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Abstract The reintegration of excised signal joints resulting from human V(D)J recombination was described as a potent source of genomic instability in human lymphoid cancers. However, such molecular events have not been recurrently reported in clinical patient lymphoma/leukemia samples. Using a specifically designed NGS-capture pipeline, we here demonstrated the reintegration of T-cell receptor excision circles (TRECs) in 20/1533 (1.3%) patients with T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL). Remarkably, the reintegration of TREC recurrently targeted the tumor suppressor gene, ZFP36L2, in 17/20 samples. Thus, our data identified a new and hardly detectable mechanism of gene deregulation in lymphoid cancers providing new insights in human oncogenesis.

Abstract The acquisition of genetic abnormalities engendering oncogene dysregulation underpins cancer development. Certain proto-oncogenes possess several dysregulation mechanisms, yet how each mechanism impacts clinical outcome is unclear. Using T-cell acute lymphoblastic leukemia (T-ALL) as an example, we show that patients harboring 5’super-enhancer (5’SE) mutations of the TAL1 oncogene identifies a specific patient subgroup with poor prognosis irrespective of the level of oncogene dysregulation. Remarkably, the MYB dependent oncogenic 5’SE can be targeted using Mebendazole to induce MYB protein degradation and T-ALL cell death. Of note Mebendazole treatment demonstrated efficacy in vivo in T-ALL preclinical models. Our work provides proof of concept that within a specific oncogene driven cancer, the mechanism of oncogene dysregulation rather than the oncogene itself can identify clinically distinct patient subgroups and pave the way for future super-enhancer targeting therapy.

Whereas the prognosis of adult patients with Philadelphia-negative acute lymphoblastic leukemia (ALL) has greatly improved since the advent of pediatric-inspired regimens, the impact of initial central nervous system (CNS) involvement has not been formerly re-evaluated. We report here the outcome of patients with initial CNS involvement included in the pediatric-inspired prospective randomized GRAALL-2005 study. Between 2006 and 2014, 784 adult patients (aged 18-59 years) with newly diagnosed Philadelphia-negative ALL were included, of whom 55 (7%) had CNS involvement. In CNSpositive patients, overall survival was shorter (median 1.9 years vs. not reached, HR=1.8 [1.3-2.6], P

Abstract T-cell acute lymphoblastic leukemias (T-ALL) represent 15% of pediatric and 25% of adult ALL. Since they have a particularly poor outcome in relapsed/refractory cases, identifying prognosis factors at diagnosis is crucial to adapting treatment for high-risk patients. Unlike acute myeloid leukemia and BCP ALL, chromosomal rearrangements leading to chimeric fusion-proteins with strong prognosis impact are sparsely reported in T-ALL. To address this issue an RT-MPLA assay was applied to a consecutive series of 522 adult and pediatric T-ALLs and identified a fusion transcript in 20% of cases. PICALM-MLLT10 (4%, n = 23), NUP214-ABL1 (3%, n = 19) and SET-NUP214 (3%, n = 18) were the most frequent. The clinico-biological characteristics linked to fusion transcripts in a subset of 235 patients (138 adults in the GRAALL2003/05 trials and 97 children from the FRALLE2000 trial) were analyzed to identify their prognosis impact. Patients with HOXA trans-deregulated T-ALLs with MLLT10, KMT2A and SET fusion transcripts (17%, 39/235) had a worse prognosis with a 5-year EFS of 35.7% vs 63.7% (HR = 1.63; p = 0.04) and a trend for a higher cumulative incidence of relapse (5-year CIR = 45.7% vs 25.2%, HR = 1.6; p = 0.11). Fusion transcripts status in T-ALL can be robustly identified by RT-MLPA, facilitating risk adapted treatment strategies for high-risk patients.

Abstract IDH1 and IDH2 mutations (IDH1/2 Mut ) are recognized as recurrent genetic alterations in acute myeloid leukemia (AML) and associated with both clinical impact and therapeutic opportunity due to the recent development of specific IDH1/2 Mut inhibitors. In T-cell acute lymphoblastic leukemia (T-ALL), their incidence and prognostic implications remain poorly reported. Our targeted next-generation sequencing approach allowed comprehensive assessment of genotype across the entire IDH1 and IDH2 locus in 1085 consecutive unselected and newly diagnosed patients with T-ALL and identified 4% of, virtually exclusive (47 of 49 patients), IDH1/2 Mut. Mutational patterns of IDH1/2 Mut in T-ALL present some specific features compared to AML. Whereas IDH2 R140Q mutation was frequent in T-ALL (25 of 51 mutations), the IDH2 R172 AML hotspot was absent. IDH2 mutations were associated with older age, an immature phenotype, more frequent RAS gain-of-function mutations and epigenetic regulator loss-of-function alterations (DNMT3A and TET2). IDH2 mutations, contrary to IDH1 mutations, appeared to be an independent prognostic factor in multivariate analysis with the NOTCH1/FBXW7/RAS/PTEN classifier. IDH2 Mut were significantly associated with a high cumulative incidence of relapse and very dismal outcome, suggesting that IDH2-mutated T-ALL cases should be identified at diagnosis in order to benefit from therapeutic intensification and/or specific IDH2 inhibitors.

