IDH Mutations Can Be Detected In 28.7% of All Normal Karyotype AML and Have Unfavourable Impact on the NPM1+/FLT3-ITD- Genotype

Abstract Abstract 102 Introduction: Mutations in IDH1 and IHD2 have recently been shown to play an important role in AML. As they code for enzymes from the citric acid cycle mutations within these genes from the mechanistical point of view are a totally new kind of mutation associated with AML. In IDH1 one mutational hot spot (amino acid R132) and in IDH2 two hotspots (R140 and R172) have been reported. We aimed at further delineating the impact of IDH1 and IDH2 mutations in AML and analyzed the interaction with other mutations in normal karyotype (NK) AML. Methods: 526 AML patients were selected according to normal karyotype and availability of mutational status for FLT3-ITD, NPM1 and MLL-PTD. Further mutation analyses were available in subgroups of the cohort (FLT3-TKD: n=318, CEBPA: n=369, RUNX1: n=174, NRAS: n=220). Female/male ratio was 283/243 and age ranged from 20.0–90.1 years (median, 66.9 years). 435 had de novo AML (82.6%), 71 AML following MDS (s-AML,13.5%) and 20 AML after previous treatment of other malignancies (t-AML, 3.8%). The respective base exchanges in R132, R140, and R172 were analysed by a melting curve assay with subsequent sequencing of the positive samples. Results: Overall, in 151 pts (28.7%) IDH mutations (IDHmut) were detected. In detail, 68 mutations (12.9% of all cases) were detected in IDH1 (R131C: n=35, R131L: n=17, R131H: n=7, R131G: n=6, R131S: n=3) and 83 mutations (15.8%) in IDH2 (R140Q: n=72, R140L: n=2, R140W: n=1, N141G: n=1, R174K: n=7). IDH1mut and IDH2mut were mutually exclusive in this cohort. IDH1mut were more frequent in females (18.2% vs 8.6 % in males, p=0.001), whereas there was no sex difference for IDH2. According to history IDH1 was equally distributed in de novo AML, s-AML and t-AML whereas IDH2 was more frequent in de novo compared to s- and t-AML (19.6% vs. 7.6 vs 11.8%, p=0.048). According to FAB the most prevalent subtype was FAB M1 with IDHmut in 23.2% compared to 9.8% in all other FAB (in detail: IDH1: 44.8% vs. 23.9%, IDH2: 27.0% vs. 15.1%; p<0.001, for both). IDH1 was underrepresented in M4 (4.9% vs. 15.0 % in all other subtypes, p=0.004), whereas the distribution of IHD2 was not different in M4 vs. all others. The immunophenotype (n= 297) of IDHmut cases tended to be more immature and featured a lower expression of monocytic markers. The analyzed 78 IDHmut cases, as compared to 219 IDHwt cases, showed a significantly higher expression of MPO and CD117 while CD116, CD11b, CD14, CD15, CD36. CD56, CD64, CD65 and CD7 were lower expressed. Age, WBC count, and platelet count were not different between IDH1, IDH2 and IDHwt cases. IDH mutations are not mutually exclusive of other mutations. However, the frequency of CEBPAmut in IDHmut compared to IDHwt was decreased (7.7% vs. 13.7, p=0.001) (IDH1: 0% vs 11.7%, p=0.022 and IDH2: 7.7% vs 13.4%, p=0.053). MLL-PTD was more frequent in IDHmut vs. IDHwt (44.7 vs. 5.8%, p=0.039), however, this is restricted to IDH1mut vs. IDH1wt (26.3 vs. 6.3%, p=0.018). RUNX1mut are distributed equally in IDH2mut and IDH2wt (20.0% vs 27.3%) but are underrepresented in IDH1mut compared to IDH1wt (2.2% vs. 28.7%, p=0.068). FLT3-ITDs are equally distributed between IDHmut and IDHwt, however, those IDH1mut with FLT3-ITD have lower FLT3-ITD/FLT3wt ratios compared to FLT3-ITD+ IDH1wt cases (mean: 0.16 vs. 0.72; p=0.005). All other mutations were distributed equally in IDHmut compared to IDHwt. For survival analysis only cases with de novo AML <65 years were included (n=164, IDHmut: n=37, n=, IDHwt: 127). In the total analysis there was no effect on overall survival or event free survival (EFS). However there was a trend for shorter EFS of the IDHmut vs. IDHwt (median: 439 days vs. not reached, p=0.080) in cases with NPM1+/FLT3-ITD- genotype. For IDH2 there was a significant adverse effect in the NPM1+/FLT3-ITD- group (median EFS: 397 vs. 679 days, p=0.045). Summary: IDH mutations belong to the most frequent mutations in NK AML and can occur together with all other known mutations. There is a high preponderance for the FAB M1 subtype and a more immature immunophenotype for both IDH mutations and a strong female preponderance for IDH1. In addition, an adverse prognostic impact of IDH mutations was shown for the NPM1+/FLT3-ITD- genotype. Further analyses should focus on the definition of the role and place of IDH mutations for therapeutic decisions in patients with AML. Disclosures: Schnittger: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Alpermann:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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In CLL with Normal Karyotype By Conventional and Genomic Array Karyotyping the Prognostic Impact of an Unmutated IGHV Status Is Stronger Than the Impact of Gene Mutations

Blood ◽

10.1182/blood.v128.22.4357.4357 ◽

2016 ◽

Vol 128 (22) ◽

pp. 4357-4357 ◽

Cited By ~ 1

Author(s):

Calogero Vetro ◽

Torsten Haferlach ◽

Manja Meggendorfer ◽

Sabine Jeromin ◽

Constance Regina Baer ◽

...

Keyword(s):

