cohort of de novo AML patients from a single centre. We studied 174 de novo AML patients [98M/76F; median age: 62 yr. (range: 16 – 88); favourable (n= 13), intermediate (n= 86) and high (n= 51) cytogenetic risk classification by the MRC group]. DNA was isolated from bone marrow samples obtained at diagnosis. In order to determine cooperating mutations, we developed a new combination of high-resolution melting (HRM) assays on a LightCycler® 480 and lastly direct sequencing, to detect somatic mutations for ASXL1 (exon 12), IDH1 (exon 4), IDH2 (exon 4), WT1 (exons 7, 8 and 9) and c-CBL (exons 8 and 9). All mutations reported in this study were confirmed al least twice. FLT3 (ITD and D835Y), NPM1 (exon 12) and CEBPa were performed as described previously by standard methods. Sequence analysis was checked by its corresponding GeneBank Accession Number. The number of patients found to carry mutations in our series was: 16 patients with ASXL1 mutations (9.2%), 16 patients with IDH mutations (2.9% had a IDH1R132, 12.6% the SNP rs11554137 and 6.3% IDH2R140), 5 patients with WT1 mutations (2.9%), 37 patients with FLT3 mutations (21.3%), 44 patients with NPM1 mutations (25,3%) and 8 patients with CEBPa mutations (4.6%). No mutations where found in c-CBL. We could not found a pattern of cooperating mutations in the studied group of genes. WT1, FLT3 and NPM1 were associated with leukocyte count >30 × 109/L at diagnosis (80% vs. 31% for WT1, P =0,022; 68% vs. 22% for FLT3, P= 0.001; and 50% vs. 24% for NPM1, P= 0.002; in mutated vs. wild-type patients, respectively). WT1 was also associated with a platelet count > 50 × 109/L at diagnosis (100% vs. 57% in mutated vs. wild-type patients, respectively; P =0,048). Besides, FLT3 and NPM1 mutations were more frequent in the intermediate cytogenetic risk group (82% and 74%; P =0.004 and P =0.047; respectively). ASXL1 and IDH mutations were not correlated with any of the clinical and biological features studied. In univariate analysis, only age and cytogenetics had an impact on overall survival (OS, median of 12mo vs. 3mo, for patients < and ≥65 yr., P <0.001 and 24mo, 11mo and 3mo for favourable, intermediate and high risk, P =0.005). Mutational status of ASXL1, IDH1, IDH2, WT1, FLT3, NPM1 and CEBPa did not impact on outcome in the whole series. However, when the analysis was restricted to patients with intermediate cytogenetic risk, patients with FLT3 mutations had a shorter OS (19mo vs. 8mo, wild-type vs. mutated patients; P =0.047) and those with WT1 mutations showed a trend towards an inferior OS (11mo vs. 1mo, wild-type vs. mutated patients; P = 0.066). In multivariate analysis in patients with intermediate cytogenetic risk, the age [HR (95% CI) = 3.3 (1.9 − 5.9) P <0.001], and FLT3 status [HR (95% CI) = 2.2 (1.2–3.9) P =0.008] retained an independent adverse significance for OS. In terms of relapse free survival any of the variables showed a significant implication. To sum up, the incidence found for the studied genes was lower than the previously reported: ASXL1, 9.2%; IDH1R132, 2.9%; IDH2R140, 6.3%; WT1, 2.9%; and c-CBL, 0%. We were unable to find a pattern of cooperating mutations in the studied group of genes or any impact of these mutations on the outcome. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3596-3596
Author(s):  
Georgia Voutiadou ◽  
Konstantina Kotta ◽  
Barbara Tachynopoulou ◽  
Apostolia Papalexandri ◽  
Chryssanthi Vadikolia ◽  
...  

