New TET2, ASXL1 and CBL Mutations Have Poor Prognostic Impact In Systemic Mastocytosis and Related Disorders

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3076-3076
Author(s):  
Fabiola Traina ◽  
Ania Jankowska ◽  
Hideki Makishima ◽  
Fred H. Hsieh ◽  
Yingchun Han ◽  
...  
Keyword(s):  
Conflicts Of Interest ◽  
Systemic Mastocytosis ◽  
Single Nucleotide Polymorphism Array ◽  
Myeloproliferative Neoplasms ◽  
Uniparental Disomy ◽  
Prognostic Impact ◽  
Biallelic Mutation ◽  
Prognostic Information ◽  
Kit Mutation ◽  
Disease Spectrum

Abstract Abstract 3076 Mastocytosis is a heterogeneous hematopoietic neoplasm characterized by proliferation and organ infiltration by clonal mast cells (MC). The disease spectrum encompasses chronic indolent forms such as cutaneous mastocytosis (CM)/indolent systemic mastocytosis (ISM) to more aggressive types such as SM with associated clonal hematologic non-mast-cell disease (SM-AHNMD), the latter most closely related to myeloproliferative neoplasms (MPN) or MDS/MPN overlap syndromes. Molecular pathogenesis of mastocytosis involves acquisition of c-KIT mutations, particularly D816V, which is present in many cases and confers resistance to imatinib. TET2 mutations are often found in MPN and MDS/MPN and also in ∼20% of SM patients without noticeable impact on survival. We have hypothesized that analysis of molecular defects in mastocytosis may shed light on disease pathogenesis and possibly convey prognostic information that may help in diagnosis and selection of rational therapies. To investigate these molecular events, we have applied single nucleotide polymorphism array-based karyotyping (SNP-A) (Affymetrix 6.0) to identify recurrent areas of loss of heterozygosity and performed a broad screen for mutations which could be present in mastocytosis including c-KIT, TET2, CBL gene family (CBL, CBLB, CBLC), ASXL1, IDH1/IDH2, which have been found in hematologic disorders related to or associated with SM. Overall survival (OS) was analyzed using the Kaplan-Meier method (Log-Rank). We studied a total of 35 mastocytosis patients classified using WHO criteria (CM, N=9; ISM, N=14; SM-AHNMD, N=9; [CMML, N=6; AML, N=1; NHL, N=2], aggressive SM (ASM) N=2; MC sarcoma, N=1). Median age of the cohort was 51 yrs (13-71). SNP-A showed a total of 20 new lesions (13 gains, 3 losses and 4 uniparental disomy [UPD]) in 10 patients (CM=1, ISM=4, SM-AHNMD=4, ASM=1). The most frequently affected chromosomes were 2, 7, 12, 13, 14 and X. UPD was only found in SM-AHNMD and ASM and it involved chromosomes 2p, 4q, 7p and 13q. No OS difference were observed between patients with new SNP lesions compared to those without (47 mo vs. 38 mo; p=.84). c-KIT sequencing showed D816V in 29% of patients (ISM=29%; SM-AHNMD=44%, ASM=100%). A total of 15 additional mutations were found in 9/35 patients. TET2 mutations were found in 8/35 (23%), including 2 patients with biallelic mutations (3 frameshift, 2 nonsense and 5 missense). TET2 mutational frequencies for CM, ISM and SM-AHNMD (only CMML) were 22% (2/9), 7% (1/14) and 56% (5/9). Majority of TET2 mutations were heterozygous, except one that was homozygous. These mutations have not been previously described in mastocytosis. We have also detected ASXL1 mutations in 3/35 (9%) patients, with biallelic mutation seen in one patient (1 frameshift, 1 nonsense and 2 missense). ASXL1 mutations were seen in 1/14 ISM and 2/9 SM-AHNMD (with CMML). To our knowledge, ASXL1 mutations have not been described in mastocytosis. A heterozygous CBL mutation was found in 1/35 patients with SM-AHNMD (CMML). No mutations were found in CBLB, CBLC and IDH1/IDH2. Interestingly, 5 patients were found to have >1 mutation, c-KIT and TET2 in 2, c-KIT/TET2/ASXL1 in 2 and TET2/CBL in 1 patient. The median OS of the cohort was 18 mo (1-85). As expected, for patients with only SM (excluding CM cases), c-KIT mutants had a worse OS than wild type (WT) c-KIT patients (17 mo vs. 52 mo; p=.02). SM patients with TET2, ASXL1 or CBL mutations, independently of c-KIT, had a worse OS than those with WT genes (17 mo vs. 52; p=.01). SM patients with c-KIT mutation who carry additional mutations had a worse OS, c-KIT + any mutation [11 mo] vs. TET2/ASXL1/CBL mutant [32 mo] vs. c-KIT mutant alone [NR] vs. WT [NR]; p<.0001. Similarly, when TET2 and c-KIT mutations were analyzed independent of CBL and ASXL1, patients with mutant c-KIT and TET2 had the poorest OS in the group (c-KIT plus TET2 [10 mo] vs. TET2 alone [32 mo] vs. c-KIT alone [NR] vs. WT [NR]; p<.0001). All patients with CM were still alive at the time of analysis. In conclusion, SNP-A lesions including UPD are karyotypic changes also seen in mastocytosis. TET2 mutations are frequently found in mastocytosis, particularly in SM-AHNMD (CMML). Novel molecular mutations frequently found in MDS and MPN, as ASXL1 and CBL, are also found in mastocytosis but at lower frequencies. More importantly, these new mutations may affect prognosis, as demonstrated by poor OS in patients who carry these mutations independently of c-KIT. Disclosures: No relevant conflicts of interest to declare.