Gene Mutation ◽

Mutation Rate ◽

Gene Mutations ◽

Normal Karyotype ◽

Prognostic Impact ◽

Employment Equity ◽

Mutation Status ◽

Genomic Array ◽

Equity Ownership ◽

The Impact

Abstract Background: In 15-20% of CLL cases no aberrations are detected by chromosome banding analysis (CBA) and FISH due to limited resolution, lack of evaluable metaphases or presence of aberrations in loci not covered by standard-panel FISH probes. As reported in our previous study (Haferlach C. et al., ASH 2015, abs ID#79545), genomic arrays (GA) detected abnormalities in almost 20% of cases classified as normal by CBA and FISH and these showed an impact on time to first treatment (TTT) (Vetro C. et al., EHA 2016, abs ID# E1069). The CLL subgroup without abnormalities in CBA, FISH, and GA has not been characterised in detail, so far. Aims: 1) to describe CLL without abnormalities by CBA/FISH/GA by evaluating an extended gene panel, the IGHV mutation status and the B-cell receptor (BCR) stereotypy; 2) to determine prognostic impact of these factors. Patients and Methods: CLL diagnosis was based on cytomorphology and immunophenotyping according to standard guidelines. From a cohort of 1190 patients at diagnosis, 133 (11%) were selected based on normal karyotype by CBA, no abnormalities by interphase FISH with probes for 17p13 (TP53), 13q14 (D13S25, D13S319, DLEU), 11q22 (ATM), centromeric region of chromosome 12 and t(11;14)(q13;q32) (IGH-CCND1) and no abnormalities by GA (SurePrint G3 ISCA CGH+SNP Microarray, Agilent, Waldbronn, Germany). IGHV mutation status and BCR stereotypy were determined according to Agathangelidis et al., Blood 2012, and DNA sequencing was performed for the following genes: ATM; SF3B1; TP53; KLHL6; KRAS; MYD88; NOTCH1; NRAS; POT1; FBXW7; HIST1H1E; XPO1; ITPKB; MAPK1; BIRC3; BRAF; DDX3X; EGR2; RIPK1; RPS15; CND2. Results: Median age was 66 years (range: 33-83). Median follow-up was 5.6 years, 33 patients (25%) received treatment since genetic analyses. 10-year overall survival (OS) was 76% and median TTT was 9.2 years. Mutations were observed in 53 patients (40%): SF3B1 (n=17; 13%); NOTCH1 (n=10; 8%); KLHL6 (n=6; 5%); TP53 (n=6; 5%); ATM (n=5; 4%); XPO1 (n=4; 3%); FBXW7 (n=3; 2%); MYD88 (n=3; 2%); DDX3X (n=2; 2%); POT1 (n=2; 1.5%); ITPKB (n=1; 1%); KRAS (n=1; 1%); NRAS (n=1; 1%); and no mutation in RPS15, CCND2, MAPK1, EGR2, BRAF, HIST1H1E, RIPK1, BIRC3. 6 patients had 2 simultaneous gene mutations and 1 patient had 3 (i.e. NOTCH1, ATM and TP53). A mutated IGHV status (IGHV-M) was present in 100 patients (75%) and an unmutated IGHV status (IGHV-U) in 33 patients (25%). IGHV-U was related to both the occurrence of any gene mutation (p<0.001) and the number of gene mutations (p=0.001). NOTCH1 was mutated in 7 out of the 33 IGHV-U patients (21%), but only in 3 out of 99 IGHV-M patients (3%) (p=0.001). XPO1 mutation occurred in 4 IGHV-U patients (12%) and none out of IGHV-M (p<0.001). Two IGHV-U patients showed POT1 mutation (6%), but no IGHV-M case (p=0.014). 9 patients out of 133 (7%) showed BCR-stereotypy. 2 were in cluster CLL#1 (both showing NOTCH1 mutation), 2 in cluster CLL#2 (both of them with SF3B1 mutation), 2 in CLL#4, 1 in CLL#8 (showing NOTCH1 and XPO1 mutations), 1 in CLL#201 (with KLHL6 mutation) and 1 in CLL#202 (with mutations in ATM, TP53 and NOTCH1 genes). In Kaplan-Meier analysis, IGHV-M patients did not reach a median TTT, while IGHV-U had a median of 5.1 years (p<0.001). Stereotypy rate was too low for reliable statistics. At univariate analysis, TTT was only influenced by: IGHV-U (relative risk (RR): 3.9, p<0.001), TP53 mutation (RR: 3.7, p=0.03), % CLL cells (RR: 1.2 per 10% increase, p=0.013), and number of mutations (RR: 1.8 per each mutation, p=0.031). Multivariate Cox regression analysis showed an independent role for IGHV-U status (RR: 3.3, p=0.002) and % CLL cells (RR: 1.2 per 10% increase, p=0.038) Only age showed an impact on OS (RR: 1.2 per decade, p<0.001). Conclusions: 1. The CLL subset without any genomic event by CBA/FISH/genomic array is characterized by very low frequency of IGHV-U status; 2. IGHV-U subgroup showed higher gene mutation rate compared to IGHV-M subgroup, in particular higher NOTCH1, XPO1 and POT1 mutation rate; 3. BCR stereotypy is less frequent than in CLL in general. 4. IGHV-U, as well as the higher disease burden (i.e. % CLL cells), has an independent negative impact on TTT. 5. Requirement for treatment is low and prognosis very favorable in CLL without any genomic event by CBA/FISH/genomic array and a mutated IGHV status. Disclosures Vetro: MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Meggendorfer:MLL Munich Leukemia Laboratory: Employment. Jeromin:MLL Munich Leukemia Laboratory: Employment. Baer:MLL Munich Leukemia Laboratory: Employment. Nadarajah:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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ETV6 Rearrangements Are Recurrent Genetic Events In Myeloid Malignancies and In AML Are Associated with NPM1- and RUNX1-Mutations and An Intermediate Prognosis

Blood ◽

10.1182/blood.v116.21.2758.2758 ◽

2010 ◽

Vol 116 (21) ◽

pp. 2758-2758

Author(s):

Claudia Haferlach ◽

Susanne Schnittger ◽

Wolfgang Kern ◽

Torsten Haferlach

Keyword(s):

De Novo ◽

Normal Karyotype ◽

Employment Equity ◽

Childhood All ◽

Myeloid Malignancies ◽

Equity Ownership ◽

De Novo Aml ◽

Diagnostic Work ◽

Work Up

Abstract Abstract 2758 Introduction: The ETV6 gene (formerly TEL) is located in the chromosomal band 12p13 and is a frequent target of deletions and chromosomal translocations in both myeloid and lymphoid leukemias. In ALL the most frequent partner gene of ETV6 is RUNX1. ALL with ETV6-RUNX1 fusions are observed in 20% of childhood ALL and are associated with favorable outcome. In contrast ETV6 rearrangements are less frequent and not well described in myeloid malignancies. Therefore, the aim of this study was to analyze ETV6 rearrangements in myeloid malignancies with respect to frequency, partner genes and impact on prognosis. Patients/Methods: 55 cases with ETV6 rearrangements were identified in a total cohort of 9,550 cases (0.5%) with myeloid malignancies (de novo AML: n=3,090, s-AML: 486, t-AML: 222, MDS: n=3,375, MDS/MPN overlap: n=210, CMML: n=447, MPN: n=1,720) which had been sent to our laboratory between 08/2005 and 07/2010 for diagnostic work-up. In all cases chromosome banding analysis was performed and in cases with abnormalities involving 12p13 FISH was carried out in addition to verify the ETV6 rearrangement. Results: ETV6 rearrangements were observed in 31 patients with de novo AML (1.0% of investigated cases), 8 with s-AML (1.7%), 5 with t-AML (2.3%), 6 with MDS (0.2%) and 5 with MPN (0.3%). No ETV6 rearrangements were detected in the cohorts of MDS/MPN or CMML. ETV6 rearrangements were significantly more frequent in s-AML and t-AML as compared to de novo AML (p<0.001). Median age in AML was 59.9 years. In 15 cases with de novo AML FAB-subtypes were available: M0: n=8, M1: n=4, M2: n=1, M4: n=1, and M7: n=1. Thus, ETV6 rearrangements are closely related to immature AML subtypes. In 25/55 cases (45.5%) the ETV6 rearrangement was the sole abnormality. Recurrent additional abnormalities were 7q-/-7 in 10 cases and del(5q) in 8 cases. 36 different partners of ETV6 were observed, recurrent partners were located on 3q26 (EVI1, n=11), 5q33 (PDGFRB, n=4), 22q12 (n=3), 2q31 (n=2), 5q31 (ACSL6, n=2), 12p12 (n=2), 17q11 (n=2). Molecular analysis was performed in addition in AML with ETV6 rearrangements for mutations in NPM1 (n=26 investigated), FLT3-ITD (n=33), FLT3-TKD (n=11), MLL-PTD (n=25) and RUNX1 (n=7). NPM1-mutations were observed in 5 cases (19.2%), FLT3-ITD in 3 cases (9.1%), FLT3-TKD in 2 cases (18.2%), MLL-PTD in 1 case (4%) and RUNX1 mutations in 4 cases (57.1%), respectively. Clinical follow-up data was available of 47 cases. No differences in overall survival (OS) and event-free survival (EFS) were observed in cases with ETV6 rearrangement whether or not additional cytogenetic abnormalities or 7q-/-7 or del(5q) were present. Next 30 de novo AML with ETV6 rearrangement were compared to 819 AML without ETV6 rearrangement. Based on cytogenetics cases were assigned into 9 subgroups: 1) t(15;17)(q22;q21), n=48; 2) t(8;21)(q22;q22), n=29; 3) inv(16)(p13q22)/t(16;16)(p13;q22), n=19; 4) 11q23/MLL abnormalities, n=28; 5) inv(3)(q21q26)/t(3;3)(q21;q26), n=6; 6) normal karyotype, n=424; 7) complex karyotype, n=71; 8) other abnormalities, n=194 and 9) ETV6 rearrangements, n=30. Median OS was not reached for groups 1, 2, 3, 4, and 6 and was 10.6 mo, 11.8 mo, 32.2 and 26.3 mo for groups 5, 7, 8, and 9 respectively. OS at 2 yrs was 95.6%, 96.3%, 76.6%, 64.9%, 26.7%, 63.3%, 23.9%, 58.5% and 60.1% for groups 1–9, respectively. The respective data for median EFS were: not reached for groups 1 and 2 and 15.9 mo, 13.5 mo, 5.1 mo, 16.6 mo, 7.5 mo, 12.5 mo and 14.0 mo for groups 3–9, respectively. Conclusions: ETV6 rearrangements are rare in myeloid malignancies. ETV6 is rearranged with a large variety of partner genes. The highest frequency of ETV6 rearrangements was observed in s-AML and t-AML. OS and EFS of AML with ETV6 rearrangements are comparable to AML with normal karyotype. Thus, the detection of ETV6 rearrangements is associated with in intermediate prognosis. Disclosures: Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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Evaluation of the New Genetic Risk Classification of the European LeukemiaNet Recommendations in 1,110 Patients with De Novo AML and Proposal of a Refined Version