Abstract: Protein tyrosine phosphatase nonreceptor type 2 (PTPN2) is a phosphatase known to be a tumor suppressor gene in T-cell acute lymphoblastic leukemia (T-ALL). Because the full clinicobiologic characteristics of PTPN2 loss remain poorly reported, we aimed to provide a comprehensive analysis of PTPN2 deletions within a cohort of 430 patients, including 216 adults and 214 children treated according to the GRAALL03/05 (#NCT00222027 and #NCT00327678) and the FRALLE2000 protocols, respectively. We used multiplex ligation-dependent probe amplification to identify an 8% incidence of PTPN2 deletion, which was comparable in adult (9%) and pediatric (6%) populations. PTPN2 deletions were significantly associated with an αβ lineage and TLX1 deregulation. Analysis of the mutational genotype of adult T-ALL revealed a positive correlation between PTPN2 deletions and gain-of-function alterations in the IL7R/JAK-STAT signaling pathway as well as PHF6 and WT1 mutations. Of note, PTPN2 and PTEN (phosphatase and tensin homolog) deletions were mutually exclusive. Regarding treatment response, PTPN2-deleted T-ALLs were associated with a higher glucocorticoid response and a trend for improved survival in children, but not in adults, with a 5-year cumulative incidence of relapse of 8% for PTPN2-deleted pediatric cases vs 26% (P = .177).

Abstract Background Controversy persists concerning screening programs (SPs), related to a potential risk of overdiagnosis or the impact on survival. One of the main questions to be addressed concerns the aggressiveness of the related treatments. Methods Using the "Cancer Cohort,” a national‐based cohort (medico‐administrative database), all women between the ages of 50 and 74 years and treated in 2014 for incident breast cancer were compared, according to whether their diagnosis was made following a mammogram performed within the framework of the SP (SP group) or outside it (NSP group). Results A total of 23 788 women were identified: 13 530 (57%) in the SP group and 10 258 (43%) in the NSP group. The women in the SP group had a higher rate of in situ or localized invasive breast cancer. They had a higher rate of breast‐conserving surgery (82% vs 70%), and a lower rate of chemotherapy (34% vs 53%). These findings were observed irrespective of the stage. They had a higher rate of pathways involving breast‐conserving surgery followed by radiotherapy. Among women with metastatic cancer, those in the SP group had a lower proportion of liver, lung, brain, and bone metastases, and a higher proportion of lymph node metastases (other than axillary), irrespective of the time to onset of the metastases. Conclusion The women in whom cancer was diagnosed following a mammogram performed in the context of the SP had less advanced cancer and less aggressive treatments. This observational study helps illustrate the benefit of the SP in France using a different approach.

Daunorubicin pharmacokinetics (PK) are characterised by an important inter-individual variability, which raises questions about the optimal dose regimen in patients with acute myeloid leukaemia. The aim of the study is to assess the joint daunorubicin/daunorubicinol PK profile and to define an optimal population PK study design. Fourteen patients were enrolled in the PK ancillary study of the BIG-1 trial and 6–8 samples were taken up to 24 h after administration of the first dose of daunorubicin (90 mg/m2/day). Daunorubicin and daunorubicinol quantifications were assessed using a validated liquid chromatography technique coupled with a fluorescence detector method. Data were analysed using a non-compartmental approach and non-linear mixed effects modelling. Optimal sampling strategy was proposed using the R function PFIM. The median daunorubicin and daunorubicinol AUC0-tlast were 577 ng/mL·hr (Range: 375–1167) and 2200 ng/mL·hr (range: 933–4683), respectively. The median metabolic ratio was 0.32 (range: 0.1–0.44). Daunorubicin PK was best described by a three-compartment parent, two-compartment metabolite model, with a double first-order transformation of daunorubicin to metabolite. Body surface area and plasma creatinine had a significant impact on the daunorubicin and daunorubicinol PK. A practical optimal population design has been derived from this model with five sampling times per subject (0.5, 0.75, 2, 9, 24 h) and this can be used for a future population PK study.

Cancer cells undergo massive alterations in their DNA methylation patterns which result in aberrant gene expression and malignant phenotypes. Abnormal DNA methylation is a prognostic marker in several malignancies, but its potential prognostic significance in adult T-cell acute lymphoblastic leukemia (T-ALL) is poorly defined. Here, we performed methylated DNA immunoprecipitation to obtain a comprehensive genome-wide analysis of promoter methylation in adult T-ALL (n=24) compared to normal thymi (n=3). We identified a CpG hypermethylator phenotype that distinguishes two T-ALL subgroups and further validated it in an independent series of 17 T-lymphoblastic lymphoma. Next, we identified a methylation classifier based on nine promoters which accurately predict the methylation phenotype. This classifier was applied to an independent series of 168 primary adult T-ALL treated accordingly to the GRAALL03/05 trial using methylation-specific multiplex ligation-dependent probe amplification. Importantly hypomethylation correlated with specific oncogenic subtypes of T-ALL and identified patients associated with a poor clinical outcome. This methylation-specific multiplex ligation-dependent probe amplification based methylation profiling could be useful for therapeutic stratification of adult T-ALL in routine practice. The GRAALL-2003 and -2005 studies were registered at http://www.clinicaltrials.gov as #NCT00222027 and #NCT00327678, respectively.