Disruption of the ASXL1 Gene Is Prevalent In PMF: Analysis of Molecular Genetics and Clinical Phenotypes

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3074-3074
Author(s):  
Brady L Stein ◽  
Donna M Williams ◽  
Michael A McDevitt ◽  
Christine L. O'Keefe ◽  
Ophelia Rogers ◽  
...  
Keyword(s):  
Molecular Genetics ◽  
De Novo ◽  
Conflicts Of Interest ◽  
Single Nucleotide Polymorphism Array ◽  
Myeloproliferative Neoplasms ◽  
Direct Sequencing ◽  
Snp Array ◽  
Uniparental Disomy ◽  
Jak2 V617f ◽  
Wild Type

Abstract Abstract 3074 Background: The myeloproliferative neoplasms, PV, ET and PMF, share phenotypic features and molecular lesions, yet PMF distinguishes itself by its unfavorable natural history and rate of leukemic evolution. These distinctions may occur as a result of cooperating genomic lesions specific to PMF compared to PV or ET. We performed single nucleotide polymorphism array (SNP-A)-based karyotyping in 210 MPN patients and identified 20q11 deletions in 10% of PMF cases and in none of the PV or ET cases. The 20q11 deletion region spanned 1,662 KB and encompassed 37 genes, of which ASXL1 was included. To test whether ASXL1 contained lesions in the MPN cohort at large, we directly sequenced key regions of the ASXL1 gene in 65 PMF, 11 PV and 14 ET cases, as well as 7 controls from the SNP-array cohort. Genomic DNA from neutrophils and in select cases, purified CD34+ cells was used for both SNP-A and direct sequencing. Clinical parameters were correlated with genomic findings and the quantitative JAK2 V617F neutrophil allele burden Molecular genetics: 26/65 (40%) of PMF cases had abnormalities in ASXL1 (4 deletions, 22 mutations) whereas none of the 32 PV, ET or control cases had such lesions. The majority of ASXL1 sequence variations were nonsense lesions including the previously reported 1934dupG which comprised 30% of all of the mutations. The residual ASXL1 allele in all 20q11 deletion cases containing the ASXL1 gene was intact. In three PMF cases, more than one distinct ASXL1 mutation was identified, and cloning experiments on two of those cases indicated that the lesions were biallelic. Using banked samples, we observed the acquisition of an ASXL1 lesion over time, and established that ASXL1 lesions detected in 2 post ET-MF cases were also detected at low levels in the ET phase of the MPN. Genotype/Phenotype Correlations: ASXL1 deletions and mutations were prevalent in de novo PMF (37%), post PV-PMF (20%) post ET-PMF (62%) and in PMF/AML (33%). ASXL1 mutations did not associate with chemotherapy exposure as the prevalence of hydroxyurea use was similar in patients with and without mutations, and ASXL1 –mutation positive cases were present in patients who had never received any form of chemotherapy. There was no dependence upon JAK2 status as the presence of ASXL1 mutations were identified in JAK2 V617F-negative cases (9/26); JAK2 V617F-heterozygous cases (10/26); and JAK2 V617F-homozygous cases (7/26). Based on results of SNP-A, patients with ASXL1 mutations were equally as likely to have uniparental disomy (involving 9p or other regions) and loss/gain abnormalities (>1MB) compared to those without ASXL1 mutations. There were no differences in sex, age, or disease duration between PMF patients with and without ASXL1 mutations. In the ASXL1-mutant group, there was a trend toward a lower median white blood cell count (8 vs. 12.5 k/cu mm; p=0.3) and hemoglobin (9.7 vs. 11 g/dl; p=0.3) compared to ASXL1-wild-type patients. Furthermore, those PMF patients with ASXL1 mutations were significantly more likely to have received anemia-directed therapy (transfusion, erythropoietin, immunomodulating agents, steroids) compared to those without mutations (15/26 (58%) vs. 11/39 (23%); p=0.02). Post ET-MF patients comprised 31% (8/26) of ASXL1-mutant cases, compared to only 10% (4/39) ASXL1- wild-type cases (p=0.03). However, the presence of an ASXL1 mutation did not associate with an accelerated transition rate from ET to MF; among the 12 post ET-MF cases in the cohort, the median time of transition from ET to MF was 15.5 years in those with ASXL1 mutations compared to 7 years in those with ASXL1 wild-type status (p=0.02). Conclusion: Disruption of the ASXL1 gene occurs in 40% of PMF cases. The association of ASXL1 lesions, due to either mutation or deletion, suggests that ASXL1 haplo-insufficiency is associated with a PMF phenotype in the context of other known and unknown lesions, and that disruption of ASXL1 function may directly contribute to the pathophysiology and clinical complications of primary and secondary myelofibrosis. These data support the concepts that cooperative lesions in addition to JAK2 V617F are critical in generating PMF, that PMF is molecularly more complex than either PV or ET, and that the transition of PV or ET to PMF is associated with the acquisition of genomic lesions, such as ASXL1, that are present in PMF at large. Disclosures: No relevant conflicts of interest to declare.

Pathogenesis of MONOSOMY 7 In BONE MARROW FAILURE SYNDROMES

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2411-2411
Author(s):  
Hideki Makishima ◽  
Fabiola Traina ◽  
Anna M Jankowska ◽  
Yuka Sugimoto ◽  
Kathryn M Guinta ◽  
...  
Keyword(s):  
Immune Escape ◽  
Chromosomal Abnormalities ◽  
Conflicts Of Interest ◽  
Single Nucleotide Polymorphism Array ◽  
Myeloproliferative Neoplasms ◽  
Bone Marrow Failure ◽  
Clonal Evolution ◽  
Uniparental Disomy ◽  
Point Mutations ◽  
Monosomy 7