Blood ◽

10.1182/blood.v118.21.413.413 ◽

2011 ◽

Vol 118 (21) ◽

pp. 413-413

Author(s):

Tamara Alpermann ◽

Wolfgang Kern ◽

Susanne Schnittger ◽

Claudia Haferlach ◽

Torsten Haferlach

Keyword(s):

Molecular Markers ◽

De Novo ◽

Prognostic Impact ◽

Employment Equity ◽

Female Ratio ◽

Mutation Status ◽

Equity Ownership ◽

De Novo Aml ◽

Favorable Group ◽

Refined Version

Abstract Abstract 413 Background: The recently published recommendations for prognostication in AML (Döhner et al. for ELN, Blood 2010;115,453–474) were based on a review of the literature and included cytogenetics as well as NPM1, CEBPA and FLT3-ITD mutation status for risk stratification. We here aimed to evaluate the prognostic impact of this approach in an independent cohort. Patients: We started with a cohort of 1,428 adults with newly diagnosed AML, which were investigated by cytomorphology, immunophenotyping, cytogenetics, and molecular genetics. We first excluded patients with t(15;17) (n=59), therapy-associated AML (n=111) and secondary AML (n=148). Thus, 1,110 patients with de novo AML and cytogenetics available in all cases were further evaluated according to ELN criteria. The following molecular markers were investigated: NPM1 (1,064/1,110), FLT3-ITD (1,066/1,110), CEBPA (880/1,110), MLL-PTD (1,064/1,110) and RUNX1 (454/1,110). Results: Male/female ratio was 1.2 (598/512), median age was 66.6 years (range 18.3 – 100.4). According to the ELN proposal 297 (26.8%) pts were assigned to the favorable group (CBF leukemias, NPM1mut/without FLT3-ITD in normal karyotype (NK), or CEBPAmut in NK), 363 (32.7%) pts were classified as intermediate I (NPM1mut/FLT3-ITD+, or NPM1wt/FLT3-ITD+, or NPM1wt without FLT3-ITD; all NK), 249 (22.4%) as intermediate II (t(9;11) or cytogenetic abnormalities not classified as favorable or adverse), and 201 (18.1%) as adverse (inv(3)/t(3;3); t(6;9); t(v;11)(v;q23); −5 or del(5q); −7; abn(17p); complex karyotype, i.e. ≥ 3 chromosome abnormalities)). Evaluation according to these criteria revealed significant differences in overall survival between the favorable subgroup and all other subgroups (inter I p<0.001; inter II 0.008, adv <0.001). Also adverse vs all other subgroups (all p<0.001) differed significantly with respect to OS. However, no significant differences were observed between both large cohorts of inter I and inter II (together 55.1% of all pts). We therefore intended to revise the ELN criteria for better discrimination of the intermediate groups. In addition to ELN recommendations we considered a threshold of 0.5 for the FLT3-ITD ratio (mut/wt) which had been suggested more valid for prognostication than the mutation status per se. For the revised classification molecular markers were mandatory for all cases with intermediate risk cytogenetics. Therefore, 100 cases had to be excluded due to missing data. Thus, 1,010 pts were reclassified into our new subgroups defined as: favorable I: CBF leukemias; favorable II:NPM1mut or biallelic CEBPAmut (without any other molecular marker and no fav or adv cytogenetics); intermediate I:FLT3-ITD ratio <0.5 (without RUNX1 or MLL-PTD and no fav or adv cytogenetics); intermediate II:FLT3-ITD ratio ≥0.5 and/or RUNX1mut and/or MLL-PTD+ (and no fav or adv cytogenetics); adverse: as defined by ELN. Patients were distributed as follows: fav I: 68 (6.7%), fav II: 286 (28.3%), inter I: 157 (15.5%), inter II: 298 (29.5%), adv: 201 (19.9%). Fav I and fav II had no significant differences in OS (median n.r. vs 62.2 mo, n.s.) and therefore were grouped together as “favorable”. This finally leads to four different prognostic subgroups: favorable: CBF leukemias; NPM1mut or biallelic CEBPAmut, intermediate I:FLT3-ITD ratio <0.5, intermediate II:FLT3-ITD ratio ≥0.5 and/or RUNX1mut and/or MLL-PTD+, adverse. Patients were distributed as follows: fav: 354 (35.0%), inter I 157 (15.5%), inter II: 298 (29.5%), adv: 201 (19.9%). Median OS differed between all subgroups: fav 62.2, inter I 24.3, inter II 12.4, adv 8.7 mo. (fav vs inter I p=0.058, vs inter II <0.001, vs adv <0.001; inter I vs inter II 0.004, vs adv <0.001; inter II vs adv 0.039). Conclusion: The new ELN proposal for prognostication in de novo AML is based on cytogenetic and molecular genetic data. Based on this proposal we further improved prognostication in a series of 1,010 pts by integrating the following molecular markers besides cytogenetics: NPM1mut, biallelic CEBPAmut and FLT3-ITD ratio <0.5 for the favorable group and FLT3-ITD ratio ≥0.5, other CEBPAmut, MLL-PTD+, or RUNX1mut for the intermediate group, and adverse based on cytogenetics only. This refined version may contribute to a better risk assessment in de novo AML patients allowing to separate 4 subgroups with striking differences in OS. Disclosures: Alpermann: MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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WT1 Mutations Are Secondary Events In AML and Show Varying Frequencies Within Genetic Subgroups and Different Impact On Prognosis

Blood ◽

10.1182/blood.v122.21.2542.2542 ◽

2013 ◽

Vol 122 (21) ◽

pp. 2542-2542

Author(s):

Susanne Schnittger ◽

Christiane Eder ◽

Tamara Alpermann ◽

Frank Dicker ◽

Madlen Ulke ◽

...

