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Pediatric acute myeloid leukemia (AML) is a rare disease whose prognosis is highly variable according to factors such as chromosomal abnormalities. Recurrent genomic rearrangements are detected in half of pediatric AML by karyotype. NUcleoPorin 98 (NUP98) gene is rearranged with 31 different fusion partner genes. These rearrangements are frequently undetected by conventional cytogenetics, as the NUP98 gene is located at the end of the chromosome 11 short arm (11p15). By screening a series of 574 pediatric AML, we detected a NUP98 rearrangement in 22 cases (3.8%), a frequency similar to CBFB-MYH11 fusion gene (4.0%). The most frequent NUP98 fusion gene partner is NSD1. These cases are homogeneous regarding their biological and clinical characteristics, and associated with bad prognosis only improved by bone marrow transplantation. We detailed the biological characteristics of these AML by exome sequencing which demonstrated few recurrent mutations (FLT3 ITD, WT1, CEBPA, NBPF14, BCR and ODF1). The analysis of the clonal structure in these cases suggests that the mutation order in the NUP98-rearranged pediatric AML begins with the NUP98 rearrangement leading to epigenetic dysregulations then followed by mutations of critical hematopoietic transcription factors and finally, activation of the FLT3 signaling pathway.

The PICALM-MLLT10 fusion gene, generated by the t(10;11)(p12-13;q14-21) translocation, is a rare but recurrent event in acute leukemias. In this study, we assessed the characteristics and outcome of 18 PICALM-MLLT10 AML patients. As compared with non PICALM-MLLT10 patients (n=72), PICALM-MLLT10 AML were characterized by more frequent extramedullary diseases, CD7 expression and higher platelet counts. Three out of four therapy-related PICALM-MLLT10 AMLs had been previously treated for diffuse large B-cell lymphoma. The complete response rate was 71% after intensive chemotherapy. PICALM-MLLT10 patients had a shorter median overall survival than patients with favorable cytogenetics (12 months vs. not reached, p=0.07) but not significantly different from those of intermediate (26 months, p=0.32) or unfavorable cytogenetic groups (8 months, p=0.13). Long term responses were achieved in a subset of patients after allogeneic stem-cell transplantation but also after high-dose cytarabine., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The PRDM16 (1p36) gene is rearranged in acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS) with t(1;3)(p36;q21), sharing characteristics with AML and MDS with MECOM (3q26.2) translocations. We used fluorescence in situ hybridization to study 39 haematological malignancies with translocations involving PRDM16 to assess the precise breakpoint on 1p36 and the identity of the partner locus. Reverse-transcription polymerase chain reaction (PCR) was performed in selected cases in order to confirm the partner locus. PRDM16 expression studies were performed on bone marrow samples of patients, normal controls and CD34(+) cells using TaqMan real-time quantitative PCR. PRDM16 was rearranged with the RPN1 (3q21) locus in 30 cases and with other loci in nine cases. The diagnosis was AML or MDS in most cases, except for two cases of lymphoid proliferation. We identified novel translocation partners of PRDM16, including the transcription factors ETV6 and IKZF1. Translocations involving PRDM16 lead to its overexpression irrespective of the consequence of the rearrangement (fusion gene or promoter swap). Survival data suggest that patients with AML/MDS and PRDM16 translocations have a poor prognosis despite a simple karyotype and a median age of 65 years. There seems to be an over-representation of late-onset therapy-related myeloid malignancies., (© 2011 Blackwell Publishing Ltd.)

The prognosis of acute myeloid leukemia (AML) is very poor in elderly patients, especially in those classically defined as having unfavorable cytogenetics. The recent monosomal karyotype (MK) entity, defined as 2 or more autosomal monosomies or combination of 1 monosomy with structural abnormalities, has been reported to be associated with a worse outcome than the traditional complex karyotype (CK). In this retrospective study of 186 AML patients older than 60 years, the prognostic influence of MK was used to further stratify elderly patients with unfavorable cytogenetics. CK was observed in 129 patients (69%), and 110 exhibited abnormalities according to the definition of MK (59%). MK(+) patients had a complete response rate significantly lower than MK(-) patients: 37% vs 64% (P = .0008), and their 2-year overall survival was also decreased at 7% vs 22% (P < .0001). In multivariate analysis, MK appeared as the major independent prognostic factor related to complete remission achievement (odds ratio = 2.3; 95% confidence interval, 1-5.4, P = .05) and survival (hazard ratio = 1.7; 95% confidence interval, 1.1-2.5, P = .008). In the subgroup of 129 CK(+) patients, survival was dramatically decreased for MK(+) patients (8% vs 28% at P = .03). These results demonstrate that MK is a major independent factor of very poor prognosis in elderly AML.