Abstract Abstract 3596 Immune phenotyping plays a critical role in the diagnosis and classification of acute leukemia. Several studies have reported a variable proportion of patients with acute myeloid leukemia (AML) expressing lymphoid-associated antigens (LAA). The exact frequency and true clinical significance of this phenomenon remains undefined due to inconsistencies between series, likely related to methodological aspects or potential case selection biases. We retrospectively evaluated the expression of LAA in blast cells from 278 consecutive and unselected patients with AML diagnosed in our Department between 2002 and 2010. The patient cohort included 168 males and 110 females with a median age of 61 years (range, 10–88); 146/278 cases were above the age of 60. Within this cohort, 190 cases (68%) had de novo AML, whereas the remaining 88 cases (32%) concerned secondary AML (sAML) to either MDS (n=80) or other non-hematologic malignancies (n=8). Patients were treated uniformly according to age with Aracytin/Idarubicin induction regimens (“3+7” or “2+5” for ages \q60 or ≥60, respectively). The immunophenotype was determined by flow cytometric analysis of (mainly) bone marrow aspirate and/or peripheral blood samples utilizing a primary CD45/side scatter (SSC) gating procedure with antibodies against CD7, CD13, CD19, CD33, CD4, CD10, CD34, CD117, CD64, HLA-DR, CD20, CD2, CD15, CD56, CD14, CD8, MPO, CD3, CD79a, CD22, TdT and lysozyme; a cut-off value for positivity of 20% was adopted. Overall, we identified 153/278 cases (55%) expressing at least one LAA. The most commonly expressed LAAs were CD4 (outside AML with monocytic differentiation), CD56, CD7, CD2, CD10 and CD79a (in 39%, 33%, 29%, 14%, 10% and 8% of LAA+ AML cases, respectively); interestingly, all CD79a-positive cases co-expressed at least one more LAA. A significant association was identified between LAA expression and cytogenetic profile: in particular, at least one LAA was detected in 37/50 cases (74%) with adverse cytogenetics (SWOG unfavorable and/or monosomal karyotype), compared to 24/41 (58%) cytogenetically favorable cases and 68/134 (51%) cytogenetically intermediate risk cases (p=0.01). No other statistically significant associations were found for LAA expression (positive vs. negative) in respect to age and complete remission (CR) rate. Furthermore, the frequency of LAA-positive cases was identical (55%) in both de novo AML (105/190 cases) and sAML (48/88 cases). Monoparametric statistical analysis was also performed individually for each of the six more frequent LAAs. Significant associations (p<0.05) were identified between: (i) CD7 expression and adverse cytogenetics; (ii) CD10 expression and adverse cytogenetics as well as failure to achieve CR, at both cohort level as well as patients \q60 years with de novo AML; and (iii) CD2 expression and shorter overall and disease-free survival (DFS and OS, respectively). Cox-multivariate analysis identified CD2 expression in addition to advanced age, sAML and adverse cytogenetic profile as negative prognostic indicators (p=0.05) for both DFS and OS. In conclusion, expression of LAAs is frequent in AML, among both de novo AML and sAML cases, and significantly associated with adverse cytogenetics. Although the negative prognostic impact of CD2 expression is noteworthy, however, the precise prognostic implications of the expression of individual LAAs are hard to define on single institution retrospective series and will require evaluation in large prospective and well-controlled studies. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2544-2544
Author(s):  
Xiuli Wang ◽  
Haiping Dai ◽  
Qian WANG ◽  
Qinrong Wang ◽  
Yang Xu ◽  
...  

Abstract Abstract 2544 Somatic mutation of the EZH2 gene is seen in myelodisplastic syndrome, myelofibrosis, and chronic myelomonocytic leukemia patients. The prevalence and prognostic impact of somatic mutations of EZH2 in patients with acute myelogenous leukemia (AML) remains unknown. In this study, we sought to determine the incidence and clinical implications of somatic EZH2 mutations in 714 patients with de novo AML by PCR amplification of the entire coding region followed by direct bidirectional DNA sequencing. EZH2 mutations were identified in 13/714 (1.8%) of AML patients and occurred almost exclusively in males (11/13, P=0.033). In univariate analysis, the presence of EZH2 mutations was significantly associated with lower blast percentage (21–30%) in bone marrow (P=0.0001) and −7/del(7q) (P=0.025). There was no difference in the incidence of mutations in 13 genes, including ASXL1, CBL, c-KIT, DNMT3A, FLT3, IDH1, IDH2, MLL, NPM1, NRAS, RUNX1, TET2, and WT1, between patients with and without EZH2 mutations. Complete remission, event-free survival or overall survival was similar between AML patients with and without EZH2 mutation (p>0.05). These results demonstrated EZH2 mutation as a recurrent genetic abnormality associated with lower blast percentage in BM and −7/del(7q) in de novo acute myeloid leukemia. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3491-3491
Author(s):  
Susanne Schnittger ◽  
Manja Meggendorfer ◽  
Vera Grossmann ◽  
Tamara Alpermann ◽  
Christiane Eder ◽  
...  