Keyword(s):

Multivariate Analysis ◽

Median Time ◽

Univariate Analysis ◽

Normal Karyotype ◽

Adverse Impact ◽

Prognostic Impact ◽

Employment Equity ◽

Genetic Aberrations ◽

Equity Ownership ◽

The Impact

Abstract Background Mutations (mut) in the WT1 gene belong to the first genetic aberrations described in AML. In contrast to recurrent fusion genes or NPM1mut WT1mut do not seem to be disease defining. Also in contrast to other mutations in AML, for most of which a certain prognostic value has been established, the impact of WT1mut still is discussed controversially. Aim Analyze the frequency and prognostic impact of WT1 mutations in comparison to other genetic aberrations. Patients and Methods 3,157 unselected AML patients (pts) were analyzed (de novo: n=2,699, s-AML: n=234, t-AML: n=224). 1,708 pts were male and 1,449 female. Median age was 67.1 years (y) (range: 17.8-100.4 y) with 1,108 pts <60 y and 2,049 ≥60 y. The mutational hot spot regions of WT1 (exons 7 and 9) were analyzed by direct Sanger sequencing with a sensitivity of ∼10%. Karyotype and WT1 mutation status was available in all cases. Other mutations were assessed in subsets: ASXL1 (n=1,951), CEBPA (n=2,670), DNMT3A (n=1,293), FLT3-ITD (n=3,149), FLT3-TKD (n=3,004), IDH1R132 (n=2,431), IDH2R140 (n=2,380), IDH2R172 (n=2,412), KRAS (n=1,409), NRAS (n=1,780), NPM1 (n=3,003), MLL-PTD (n=2,961), RUNX1 (n=2,390), TET2 (n=1,016) and TP53 (n=1,215). Results A total of 189 WT1 mutations were detected (exon 7: n=151, exon 9: n=38). The total frequency of WT1mut pts was 175/3,157 (5.5%). 11 pts were double to quadruple mutated. The frequency was heterogeneous with respect to AML subtypes. Compared to all others, significantly higher frequencies were detected in biallelic CEBPAmut (15/110; 13.6%; p=0.001), followed by t(15;17)/PML-RARA (18/164; 11.0%, p=0.004), and FLT3-ITD (58/682; 8.5%, p<0.001). Lower frequencies were observed in DNMT3Amut (18/412; 4.3%, p=0.014, ASXL1mut (6/355; 1.7%, p<0.001), IDH2R140 (5/286; 1.7%, p=0.001), and IDH1R132 (2/222; 0.9%, p<0.001). WT1mut were never detected in pts with complex karyotypes (0/175; p=0.047) or those with IDH2R172 (0/68; p=0.020). Further, WT1mut were more frequent in females (95/1,449, 6.6%) than in males (80/1,708, 4.7%) (p=0.014) and in younger pts (<60 y: 102/1,108, 9.2% vs ≥ 60 y: 73/2,049, 3.6%; p<0.001). Median age of pts with WT1mut was 55.5 y compared to 63.6 in WT1wt (p<0.001). Further, WT1mut were associated with lower platelet count (58.4 vs 84.7 x109/L; p<0.001) and lower hemoglobin level (8.8 vs 9.3 g/dL, p=0.001). There was no association to the history of the disease or white blood cell count. Stability of WT1mut was analyzed in 35 paired diagnostic and relapse samples (median time of relapse after diagnoses: 11.1 months (m); range: 2.6-60.6 m). In 23 cases (65.7%) the WT1mut was retained at relapse and in 12 cases (34.3%) it was lost. In 5 cases a sample at 2nd relapse was available (median time from 1st relapse: 8.5 m, range: 6.0-18.0 m). 3 of these cases retained and 2 lost the WT1mut. Analysis of prognostic impact was restricted to intensively treated pts (n=1,936, WT1mut: n=132, 6.8%). In the total cohort, there was no impact of WT1mut on prognosis. In pts ≥60 y there was a trend to shorter event free survival (EFS) for WT1mut (9.3 vs 12.3 m, p=0.052). In the two prognostically favorable groups with high WT1mut incidences (biallelic CEBPAmut and PML-RARA) no effect on outcome was seen. When restricting the analysis to normal karyotype AML (WT1mut: n=85, WT1wt: n=1,093) WT1mut pts had shorter EFS (10.8 vs 17.9 m, p=0.008). This was true for the younger (12.2 vs 29.0 m, p=0.007) as well as for the older pts (9.3 vs 13.9 m, p=0.016). In a multivariate analysis all parameters with significant impact on EFS in univariate analysis were included: age (p<0.001, HR: 1.24), ASXL1mut (p<0.001, HR: 1.36), FLT3-ITD (p<0.001, HR: 1.55), NPM1mut/FLT3-ITD wild-type (p<0.001, HR:1.55), RUNX1 (p=0.019, HR: 1.23, and WT1mut (p=0.009, HR: 1.64). In multivariate analysis WT1mut was found to have independent adverse impact on EFS (p=0.002, HR: 1.64) besides FLT3-ITD status (p<0.001, HR: 1.71) and age (p<0.001, HR: 1.28). Conclusions WT1 mutations are 1) more frequent in females and younger AML, 2) more frequent in t(15;17)/PML-RARA, biallelic CEBPAmut, FLT3-ITD mutated AML, and nearly mutually exclusive of ASXL1, IDH1, IDH2 and complex karyotype. 3) The distribution pattern in different genetic subtypes and the instability during follow-up as shown by paired sample analyses clearly emphasize a secondary character of this mutation. 4) For AML with normal karyotype an independent adverse impact of WT1mut on EFS was shown. Disclosures: Schnittger: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Eder:MLL Munich Leukemia Laboratory: Employment. Alpermann:MLL Munich Leukemia Laboratory: Employment. Dicker:MLL Munich Leukemia Laboratory: Employment. Ulke:MLL Munich Leukemia Laboratory: Employment. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Kuznia:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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AML with RUNX1 Mutations and Loss of RUNX1 Wild-Type - a Distinct Subset?

Blood ◽

10.1182/blood.v126.23.2578.2578 ◽

2015 ◽

Vol 126 (23) ◽

pp. 2578-2578

Author(s):

Claudia Haferlach ◽

Niroshan Nadarajah ◽

Annette Fasan ◽

Karolína Perglerová ◽

Wolfgang Kern ◽

...

Keyword(s):