Abstract Background Acute myeloid leukaemia (AML) with 17p abnormalities (abn(17p)) carries a very poor prognosis due to high refractoriness to conventional chemotherapy, and allogeneic stem cell transplantation (allo-SCT) appears as the only potential curative option. Methods To address outcomes after allo-SCT in patients with abn(17p), we retrospectively analysed de novo or secondary AML undergoing SCT between 2000 and 2013 from the EBMT registry. Results One hundred thirty-nine patients with confirmed abn(17p) have been selected. At the time of transplant, one hundred twenty-five were in first remission (CR1). Median age was 54 years old. Abn(17p) was associated with a monosomal karyotype in 83% of patients, complex karyotype in 91%, monosomy 5 or 5q deletion (-5/5q-) in 55%, monosomy 7 (-7) in 39% and both -5/5q and -7 in 27%. Seventy-three patients (59%) had a reduced-intensity conditioning regimen. The 2-year overall survival (OS) and leukaemia-free survival (LFS) were 28 and 24%, respectively. The 2-year non-relapse mortality (NRM) was 15%, and 2-year relapse incidence (RI) was 61%. The cumulative incidence of grade II to IV acute graft-versus-host disease (GvHD) was 24% and that of chronic GvHD was 21%. In multivariate analysis, the presence of a -5/5q- in addition to abn(17p) was significantly and independently associated with worse OS, LFS and higher RI. Age and donor types did not correlate with outcome. Conditioning intensity was not statistically associated with OS, LFS and NRM when adjusted for patients’ age. Conclusions In contrast to the dismal prognosis reported for AML patients harbouring abn(17p) undergoing conventional chemotherapy, allogeneic SCT provides responses in about 25% of those patients transplanted in CR1.

The prognostic implications of DNMT3A genotype in T-cell acute lymphoblastic leukemia are incompletely understood. We performed comprehensive genetic and clinico-biological analyses of T-cell acute lymphoblastic leukemia patients with DNMT3A mutations treated during the GRAALL-2003 and -2005 studies. Eighteen of 198 cases (9.1%) had DNMT3A alterations. Two patients also had DNMT3A mutations in non-leukemic cell DNA, providing the first potential evidence of age-related clonal hematopoiesis in T-cell acute lymphoblastic leukemia. DNMT3A mutation was associated with older age (median 43.9 years vs. 29.4 years, P

NKp46 is a major determinant of natural killer (NK) cell function and it is implicated in tumor immune surveillance in acute myeloid leukemia (AML). The purpose of this study was to investigate the prognostic significance of NKp46 expression in an independent cohort of patients with AML, and to investigate the impact of NKp46 on clinical outcome after allogeneic stem cell transplantation (allo-SCT). NKp46 expression was assessed at diagnosis on NK cells by flow cytometry (N = 180 patients). Clinical outcome was evaluated with regard to NKp46 expression. Patients with NKp46high phenotype at diagnosis had better progression-free survival (PFS) and overall survival (OS) than patients with NKp46low phenotype (74.3% vs. 46.6%, p = 0.014; 82.6% vs. 57.1%, p = 0.010, respectively). In multivariate analysis, high NKp46 was an independent factor for improved OS (HR = 0.409, p = 0.010) and PFS (HR = 0.335, p = 0.011). Subgroup analysis revealed that allo-SCT had a favorable impact on PFS in patients with NKp46high phenotype (p = 0.025). By contrast, allo-SCT did not impact PFS in patients with low NKp46 expression (p = 0.303). In conclusion, we validate the prognostic value of NKp46 expression at diagnosis in AML. However, the prognostic value of NKp46 expression is limited to patients treated with allo-SCT, thus suggesting that NKp46 status may be predictive for allo-SCT responsiveness.

Accumulating evidence highlights natural killer (NK) cell parameters as potential prognostic factors in cancer patients, which provides a strong rationale for developing therapeutic strategies aiming at restoring NK cell. However, reaching this point warrants better characterization of tumor-induced NK cell alterations. Our group recently reported heterogeneous NK maturation in acute myeloid leukemia (AML) patients. However, the clinical significance of such observations remained to be assessed on a larger cohort of patients. NK maturation based on expression of CD56, CD57, and KIR was assessed by flow cytometry in newly diagnosed AML patients (N = 87 patients from GOELAMS-LAM-IR-2006 multicenter trial). Clinical outcome was evaluated with regard to NK maturation profiles. Unsupervised integrated analysis of NK maturation markers confirmed the existence of three distinct groups of patients [hypomaturation (24.1%), intermediate maturation (66.7%), and hypermaturation (9.2%)]. In univariate analysis, significant differences in overall survival (OS) (P = 0.0006) and relapse-free survival (RFS) (P