Abstract Abstract 3491 Introduction: Chronic myeloid monocytic leukemia (CMML) has been associated with a high number of somatic mutations in diverse genes and various mutant genotype combinations were observed. The patterns of marker combinations and prognostic impact of single markers are poorly understood. Aims: Comprehensive analysis of the genetic marker profile in a large CMML cohort and evaluation of potential prognostic implications. Patients and Methods: In total, 268 cases with CMML (CMML-1 n=191, CMML-2 n=77) were included. The cohort comprised 186 males and 82 females with a median age of 73.0 yrs (range: 21.9 – 93.3 yrs). In 262 cases cytogenetic data was available: 185 cases (70.6%) had a normal karyotype and 77 (29.4%) showed aberrant karyotypes. Data on mutations were available in all patients for SRSF2, U2AF1, JAK2 V617F, and in subcohorts for: ASXL1 (n=255), CBL (n=267), EZH2 (n=205), KIT D816 (n=263), KRAS (n=260), NRAS (n=266), RUNX1 (n=267), SF3B1 (n=240), and TET2 (n=157). Mutations were analyzed by a combination of amplicon deep-sequencing (Roche 454, Branford, CT), direct Sanger sequencing, real time PCR or melting curve analyses. Analysis for overall survival was restricted to 185 cases with evaluable clinical data (median follow-up: 427 days, median OS: 51%). Results: In total 633 mutations were detected in 268 patients (median: 2 per patient, range 0–7). In CMML-1 the mean number of mutations was equal to CMML-2 (2.38 vs. 2.55, p=n.s.). In detail, the most frequent mutations were detected in TET2 (61.1%; 96/157), followed by SRSF2 (47.8%; 128/268), ASXL1 (44.7%; 144/255), RUNX1 (22.8%; 61/267), CBL (19.1%; 51/267), NRAS (15.4%; 41/266), KRAS (10.8%; 28/260), EZH2 (9.3%; 19/205), JAK2 (6.7%; 18/268), U2AF1 (5.2%; 14/268), SF3B1 (5.0%; 12/240), and KIT (4.2%; 11/263). Impact on survival was tested for all 12 gene mutations. A significant difference in overall survival (OS) was observed only for ASXL1 mut vs ASXL1 wt patients (median OS: 19.4 months vs not reached; p=0.003). None of the other gene mutations showed a significant impact on OS. In a next step mutations from the RAS pathway (NRAS, KRAS, CBL) were combined into one group (n=85) and were analyzed in comparison to all others (n=90). However, no impact on OS was detected. Next, patients with at least one mutation in a gene from the splicing machinery (U2AF1, SRSF2, SF3B1) (n=109) were combined and tested vs all other patients (n=57), however, no prognostic relevance was found. In addition, no difference in outcome was observed between CMML-1 and CMML-2 patients. Of note, the adverse impact of ASXL1 mut was restricted to the CMML-2 subcohort (25 mut, 31 wt, median OS: 17.3 months vs n.r.; p=0.001), whereas there was no effect in CMML-1 pts (59 mut and 54 wt). We also evaluated the cytogenetic risk score introduced by Such et al. (Haematologica 2011) and were not able to find differences in survival (neither pairwise between the respective subgroups, nor overall). However, we were able to show prognostic impact of ASXL1 mut within the cytogenetic risk groups suggested by Such: within the favorable subgroup ASXL1 mut patients (n=56) had worse outcome than ASXL1 wt (n=65) (median 19.4 months vs n.r.; p=0.027). This was true also for the adverse subgroup showing a trend to worse outcome for ASXL1 mut vs ASXL1 wt (n=16 vs n=9; median 17.3 months vs n.r.; p=0.057). No difference was seen between the 9 ASXL1 mut and 8 ASXL1 wt patients within the intermediate risk group. In the univariable cox regression analysis taking age, gender, type dysplastic vs proliferative, CMML-1 vs CMML-2, WBC, hemoglobin (Hb), Such score and ASXL1 mut into account, the following parameters were found to be relevant for outcome: age (p=0.001, HR 1.74 per decade), WBC (p=0.044, HR 1.08 per 10×109/L), Hb (p<0.001, HR 0.70, ASXL1 mut (p=0.004, HR 2.38). These parameters entered the multivariable analysis and age (p=0.005, HR: 1.61 per 10 yrs of increase), Hb (p<0.001 HR 0.704) and mutated ASXL1 status (p=0.009, HR 2.30) were independent prognostic parameters for OS. Conclusion: 1) CMML-1 as well as CMML-2 are genetically complex diseases each showing a high number of mutations. 2) One of the most frequently mutated genes in both subgroups is ASXL1. 3) ASXL1 is the only one out of 12 genes which is independently associated with adverse outcome. Disclosures: Schnittger: MLL Munich Leukemia Laboratory: Equity Ownership. Meggendorfer:MLL Munich Leukemia Laboratory: Employment. Grossmann:MLL Munich Leukemia Laboratory: Employment. Alpermann:MLL Munich Leukemia Laboratory: Employment. Eder:MLL Munich Leukemia Laboratory: Employment. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Equity Ownership.


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