De Novo ◽

Chromosome 21 ◽

Prognostic Impact ◽

Wild Type ◽

Mutation Load ◽

Employment Equity ◽

Runx1 Gene ◽

Equity Ownership ◽

De Novo Aml ◽

Runx1 Mutation

Abstract Background: Mutations in RUNX1 have been reported in 5 to 20% of AML. RUNX1 mutated AML is associated with a myeloid rather than monocytic differentiation, shows a typical pattern of cytogenetic abnormalities with a high frequency of trisomy 8 or 13, has a typical pattern of additional molecular mutations with a high frequency of accompanying ASXL1 and SF3B1 mutations and is nearly mutually exclusive of NPM1 and CEBPA double mutations and other entity-defining genetic abnormalities. In a subset of patients with RUNX1 mutations loss of the wild-type allele can be assumed due to a high mutation load. The aim of this study was the detailed analysis of a subset of RUNX1 mutated AML with RUNX1 wild-type loss with respect to accompanying cytogenetic and molecular genetic abnormalities and prognostic impact. Patients and Methods: A cohort of 467 AML with RUNX1 mutations (mut) at diagnosis identified during diagnostic work-up in our laboratory were the basis of this study. Median age was 72 years (yrs) (range 18-91 yrs), and male:female ratio 296: 171. 366 patients had de novo AML, 77 s-AML following MDS, 24 t-AML. For all patients (pts) cytogenetics and for 341 data on FAB subtype was available. Mutation data was available for NPM1 (n=456), MLL-PTD (n=453), CEBPA (n=449), FLT3-ITD (n=457), FLT3-TKD (n=457), WT1 (n=398), ASXL1 (n=313), TP53 (n=231), DNMT3A (n=177), TET2 (n=174), NRAS (n=305), KRAS (n=213) and SF3B1 (n=119). 64 patients with a mutation load of RUNX1 mutation >70% evaluated by sequencing analysis were selected for further analysis. All 64 cases were analysed by genomic arrays (SurePrint G3 ISCA CGH+SNP Microarray, Agilent, Waldbronn, Germany) to determine the copy number state and copy neutral loss of heterozygosity (CN-LOH). Median age was 73 yrs (range 24-87 yrs), and male:female ratio was 27: 37. 50 patients had de novo AML, 11 s-AML following MDS, 3 t-AML. Results: Array CGH revealed a cytogenetically cryptic deletion on the long arm of chromosome 21 encompassing the RUNX1 gene in 5/64 (8%) patients while a CN-LOH on 21q including the RUNX1 gene was observed in 45 cases (70%). Thus in 50 cases (78%) with a high RUNX1 mutation load a RUNX1 wild-type loss (wt-loss) was detected by array CGH. In 43% (6/14) of the remaining cases the high RUNX1 mutation load was caused by amplification of the long arm of chromosome 21 either due to gain of whole chromosomes 21 or to an isochromosome 21q. First we focused on the characterization of RUNX1 mutated cases with RUNX1 wt-loss. In 22/50 cases (44%) an aberrant karyotype was observed with a distinct aberration pattern. 11 cases harbored +13, 5 had +8 and 6 cases a loss of 7q. No other recurrent abnormalities were observed. With respect to concurrent mutations the following frequencies were found: ASXL1 (42%), FLT3 -ITD (34%), TET2 (21%), KRAS (11%), MLL-PTD (8%), NRAS (7%), and FLT3-TKD (6%). No NPM1 mutation or CEBPA double mutations were identified. Comparison of those cases with RUNX1 wt-loss to all other RUNX1 mutated AML (n=417) revealed a significantly higher frequency of +13 (22% vs 9%, p=0.01) and FLT3 -ITD (34% vs 19%, p=0.015). FAB subtypes M0 and M1 were more frequent (46% vs 12%, p<0.001; 35% vs 22%, n.s.) and M2 and M4 less frequent (14% vs 46%, p<0.0001; 5% vs 17%, n.s.). Survival analyses were restricted to 212 de novo AML pts with RUNX1 mut who received intensive chemotherapy (median overall survival (OS): 20 months (mo), median event-free survival (EFS): 12 mo). Median OS and EFS was shorter in patients with RUNX1 wt-loss compared to those without (15 vs 20 mo, n.s., 10 vs 12 mo, p=0.04). In univariate Cox regression analysis a negative impact on OS was observed for RAS mut (relative risk (RR): 2.2, p=0.005), male gender (RR: 1.6, p=0.02), and age (RR: 1.3 per decade, p<0.001). Shorter EFS was associated with RUNX1 wt-loss (RR: 1.7, p=0.04), RAS mut (RR: 1.9, p=0.02) and age (RR: 1.2 per decade, p<0.001). In multivariate analysis RAS mut (OS: RR: 2.4, p=0.002; EFS: RR: 2.0, p=0.008) and age (OS: RR: 1.3 per decade, p<0.001; EFS: RR: 1.2 per decade, p<0.001) had independent prognostic impact. Conclusions: RUNX1 mutated AML with wild-type loss is a distinct AML subset that does not overlap with any of the genetically defined WHO categories and is characterized by an immature phenotype (81% FAB Subtype M0 and M1) and a higher frequency of +13 and FLT3-ITD as compared to RUNX1 mutated AML without wild-type loss. Wild-type loss and RAS mutations are associated with inferior outcome in RUNX1 mutated AML. Disclosures Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Nadarajah:MLL Munich Leukemia Laboratory: Employment. Fasan:MLL Munich Leukemia Laboratory: Employment. Perglerová:MLL2 s.r.o.: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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Methylation of the Proximal, Distal and Core Promoter of CEBPA in 574 Cases with Normal Karyotype AML and 44 with t(8;21) Disclosed Different Frequencies but No Impact on Prognosis

Blood ◽

10.1182/blood.v118.21.2560.2560 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2560-2560

Author(s):

Annette Fasan ◽

Tamara Alpermann ◽

Vera Grossmann ◽

Christiane Eder ◽

Claudia Haferlach ◽

...

Keyword(s):

Mrna Expression ◽

De Novo ◽

Core Promoter ◽

Normal Karyotype ◽

Employment Equity ◽

Equity Ownership ◽

De Novo Aml ◽

Cebpa Mutations ◽

Distal Promoter ◽

Mrna Expression Levels

Abstract Abstract 2560 Background: Loss of CEBPA function due to mutations is thoroughly explored in AML. Recently epigenetic modifications such as promoter methylation have gained increasing interest as additional mechanisms for transcriptional regulation of cancer related genes. In this context, the clinical impact of aberrant CEBPA promoter methylation (PM) in AML is controversially discussed. The aim of this study was to clarify the frequency and the significance of aberrant CEBPA PM with regard to clinical features in a large cohort of de novo AML patients. The study comprises the CEBPA core promoter as well as the distal and proximal CEBPA promoter region as it has been shown that these upstream located regions also bear promoter activity. Patients:CEBPA PM was analyzed in a cohort of 574 de novo AML patients with normal karyotype (NK-AML) and without CEBPA mutations. The cohort was composed of 268 females and 306 males. Age ranged from 20.0 to 89.6 years (median: 63.7). In addition, methylation status was assessed in 48 patients with biallelic (n=10) or monoallelic (n=38) CEBPA mutations to exclude coincidence with CEBPA PM. As the fusion transcript RUNX1-RUNX1T1 is known to down-regulate CEBPA mRNA and protein levels in AML, we also analyzed CEBPA distal PM status in 44 RUNX1-RUNX1T1 positive AML patients to evaluate a possible correlation between CEBPA distal PM and RUNX1-RUNX1T1 induced down-regulation of CEBPA expression. All patients were intensively treated using standard AML protocols. Methods: Proximal PM and distal PM were analyzed in the total cohort using Sanger sequencing. Core PM was screened by methylation specific PCR in a subcohort of 326 CEBPA unmutated cases. Methylation data was correlated to clinical outcomes and to the presence of FLT3-ITD (n=175/568), NPM1 (n=256/565), RUNX1 (n=91/275), MLL-PTD (n=76/567), IDH1G105 (n=47/353), IDH1R132 (n=38/371), IDH2R140 (n=65/332) and IDH2R172 (n=12/342) molecular mutations. In addition, CEBPA mRNA expression levels were assessed by quantitative real time PCR (Taqman®, Life Technologies, Carlsbad, CA) in 39 cases with CEBPA distal PM and in 8 cases of the NK-AML cohort tested negative for CEBPA distal PM. CEBPA expression was normalized against the expression of the control gene ABL1. Results: The CEBPA distal promoter was methylated in 54/574 cases (9.4%) whereas CEBPA proximal PM was found in none of the 574 cases. Methylation of the CEBPA core promoter was detected in only 8 of 326 cases (2.5%). As CEBPA proximal and core PM seem to be rare events in AML, they were excluded from further analysis. None of the 48 CEBPA mutated cases revealed any PM and thus aberrant CEBPA PM and mutation status were mutually exclusive. Surprisingly, analysis of CEBPA mRNA expression level revealed no difference between CEBPA distal PM positive and CEBPA distal PM negative cases (mean ± SD 145 ± 97.9 and range 2.7–474.2 vs. 141.4 ± 85.3 and 23.1–259.2, n.s.) suggesting that CEBPA distal PM has no influence on CEBPA mRNA expression in NK-AML. In contrast, we observed a significantly higher frequency of CEBPA distal PM in patients with RUNX1-RUNX1T1 positive AML (n=17/44; 38.6%) compared to the NK-AML cohort (n=55/572; 9.4%) (p<0.001) indicating a correlation between RUNX1-RUNX1T1 induced down-regulation of CEBPA expression and CEBPA distal PM. In the NK-AML cohort, there was no correlation between CEBPA distal PM and age, sex, white blood cell count or Hb levels at diagnosis compared to unmethylated cases. We also were not able to detect a significant correlation between the presence of CEBPA distal PM and the other molecular mutations except for the frequency of IDH2R140 mutations which was significantly lower in CEBPA distal PM positive compared to CEBPA distal PM negative cases (21/267; 7.9% vs. 13/65, 20%, p=0.010). In addition, CEBPA distal PM was not related to overall survival, event free survival or incidence of relapse in NK-AML. Also in subcohorts that were defined by specific molecular mutations (FLT3-ITD, NPM1, RUNX1, MLL-PTD, IDH1, or IDH2) no prognostic impact of CEBPA distal PM could be shown. Conclusion:CEBPA PM in NK-AML was detected in 11.9% of all cases and seems to be mainly restricted to the distal promoter (9.4%). In contrast to RUNX1/RUNX1T1 positive AML no impact of CEBPA PM on CEBPA mRNA expression levels was detected in NK AML. We also conclude that the presence of aberrant CEBPA PM has no clinical relevance in NK-AML and therefore is negligible as prognostic marker. Disclosures: Fasan: MLL Munich Leukemia Laboratory: Employment. Alpermann:MLL Munich Leukemia Laboratory: Employment. Grossmann:MLL Munich Leukemia Laboratory: Employment. Eder:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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The Prognostic Impact of High EVI1 expression In AML Is Due to Its Close Correlation to Rearrangements Involving EVI1 or MLL, which Are Cytogenetically Cryptic In a Subset of Patients: a Study on 332 Cases.