Abstract Abstract 2411 One of the most serious complications of aplastic anemia (AA) is the clonal evolution to myelodysplastic syndrome (MDS). Monosomy 7 (del[7]) is the most common chromosomal aberration encountered in this setting, but it can also occur in primary MDS along with deletion 7q (del[7q]). In our whole cohort of AA, we detected del[7] in 24 cases of clonal evolution; however, unlike in MDS no cases of del[7q] were observed. In contrast, in MDS or myelodysplastic/myeloproliferative neoplasms, del[7]/[7q] were present in 12% and 11%, respectively. Based on an initial observation of an index AA case with a mutation of CBL, we speculated that certain molecular events such as point mutations can promote or are at least associated with the evolution of del[7]. Given the distinct distribution of del[7] and del[7q] in primary and secondary MDS (derived from AA), we stipulate that the associated mutational pattern will be distinct. This may be due to different driving mechanisms, such as immune escape or a growth factor-rich milieu in AA. Pursuant to this theory, we performed a screen for CBL, RUNX1, TET2, UTX, EZH2, DNMT3A, ASXL1 and IDH family mutations in patients who developed del[7] after AA (N=24). 14 cases were adults and 10 were pediatric cases. In addition, we analyzed 15 del[7], 13 del[7q] and 10 UPD[7q] abnormalities in patients with MDS without antecedent AA. We identified 3 CBL (13%), 5 RUNX1 (20%), 1 TET2 and 1 DNMT3A mutation in patients with del[7] after AA; all CBL mutations are observed in adult cases of AA (21%). However, 0, 1, and 2 CBL mutations were found in primary MDS with del[7], del[7q] and UPD[7q], respectively. In contrast, RUNX1 mutations were seen in both AA sub-groups (14% and 30% in adults and children, respectively). Also, no differences were seen with regard to the distribution of RUNX1 mutations in either post-AA MDS with del[7] or primary MDS with del[7], del[7q] and UPD[7q]. Most significantly, ASXL1 was found to be the most frequently mutated gene in the cohort without AA (37%), although no mutations were seen in patients with del[7] after AA. Additionally, UTX and EZH2, both involved in the trimethylation of histone H3 lysine 27, were found to be mutated only in cases of MDS with UPD[7q] and del[7q], but no mutations were seen in primary and AA-derived MDS with del[7]. When studied serially, none of the tested mutations was seen in the initial AA phase, but the mutated clone increased gradually during clonal evolution of del[7]. We also investigated the presence of additional chromosomal abnormalities using single nucleotide polymorphism array (SNP-A)-based karyotyping in the cases with del[7] after AA. In addition to del[7], 22 gains, 20 losses and 4 regions of somatic uniparental disomy (UPD) were identified. These abnormalities, including microdeletions, were found in 50% and 60% of adult and pediatric cases, respectively. Recurrent lesions were detected on chromosome 6, 8 and 21. A microdeletion on chromosome X involved the tumor-associated gene PHF6 in a male case. In another patient, trisomy 21 was accompanied by a RUNX1 mutation. Regions of UPD included 6p resulted in loss of heterozygosity of MHC class I and 11q was associated with homozygous CBL mutations in 2 cases. In sum, our analysis supports the theory that distinct mechanisms of molecular progression during MDS evolution may be operative in AA and primary MDS. Moreover, del[7], del[7q] and UPD[7q] have distinct molecular profiles with frequent TET2 mutations in del[7q] and UPD[7q]. ASXL1 mutations appear to be most ubiquitous promoting event in MDS with LOH [7/7q], suggestive of their “type II' nature. In contrast, other mutations such as those in CBL may be selected for e.g., through cytokine-rich milieu and activation of CBL-regulated receptor tyrosine kinases. Disclosures: No relevant conflicts of interest to declare.

KIT Mutations Are Rare Among Elderly AML Patients: A SWOG Report

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2510-2510
Author(s):  
Fabiana Ostronoff ◽  
Megan Othus ◽  
Phoenix A. Ho ◽  
Stephen H. Petersdorf ◽  
Jeanne E. Anderson ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Elderly Patients ◽  
Conflicts Of Interest ◽  
Direct Sequencing ◽  
Prognostic Significance ◽  
Age Groups ◽  
Prognostic Impact ◽  
Kit Mutation ◽  
Elderly Aml ◽  
Normal Cytogenetics

Abstract Abstract 2510 Background: KIT receptor tyrosine kinase mutations are recurrent genetic alteration found in acute myeloid leukemia (AML) with higher prevalence in those with core binding factor (CBF) AML. Different prognostic significance of these mutations has been found in pediatric and adult AML studies. However, prevalence and prognostic impact of KIT mutations in elderly patients with AML has not been established. In this study, we evaluated the prevalence of KIT mutation and its correlation with cytogenetic, molecular subtypes and clinical outcome in elderly AML patients. Methods: Diagnostic specimens from for 207 patients with AML registered on SWOG trials S-9031 and S-9333 were available for KIT mutation analysis. Both of these clinical protocols enrolled AML patients > 55 years. The samples were analyzed for the presence of KIT mutations via direct sequencing of exons 8 and 17. Results: In the cohort of 207 patients tested, the median age, WBC, and blast count at diagnosis were 68 years (range, 56–88 years), 29,6 × 109/L (range, 7–289 × 109/L) and 67% (0–99%), respectively. Favorable, intermediate and unfavorable cytogenetics were present in 8%, 57% and 26% of the patients, respectively. Nine percent of the patients had cytogenetics abnormalities of unknown significance. Normal cytogenetics was present in 48% of the patients. Fifty-three patients (26%) harbored mutations for FLT3-ITD, 37 (19%) for DNMT3A, 52 (31%) for NPM1 and 50 (24%) for IDH1/2. Only 3 patients were positive for CEBPA mutation. Of the 207 patient specimens tested, KIT exon 17 mutations were detected in 4 patients (2%). Exon 8 mutations were not identified. The characteristics of the 4 patients with KIT mutations are described in the table. Of the 4 patients who harbored the KIT mutation, 2 had intermediate, 1 had unfavorable risk cytogenetics and 1 patient did not have available cytogenetic data. None of the patients with CBF had KIT mutations. In terms of other molecular markers, all 4 patients were wild-type for NPM1, CEBPA, DNMT3A, IDH1/2 and FLT3-ITD. The very small number of KIT mutations in this group of patient precluded correlation between KIT mutations and clinical outcome. Conclusion: The prognostic impact of KIT mutations has been shown to vary according to cytogenetics subgroups. Most studies report a negative prognostic impact of these mutations in patients with CBF AML. The prognostic implications of KIT mutations also seem to vary among different age groups, with pediatric studies indicating they have no prognostic significance and adult studies indicating a negative prognostic impact. To date, there is no large study reporting on the incidence and prognostic impact of KIT mutations in elderly patients with AML. The very low incidence of KIT mutations in our study highlights the age-specific characteristics of AML and may correlate with lower prevalence of CBF translocations in older AML. Further studies investigating the relationship among different somatic mutations in elderly AML patients may help to clarify the pathogenetic mechanism of certain AML subtypes in this patient population. Disclosures: No relevant conflicts of interest to declare.

