Erythroleukemia: Classification.

Acute erythroid leukemia (AEL) is a rare (2%-5%) form of acute myeloid leukemia (AML). Molecular alterations found in AEL resemble those of other AMLs. We report a classification of AELs in three major classes, with different prognosis and some specific features such as a tendency to mutual exclusion of mutations in epigenetic regulators and signaling genes.

Azacitidine Plus Venetoclax for the Treatment of Relapsed and Newly Diagnosed Acute Myeloid Leukemia Patients.

Venetoclax (VEN) belongs the BH3-mimetic class that selectively targets BCL-2, activating apoptosis. The combination of VEN and azacitidine (AZA) has changed the paradigm of treatment of newly diagnosed (ND) acute myeloid leukemia (AML) patients ineligible for intensive chemotherapy. There is scarce evidence for the use of VEN-AZA for relapsed or refractory (R/R) AML. We compared the outcome of 39 R/R AML and 38 ND AML patients treated between 01/20 and 12/21. The median age was 69 (22-86) and 73 (61-81) in the R/R and ND groups, respectively. Adverse cytogenetics were found in 36% of patients in the R/R group and 59% of patients in the ND group. Overall response rate was 37% in R/R AML, including 13% CR, 8% CRi, 3% PR and 13% MLFS, and 58% in the ND AML, including 32% CR, 13% CRi and 13% MLFS. Adverse cytogenetics was associated with treatment failure in the R/R group (Relative Risk = 0.13, p = 0.005). Median overall survival (OS) was 5.9 months in the R/R group and 9.4 months in the ND group. Median OS was 2.2 months in the adverse cytogenetics group versus 8.7 months in the intermediate cytogenetics group in the R/R group (p = 0.02). Median leukemia-free survival was not different between the two groups (9.4 months and 10.3 months), indicating that VEN-AZA can be an efficient salvage treatment for selected R/R AML patients. In conclusion, VEN-AZA is a promising treatment for ND AML and for selected R/R AML patients.

Myeloid malignancies with translocation t(4;12)(q11-13;p13): molecular landscape, clonal hierarchy and clinical outcomes.

Translocation t(4;12)(q11-13;p13) is a recurrent but very rare chromosomal aberration in acute myeloid leukaemia (AML) resulting in the non-constant expression of a CHIC2/ETV6 fusion transcript. We report clinico-biological features, molecular characteristics and outcomes of 21 cases of t(4;12) including 19 AML and two myelodysplastic syndromes (MDS). Median age at the time of t(4;12) was 78 years (range, 56-88). Multilineage dysplasia was described in 10 of 19 (53%) AML cases and CD7 and/or CD56 expression in 90%. FISH analyses identified ETV6 and CHIC2 region rearrangements in respectively 18 of 18 and 15 of 17 studied cases. The t(4;12) was the sole cytogenetic abnormality in 48% of cases. The most frequent associated mutated genes were ASXL1 (n = 8/16, 50%), IDH1/2 (n = 7/16, 44%), SRSF2 (n = 5/16, 31%) and RUNX1 (n = 4/16, 25%). Interestingly, concurrent FISH and molecular analyses showed that t(4;12) can be, but not always, a founding oncogenic event. Median OS was 7.8 months for the entire cohort. In the 16 of 21 patients (76%) who received antitumoral treatment, overall response and first complete remission rates were 37% and 31%, respectively. Median progression-free survival in responders was 13.7 months. Finally, t(4;12) cases harboured many characteristics of AML with myelodysplasia-related changes (multilineage dysplasia, MDS-related cytogenetic abnormalities, frequent ASXL1 mutations) and a poor prognosis.

Dual origin of relapses in retinoic-acid resistant acute promyelocytic leukemia.

Retinoic acid (RA) and arsenic target the t(15;17)(q24;q21) PML/RARA driver of acute promyelocytic leukemia (APL), their combination now curing over 95% patients. We report exome sequencing of 64 matched samples collected from patients at initial diagnosis, during remission, and following relapse after historical combined RA-chemotherapy treatments. A first subgroup presents a high incidence of additional oncogenic mutations disrupting key epigenetic or transcriptional regulators (primarily WT1) or activating MAPK signaling at diagnosis. Relapses retain these cooperating oncogenes and exhibit additional oncogenic alterations and/or mutations impeding therapy response (RARA, NT5C2). The second group primarily exhibits FLT3 activation at diagnosis, which is lost upon relapse together with most other passenger mutations, implying that these relapses derive from ancestral pre-leukemic PML/RARA-expressing cells that survived RA/chemotherapy. Accordingly, clonogenic activity of PML/RARA-immortalized progenitors ex vivo is only transiently affected by RA, but selectively abrogated by arsenic. Our studies stress the role of cooperating oncogenes in direct relapses and suggest that targeting pre-leukemic cells by arsenic contributes to its clinical efficacy.