Blood ◽

10.1182/blood.v116.21.1676.1676 ◽

2010 ◽

Vol 116 (21) ◽

pp. 1676-1676

Author(s):

Claudia Haferlach ◽

Vera Grossmann ◽

Melanie Zenger ◽

Tamara Alpermann ◽

Alexander Kohlmann ◽

...

Keyword(s):

Chromosome Banding ◽

Normal Karyotype ◽

Fish Analysis ◽

Prognostic Impact ◽

Employment Equity ◽

Npm1 Mutation ◽

Banding Analysis ◽

Chromosome Banding Analysis ◽

Equity Ownership ◽

The Impact

Abstract Abstract 1676 Introduction: High EVI1 expression has been proposed as a negative prognostic factor in AML. An association between high EVI1 expression and distinct cytogenetic subgroups, such as 3q26-rearrangements, MLL-rearrangements and -7/7q- have been reported. Both 3q26- and MLL-rearrangements can be difficult to detect by chromosome banding analyses or may even be cytogenetically cryptic in a subset of patients due to limited resolution. Therefore, only studies using FISH for the detection of cryptic EVI1- or MLL-rearrangements can clarify their frequencies in AML with elevated EVI1 expression. Methods/Patients:: The study cohort was composed of 332 AML cases with a) normal karyotype (NK) (n=211), b) -7/7q- (n=77), and for comparison c) 3q26-rearrangements (n=38), and d) MLL-rearrangement (n=6). In all cases EVI1 expression was investigated using quantitative PCR calculating a % EVI1/ABL1 expression. In all cases FISH for EVI1 rearrangement was performed in addition to chromosome banding analysis. Cases with high EVI1 expression were also analyzed for MLL rearrangements by FISH. Results: In the total cohort, EVI1 expression varied between 0 and 1614 (median: 21.1). The highest EVI1 expression was measured in cases with cytogenetically identified 3q26-rearrangements (range: 6.1–566.4; median: 81.9) and in AML with MLL-rearrangements (range: 46.7–831; median: 239). The EVI1 expression was significantly lower in AML with NK (range: 0–1614; median: 0.5, p<0.001) and AML with -7/7q- (range: 0.03–199; mean: 34.5; median: 10.7, p<0.001). In the subgroup of cases with NK 4 MLL-rearrangements (1.9%) were detected by FISH and subsequently verified by fusion gene specific PCR. In addition, 4 cases with cryptic EVI1-rearrangements (1.9%) were identified by FISH analysis. Further genetic analysis revealed that these were due to t(3;8)(q26;q24) (n=2) and t(3;21)(q26;q11) (n=1). In one case, the EVI1-rearrangement could not be further analyzed due to lack of material. In the -7/7q- cohort 14/77 cases (18.2%) with cytogenetically cryptic EVI1 rearrangement including 3 novel recurrent abnormalities were detected: t(3;21)(q26;q11) (n=3), inv(3)(p24q26) (n=4) and t(3;8)(q26;q24) (n=2). In 5 cases FISH analysis revealed that the 7q- was not caused by an interstitial deletion but due to an unbalanced rearrangement between chromosomes 7 and 3: der(7)t(3;7)(q26;q21). In these 5 cases high-resolution SNP microarray were performed and revealed breakpoints in the CDK6 gene and centromeric of the EVI1 gene. Further mutation screening revealed that none of the cases with EVI1- or MLL-rearrangement harboured mutations in NPM1 or CEPBA. In 254 cases clinical follow-up data was available. Different cut-off levels of EVI1 expression were tested, and a cut-off at 30% EVI1/ABL1 expression was the lowest level that had a significant impact on outcome. Separating the cohort at this cut-off into high EVI1 (n=67) and low EVI1 expressors (n=187) showed a shorter EFS in patients with high EVI1-expression (p=0.001; relative risk (RR)=1.87, median EFS 6.2 vs 15.0 months (mo)), while no impact on OS was observed. When the same analyses were performed with respect to EVI1-rearrangements we observed both a significantly shorter EFS in cases with EVI1-rearrangement (n=39) vs all others (n=215) (p=0.001; RR=2.03, median EFS 4.6 vs 15.0 mo) and a significantly shorter OS (p=0.026; RR=1.73, median OS 10.1 vs 26.3 mo). Analyzing the impact of high EVI1 expression separately in the cohort without EVI1 rearrangement revealed no impact of EVI1 expression on EFS. Conclusions: The negative prognostic impact of high EVI1 expression is strongly associated with EVI1- or MLL-rearrangements and is absent in AML without EVI1- and MLL-rearrangement. Applying FISH in addition to chromosome banding analysis we identified cryptic rearrangements in 3.8% of AML with normal karyotype and in 18.2% of AML with -7/7q-, including 3 novel recurrent cytogenetically cryptic EVI1-rearrangements. This data supports the routine performance of FISH screening for EVI1- and MLL-rearrangements in patients with normal karyotype or 7q-/-7 and without NPM1 mutation and CEPBA mutation to assign patients to the correct biologic entity. The postulated independent prognostic impact of EVI1 expression should be tested further including this laboratory workflow as these parameters may have important impact on prognosis and future treatment strategies. Disclosures: Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Grossmann:MLL Munich Leukemia Laboratory: Employment. Zenger:MLL Munich Leukemia Laboratory: Employment. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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Specific Molecular Mutations with Prognostic Relevance in AML with Normal Karyotype Are Also Associated with Outcome in AML with Aberrant Karyotype: A Study on 1981 Cases,

Blood ◽

10.1182/blood.v118.21.3517.3517 ◽

2011 ◽

Vol 118 (21) ◽

pp. 3517-3517

Author(s):

Claudia Haferlach ◽

Torsten Haferlach ◽

Tamara Alpermann ◽

Wolfgang Kern ◽

Susanne Schnittger

Keyword(s):