Outcomes of Patients with Myelodysplastic Syndromes/Myeloproliferative Neoplasms with Emphasis On MDS/MPN-Unclassified

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5025-5025
Author(s):  
Charikleia Kelaidi ◽  
Varnavas Constantinou ◽  
George Papaioannou ◽  
Niki Stavroyianni ◽  
Chrysanthi Vadikoliou ◽  
...  
Keyword(s):  
Disease Progression ◽  
Myelodysplastic Syndromes ◽  
Response Rate ◽  
Conflicts Of Interest ◽  
Systemic Mastocytosis ◽  
Myeloproliferative Neoplasms ◽  
Univariate Analysis ◽  
Jak2 V617f ◽  
Female Ratio ◽  
Wbc Count

Abstract Abstract 5025 Background: Data on outcomes of patients (pts) with myelodysplastic syndromes/myeloproliferative neoplasms (MDS/MPN), especially MDS/MPN-unclassified (MDS/MPN-U), are scarce. Patients/methods: We retrospectively studied pts followed in our center, with MDS/MPN according to WHO 2008 criteria. Because of overlap characteristics of MPN and MDS, pts with systemic mastocytosis associated with MDS (SM/MDS) were also included. Pts with previous MDS or MPN were excluded. Response and disease progression were defined according to IWG 2006 criteria. Results: Twenty-five pts with MDS/MPN were included. Median age was 70 y (range 19–79). Male/female ratio was 1.77/1. Diagnosis was CMML-1 N=7, CMML-2 N=7, JMML N=1, MDS/MPN-U N=8, systemic mastocytosis (SM)/MDS N=2, with one additional pt with CMML subsequently developing SM. At diagnosis, median WBC count was 18.8 G/L (range 3–120), ANC 15.5 G/L (0.6–70), monocytes 1.9 G/L (0.1–16), left shift 16% (0–28), Hb 11.2 g/dL (6–17), platelets 99 G/L (10–680), peripheral and bone marrow (BM) blasts 5% (0–17) and 7% (2–19), respectively (resp.). 25% of pts had platelets count ≥400 G/L. Splenomegaly, B-symptoms and BM fibrosis were present in 23%, 57% and 27% of pts, resp. Karyotype was fav, int and unfav in 55%, 36% and 9% of pts, with −7, +8, del(12)(p11), del(12)(q14;q21), +10, +21, and previously unreported t(9;12)(q13;q13) in 3, 6, and 1 pt each, resp., while +21 and i(17)(q10) appeared during disease progression other than AML transformation. IPSS was low/int-1 and int-2/high in 50% and 50% of pts, resp. JAK2 V617F and CKIT D816V mutations were detected in 2/6 pts and 2/2 SM/MDS pts, resp. 70% and 29% of pts were transfused at diagnosis with PRBC and platelets, resp. Treatment included erythropoiesis stimulating agents (ESAs), low dose chemotherapy, intensive chemotherapy (IC) and azacitidine (AZA) in 40%, 36%, 16% and 48% of pts resp. Response rate to ESAs, IC and AZA was 60%, 14% and 14% resp. Response rate to AZA in CMML-1 pts was 33%. Dasatinib yielded no response in 1 SM/MDS pt with CKIT D816V. 3-year cumulative incidence of AML and median overall survival (OS) in pts with CMML-1, CMML-2 and MDS/MPN-U were 20%, 40% and 0 (P=0.059) and 39, 8, and 20 mo (P=0.50), resp. The pt with JMML died from AML transformation 3 months after diagnosis. 2/3 pts with SM/MDS died from disease progression w/o AML at a median of 10 mo after diagnosis. Median survival after disease progression other than AML transformation was 35, 15 and 14 mo in pts with CMML-1, CMML-2 and MDS/MPN-U, resp. (P=0.88). Cause of death was disease progression other than AML, AML transformation and unrelated to disease in 50%, 50%, and 0 and 80%, 0 and 20% of cases in CMML and MDS/MPN-U, resp. (P=0.10). Percentage of circulating blasts ≥5% was the only independent factor affecting risk of AML transformation in the overall population (P=0.0004). Diagnosis other than CMML-1, WBC ≥30 G/L, % of circulating blasts ≥5% and IPSS high/int-2 were associated with worse survival in univariate analysis (P=0.06, 0.03, 0.04 and 0.08, resp.). No predictive factor of OS was found in multivariate analysis. Conclusion: MDS/MPN are heterogeneous disorders with respect to disease progression and AML transformation. MDS/MPN-U tended to differ from CMML-1 by shorter survival after disease progression other than AML, and from CMML-2 by lower risk of AML transformation. Mortality of pts with MDS/MPN-U was mainly attributed to disease progression without AML transformation. Alternatively to hypomethylating agents, therapeutic options in pts with MDS/MPN-U could include JAK2 inhibitors. Disclosures: No relevant conflicts of interest to declare.