Adults with relapsed/refractory acute lymphoblastic leukemia have an unfavourable prognosis, which is influenced by disease and patient characteristics. To further evaluate these characteristics, a retrospective analysis of 1,706 adult patients with Ph-negative relapsed/refractory B-precursor acute lymphoblastic leukemia diagnosed between 1990–2013 was conducted using data reflecting the standard of care from 11 study groups and large centers in Europe and the United States. Outcomes included complete remission, overall survival, and realization of stem cell transplantation after salvage treatment. The overall complete remission rate after first salvage was 40%, ranging from 35%–41% across disease status categories (primary refractory, relapsed with or without prior transplant), and was lower after second (21%) and third or greater (11%) salvage. The overall complete remission rate was higher for patients diagnosed from 2005 onward (45%, 95% CI: 39%–50%). One- and three-year survival rates after first, second, and third or greater salvage were 26% and 11%, 18% and 6%, and 15% and 4%, respectively, and rates were 2%–5% higher among patients diagnosed from 2005. Prognostic factors included younger age, longer duration of first remission, and lower white blood cell counts at primary diagnosis. This large dataset can provide detailed reference outcomes for patients with relapsed/refractory Ph-negative B-precursor acute lymphoblastic leukemia. clinicaltrials.gov identifier: 02003612

Gene expression studies have consistently identified a HOXA-overexpressing cluster of T-cell acute lymphoblastic leukemias, but it is unclear whether these constitute a homogeneous clinical entity, and the biological consequences of HOXA overexpression have not been systematically examined. We characterized the biology and outcome of 55 HOXA-positive cases among 209 patients with adult T-cell acute lymphoblastic leukemia uniformly treated during the Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL)-2003 and -2005 studies. HOXA-positive patients had markedly higher rates of an early thymic precursor-like immunophenotype (40.8% versus 14.5%, P=0.0004), chemoresistance (59.3% versus 40.8%, P=0.026) and positivity for minimal residual disease (48.5% versus 23.5%, P=0.01) than the HOXA-negative group. These differences were due to particularly high frequencies of chemoresistant early thymic precursor-like acute lymphoblastic leukemia in HOXA-positive cases harboring fusion oncoproteins that transactivate HOXA. Strikingly, the presence of an early thymic precursor-like immunophenotype was associated with marked outcome differences within the HOXA-positive group (5-year overall survival 31.2% in HOXA-positive early thymic precursor versus 66.7% in HOXA-positive non-early thymic precursor, P=0.03), but not in HOXA-negative cases (5-year overall survival 74.2% in HOXA-negative early thymic precursor versus 57.2% in HOXA-negative non-early thymic precursor, P=0.44). Multivariate analysis further revealed that HOXA positivity independently affected event-free survival (P=0.053) and relapse risk (P=0.039) of chemoresistant T-cell acute lymphoblastic leukemia. These results show that the underlying mechanism of HOXA deregulation dictates the clinico-biological phenotype, and that the negative prognosis of early thymic precursor acute lymphoblastic leukemia is exclusive to HOXA-positive patients, suggesting that early treatment intensification is currently suboptimal for therapeutic rescue of HOXA-positive chemoresistant adult early thymic precursor acute lymphoblastic leukemia. Trial Registration: The GRAALL-2003 and -2005 studies were registered at http://www.clinicaltrials.gov as #NCT00222027 and #NCT00327678, respectively.

In t(8;21)(q22;q22) acute myeloid leukemia, the prognostic value of early minimal residual disease assessed with real-time quantitative polymerase chain reaction is the most important prognostic factor, but how long-term minimal residual disease monitoring may contribute to drive individual patient decisions remains poorly investigated. In the multicenter CBF-2006 study, a prospective monitoring of peripheral blood and bone marrow samples was performed every 3 months and every year, respectively, for 2 years following intensive chemotherapy in 94 patients in first complete remission. A complete molecular remission was defined as a (RUNX1-RUNX1T1/ABL1)×100 ≤ 0.001%. After the completion of consolidation therapy, a bone marrow complete molecular remission was observed in 30% of the patients, but was not predictive of subsequent relapse. Indeed, 8 patients (9%) presented a positive bone marrow minimal residual disease for up to 2 years of follow-up while still remaining in complete remission. Conversely, a peripheral blood complete molecular remission was statistically associated with a lower risk of relapse whatever the time-point considered after the completion of consolidation therapy. During the 2-year follow-up, the persistence of peripheral blood complete molecular remission was associated with a lower risk of relapse (4-year cumulative incidence, 8.2%), while molecular relapse confirmed on a subsequent peripheral blood sample predicted hematological relapse (4-year cumulative incidence, 86.9%) within a median time interval of 3.9 months. In t(8;21)(q22;q22) acute myeloid leukemia, minimal residual disease monitoring on peripheral blood every 3 months allows for the prediction of hematological relapse, and to identify patients who could potentially benefit from intervention therapy.