Important Implication ◽

Mutation Screening ◽

Normal Karyotype ◽

Prognostic Impact ◽

Employment Equity ◽

Equity Ownership ◽

The Impact ◽

Length Mutations ◽

Tandem Duplications

Abstract Abstract 3517 Background and Aim: The karyotype and molecular mutations are well established prognostic parameters in AML. However, the impact on outcome of molecular mutations has been evaluated mainly in the subset of AML with normal karyotype (NK). The aim of this study was 1. to determine the frequency of NPM1 mutations (NPM1 mut), partial tandem duplications within the MLL gene (MLL -PTD), length mutations within the FLT3 gene (FLT3 -ITD) and CEPBA mutations (CEPBA mut) in distinct cytogenetic subgroups and 2. to evaluate the prognostic impact of these mutations in relation to chromosome abnormalities. Patients and Methods: 1981 patients with AML and evaluable cytogenetics were included. Mutation data was available in the majority of cases: NPM1: 1646, CEPBA: 1324, FLT3 -ITD: 1726 and MLL -PTD: 1656. Based on the karyotype the cohort was subdivided according to revised MRC criteria (Grimwade et al. Blood 2010) and in addition into distinct cytogenetic subgroups. Results: According to cytogenetics 170 cases were assigned to the favorable MRC class (MRCF), 1414 to the intermediate MRC (MRCI) and 397 to the unfavorable MRC subset (MRCU). The frequency of NPM1 mut, CEPBA mut, MLL -PTD and FLT3 -ITD differed significantly between MRC classes and distinct cytogenetic groups. In the MRCI subset we evaluated overall survival (OS) between patients with normal or aberrant karyotype (AK) within the respective mutation groups. Within NPM1 mut, CEPBA mut, MLL -PTD+ and FLT3 -ITD+ patients no significant differences in OS were observed between patients with NK or AK. When separating CEPBA mut into biallelic (n=52) and monoallelic cases (n=40) also no difference in OS was observed between pats with NK or AK. Next we tested the prognostic impact of the respective molecular mutations within MRCI including 966 cases with NK and 448 cases with AK. OS was significantly longer in patients with NPM1 mut or CEPBA mut (median OS (mOS) 49.6 months (mo) vs 18.6 mo, p=0.003; not reached (n.r.) vs 21.1 mo, p=0.016) and significantly worse for patients with MLL -PTD or FLT3 -ITD (mOS 10.8 vs 23.0 mo, p=0.039; 13.8 vs 24.9 mo, p=0.003). Analyzing biallelic and monoallelic CEPA mut separately revealed that only biallelic CEPBA mut was associated with a longer OS (p=0.006). Restricting the analysis to MRCI patients with aberrant karyotype revealed a longer OS for patients with NPM1 mut/FLT3 -ITD-, and a shorter OS for patients with FLT3 -ITD (mOS n.r. vs 18.0 mo, p=0.033; 5.7 vs 23.0 mo, p=0.015). A trend towards better OS was observed for biallelic CEBPA mut. Conclusions: 1. The frequency of molecular mutations varies significantly between distinct cytogenetic subsets. They are particularly common in AK within MRCI. NPM1 mut, CEBPA mut and MLL -PTD were not observed in MRCF, in AML with 11q23/MLL -rearrangements, or in 3q26/EVI1 -rearrangements. Their frequency was below 5% in AML with complex karyotype. 2. The outcome of NPM1 mut, CEPBA mut and MLL -PTD+ cases was not different in AML with normal or aberrant karyotype within MRCI. 3. This data suggest to extend mutation screening for NPM1 mut, CEPBA mut, MLL -PTD and FLT3 -ITD to all AML with intermediate risk cytogenetics, as they are significantly associated with outcome not only in AML with normal karyotype but also in AML with cytogenetic abnormalities assigned to MRCI. This consequently will lead to better characterization of a reasonable number of cases from MRCI with important implication on treatment. Disclosures: Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Alpermann:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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ASXL1 exon 12 Mutations Are Frequent in AML with Intermediate Risk Karyotype and Are Independently Associated with An Extremely Poor Outcome

Blood ◽

10.1182/blood.v118.21.416.416 ◽

2011 ◽

Vol 118 (21) ◽

pp. 416-416

Author(s):

Susanne Schnittger ◽

Christiane Eder ◽

Tamara Alpermann ◽

Annette Fasan ◽

Vera Grossmann ◽

...

Keyword(s):

De Novo ◽

Strong Association ◽

Multivariable Analysis ◽

Adverse Impact ◽

Prognostic Impact ◽

Intermediate Risk ◽

Employment Equity ◽

Mutational Status ◽

Equity Ownership ◽

The Impact

Abstract Abstract 416 Introduction: ASXL1 mutations have recently been described in a number of different myeloid malignancies. Data on frequency, association with other markers and outcome in AML are rare. Aim: The aim of this study was to evaluate ASXL1 mutations (ASXL1mut) in AML with intermediate risk karyotype for frequency, association with other mutations and impact on outcome. Methods: We analyzed 476 cases with intermediate risk de novo AML for ASXL1 mutations by direct Sanger sequencing of exon 12. Other mutations were analyzed as described previously and were available in part of the patients (NPM1: n=474, FLT3-ITD: n=473, FLT3-TKD: n=407, MLL-PTD: n=474, CEBPA: n=447, RUNX1: n=150, WT1: n=384, IDH1: n=464 and IDH2: n=444, TET2: n=109, NRAS: n=191; KRAS: n=110, DNMT3A: n=83). 397 cases had a normal karyotype (NK) and 79 had intermediate risk aberrant cytogenetics (according to MRC). Female/male ratio was 221/255 and age ranged from 18.5–100.4 y (median: 66.4). Results: Overall, in 70/476 patients (14.7%) ASXL1mut were detected. In detail, the most frequent mutation was p.G646WfsX12 (n=36) followed by p.E635RfsX15 (n=9), and p.Y591X (n=2). The remaining 21 mutations were non-recurrent consisting of 2 frameshift, 13 nonsense and 6 missense mutations. All mutations were detected with a mutation/wildtype load of 40–50% and none of the cases had more than one ASXL1mut. ASXL1mut were more frequent in males than in females (56/255, 22.0% vs 14/221, 6.3%, p=0.001) and were associated with higher median age (72.4 yrs vs 64.1 yrs, p<0.001). In detail, in the cohort > 65 yrs 21.7% (n=55/254) and in those <65 yrs only 6.8% (n=15/222) were ASXL1mut (p<0.001). With respect to morphology ASXL1mut were more frequent in AML without maturation than in all others (37.5% vs 14.3%, p=0.022). In 242 cases immunophenotyping data was available and cases with ASXL1mut (n=34) had a higher expression of CD13 (mean±SD, 55±23% vs. 43±25%, p=0.012), CD34 (46±32% vs. 24±26%, p<0.001), CD133 (29±27% vs. 16±23%, p=0.006) and HLA-DR (42±25% vs. 30±24%, p=0.009) as well as a lower expression of CD33 (66±21% vs. 77±21%, p=0.005) and thus had a more immature immunophenotype as compared to ASXL1wt. There was no association with leukocyte or platelet counts. With regard to cytogenetics ASXL1mut were more frequent in those with aberrant karyotype than in NK (20/79, 25.3% vs 50/397, 12.6%, p=0.008). Generally, ASXL1mut were observed together with all other molecular mutations but there was a strong correlation to RUNX1mut (n=18/43, 41.9% vs 19/107, 17.8% in RUNX1wt, p=0.003) and a negative correlation with NPM1mut (n=9/274; 3.3% vs. n=61/200, 30.5% in NPM1wt, p<0.001) and DNMT3Amut (1/26, 3.8% vs. 19/55 in DNMT3A, 34.5%, p=0.002). Patients with ASXL1mut had a shorter overall survival (OS) (median: 11.2 vs 38.8 months, p<0.001) and event free survival (EFS) (median: 9.0 vs 23.9 months, p<0.001). In detail, this adverse impact could be shown for both NK (OS: median: 10.9 vs 38.3 months, p<0.001; EFS: 9.8 vs. 26.5 months, p<0.001) and intermediate risk aberrant cytogenetics (OS: median: 8.6 vs 38.8 months, p<0.001; EFS: 5.3 vs 21.5 months, p=0.011), separately. Although the ASXL1mut were much more frequent in the elderly and compared to the ASXL1wt had a shorter OS (median: 7.0 vs 16.3 months, p=0.002) an adverse effect on survival could also be shown in the cohort <65 yrs (median OS: 11.6 vs 47.3 months, p<0.001 and median EFS: 9.3 vs 34.5 months, p<0.001). Because of the high coincidence of the two mutations the impact of ASXL1mut in dependence of RUNX1 status was analyzed. In the RUNX1mut (n=43) the ASXL1mut (n=18) still had an adverse impact on EFS (median: 5.3 vs 15.6 months, p=0.010) and a trend for shorter OS (10.7 vs. 20.5 months, p=0.079). In a multivariable analysis ASXL1 is an unfavourable factor for OS independent of age and RUNX1 mutational status (p=0.026, RR: 2.0). Conclusions:ASXL1 mutations belong to the most frequent mutations in intermediate risk AML. There is a strong association with male sex, high age, immature phenotype and RUNX1mut. Still, ASXL1mut retained its independent very poor prognostic impact. Although the number of known molecular markers in AML is continuously increasing and selection of the most import markers for diagnostic work-up seems challenging this data indicates that ASXL1 is one of the most prominent candidates. Disclosures: Schnittger: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Eder:MLL Munich Leukemia Laboratory: Employment. Alpermann:MLL Munich Leukemia Laboratory: Employment. Fasan:MLL Munich Leukemia Laboratory: Employment. Grossmann:MLL Munich Leukemia Laboratory: Employment. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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Further Insights Into The Molecular Landscape Of De Novo Acute Myeloid Leukemia (AML) Investigating 1,291 Patients

