Clinical features of adult acute leukemia with 11q23 abnormalities in Japan: a co-operative multicenter study

[Prognostic analysis of allogeneic hematopoietic stem-cell transplantation in 47 patients with acute myeloid leukemia and MLL rearrangement]

Objective: To investigate the prognosis of allogeneic hematopoietic stem-cell transplantation (allo-HSCT) for patients with acute myeloid leukemia and MLL rearrangement. Methods: From September 2009 to May 2016, the clinical data of 47 patients with MLL-rearranged AML undergoing allo-HSCT in the First Affiliated Hospital of Soochow University were retrospectively analyzed. Results: Among 47 MLL-rearranged AML patients, 24 were male and 23 female. The median age was 30 (15-58) years old. There are 36 (76%) patients were FAB-types M4/M5. Two-year overall survival (OS), disease-free survival (DFS), relapse incidence and transplant-related mortality (TRM) were (64.4±8.4)%, (47.3±9.3)%, 41.0% and 17.9%, respectively. Of them, 45 patients were detected with 11q23 translocations, and 2 patients with normal karyotype were MLL partial tandem duplication. According to different chromosome karyotype, 47 patients were divided into three groups: 16 cases of t (6; 11), 15 cases of t (9; 11) and 16 cases of other types. Overall survival was compared between the three groups, there was no significant difference (χ(2)=1.509, P=0.472). On multivariate analysis, independent risk factor on OS was transplant age >45 years [HR=4.454(95%CI 1.314-15.099), P=0.016]. The multivariate analysis also confirmed the higher TRM in patients at non-CR state when transplanted [HR=10.370(95%CI 1.043-103.110), P=0.046]. Positive minimal residual disease (MRD) before transplantation was a negative prognostic factor on DFS [HR=4.236(95%CI 1.238-14.495), P=0.021] and relapse incidence (RI) [HR=5.491(95%CI 1.371-21.995), P=0.016]. Conclusion: Transplant age (>45 years), allo-HSCT in non-CR state adn positive MRD before transplantation were negative prognostic factors in allo-HSCT for MLL-rearranged AML patients.

Allogeneic hematopoietic cell transplantation in adult acute myeloid leukemia with 11q23 abnormality: a retrospective study of the Adult Acute Myeloid Leukemia Working Group of the Japan Society for Hematopoietic Cell Transplantation (JSHCT)

An 11q23 abnormality presents in approximately 5% of adults with acute myeloid leukemia (AML) and is associated with adverse outcomes even after allogeneic hematopoietic cell transplantation (allo-HCT). To evaluate the outcomes and prognostic factors following allo-HCT for adult AML with 11q23 abnormality, we retrospectively analyzed the Japanese registration data of 322 adult AML patients with 11q23 abnormality who had received allo-HCT between 1990 and 2014. In total, the disease status at HCT was first complete remission (CR1) in 159 (49%) patients. The probability of overall survival and the cumulative incidence of relapse at 3 years were 44 and 44%, respectively. In the multivariate analysis, disease status beyond CR1 at the time of HCT was significantly associated with a higher overall mortality and relapse. The 11q23 fusion partner did not have a significant impact on survival. We also evaluated the prognostic value of minimal residual disease (MRD) status at HCT on transplant outcomes among hematological CR patients. MRD status at HCT was the significant prognostic indicator for hematological relapse and survival. These data suggested that allo-HCT offered a curative option for adult AML with 11q23 abnormality. Pretransplant MRD status was the significant prognostic indicator for relapse and survival in CR patients.

The Superiority of Allogeneic Hematopoietic Stem Cell Transplantation Over Chemotherapy Alone in the Treatment of Acute Myeloid Leukemia Patients with Mixed Lineage Leukemia (MLL) Rearrangements

BACKGROUND Acute myeloid leukemia (AML) patients with mixed lineage leukemia (MLL) gene rearrangements always had a very poor prognosis. In this study, we report the incidence of MLL rearrangements in AML patients using gene analysis, as well as the clinical significance and prognostic features of these rearrangements. MATERIAL AND METHODS This retrospective study took place from April 2008 to November 2011 in the People's Liberation Army General Hospital. A total 433 AML patients were screened by multiple nested reverse transcription polymerase chain reaction (RT-PCR) to determine the incidence of the 11 MLL gene rearrangements. There were 68 cases of MLL gene rearrangements, for a positive rate of 15.7%. A total of 24 patients underwent allogeneic hematopoietic stem cell transplantation (Allo-HSCT), and 34 patients received at least 4 cycles of chemotherapy. Ten patients were lost to follow-up. RESULTS The median follow-up was 29 months. The complete remission (CR) rate was 85.4%. The overall survival (OS) was 57.4±5.9 months for the Allo-HSCT group and 21.0±2.1 months for the chemotherapy group. The Allo-HSCT group had superior survival compared with the chemotherapy group (5-year OS: 59±17% vs. 13±8%, P<0.01; 5-year disease-free survival [DFS]: 65±10% vs. 40±16%, P>0.05). Multivariate analysis showed that transplantation, platelets >50×10^9/L at onset, and CR are associated with a better OS in MLL rearranged AML patients. Patients with thrombocytopenia and extramedullary involvement were prone to relapse. CONCLUSIONS Our results suggest that Allo-HSCT is superior to chemotherapy alone for treating MLL rearranged AML patients. Patients treated with Allo-HSCT have a better prognosis and a longer survival. CR is an independent prognostic factor for OS, and extramedullary involvement is an independent prognostic factor for DFS. MLL rearranged AML patients with thrombocytopenia at onset <50×10^9 had very bad OS and DFS.