Background: Epidemiological data on myeloid malignancies are very rare in the literature due to a lack of registration by cancer registries until 2000. The Registry of Hematologic Malignancies of the Côte d'Or Department in France has, however, steadfastly registered data on cases occurring in the Department since 1980, resulting, to date, in a database of over 5,000 cases classified according to the ICD-O-3 classification, following the most recent World Health Organization classification criteria., Design and Methods: Twenty-five years of data on myeloid malignancies, including acute myeloid leukemia, myeloproliferative neoplasms, myelodysplastic syndromes and myelodysplastic/myeloproliferative syndromes were analyzed. World population standardized incidence rates were calculated as were as observed and relative survival., Results: Incidence rates per 100,000 inhabitants/year were 2.5 for acute myeloid leukemia, 1.3 for myelodysplastic syndromes, 3.2 for myeloproliferative neoplasms and 0.6 for myelodysplastic/myeloproliferative syndromes. It was found that the incidence rate of myelodysplastic syndromes increased significantly over the period. The median overall survival is 8.9 months for patients with acute myeloid leukemia, 33.8 months for patients with myelodysplastic syndromes, 91.7 months for those with myeloproliferative neoplasms and 26.6 months for patients with myelodysplastic/myeloproliferative syndromes. Observed and relative 20-year survival rates are, respectively, 12% and 13% in acute myeloid leukemia, 2% and 6% in myelodysplastic syndromes and 20% and 34% in myeloproliferative neoplasms., Conclusions: These population-based data on myeloid malignancies are the first data collected over such a long period and provide interesting information for clinicians and public health authorities, particularly given the paucity of other long-term, population-based data from cancer registries.

Thirty cases of acute myeloid leukaemia (AML) with MYST histone acetyltransferase 3 (MYST3) rearrangement were collected in a retrospective study from 14 centres in France and Belgium. The mean age at diagnosis was 59.4 years and 67% of the patients were females. Most cases (77%) were secondary to solid cancer (57%), haematological malignancy (35%) or both (8%), and appeared 25 months after the primary disease. Clinically, cutaneous localization and disseminated intravascular coagulation were present in 30 and 40% of the cases, respectively. AMLs were myelomonocytic (7%) or monocytic (93%), with erythrophagocytosis (75%) and cytoplasmic vacuoles (75%). Immunophenotype showed no particularity compared with monocytic leukaemia without MYST3 abnormality. Twenty-eight cases carried t(8;16)(p11;p13) with MYST3-CREBBP fusion, one case carried a variant t(8;22)(p11;q13) and one case carried a t(8;19)(p11;q13). Type I (MYST3 exon 16-CREBBP exon 3) was the most frequent MYST3-CREBBP fusion transcript (65%). MYST3 rearrangement was associated with a poor prognosis, as 50% of patients deceased during the first 10 months. All those particular clinical, cytologic, cytogenetic, molecular and prognostic characteristics of AML with MYST3 rearrangement may have allowed an individualization into the World Health Organization classification.

Based on our previous demonstration that quinine could be used clinically to reverse P-glycoprotein-mediated resistance, we designed a multicenter, randomized trial aiming to determine whether quinine would improve the survival of adult patients (15-60 years old) with de novo acute myelogenous leukemia (AML). These patients randomly received (n = 213) or did not receive (n = 212) a 30 mg/kg/day continuous intravenous infusion of quinine in combination with induction chemotherapy combining idarubicine and cytarabine and, depending on bone marrow examination at day 20, an additional course of cytarabine and mitoxantrone. The mean steady-state quinine concentration was 7.8 mg/L and the mean multidrug resistance reversing activity of serum was 1.96. Complete remission (CR) was obtained in 344 patients (80.9%) without significant influence of quinine. Of the patients in complete remission, 82 were assigned to receive HLA-matched bone marrow transplants, whereas 262 were assigned to 2 courses of intensive consolidation chemotherapy, with or without quinine, depending on initial randomization. The 4-year actuarial overall survival (OS) of the 425 eligible patients was 42.0% +/- 2.5%, without significant influence of quinine. Of 160 patients who could be studied, 54 demonstrated rhodamine 123 efflux. In these patients, quinine significantly improved the CR rate from 12 of 25 (48.0%) to 24 of 29 (82.8%) (P =.01). However, there was no significant difference in OS. Neither mdr1 gene nor P-glycoprotein expression influenced the outcome. We conclude that quinine does not improve the survival of adult patients with de novo AML, even though it improves CR rate in a small subgroup of patients defined by rhodamine 123 efflux.