Impact of gene mutations on treatment response and prognosis of acute myeloid leukemia secondary to myeloproliferative neoplasms.

Acute myeloid leukemias secondary (sAML) to myeloproliferative neoplasms (MPN) have variable clinical courses and outcomes, but remain almost always fatal. Large cohorts of sAML to MPN are difficult to obtain and there is very little scientific literature or prospective trials for determining robust prognostic markers and efficient treatments. We analyzed event-free survival (EFS) and overall survival (OS) of 73 patients with MPN who progressed to sAML, based on their epidemiological characteristics, the preexisting MPN, the different treatments received, the different prognostic groups and the responses achieved according to the ELN, and their mutational status determined by next-generation DNA sequencing (NGS). For 24 patients, we were able to do a comparative NGS analysis at both MPN and sAML phase. After acute transformation EFS and OS were respectively of 2.9 months (range: 0-48.1) and 4.7 months (range: 0.1-58.8). No difference in EFS or OS regarding the previous MPN, the ELN2017 prognostic classification, the first-line therapy or the response was found. After univariate analysis, three genes, TP53, SRSF2 and TET2, impacted pejoratively sAML prognosis at sAML time. In multivariate analysis, TP53 (P = .0001), TET2 (P = .011) and SRSF2 (P = .018) remained independent prognostic factors. Time to sAML transformation was shorter in SRSF2-mutated patients (51.2 months, range: 14.7-98) than in SRSF2-unmutated patients (133.8 months, range: 12.6-411.2) (P < .001). Conventional clinical factors (age, karyotype, ELN2017 prognostic classification, treatments received, treatments response, Allo-SCT…) failed to predict the patients' outcome. Only the mutational status appeared relevant to predict patients' prognosis at sAML phase.

JAM-C Identifies Src Family Kinase-Activated Leukemia-Initiating Cells and Predicts Poor Prognosis in Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) originates from hematopoietic stem and progenitor cells that acquire somatic mutations, leading to disease and clonogenic evolution. AML is characterized by accumulation of immature myeloid cells in the bone marrow and phenotypic cellular heterogeneity reflective of normal hematopoietic differentiation. Here, we show that JAM-C expression defines a subset of leukemic cells endowed with leukemia-initiating cell activity (LIC). Stratification of de novo AML patients at diagnosis based on JAM-C-expressing cells frequencies in the blood served as an independent prognostic marker for disease outcome. Using publicly available leukemic stem cell (LSC) gene expression profiles and gene expression data generated from JAM-C-expressing leukemic cells, we defined a single cell core gene expression signature correlated to JAM-C expression that reveals LSC heterogeneity. Finally, we demonstrated that JAM-C controls Src family kinase (SFK) activation in LSC and that LIC with exacerbated SFK activation was uniquely found within the JAM-C-expressing LSC compartment. Cancer Res; 77(23); 6627-40. ©2017 AACR.

Impact of cytogenetic abnormalities in adults with Ph-negative B-cell precursor acute lymphoblastic leukemia.

Multiple cytogenetic subgroups have been described in adult Philadelphia chromosome (Ph)-negative B-cell precursor (BCP) acute lymphoblastic leukemia (ALL), often comprising small numbers of patients. In this study, we aimed to reassess the prognostic value of cytogenetic abnormalities in a large series of 617 adult patients with Ph-negative BCP-ALL (median age, 38 years), treated in the intensified Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL)-2003/2005 trials. Combined data from karyotype, DNA index, fluorescence in situ hybridization, and polymerase chain reaction screening for relevant abnormalities were centrally reviewed and were informative in 542 cases (88%), allowing classification in 10 exclusive primary cytogenetic subgroups and in secondary subgroups, including complex and monosomal karyotypes. Prognostic analyses focused on cumulative incidence of failure (including primary refractoriness and relapse), event-free survival, and overall survival. Only 2 subgroups, namely t(4;11)/KMT2A-AFF1 and 14q32/IGH translocations, displayed a significantly worse outcome in this context, still observed after adjustment for age and after censoring patients who received allogeneic stem cell transplantation (SCT) in first remission at SCT time. A worse outcome was also observed in patients with low hypodiploidy/near triploidy, but this was likely related to their higher age and worse tolerance to therapy. The other cytogenetic abnormalities, including complex and monosomal karyotypes, had no prognostic value in these intensive protocols designed for adult patients up to the age of 60 years.