Incidence and Outcomes of Myeloproliferative Neoplasms (MPN) in Adolescents and Young Adults (AYAs).

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2845-2845 ◽  
Author(s):  
Naveen Pemmaraju ◽  
Hagop M Kantarjian ◽  
Jorge E. Cortes ◽  
Alfonso Quintas-Cardama ◽  
Sherry A. Pierce ◽  
...  
Keyword(s):  
Conflicts Of Interest ◽  
Systemic Mastocytosis ◽  
Myeloproliferative Neoplasms ◽  
Hypereosinophilic Syndrome ◽  
Hematologic Malignancies ◽  
Kaplan Meier ◽  
Female Predominance ◽  
Significant Difference ◽  
Baseline Characteristics ◽  
Better Than

Abstract Abstract 2845 Background: The MPNs are a family of chronic hematologic malignancies that typically affect pts ages 60–70s. However, there is growing awareness of hematologic malignancies developing in young pts, particularly a unique subset of pts known as AYAs. Little is known about incidence and outcomes of AYA pts with MPNs. Objectives: To determine the incidence and outcomes of MPN AYA pts. Results: We retrospectively reviewed charts of 1,616 MPN pts evaluated at our institution from 1986–2011. A total of 171 MPN pts (11%) were identified whose ages were 16–39, defined as AYA pts (per NCCN guideline recommendations on AYA cancers). Breakdown by MPN subtype: Essential Thrombocytosis, ET (n=78, 46% of AYA MPNs), Polycythemia Vera, PV (n=25, 15%), Myelofibrosis, MF(n=24, 14%), [3 post-ET, 1 post-PV, 20 primary MF], Hypereosinophilic syndrome, HES (n=22, 13%), and Systemic Mastocytosis, SM (n=22, 13%). Baseline characteristics of AYA MPN pts detailed in Table 1. Only significant difference among AYA and non-AYA pts in terms of baseline CBC parameters was WBC: 6.4 (0.4–108.4) in AYA MF vs 10.1 (0.6–361) in non-AYA MF, p=0.0049. Analysis of median overall survival (OS), by Kaplan-Meier method, compared by age group (AYA vs non-AYA pts) and broken down by MPN subtype, shown in Table 2. Conclusion: MPN AYA pts constitute 11% of MPN pts at our institution. Overall, their 5- and 10- yr OS were significantly better than their older counterparts in the 3 major MPN subtypes (ET, PV, MF) and trended towards better survival but not statistically significant in HES and SM. Among AYA MPN pts, female predominance was noted among ET and SM pts and only 1 transformation event was noted among all MPN AYA pts in this analysis. Disclosures: No relevant conflicts of interest to declare.

KIT D816V Mutation Positive Bone Marrow Mesenchymal Stem Cells in Indolent Systemic Mastocytosis Are Associated with Disease Progression

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4058-4058
Author(s):  
Andres C Garcia-Montero ◽  
Maria Jara-Acevedo ◽  
Ivan Alvarez-Twose ◽  
Cristina Teodosio ◽  
Laura Sanchez-Muñoz ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Disease Progression ◽  
X Chromosome ◽  
Conflicts Of Interest ◽  
Systemic Mastocytosis ◽  
Kit Mutation ◽  
Indolent Systemic Mastocytosis ◽  
Kit D816v

Abstract PURPOSE: Multilineageinvolvement of bone marrow (BM) hematopoiesis by the somatic KIT D816V mutation is present in a subset of adult indolent systemic mastocytosis (ISM) patients in association with a poorer prognosis. Here we investigated the potential involvement of BM mesenchymal stem cells (MSC) from ISM patients by the KIT D816V mutation and its potential impact on disease progression and outcome. METHODS: The KIT D816V mutation was investigated in highly-purified BM MSC and other BM cell populations from 83 ISM patients followed for a median of 116 months. MC clonality was further evaluated in female patients by the pattern of inactivation of the X chromosome (XCIP). RESULTS: KIT D816V-mutated MSC were detected in 22/83 (27%) ISM patients. All MSC-mutated patients had multilineage KIT mutation (100% vs. 30%, p=0.0001) and they more frequently showed involvement of lymphoid plus myeloid BM cells (59% vs 22%; P =.03) and a polyclonal XCIP of the KIT- mutated BM MC (64% vs 0%; P =0.01) vs other multilineage ISM cases. Moreover, presence of KIT D816V-mutated MSC was associated with more advanced disease features of ISM, a greater rate of disease progression (50% vs 17%; P =.04) and a shorter progression-free survival at 10, 20 and 30 years (P ≤.003). CONCLUSION: Overall, these results support the notion that ISM patients with mutated MSC may have acquired the KIT mutation in a common pluripotent progenitor cell, prior to differentiation into MSC and hematopoietic precursor cells, before the X-chromosome inactivation process occurs. From a clinical point of view, acquisition of the KIT mutation in an earlier BM precursor cell confers a significantly greater risk for disease progression and a poorer outcome. Disclosures No relevant conflicts of interest to declare.