Core-binding factor acute myeloid leukemia is a favorable acute myeloid leukemia subset cytogenetically defined by t(8;21) or inv(16)/t(16;16) rearrangements, disrupting RUNX1 (previously CBFA/AML1) or CBFB transcription factor functions. The receptor tyrosine kinase KIT is expressed in the vast majority of these acute myeloid leukemias and frequent activating KIT gene mutations have been associated with a higher risk of relapse. This phase II study aimed to evaluate dasatinib as maintenance therapy in patients with core-binding factor acute myeloid leukemia in first hematologic complete remission, but at higher risk of relapse due to molecular disease persistence or recurrence. A total of 26 patients aged 18–60 years old previously included in the CBF-2006 trial were eligible to receive dasatinib 140 mg daily if they had a poor initial molecular response (n=18) or a molecular recurrence (n=8). The tolerance of dasatinib as maintenance therapy was satisfactory. The 2-year disease-free survival in this high-risk population of patients was 25.7%. All but one patient with molecular recurrence presented subsequent hematologic relapse. Patients with slow initial molecular response had a similar disease-free survival when treated with dasatinib (40.2% at 2 years) or without any maintenance (50.0% at 2 years). The disappearance of KIT gene mutations at relapse suggests that clonal devolution may in part explain the absence of efficacy observed with single-agent dasatinib in these patients (n. EudraCT: 2006-006555-12).

Early response to chemotherapy has a major prognostic impact in acute myeloid leukemia patients treated with a double induction strategy. Less is known about patients treated with standard-dose cytarabine and anthracycline. We designed a risk-adapted remission induction regimen in which a second course of intermediate-dose cytarabine was delivered after standard “7+3” only if patients had 5% or more bone marrow blasts 15 days after chemotherapy initiation (d15-blasts). Of 823 included patients, 795 (96.6%) were evaluable. Five hundred and forty-five patients (68.6%) had less than 5% d15-blasts. Predictive factors for high d15-blasts were white blood cell count (P

Neuropilins and semaphorins are known as modulators of axon guidance, angiogenesis, and organogenesis in the developing nervous system, but have been recently evidenced as also playing a role in the immune system. Here we describe the expression and role of semaphorin 3F (SEMA3F) and its receptor neuropilin-2 (NRP2) in human T cell precursors. NRP2 and SEMA3F are expressed in the human thymus, in both lymphoid and non-lymphoid compartments. SEMA3F have a repulsive effect on thymocyte migration and inhibited CXCL12- and sphingosine-1-phosphate (S1P)-induced thymocyte migration by inhibiting cytoskeleton reorganization prior to stimuli. Moreover, NRP2 and SEMA3F are expressed in human T-cell acute lymphoblastic leukemia/lymphoma primary cells. In these tumor cells, SEMA3F also blocks their migration induced by CXCL12 and S1P. Our data show that SEMA3F and NRP2 are further regulators of human thymocyte migration in physiological and pathological conditions.

CALM-AF10 (also known as PICALM-MLLT10) is the commonest fusion protein in T-cell acute lymphoblastic leukemia, but its prognostic impact remains unclear. Molecular screening at diagnosis identified CALM-AF10 in 30/431 (7%) patients with T-cell acute lymphoblastic leukemia aged 16 years and over and in 15/234 (6%) of those aged up to 15 years. Adult CALM-AF10-positive patients were predominantly (72%) negative for surface (s)CD3/T-cell receptor, whereas children were predominantly (67%) positive for T-cell receptor. Among 22 adult CALM-AF10-positive patients treated according to the LALA94/GRAALL03-05 protocols, the poor prognosis for event-free survival (P=0.0017) and overall survival (P=0.0014) was restricted to the 15 T-cell receptor-negative cases. Among CALM-AF10-positive, T-cell receptor-negative patients, 82% had an early T-cell precursor phenotype, reported to be of poor prognosis in pediatric T-cell acute lymphoblastic leukemia. Early T-cell precursor acute lymphoblastic leukemia corresponded to 22% of adult LALA94/GRAALL03-05 T-cell acute lymphoblastic leukemias, but had no prognostic impact per se. CALM-AF10 fusion within early T-cell precursor acute lymphoblastic leukemia (21%) did, however, identify a group with a poor prognosis with regards to event-free survival (P=0.04). CALM-AF10 therefore identifies a poor prognostic group within sCD3/T-cell receptor negative adult T-cell acute lymphoblastic leukemias and is over-represented within early T-cell precursor acute lymphoblastic leukemias, in which it identifies patients in whom treatment is likely to fail. Its prognosis and overlap with early T-cell precursor acute lymphoblastic leukemia in pediatric T-cell acute lymphoblastic leukemia merits analysis. The clinical trial GRAALL was registered at Clinical Trials.gov number NCT00327678.

IL-34 is a recently identified cytokine that signals via the M-CSF receptor and promotes monocyte survival. Depending on the environment, monocytes can differentiate into macrophages (Mφ) or dendritic cells (DC). A wide spectrum of Mφ and DC subsets, with distinct phenotypes and functions, has been described. To date, the phenotype of monocytes exposed to IL-34 remains unexplored. We report here that IL-34 induces the differentiation of monocytes into CD14(high) CD163(high) CD1a(-) Mφ (IL-34-Mφ). Upon LPS stimulation, IL-34-Mφ exhibit an IL-10(high) IL-12(low) M2 profile and express low levels of the costimulatory molecules CD80 and CD86. IL-34-Mφ exhibit poor T cell costimulatory properties, and have potent immunosuppressive properties (decrease of TCR-stimulated T cell proliferation). For all the parameters analyzed, IL-34-Mφ are phenotypically and functionally similar to M-CSF-Mφ. IL-34 appears as efficient as M-CSF in inducing the generation of immunosuppressive Mφ. Moreover, the generation of IL-34-Mφ is mediated through the M-CSF receptor, is independent of endogenous M-CSF consumption and is potentiated by IL-6. In an attempt to identify strategies to prevent a deleterious M2 cell accumulation in some pathological situations, we observed that IFNγ and GM-CSF prevent the generation of immunosuppressive Mφ induced by IL-34. IFNγ also switches established IL-34-Mφ into immunostimulatory Mφ. In conclusion, we demonstrate that IL-34 drives the differentiation of monocytes into immunosuppressive M2, in a manner similar to M-CSF, and that IFNγ and GM-CSF prevent this effect.