Blood ◽

10.1182/blood.v122.21.607.607 ◽

2013 ◽

Vol 122 (21) ◽

pp. 607-607

Author(s):

Torsten Haferlach ◽

Ulrike Bacher ◽

Tamara Alpermann ◽

Wolfgang Kern ◽

Alexander Kohlmann ◽

...

Keyword(s):

De Novo ◽

Median Number ◽

Genetic Alterations ◽

The Cancer Genome Atlas ◽

Research Network ◽

Prognostic Impact ◽

Coding Region ◽

Employment Equity ◽

Equity Ownership ◽

De Novo Aml

Abstract Background The Cancer Genome Atlas Research Network (TCGA) published a hallmark sequencing study on molecular mutations in 200 fully characterized adult de novo AML (NEJM 2013). According to their data AML harbor in average 13 mutations in the coding region of the genome of which 5 are in genes known to be recurrently mutated in AML. Further, detailed data on co-occurrence and mutual exclusiveness of molecular mutations was presented. However, given the heterogeneity of AML a cohort of 200 AML might not be fully representative. Aims 1. Compare the published mutation frequency to our cohort 2. Evaluate, whether the mutation frequencies vary with age. 3. Determine the number of additional mutations in genetically defined AML subgroups 4. Analyze the co-occurrence of molecular mutations. Patients and Methods 1,291 adult de novo AML (700 m/591 f; median: 68 yrs; 18-100 yrs) were analyzed for mutations by different PCR assays and next-generation sequencing including the 11 most frequently mutated genes reported by TCGA (FLT3-ITD/-TKD, NPM1, DNMT3A, IDH1, IDH2, TET2, RUNX1, TP53, NRAS, CEPBA, WT1) and also ASXL1, KRAS, MLL-PTD (that had been found at lower frequencies by TCGA), and CBL. Cytogenetics was performed in all cases. Results Mutations were found in NPM1: n=410/1,189 (34.5%), DNMT3A: n=105/340 (30.9%), TET2: n=104/349 (29.8%), FLT3-ITD: n=305/1,231 (24.8%), RUNX1: n=201/1,045 (19.2%), IDH2: n=154/938 (16.4%), ASXL1: n=157/1,000 (15.7%), TP53: n=97/743 (13.1%), NRAS: n=101/842 (12.0%), IDH1: n=93/1,053 (8.8%), FLT3-TKD: n=94/1,132 (8.3%), MLL-PTD: 98/1,181 (8.3%), CEPBA: n=84/1,105 (7.6%) (double-mut: n=38; single-mut: n=46), KRAS: n=38/552 (6.9%), WT1: n=58/918 (6.3%), and CBL: 8/352 (2.3%). These mutation frequencies are comparable to those reported by TCGA. Only ASXL1 mutations were less frequently observed by TCGA (2.5%). The following mutations were more frequent in pts <60 yrs: FLT3-ITD (P=0.003), NPM1mut and WT1mut (P<0.001 for both). In contrast, ASXL1, RUNX1 (P<0.001, each) and TET2mut (P=0.005) were more frequent in pts ≥60yrs. A total of 802 pts were investigated for at least 9 markers (ASXL1, FLT3-ITD, FLT3-TKD, CEBPA, MLL-PTD, IDH1, IDH2, NPM1, RUNX1): The median number of molecular mutations was 2 (range, 0-5; mean±SD, 1.6±0.9). The lowest number of additional mutations was observed in pts with RUNX1-RUNX1T1 (0.3±0.6) and reciprocal MLL rearrangements (mean±SD, 0.4±0.6) followed by CBFB-MYH11 (0.6±0.8), NPM1 (0.9±0.7), CEPBAmut (0.9±1.0), and MLL-PTD (1.2±0.7). In concordance with TCGA results, a significant coincidence of ASXL1mut with IDH2mut and RUNX1mut was found. A total of 335 pts was screened for FLT3-ITD, DNMT3Amut, and NPM1mut in parallel and there was a high coincidence: 27/335 (8.1%) with all 3 mutations and further 63 (18.8%) with 2 out of 3; all combinations P<0.001, each). Beyond the observations within the TCGA study, we found additional positive correlations such as IDH1mut to DNMT3A (P=0.004) and as well to NPM1mut (P=<0.001), and FLT3-ITD to MLL-PTD (P=0.010) as well as to WT1mut (p=0.001). Furthermore, according to the TCGA data, the following mutations were mutually exclusive: TP53mut to NPM1mut and to FLT3-ITD (P<0.001, each), and in addition RUNX1mut to NPM1mut (P<0.001). However, we could not confirm the mutual exclusiveness of RUNX1mut and FLT3-ITD as 21.0% of RUNX1mut AML also showed FLT3-ITD. Beyond the TCGA data, we found the following mutations to show significant negative correlations: MLL translocations were significantly negatively correlated with FLT3-ITD, NPM1, DNMT3A, IDH2, and RUNX1mut, as well were RUNX1-RUNX1T1 rearrangements with FLT3-ITD, NPM1, and IDH2mut, and CBFB-MYH11 rearrangements with FLT3-ITD and NPM1mut. Conclusions 1) Investigation of a large cohort of de novo AML largely confirmed the mutation frequencies of the TCGA data, but revealed a higher frequency of ASXL1mut. 2) In addition, we depicted new patterns of positive and negative correlations of genetic alterations. 3) This further emphasizes the variety of pathways of leukemogenesis in de novo AML requiring additional analyses to delineate the prognostic impact of different marker combinations and their impact on treatment decisions. Disclosures: Haferlach: MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Bacher:MLL Munich Leukemia Laboratory: Employment. Alpermann:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

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