Prevalence and Prognostic Impact of Allelic Imbalances Associated with Leukemic Transformation of Philadelphia Chromosome-Negative Myeloproliferative Neoplasms.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1280-1280
Author(s):  
Nils Heinrich Thoennissen ◽  
Utz O. Krug ◽  
Dhong Hyun Lee ◽  
Norohiko Kawamata ◽  
Terra L Lasho ◽  
...  
Keyword(s):  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasms ◽  
Philadelphia Chromosome ◽  
Snp Array ◽  
Chronic Phase ◽  
Prognostic Impact ◽  
Genomic Alterations ◽  
Leukemic Transformation ◽  
Blast Phase ◽  
Hematopoietic Stem

Abstract Abstract 1280 Poster Board I-302 Philadelphia-chromosome negative myeloproliferative neoplasms (MPNs) including polycythemia vera (PV), essential thrombocytosis (ET), and primary myelofibrosis (PMF) are defined as clonal hematopoietic stem cell disorders. These disorders show an inherent tendency for transformation into leukemia (MPN-blast phase) which is hypothesized to be accompanied by acquisition of additional genomic lesions. We, therefore, obtained a comprehensive profile of genomic alterations associated with leukemic transformation by using single-nucleotide polymorphism (SNP) array in 88 MPN patients, as well as 71 cases with MPN-blast phase, and correlated these findings with their clinical parameters. A relatively high number of genomic alterations was found in MPN after leukemic transformation with 4.6 ± 0.6 abnormalities per sample compared to only 1.4 ± 0.2 changes per patient in chronic phase (p<0.001). Compared to the cytogenetic data, SNP-chip analysis detected about 47% additional chromosomal changes in the MPN samples, and 31% more in the MPN-blast phase cases, whereas SNP-array allelokaryotyping practically captured all cytogenetic abnormalities in our study population. Several additionally altered regions were detected in patients with MPN-blast phase compared to chronic phase, including both deletion and copy-number neutral-loss of heterozygosity (CNN-LOH) on chromosome 12p (9%) and 21q (9%), involving ETV6 and RUNX1. Notably, deletion and CNN-LOH on 17p involving TP53 were diagnosed in 18% of MPN-blast phase samples, which was highly associated with preceding treatment with alkylating agents (p=0.016). Moreover, trisomy 8, as well as amplification of 8q24.21 involving the MYC gene, were detected in 13% of patients with MPN-blast phase who were almost exclusively negative for the JAK2V617F mutation. Genome-wide inspection of further critical regions with promising new candidate genes involved in the evolution to the MPN-leukemic phase included deletion and CNN-LOH on 7q22.1 (SH2B2) in 18%, duplication/amplification on 19p13.2 (PIN1, ICAM1, CDC37) in 13% and 21q22.2 (ERG) in 9% of MPN patients with blast crisis. In contrast, we detected a decreased frequency of JAK2V617F in MPN-blast phase samples (52%) compared to chronic phase (71%). Also, the percentage of patients with homozygous mutant JAK2 as a result of CNN-LOH was lower in the MPN-blast phase (43%) compared to the chronic phase (53%). Taken together, the data suggest that gain-of-function mutation of JAK2 is not a perquisite for leukemic transformation. Remarkably, CNN-LOH on either 7q or 9p was related to decreased survival after leukemic transformation (p=0.02 and p=0.012, respectively). Given the variety of allelic imbalances, our data suggest that MPN-blast phase appears to be a heterogeneous disease prone to have evolved multiple mechanisms to provide a proliferative advantage to the abnormal leukemic clone. Our analysis of MPN genomes in the chronic compared to the leukemic stage provided new prognostic insights, as well as novel causative genes which might be involved in the transformation to MPN-blast phase. Disclosures No relevant conflicts of interest to declare.

Cbl and TET2 Mutations Are Present in Refractory Ph+ Disorders Including Accelerated and Blast Crisis CML and ALL.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2173-2173
Author(s):  
Hideki Makishima ◽  
Anna M. Jankowska ◽  
Heather Cazzolli ◽  
Bartlomiej P Przychodzen ◽  
Courtney Prince ◽  
...  
Keyword(s):  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasms ◽  
Blast Crisis ◽  
Uniparental Disomy ◽  
Ring Finger ◽  
Chronic Phase ◽  
Homozygous Deletion ◽  
Juvenile Myelomonocytic Leukemia ◽  
Tet2 Mutation ◽  
Myelomonocytic Leukemia

Abstract Abstract 2173 Poster Board II-150 Loss of heterozygosity (LOH) due to acquired uniparental disomy (UPD) is a commonly observed chromosomal lesion in myeloproliferative neoplasms (MPN) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) including chronic myelomonocytic leukemia (CMML). Most recurrent areas of LOH point towards genes harboring mutations. For example, UPD11q23.3 and UPD4q24 were found to be associated with c-Cbl and TET2 mutations, respectively. Cbl family mutations (c-Cbl and Cbl-b) have been associated with atypical MDS/MPN including CMML and juvenile myelomonocytic leukemia (JMML) as well as more advanced forms of MDS and secondary AML (sAML). Ring finger mutants of Cbl abrogate ubiquitination and thereby tumor suppressor function related to inactivation of phosphorylated receptor tyrosine kinases, Src and other phosphoproteins. TET2 mutations are present in a similar disease spectrum. The TET family of proteins is involved in conversion of methylcytosine to methylhydroxycytosine which cannot be recognized by DNMT1. Thereby, the proteins seem to counteract maintenance hypermethylation. In our screen of MDS/MPN, we found c-Cbl and Cbl-b ring finger mutations in 5/58 (9%) of CMML and AML derived from CMML, 2/39 (5%) MDS/MPNu, 4/21 (19%) JMML and 14/148 (9%) RAEB/sAML. In the same cohort, TET2 mutations were present in 37% and 14% of patients with MDS/MPN and MDS, respectively. Of note we did not find any TET2 mutations in JMML. We and others have also noted that TET2 and c-Cbl mutations were also detected in atypical chronic myeloid leukemia. While translocations resulting in BCR/ABL fusion characterize CML, we stipulated that in analogy to other chronic myeloproliferative diseases, TET2 and c-Cbl mutations may be also present in CML and contribute to phenotypic heterogeneity within BCR/ABL associated disorders. In particular, progression of CML to accelerated phase (AP) or blast crisis (BC) could be associated with acquisition of additional lesions. When 22 patients with CML chronic phase (CP) were screened, no TET2 and c-Cbl mutations were found. However, we identified 1 c-Cbl, 2 Cbl-b (6%) and 6 TET2 (12%) mutations in 51 patients with CML-AP (N=18) and CML-BC (N=33) with myeloid and lymphoid/mix 24 and 9 phenotype, respectively. These mutations were mutually exclusive. We also noted that TET2 mutations were present in 1/9 CML in BC with lymphoid phenotype. We subsequently screened Ph+ ALL cases (N=9) and found a TET2 mutation in 1 case but no Cbl family mutations. In contrast when 9 Ph- ALL cases were screened as controls, neither TET2 or Cbl mutations were found. SNP-A analysis revealed 2 cases of LOH involving chromosome 4 (UPD4q24 and del4) in a patient with lymphoid blast crisis and Ph+ ALL, respectively. However, UPD was not found in Cbl family gene regions (11q23.3 or 3q13.11). A homozygous deletion of Cbl-b region was seen in a CP patient. Cbl family mutations were associated with a more complex karyotype than TET2 mutations (67% vs. 17% cases with abnormal phenotype). Patients with Cbl family mutations were resistant to imatinib which was effective in only 2 out of 6 patients with TET2mutations. Dasatinib was effective in 2 patients with TET2 mutation. Median over all survival of progressed CML was 47, 49 and 48 months in patients with Cbl, TET2 or no mutations, respectively. In conclusion, our results indicate that Cbl family mutations can occur as secondary lesions in myeloid type aggressive CML (AP and myeloid BC), but not in lymphoid types. TET2 mutations were identified in both lymphoid BC and Ph1+ALL, as well as myeloid BC and AP. In contrast to CMML or JMML in which a vast majority of mutations are homozygous, all Cbl family mutations were heterozygous (no LOH). Similarly, all but two TET2 mutations were heterozygous (1 hemizygous in del4 and 1 homozygous case in UPD4q), suggesting that additional cooperating lesions affecting corresponding pathways may be present. These mutations likely represent secondary lesions which contribute to more either progression (CML) or more aggressive features (Ph+ ALL) and characterize disease refractory to therapy with imatinib. Disclosures: No relevant conflicts of interest to declare.