Background Acute myeloid leukemias arise from a rare population of leukemic cells, known as leukemic stem cells, which initiate the disease and contribute to frequent relapses. Although the phenotype of these cells remains unclear in most patients, these cells are enriched within the CD34+CD38low/− compartment expressing the interleukin-3 alpha chain receptor, CD123. The aim of this study was to determine the prognostic value of the percentage of blasts with the CD34+CD38low/−CD123+ phenotype.Design and Methods The percentage of CD34+CD38low/−CD123+ cells in the blast population was determined at diagnosis using flow cytometry. One hundred and eleven patients under 65 years of age with de novo acute myeloid leukemia and treated with intensive chemotherapy were retrospectively included in the study. Correlations with complete response, disease-free survival and overall survival were evaluated with univariate and multivariate analyses.Results A proportion of CD34+CD38low/−CD123+ cells greater than 15% at diagnosis and an unfavorable karyotype were significantly correlated with a lack of complete response. By logistic regression analysis, a percentage of CD34+CD38low/−CD123+ higher than 15% retained significance with an odds ratio of 0.33 (0.1–0.97; P=0.044). A greater than 1% population of CD34+CD38low/−CD123+ cells negatively affected disease-free survival (0.9 versus 4.7 years; P

Ten-eleven translocation 2 (TET2) mutations have been involved in myeloid malignancies. This retrospective study aims at evaluating the frequency and impact of TET2 mutations in 247 secondary acute myeloid leukemia cases referred to as myelodysplasia-related changes (n=201) or therapy-related (n=46) leukemias. Mutation of at least one copy of the TET2 gene was detected in 49 of 247 (19.8%) patients who presented with older age, higher hemoglobin level, higher neutrophil and monocyte counts, and lower platelet count. TET2 mutations were significantly less frequent in therapy-related (8.7%) than myelodysplasia-related changes (22.3%; P=0.035) leukemias and strongly associated with normal karyotype (P

Background The prognosis of acute lymphoblastic leukemia in the elderly is poor. The GRAALL-SA1 phase II, randomized trial compared the efficacy and toxicity of pegylated liposomal doxorubicin versus continuous-infusion doxorubicin in patients 55 years or older with Philadelphia chromosome-negative acute lymphoblastic leukemia.Design and Methods Sixty patients received either continuous-infusion doxorubicin (12 mg/m2/day) and continuous-infusion vincristine (0.4 mg/day) on days 1–4 or pegylated liposomal doxorubicin (40 mg/m2) and standard vincristine (2 mg) on day 1, accompanied by dexamethasone, followed at day 28 by a second cycle, reinforced by cyclophosphamide. End-points were safety, outcome and prognostic factors.Results Myelosuppression was reduced in the pegylated liposomal doxorubicin arm with shorter severe neutropenia (P=0.05), shorter severe thrombocytopenia (P=0.03), and fewer red blood cell transfusions (P=0.04). Grade 3/4 infections and Gram-negative bacteremia were reduced in the pegylated liposomal doxorubicin arm (P=0.04 and P=0.02, respectively). There was a trend towards fewer cardiac events among the patients who received pegylated liposomal doxorubicin (1/29 versus 6/31). The complete remission rate was 82% and, with a median follow-up of 4 years, median event-free survival and overall survival were 9 and 10 months, respectively. Despite the better tolerance of pegylated liposomal doxorubicin, no differences in survival were observed between the two arms, due to trends towards more induction refractoriness (17 versus 3%, P=0.10) and a higher cumulative incidence of relapse (52% versus 32% at 2 years, P=0.20) in the pegylated liposomal doxorubicin arm.Conclusions With the drug schedules used in this study, pegylated liposomal doxorubicin did not improve the outcome of elderly patients with acute lymphoblastic leukemia despite reduced toxicities.

Deletion of the 17p13 chromosomal region [del(17p)] is associated with a poor outcome in multiple myeloma. Most of the studies have targeted the TP53 gene for deletion analyses, although no study showed that this gene is the deletion target. In order to address this issue, we sequenced the TP53 gene in 92 patients with multiple myeloma at diagnosis, 54 with a del(17p) and 38 lacking del(17p). At least one mutation was found in 20 patients, all of them presenting a del(17p). The analysis of the mutation location showed that virtually all of them occurred in highly conserved domains involved in the DNA-protein interactions. In conclusion, we showed that 37% of the myeloma patients with del(17p) present a TP53 mutation versus 0% in patients lacking the del(17p). The prognostic significance of these mutations remains to be evaluated.

