Fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin with gemtuzumab ozogamicin improves event-free survival in younger patients with newly diagnosed aml and overall survival in patients with npm1 and flt3 mutations

Purpose To determine the optimal induction chemotherapy regimen for younger adults with newly diagnosed AML without known adverse risk cytogenetics. Patients and Methods One thousand thirty-three patients were randomly assigned to intensified (fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin [FLAG-Ida]) or standard (daunorubicin and Ara-C [DA]) induction chemotherapy, with one or two doses of gemtuzumab ozogamicin (GO). The primary end point was overall survival (OS). Results There was no difference in remission rate after two courses between FLAG-Ida + GO and DA + GO (complete remission [CR] + CR with incomplete hematologic recovery 93% v 91%) or in day 60 mortality (4.3% v 4.6%). There was no difference in OS (66% v 63%; P = .41); however, the risk of relapse was lower with FLAG-Ida + GO (24% v 41%; P < .001) and 3-year event-free survival was higher (57% v 45%; P < .001). In patients with an NPM1 mutation (30%), 3-year OS was significantly higher with FLAG-Ida + GO (82% v 64%; P = .005). NPM1 measurable residual disease (MRD) clearance was also greater, with 88% versus 77% becoming MRD-negative in peripheral blood after cycle 2 (P = .02). Three-year OS was also higher in patients with a FLT3 mutation (64% v 54%; P = .047). Fewer transplants were performed in patients receiving FLAG-Ida + GO (238 v 278; P = .02). There was no difference in outcome according to the number of GO doses, although NPM1 MRD clearance was higher with two doses in the DA arm. Patients with core binding factor AML treated with DA and one dose of GO had a 3-year OS of 96% with no survival benefit from FLAG-Ida + GO. Conclusion Overall, FLAG-Ida + GO significantly reduced relapse without improving OS. However, exploratory analyses show that patients with NPM1 and FLT3 mutations had substantial improvements in OS. By contrast, in patients with core binding factor AML, outcomes were excellent with DA + GO with no FLAG-Ida benefit

A study of the role of ATM mutations in the pathogenesis of B-cell chronic lymphocytic leukaemia

Mutations in the ATM gene have previously been identified in CLL tumours. In this project, I have demonstrated that their detection would have prognostic value. With a prevalence of 12%, ATM mutations represent the commonest single gene defect to be detected in CLL tumours and they identified a subgroup of CLL patients that had a significant reduction in both treatment free and overall survival. Furthermore, ATM mutations provided prognostic information that was independent of age, clinical stage, the mutation status of the IGVH genes and TP53 mutations. The temporal acquisition of the ATM mutations and their relationship with loss of an ATM allele via a chromosomal 11q deletion provides clues into their mechanism of action. There was only a partial correlation between CLL tumours with mutations in the ATM gene and those with a chromosome 11q deletion. In certain cases, the ATM mutations represented germ-line changes and in others were acquired very early in the disease course raising the possibility that they might contribute to the initial clonal transformation process. However, in some CLL tumours, the ATM mutations had been acquired after the development of the tumour clone during disease progression indicating that there may be a step-wise acquisition of ATM allelic defects during the ontogeny of CLL. The ATM protein is the key coordinator of the cellular response to DNA double strand breaks. In this study, I showed that bi-allelic defects in the ATM gene lead to deficient ATM dependent responses, including the up regulation of p53, following both ionising irradiation and also treatment with the chemotherapeutic drug, Fludarabine. Thus an important mechanism accounting for the poor outcome in CLL patients with ATM mutations is likely to relate to chemo-resistance. Interestingly, there were differential responses to DNA damage with both irradiation and fludarabine amongst the category of tumours with an 11q deletion according to the status of the remaining ATM allele. Therefore, ATM mutations can stratify tumours with a chromosome 11q deletion into two functional subgroups. The identification of CLL tumours with ATM mutations would therefore predict those patients that will have a poor clinical outcome and be both more likely to require early treatment for their disease. Patients whose tumours had bi-allelic ATM defects will be expected to have deficient responses to DNA damaging chemotherapeutic drugs, while those with mono-allelic ATM defects might identify a group in whom the use of DNA damaging agents could provide selective pressure for the emergence of sub-clones that have subsequently acquired bi-allelic ATM defects

Mutations in the ATM gene lead to impaired overall and treatment-free survival that is independent of IGVH mutation status in patients with B-CLL

The ataxia telangiectasia mutated (ATM) protein is the principal activator of the p53 protein in the response to DNA double-strand breaks. Mutations in the ATM gene have been previously found in B-cell chronic lymphocytic leukemias (B-CLLs) but their clinical significance is unknown. We analyzed 155 CLL tumors and found 12% with ATM mutations and 4% with TP53 mutations; 2 tumors contained mutations in both genes. Retrospective analysis on selected samples indicated that the ATM mutations were usually present at diagnosis. Compared with patients with wild-type ATM/TP53 genes, patients with ATM mutations had statistically significantly reduced overall and treatment-free survival. Although present in both IGVH mutation subgroups, ATM mutations were associated with unmutated IGVH genes and they provided independent prognostic information on multivariate analysis. Mutations in the ATM gene resulted in impaired in vitro DNA damage responses. Tumors with ATM mutations only partially correlated with tumors with loss of an ATM allele through an 11q deletion and, interestingly, those 11q-deleted tumors with a second wild-type ATM allele had a preserved DNA damage response. The majority of patients with ATM mutations were refractory to DNA damaging chemotherapeutic drugs and as such might benefit from therapies that bypass the ATM/p53 pathway

Insights into the multistep transformation process of lymphomas: IgH-associated translocations and tumour suppressor gene mutations in clonally related composite Hodgkin and non-Hodgkin lymphomas

Insights into the multistep transformation process of lymphomas: IgH-associated translocations and tumor suppressor gene mutations in clonally related composite Hodgkin's and non-Hodgkin's lymphomas. Leukemia, vol. 19, 2005, pp. 1452-1458 Schmitz R, Renne C, Rosenquist R, Tinguely M, Distler V, Menestrina F, Lestani M, Stankovic T, Austen B, Brauninger A, Hansmann ML, Kuppers R. Institute for Cell Biology (Tumor Research), University of Duisburg-Essen Medical School, Essen, Germany. [email protected] Clonally related composite lymphomas of Hodgkin's lymphoma (HL) and Non-Hodgkin's lymphoma (NHL) represent models to study the multistep transformation process in tumorigenesis and the development of two distinct tumors from a shared precursor. We analyzed six such lymphomas for transforming events. The HLs were combined in two cases with follicular lymphoma (FL), and in one case each with B-cell chronic lymphocytic leukemia, splenic marginal zone lymphoma, mantle cell lymphoma (MCL) and diffuse large B-cell lymphoma (DLBCL). In the HL/FL and HL/MCL combinations, BCL2/IGH and CCND1/IGH translocations, respectively, were detected in both the HL and NHL. No mutations were found in the tumor suppressor genes FAS, NFKBIA and ATM. The HL/DLBCL case harbored clonal replacement mutations of the TP53 gene on both alleles exclusively in the DLBCL. In conclusion, we present the first examples of molecularly verified IgH-associated translocations in HL, which also show that BCL2/IGH or CCND1/IGH translocations can represent early steps in the pathogenesis of composite HL/FL or HL/MCL. The restriction of the TP53 mutations to the DLBCL in the HL/DLBCL case exemplifies a late transforming event that presumably happened in the germinal center and affected the fate of a common lymphoma precursor cell towards development of a DLBCL. Leukemia (2005) 19, 1452-1458