Cytogenetic studies of acute myeloid leukaemias reveal non-random chromosomal abnormalities in 50-70% of karyotypes. Some are correlated with morphological and immunological parameters and constitute a prognostic factor independent of the other factors of risk: favourable for acute leukaemias myeloid with translocations t(8;21), t(15;17) and inversion or translocation of the chromosome 16, inv(16)/t(16;16), poor with deletion of the long arm of chromosome 5 del(5q), rearrangement of the 11q23 region and complex karyotypes. The distribution of the anomalies depends on the age: 11q23 and t(8;21) more frequent for the child, del(5q) and complex anomalies more frequent for the adult. The karyotypes are essential for the diagnosis, the follow-up of the patients and the evaluation of the relapse. It plays a fundamental part in the detection of new genes and their partners implied in the leucemogenese. The knowledge of their function is essential to open new therapeutic ways.

Mutations of the AML1 gene are frequent molecular abnormalities in minimally differentiated acute myeloblastic leukemia (M0 AML), a rare type of AML. In this retrospective multicenter study, morphologic, immunophenotypical, cytogenetic, and molecular features of 59 de novo M0 AML cases were analyzed and correlated to AML1 mutations. Point mutations of AML1 gene were observed in 16 cases (27%). They were correlated with higher white blood cell (WBC) count (P =.001), greater marrow blast involvement (P =.03), higher incidence of immunoglobulin H/T-cell receptor (IgH/TCR) gene rearrangement (P <.0001), and with a borderline significant lower incidence of complex karyotypes. In the 59 patients, FLT3 mutations were the only significant prognostic factors associated with short survival.

This study prospectively analysed the relationships between immunophenotypic and cytogenetic features of blast cells in 432 acute non-lymphoblastic leukemias (ANLL) at presentation. An abnormal karyotype was detected in 232 cases (54%). These abnormalities were related to immunophenotypic markers as detected using a consensual panel of monoclonal antibodies allowing lineage assignment and investigation of myeloid marker expression on blast cells. In univariate analysis, CD9, CD10, CD15, CD34 and TdT expression appeared significantly associated with chromosomal anomalies. Multivariate analysis identified CD34 and CD9 expression as independently predictive of the presence of at least one cytogenetic abnormality (P < 10(-4) and P < 0.03, respectively). Significant associations between immunophenotypic and karyotypic features were observed both within individual FAB subgroups and independently from morphological criteria. Specific features were seen in five ANLL entities: M0 or M1/B lineage antigen positivity/t(9;22) or del(11)(q23); M2/CD13-/t(8;21); M4/CD13+, CD34+, CD36+/inv(16); M4 or M5/lack of B lineage antigen/del(11)(q23) or t(9;11). More practically, and although the relationships demonstrated only represent a fraction of homogeneous immunophenotypic subgroups, identification of such immunophenotypic features should prompt careful karyotypic examination, eventually using molecular biology analysis on non-growing cells.

The expression of the P-glycoprotein which is associated with the development of multidrug resistance in various cell lines was investigated in 87 fresh acute leukaemia and multiple myeloma samples using the specific mouse monoclonal antibody MRK16 in an indirect immunofluorescence assay. Considering a 10% positive cell cut-off value, a heterogeneous expression of P-glycoprotein was observed in 5/22 (22.7%) de novo acute leukaemias, 7/22 (31.8%) relapse or secondary acute leukaemias, 14/27 (51.8%) acute transformation of myeloproliferative or myelodysplastic syndromes and 5/16 (31.2%) multiple myelomas. This expression was not associated with specific cytogenetic abnormalities, especially alterations of chromosome 7q. Verapamil, a calcium channel blocker, has been demonstrated to circumvent the multidrug resistance in cell lines, possibly by interfering with P-glycoprotein function. Using the microculture tetrazolium assay, verapamil was demonstrated to increase the sensitivity of fresh leukaemic or myeloma cells to doxorubicin in 19/43 (43.1%) samples. The doxorubicin IC50 level and the capacity of verapamil to increase the sensitivity of blast cells to doxorubicin in vitro did not correlate with the expression of P-glycoprotein. We conclude that high non-cytotoxic concentrations of verapamil were able to increase the in vitro doxorubicin sensitivity of fresh acute leukaemia and myeloma cells without detectable expression of the P-glycoprotein.