Background Alterations in the PI3K/Akt pathway are found in a wide range of cancers and the development of PI3K inhibitors represents a promising approach to cancer therapy. Constitutive PI3K activation, reflecting an intrinsic oncogenic deregulation of primary blast cells, is detected in 50% of patients with acute myeloid leukemia. However, the mechanisms leading to this activation are currently unknown. As we previously reported IGF-1 autocriny in acute myeloid leukemia cells, we investigated whether IGF-1 signaling was involved in the constitutive activation of PI3K.Design and Methods We analyzed the IGF-1/IGF-1R signaling pathway and PI3K activity in 40 acute myeloid leukemia bone marrow samples. Specific inhibition of IGF-1/IGF-1R signaling was investigated using neutralizing anti-IGF-1R, anti-IGF-1 antibodies or IGF-1 short interfering RNA. The anti-leukemic activity of the neutralizing anti-IGF-1R was tested by analyzing its effects on leukemic progenitor clonogenicity, blast cell proliferation and survival.Results In all samples tested, we found that functional IGF-1R was constantly expressed in leukemic cells. In the acute myeloid leukemia samples with PI3K activation, we found that the IGF-1R was constitutively phosphorylated, although no IGF-1R activating mutation was detected. Specific inhibition of IGF-1R signaling with neutralizing anti-IGF-1R strongly inhibited the constitutive phosphorylation of both IGF-1R and Akt in 70% of the PI3K activated samples. Moreover, both incubation with anti-IGF-1 antibody and IGF-1 short interfering RNA inhibited Akt phosphorylation in leukemic cells. Finally, neutralizing anti-IGF-1R treatment decreased the clonogenicity of leukemic progenitors and the proliferation of PI3K activated acute myeloid leukemia cells.Conclusions Our current data indicate a critical role for IGF-1 autocriny in constitutive PI3K/Akt activation in primary acute myeloid leukemia cells and provide a strong rationale for targeting IGF-1R as a potential new therapy for this disease.

The prognostic significance of CD20 expression in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) has been mostly studied in children and yielded conflicting results. In 143 adults with Philadelphia chromosome-negative BCP-ALL treated in the multicentric GRAALL 2003 trial, CD20 positivity over 20% was observed in 32% of patients. While not influencing complete remission achievement, CD20 expression was associated with a higher cumulative incidence of relapse (CIR) at 42 months (P=0.04), independently of the ALL high-risk subset (P=0.025). Notably, the negative impact of CD20 expression on CIR was only observed in patients with a white blood cell count (WBC) over 30×109/L (P=0.006), while not in those with a lower WBC. In the former subgroup, this impact translated into lower event-free survival (15% vs. 59% at 42 months, P=0.003). CD20 expression thus appears to be associated with a worse outcome, which reinforces the interest of evaluating rituximab combined to chemotherapy in CD20-positive adult BCP-ALL. ClinicalTrials.gov ID, NCT00222027.

Background Acquired somatic deletions and loss-of-function mutations in one or several codons of the TET2 (Ten-Eleven Translocation-2) gene were recently identified in hematopoietic cells from patients with myeloid malignancies, including myeloproliferative disorders and myelodys-plastic syndromes. The present study was designed to determine the prevalence of TET2 gene alterations in chronic myelomonocytic leukemias.Design and Methods Blood and bone marrow cells were collected from 88 patients with chronic phase chronic myelomonocytic leukemia and from 14 with acute transformation of a previously identified disease. Polymerase chain reaction analysis and direct sequencing were used to sequence exons 3 to 11 of the TET2 gene. Annotated single nucleotide polymorphisms were excluded. Survival curves were constructed by the Kaplan-Meier method.Results We detected TET2 mutations in 44 of 88 (50%) patients with chronic myelomonocytic leukemia, which suggests that TET2 gene mutations are especially frequent in this myeloid disease. A TET2 gene alteration was identified in 18 of the 43 patients studied at diagnosis and was associated with a trend to a lower overall survival rate; confining the analysis to the 29 patients with chronic myelomonocytic leukemia-1, according to the WHO classification, the difference in overall survival between patients with or without TET2 gene mutations became statistically significant.Conclusions TET2 gene alterations are more frequent in chronic myelomonocytic leukemia than in other subgroups of hematopoietic diseases studied so far and could negatively affect the patients’ outcome. The striking association between TET2 gene alterations and monocytosis, already observed in patients with systemic mastocytosis, could indicate a negative role of TET2 in the control of monocytic lineage determination.