Leukemogenic rearrangements at the mixed lineage leukemia gene (MLL)-multiple rather than a single mechanism

Despite manifold efforts to achieve reduced-intensity and -toxicity regimens, secondary leukemia has remained the most severe side effect of chemotherapeutic cancer treatment. Rearrangements involving a short telomeric <1 kb region of the mixed lineage leukemia (MLL) gene are the most frequently observed molecular changes in secondary as well as infant acute leukemia. Due to the mode-of-action of epipodophyllotoxins and anthracyclines, which have widely been used in cancer therapy, and support from in vitro experiments, cleavage of this MLL breakpoint cluster hotspot by poisoned topoisomerase II was proposed to trigger the molecular events leading to malignant transformation. Later on, clinical patient data and cell-based studies addressing a wider spectrum of stimuli identified cellular stress signaling pathways, which create secondary DNA structures, provide chromatin accessibility, and activate nucleases other than topoisomerase II at the MLL. The MLL destabilizing signaling pathways under discussion, namely early apoptotic DNA fragmentation, transcription stalling, and replication stalling, may all act in concert upon infection-, transplantation-, or therapy-induced cell cycle entry of hematopoietic stem and progenitor cells (HSPCs), to permit misguided cleavage and error-prone DNA repair in the cell-of-leukemia-origin.

Efficacy of myeloablative allogeneic hematopoietic stem cell transplantation in adult patients with MLL-ELL-positive acute myeloid leukemia

Acute myeloid leukemia (AML) with mixed lineage leukemia-eleven-nineteen lysine-rich leukemia (MLL-ELL) is a rare subtype of MLL-rearranged AML. The outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for patients with this disease remains unknown. In the present study, we retrospectively investigated the efficacy of allo-HSCT in eight adult MLL-ELL-positive AML patients. Although all eight patients achieved first complete remission (CR1), three (37.5 %) patients experienced relapse after induction therapy. Five (62.5 %) patients underwent allo-HSCT during CR1, whereas two (25.0 %) underwent allo-HSCT during disease relapse, and one (12.5 %) during CR2. All three patients who received allo-HSCT beyond CR1 died due to AML progression after allo-HSCT. Of the five patients who received allo-HSCT during CR1, three (60.0 %) remained alive at study conclusion. The overall survival rate at five years was 50.0 %. Intriguingly, clonally expanded non-leukemic cells expressing MLL-ELL during consolidation therapy were found to be eradicated after allo-HSCT during the monitoring of minimal residual disease in one patient; this indicates that allo-HSCT is efficacious for eliminating pre-leukemic cells resistant to chemotherapy. In conclusion, allo-HSCT soon after CR1 represents a promising therapeutic option for adult AML patients with MLL-ELL, although the outcome of allo-HSCT for patients beyond CR1 was dismal.

Prognostic significance of 11q23 aberrations in adult acute myeloid leukemia and the role of allogeneic stem cell transplantation

The clinical features and outcomes of 148 patients with acute myeloid leukemia (AML) and 11q23 chromosomal abnormalities were compared with those of 2640 patients with non-11q23 AML. Patients with t(9;11) ), t(6;11) or other 11q23 balanced translocations (t(11;v)(q23;v)) presented at a younger age and with higher percentage of bone marrow blasts. Unbalanced 11q23 abnormalities were commonly associated with deletions of chromosomes 5q, 7q and/or complex karyotypes. In multivariate analysis, when compared with patients with non-11q23 AML and unfavorable-risk karyotype, there was a significant difference in overall survival (OS) for patients with t(9;11) (P=0.004), whereas there were no differences in OS for patients with t(6;11) (P=0.62), t(11;19) (P=0.20) and unbalanced 11q23 aberrations (P=0.85) or t(11;v)(q23;v) (P=0.59), indicating that t(9;11) has an independent intermediate prognostic significance, with all others being poor prognostic factors for OS; this was further confirmed by comparing them with patients with non-11q23 AML and intermediate-risk karyotype. Using intention-to treat analysis based on donor availability, we also noted that allogeneic stem cell transplant in first remission had a significant benefit toward improving OS (P<0.001) and relapse-free survival (P<0.001) in patients with AML and 11q23 abnormalities.

Rearrangement of the myeloid/lymphoid leukemia gene in therapy-related myelodysplastic syndrome in patients previously treated with agents targeting DNA topoisomerase II

BACKGROUND

Therapy-related acute myeloid leukemias (t-AML), with balanced translocations affecting the 11q23 point in the myeloid/lymphoid leukemia (MLL) gene, are one of the most serious complications of treatments with topoisomerase II inhibitors. However, only a few reports of t-AML exist. We aimed to study if these translocations are cumulative-dose-dependent, their frequency in therapy-related myelodysplastic syndrome and the relationship between their presence, the type of therapy and the response criteria.

METHODS

This retrospective study included 120 patients with various malignancies (108 non-Hodgkin's lymphoma, 8 Hodgkin's disease and 4 neuroblastoma) in remission, being treated with topoisomerase 2 inhibitors; 74 had been diagnosed with therapy-related myelodysplasia and 46 did not have dysplasia. All bone marrow biopsy samples were evaluated by fluorescence in situ hybridization for 11q23 point breakage in the MLL gene.

RESULTS

MLL gene rearrangement frequency was 6% in dysplastic versus 2% in nondysplastic groups; p < 0.001. It was associated with a worse overall survival (mean 13 ± 2 vs. 39 ± 3 months, log-rank p value <0.0001). It was dose-dependent with a cut-off value of 290 mg/kg of topoisomerase II inhibitors as assessed by ROC curve (area under the curve 0.84 ± 0.05, p < 0.0001).

CONCLUSIONS

It is proposed that the MLL gene is etiopathogenetically relevant for hematological neoplasias transformation and survival.