Single Nucleotide Polymorphism Array (SNP-A) Genomic Profiling of Mantle Cell Lymphoma (MCL) Against a Large Control Database Reveals Recurring Copy Number Alterations (CNAs) and Copy Neutral Loss of Heterozygosity (CN-LOH)

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2001-2001
Author(s):  
Michael J. Rauh ◽  
Juraj Bodo ◽  
Eric Hsi ◽  
Bill Richendollar ◽  
Yuka Sugimoto ◽  
...  
Keyword(s):  
High Resolution ◽  
Copy Number ◽  
Conflicts Of Interest ◽  
Single Nucleotide Polymorphism Array ◽  
Neutral Loss ◽  
Snp Array ◽  
Uniparental Disomy ◽  
Tissue Micro Array ◽  
Ki 67 ◽  
Normal Controls

Abstract Abstract 2001 Background: MCL is characterized by extreme genomic instability. Conventional techniques such as metaphase cytogenetics are unable to detect small deletions, amplifications, or uniparental disomy (UPD) in the MCL tumor genome. SNP-A analysis permits high resolution karyotyping and detection of unbalanced DNA defects, including somatic UPD. We performed SNP-A analysis on MCL tumor samples, excluded CNA present in normal controls, and assessed our results in context of clinical outcome and Ki-67 index. Methods: With IRB approval, available frozen tissue from 18 patients diagnosed with cyclin D1-positive MCL between 1997–2006 was analyzed using high-resolution genome-wide human SNP Array 6.0 (Affymetrix). Signal intensity and SNP calls were determined using the Gene Chip Genotyping Analysis Software Version 4.0 (GTYPE) (Affymetrix). Copy number was also determined. Somatic MCL CNAs and CN-LOH were discerned from germline variants (CNV) by comparing to a database of 1535 normal controls subjected to 250K and/or SNP Array 6.0 analysis. Clinical data was available for all patients, and 15/18 samples were subject to immunohistochemistry (IHC) for Ki67 using an automated immunostainer (Discovery; Ventana Medical Systems). Kaplan-Meier survival analysis was performed. Results: Analysis of 18 MCL patient samples revealed an average 13 CNAs (6.2 gains, 6.4 losses) and 0.4 CN-LOH per patient (Figure 1). Gains were frequently observed in 3q (33%), 8q (22%), 12q (17%), and 18q (11%). A unique 12q micro-gain in one patient narrowed the minimal common region (MCR) to linear region 130.4 – 131.3 Mbp, overlapping with an area of CN-LOH, and including candidate genes MMP17 (upregulated in invasive breast cancer), ULK1 (regulator of autophagy), and EP400 (regulator of chromatin remodeling, proliferation and apoptosis). Recurring deletions were observed at 11q (50%), 1p, 6q (39%), 9p (33%), 13 q (28%), 9q (22%), 7q, and 17p (17%). Similar to prior studies, losses at 1p encompassing CDKN2C and FAF were seen though we further narrowed a common MCR, spanning 93.1–99.7 Mpb and including ARHGAP29 (PARG1)—previously identified in MCL by aCGH/gene expression, whose promoter is a frequent target of MCL methylation. As previously reported, losses in components of the Hippo tumor suppressor pathway were frequently affected by these recurring deletions (6q: LATS1, 9p: MOBKL2B) and by one deletion on 19p (MOBK2LA). Other high-frequency losses encompassed CDKN2A, CDKN2B, and MTAP (on 9p), RB1 and DLEU1/2/miR15a/16-1 (13q), and TP53 (17p). Unique homozygous losses were detected at 9p (3.2-3.3 Mbp; involving only RFX3), 11q (94.5-111.7 Mbp; spanning the ATM region), and 13q (82.7-99.5 Mbp; including the miR17-92 region), and micro-deletions at 6q (121.1-121.9; GJA1/Cx43), 12p (7.5-7.6; CD163), and 13q (73.3-73.4; KLF12, and 75.2–75.3; LMO7). CN-LOH was observed at 6p, similar to prior studies, though we found novel regions of UPD at 4p, 8q, 18q, 19q, and 22q. An overall survival of 3.6 years and relapse-free survival of 1.3 years was observed. Survival was significantly worse among 8 pts with Ki67 >75% (OS 1.4 years, p=.003), but was unaffected by del 11q, del 9p, gain 3q, or gain 8q. Conclusions: SNP-A analysis of 18 primary samples confirms that gains in 3q and 8q and losses in 11q, 6q, and 9p represent common secondary genetic lesions in MCL, and are not frequent in normal controls. We narrowed the MCR of several deletions, potential targets for gene sequencing, and confirm the presence of deletions of potential relevance to the Hippo pathway. Further analysis of our findings in light of tissue micro-array and fluorescence in-situ hybridization studies is underway, to assess pathobiologic consequences of genomic lesions as well as potential therapeutic targets. Disclosures: No relevant conflicts of interest to declare.