Background The effects of L-asparaginase on hemostasis during induction chemotherapy are less defined in adults than in children. We, therefore, studied the effects of L-asparaginase in adult patients.Design and Methods This was a retrospective analysis of 214 patients treated with L-asparaginase (7500 IU/m2 x 6) for acute lymphoblastic leukemia or lymphoblastic lymphoma. Between day 1 of the induction course and discharge, clinical events, and biological and therapeutic modifications were reviewed.Results Antithrombin and fibrinogen levels were lower than 60% and 1 g/L in 71% and 73% of patients, respectively. Twenty thromboses occurred in 9.3% of the patients; these patients had a median antithrombin level of 53% (range, 21–111) at the time of the event. Forty-two episodes of bleeding occurred in 31 patients with a median fibrinogen level of 1.3 g/L. Infusions of L-asparaginase were reduced or delayed in 64% of patients due to low fibrinogen and/or antithrombin levels. Fresh-frozen plasma, antithrombin and fibrinogen were infused in 31%, 41% and 52% of patients, respectively. The mean antithrombin and fibrinogen levels increased from 61% to 88% and from 1 to 1.4 g/L after infusion of antithrombin or fibrinogen respectively, while both levels remained unchanged after the infusion of fresh-frozen plasma. In patients who received antithrombin concentrates L-asparaginase injections were less frequently omitted or delayed (53% vs. 72%, p=0.005), the rate of thrombosis was lower (4.8% vs. 12.2%, p=0.04) and the disease-free survival was also reduced (p=0.05).Conclusions This retrospective study suggests that antithrombin concentrates may have a beneficial effect on the outcome of adults treated for acute lymphoblastic leukemia with L-asparaginase; prospective studies are essential to confirm this hypothesis.

Background and Objectives T-lymphoblastic lymphoma is an infrequent disease usually treated as T-acute lymphoblastic leukemia with an induction chemotherapy course and sequential reinduction and maintenance chemotherapy. The T-LBL/ALL-GOELAL02 study evaluated the impact of randomized reinduction chemotherapy against intensified conditioning followed by autologous stem cell transplantation (ASCT), after an induction regimen of the type used for acute lymphoblastic leukemia (ALL).Design and Methods Patients with favorable characteristics were randomized to receive chemotherapy or ASCT. Patients with unfavorable characteristics (bone marrow involvement and age over 35 years old or leukocytosis >30 × 109/L or failure to achieve medullar complete remission [CR] after one induction course) received a second induction course and ASCT.Results Among 45 patients, the CR rate was 71% after induction and 87% after a second induction course. Within the group of 27 patients with favorable characteristics, ten received ASCT and 17 chemotherapy. Ten patients in the group with unfavorable characteristics received ASCT. The 7-year overall survival and progression-free survival rates were 64 and 65%, respectively. Surprisingly, CR obtained after only two induction courses was associated with improved overall survival (p=0.04). None of the known prognostic factors significantly affected survival.Interpretation and Conclusions Randomized maintenance or high-dose therapy (HDT) and ASCT or intensified HDT according to initial presentation gave similar overall and relapse-free survival rates. However, HDT allowed sparing of mediastinal irradiation and shortened treatment duration.

Background and Objectives Treatment of acute myeloid leukemia (AML) in older patients remains unsatisfactory. The BGMT 95 trial for older patients set out to improve the outcome of these patients by adding a third drug (lomustine) to a 5+7 idarubicin and cytarabine schedule at induction and evaluating intermediate-dose cytarabine as consolidation.Design and Methods A multicenter randomized trial was performed comparing induction therapy with idarubicin and cytarabine, 5+7 (IC) to induction therapy with the same drugs plus lomustine (CCNU), 200 mg\m2 orally on day 1 (ICL). Patients in complete remission (CR) were then randomized to receive either maintenance therapy or intensification with intermediate-dose cytarabine and idarubicin followed by maintenance therapy.Results Between 1995 and 2001, 364 patients (≥60 years) from ten centers were included. The CR rate was 58% for patients in the IC arm and 67% for patients in the ICL arm (p=0.104). The median overall survival (OS) was 7 and 12 months respectively (p=0.05), but OS at 2 years was not statistically different: 31±7% for patients in the ICL arm vs 24±6% for those in the IC arm. The two post-remission strategies yielded similar results.Interpretation and Conclusions Adding lomustine to induction with idarubicin and cytarabine therapy did not statistically improve survival in elderly patients with AML. Adding intermediate-dose cytarabine to consolidation therapy did not improve outcome.

Background and Objectives High-dose chemotherapy with allogeneic stem cell transplantation (SCT) has proven to be a successful treatment for low-grade lymphoma (LGL), but is associated with considerable transplant-related mortality (TRM). In an effort to reduce toxic mortality while maintaining the graft-versus-leukemia effect, allogeneic SCT has been combined with a reduced-intensity conditioning (RIC) regimen. The aim of this study was to determine the outcome of patients with LGL treated with RIC allogeneic SCT.Design and Methods This retrospective multicenter study included 73 patients with relapsed or refractory LGL allografted after a RIC regimen between 1998 and 2005 whose data were recorded in a French registry.Results Patients received a median of three lines of therapy prior to RIC allogeneic SCT. The most widely used conditioning regimens were fludarabine + busulfan + antithymocyte globulin (n=43) and fludarabine + total body irradiation (n=21). Prior to allografting, patients were in complete response (CR; n=21), partial response (PR; n=33) or had chemoresistant disease (n=19). The median follow-up was 37 months (range, 16 to 77 months). In patients in CR, PR and chemoresistant disease, the 3-year overall survival rates were 66%, 64% and 32%, respectively, while the 3-year event-free survival rates were 66%, 52% and 32%, respectively. The 3-year cumulative incidences of TRM were 32%, 28% and 63%, respectively. The incidence of relapse was 9.6%.Interpretation and Conclusions Although associated with significant TRM, RIC allogeneic SCT in advanced chemosensitive disease leads to long-term survival.