Cytogenetics in the management of acute myeloid leukemia: an update by the Groupe francophone de cytogénétique hématologique (GFCH).

The karyotype is critical for the evaluation of acute myeloid leukemia (AML) at diagnosis. Cytogenetic abnormalities detected in AML are one of the most powerful independent prognostic factors. It impacts on the choice of treatment in clinical trials. All chromosomes can be targeted, common chromosomal abnormalities are recurrent and may be associated with a cytological well-defined type. In 40% of the cases, the karyotype is normal and must be associated with molecular biology studies that can refine the prognosis. The usefulness of the karyotype is more limited during the follow-up of the patient due to its limited sensitivity, but it is still useful in the clinical management of relapse. Since 2001, the WHO (World Health Organization) classification of hematological malignancies integrates cytogenetic data in the classification of AML. Karyotype is therefore mandatory in the diagnosis of AML.

Cytogenetics in the management of "chronic myeloid leukemia": an update by the Groupe francophone de cytogénétique hématologique (GFCH).

Cytogenetic evaluation is one the most important criteria for diagnosis and response to treatment in chronic myeloid leukemia, and recent baseline prognostic factors including particular additional clonal cytogenetic abnormalities have been established. The French cytogenetic group in hematology GFCH proposes here an updating of recommendations for cytogenetic assessment of CML in the era of tyrosine kinase inhibitors.

Cytogenetics in the management of Philadelphia-negative myeloproliferative neoplasms: an update by the Groupe francophone de cytogénétique hématologique (GFCH).

The recent years have witnessed tremendous progress in the molecular characterization of Philadelphia-negative myeloproliferative neoplasms (MPN). Beside a better understanding of pathophysiology, these abnormalities often constitute very useful diagnostic markers in diseases where exclusion of reactive states used to be the strongest argument. However, conventional and molecular cytogenetics keep a major interest in MPN, either as a second line exploration, in cases where no molecular marker is available, for differential diagnosis or as a proof of clonality or in first line for cases with hyperleukocytosis, for differential diagnosis (CML), to evidence druggable targets (ABL1, RET, PDGFR…) or as a prognosis marker. In this article, we will review the interest of cytogenetic techniques in myeloproliferative neoplasms.

Characterization of leukemias with ETV6-ABL1 fusion.

To characterize the incidence, clinical features and genetics of ETV6-ABL1 leukemias, representing targetable kinase-activating lesions, we analyzed 44 new and published cases of ETV6-ABL1-positive hematologic malignancies [22 cases of acute lymphoblastic leukemia (13 children, 9 adults) and 22 myeloid malignancies (18 myeloproliferative neoplasms, 4 acute myeloid leukemias)]. The presence of the ETV6-ABL1 fusion was ascertained by cytogenetics, fluorescence in-situ hybridization, reverse transcriptase-polymerase chain reaction and RNA sequencing. Genomic and gene expression profiling was performed by single nucleotide polymorphism and expression arrays. Systematic screening of more than 4,500 cases revealed that in acute lymphoblastic leukemia ETV6-ABL1 is rare in childhood (0.17% cases) and slightly more common in adults (0.38%). There is no systematic screening of myeloproliferative neoplasms; however, the number of ETV6-ABL1-positive cases and the relative incidence of acute lymphoblastic leukemia and myeloproliferative neoplasms suggest that in adulthood ETV6-ABL1 is more common in BCR-ABL1-negative chronic myeloid leukemia-like myeloproliferations than in acute lymphoblastic leukemia. The genomic profile of ETV6-ABL1 acute lymphoblastic leukemia resembled that of BCR-ABL1 and BCR-ABL1-like cases with 80% of patients having concurrent CDKN2A/B and IKZF1 deletions. In the gene expression profiling all the ETV6-ABL1-positive samples clustered in close vicinity to BCR-ABL1 cases. All but one of the cases of ETV6-ABL1 acute lymphoblastic leukemia were classified as BCR-ABL1-like by a standardized assay. Over 60% of patients died, irrespectively of the disease or age subgroup examined. In conclusion, ETV6-ABL1 fusion occurs in both lymphoid and myeloid leukemias; the genomic profile and clinical behavior resemble BCR-ABL1-positive malignancies, including the unfavorable prognosis, particularly of acute leukemias. The poor outcome suggests that treatment with tyrosine kinase inhibitors should be considered for patients with this fusion.