MicroRNAs in Intermediate Risk Cytogenetic Acute Myeloid Leukemia Add Relevant Prognostic Information to Molecular Categorization

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 235-235
Author(s):  
Marina Díaz-Beyá ◽  
Alfons Navarro ◽  
Tania Díaz ◽  
Marta Pratcorona ◽  
Maria Rozman ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Mirna Expression ◽  
Conflicts Of Interest ◽  
Detection System ◽  
Intensive Therapy ◽  
Molecular Characteristics ◽  
Prognostic Impact ◽  
Intermediate Risk ◽  
Prognostic Information ◽  
Mutational Status

Abstract Abstract 235 The prognosis of AML patients within the intermediate cytogenetics category is mainly determined by the mutational status of some relevant genes, such as NPM1 mutations (NPMmut), or biallelic CEBPA mutations (CEBPAmut), associated with a favorable outcome, and with the presence of FLT3 internal tandem duplication (FLT3-ITD), which correlates with an adverse prognosis. Nonetheless, additional biological features such as microRNA (miRNA) expression pattern might contribute to refine prognosis and guide therapy in this setting. The aim of the present study is to investigate whether miRNA expression is associated with molecular characteristics and clinical outcome in intermediate-risk AML patients (IR-AML). We have analyzed samples from 85 IR-AML patients (median age, 52 [range, 18–71]; 52% males) who received intensive therapy from 1994 to 2009. Forty-three patients (51%) harbored NPMmut, 37 (44%) harbored FLT3-ITD (including 23 with NPMmut), and 11 (13%) harbored CEBPAmut, including 7 with biallelic mutations. The expression of 670 mature miRNAs was analyzed by multiplex Real Time PCR using TaqMan Human MicroRNA Arrays (Applied Biosystems). All PCR reactions were performed using an ABI 7900 HT sequence detection system. miRNA expression data was analyzed by the 2−DDCt method, using RNU48 as endogenous control. Statistical analysis was performed with BRB Array Tools, SPSS version 15.0.1 and R software version 2.9.0. Supervised analysis by means of t-test based on multiplex permutations (class comparisons analysis, p<0.001) revealed a distinctive miRNA signature in patients with NPMmut, with overexpression of miR-10a, miR-10a*, miR-10b and miR-196b, and downregulation of miR-126, miR126*, miR-424, miR-424* and miR-335, as well as patients with biallelic CEBPAmut, characterized by downregulation of miR-196b and upregulation of miR-181a. Response rate in this series of patients was 84%, with 5-year survival of 43±11% and relapse incidence (RI) of 55±14%. Multivariate analysis for overall survival(OS) including NPM status, FLT3-ITD status, age, WBC, and Log Rank OS significant miRNAs (miR-632, miR-23b, miR-409-3p, let-7a*, miR-565 and miR-196b) identified age, absence of NPMmut, and FLT3-ITD as unfavorable variables together with low expression of miR-409-3p (p<0.001; HR=3.3, 95% CI: 1.7–6.4), and increased level of let-7a* (p=0.026; HR=5.1, 95% CI: 1.21–21.5) and miR-196b (p=0.056; HR=7.27, CI: 0.95–55.6). Concerning risk of relapse (RR), multivariate analysis including NPM status, age, FLT3-ITD, WBC, and Log Rank RR significant miRNAs (miR-632, miR-155*, miR-135a, miR-409-3p, miR-150, miR-23a* and miR-363) the absence of NPMmut, FLT3-ITD and increasing leukocyte count were associated with a higher RI. Remarkably, decreased miR-409-3p expression (p=0.011; HR=3.3, 95% CI: 1.3–8.2) and miR-135a (p=0.02; HR=4.2, 95% CI: 1.2–14.2), together with higher levels of miR-23a* (p<0.001; HR=6.2, 95% CI: 2.61–14.7) were independently associated with a higher relapse risk. Of note, a decreased miR-409-3p level retained its adverse prognosis value in the subgroup of patients without favorable molecular markers (i.e., wild-type NPM1 and CEBPA and/or FLT3-ITD;p=0.001) together with low miR-361-3p (p=0.013, HR= 2.4, CI: 1.2–5.1). On the contrary, let-7a* levels segregated subgroups of patients in the category of favorable genotype (i.e., mutated NPM1 without FLT3-ITD p=0.027). In this series of patients of intermediate-risk cytogenetic AML, measurement of expression levels of several miRNAs such as miR-409-3p, miR-135a, let-7a* or miR-23a* showed independent prognostic value, and contribute to predict the outcome within specific molecular subgroups. Nonetheless, confirmation of the prognostic impact of these miRNAs and investigation of possible underlying mechanisms account for this effect require future studies. Disclosures: No relevant conflicts of interest to declare.

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