To clarify the cooperative roles of recurrently identified mutations and to establish a more precise risk classification system in acute myeloid leukemia (AML), we comprehensively analyzed mutations in 51 genes, as well as cytogenetics and 11 chimeric transcripts, in 197 adult patients with de novo AML who were registered in the Japan Adult Leukemia Study Group AML201 study. We identified a total of 505 mutations in 44 genes, while only five genes, FLT3, NPM1, CEBPA, DNMT3A and KIT, were mutated in more than 10% of the patients. Although several cooperative and exclusive mutation patterns were observed, the accumulated mutation number was higher in cytogenetically normal AML and lower in AML with RUNX1-RUNX1T1 and CBFB-MYH11, indicating a strong potential of these translocations for the initiation of AML. Furthermore, we evaluated the prognostic impacts of each sole mutation and the combinations of mutations and/or cytogenetics, and demonstrated that AML patients could be clearly stratified into five risk groups for overall survival by including the mutation status of DNMT3A, MLL-PTD and TP53 genes in the risk classification system of the European LeukemiaNet. These results indicate that the prognosis of AML could be stratified by the major mutation status in combination with cytogenetics.

Summary. To elucidate the mechanisms by which haemopoietic progenitor cells lodge in the bone marrow, we examined the secretion of chemoattractants for haemopoietic progenitor cells by bone marrow and lung endothelial cells. The bone marrow endothelial cells, but not lung endothelial cells, secreted chemoattractants for the haemopoietic progenitor cell line, FDCP-2, and normal haemopoietic progenitor cells. Checkerboard analysis demonstrated that the conditioned medium of the bone marrow endothelial cells had chemotactic activity and random motilitystimulating activity. The bone marrow endothelial cells expressed stromal-cell-derived factor-1 (SDF-1) mRNA and produced SDF-1 protein, whereas the lung endothelial cells did not. Adhesion of FDCP-2 cells to the bone marrow endothelial cells was partially inhibited by anti-SDF-1 antibody. These ®ndings suggest that the chemoattractants for haemopoietic progenitor cells including SDF-1 and random motility-stimulating factor(s) selectively secreted by the bone marrow endothelial cells may contribute to the homing of haemopoietic progenitor cells to bone marrow.

W/R-PC suspended in M-sol in the presence of less than 20 mL plasma can be transfused safely and eliminate a wide range of adverse reactions to plasma-PC.

The objective of this prospective clinical trial (JALSG-STIM213, UMIN000011971) was to evaluate treatment-free remission (TFR) rates after discontinuation of imatinib in chronic myeloid leukemia (CML). CML patients who received imatinib treatment for at least 3 years and sustained deep molecular response for at least 2 years were eligible. Molecular recurrence was defined as loss of major molecular response (MMR). Of the 68 eligible patients, 38.2% were women, the median age was 55.0 years, and the median duration of imatinib treatment was 97.5 months. The 12-month TFR rate was 67.6%. Patients who lost MMR were immediately treated with imatinib again; all re-achieved MMR. Three-year treatment-free survival (TFS) was estimated as 64.6% using the Kaplan-Meier method. Undetectable molecular residual disease (UMRD) was defined as no BCR-ABL1 in > 100,000 ABL1 control genes using international scale polymerase chain reaction. UMRD at the study baseline was found to be predictive of continuation of TFR. Our findings suggest that CML patients who meet all the eligibility criteria that have commonly been used in the TFR trials are able to discontinue imatinib use safely. TFR may thus be valuable as a new goal for CML treatment in Japan.

To assess the impact of minimal residual disease (MRD) and tyrosine kinase inhibitor (TKI) administration on allogeneic hematopoietic cell transplantation (allo-HCT) for Ph-positive ALL (Ph+ALL), we retrospectively analyzed data from a registry database for 432 adult Ph+ALL patients in first CR (CR1) who received pre-transplant TKI administration. Negative MRD (MRD(− )) at allo-HCT was achieved in 277 patients. OS in patients transplanted in MRD( − ) was significantly better than that in patients transplanted in MRD(+) (MRD( − ): 67% vs MRD(+): 55% at 4 years; P = 0.001). MRD( − ) at allo-HCT was a significant risk factor for survival along with age at allo-HCT in multivariate analyses. Incidence of relapse in patients transplanted in MRD( − ) was significantly lower than that in patients transplanted in MRD(+) (MRD( − ): 19% vs MRD(+): 29% at 4 years; P = 0.006). In multivariate analyses, MRD(+) at allo-HCT was a significant risk factor for relapse. A post-transplant TKI was administered to 103 patients. In subanalyses regarding the effect of post-transplant TKI administration, post-transplant TKI administration was a significant risk factor for relapse in multivariate analyses (P o0.0001). MRD status at allo-HCT is one of the most important predictive factors for Ph +ALL patients transplanted in CR1.

High-dose methotrexate (Hd-MTX) therapy has recently been applied to the treatment of adult acute lymphoblastic leukemia (ALL) based on pediatric protocols; however, its effectiveness for adult ALL has not yet been confirmed in a rigorous manner. We herein conducted a randomized phase III trial comparing Hd-MTX therapy with intermediate-dose (Id)-MTX therapy. This study was registered at UMIN-CTR (ID: C000000063). Philadelphia chromosome (Ph)-negative ALL patients aged between 25 and 64 years of age were enrolled. Patients who achieved complete remission (CR) were randomly assigned to receive therapy containing Hd-MTX (3 g/m) or Id-MTX (0.5 g/m). A total of 360 patients were enrolled. The CR rate was 86%. A total of 115 and 114 patients were assigned to the Hd-MTX and Id-MTX groups, respectively. The estimated 5-year disease-free survival rate of the Hd-MTX group was 58%, which was significantly better than that of the Id-MTX group at 32% (P=0.0218). The frequencies of severe adverse events were not significantly different. We herein demonstrated the effectiveness and safety of Hd-MTX therapy for adult Ph-negative ALL. Our results provide a strong rationale for protocols containing Hd-MTX therapy being applied to the treatment of adult ALL.

Summary:It is difficult to treat lung complications caused by chronic graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (allo-SCT). We retrospectively analyzed the characteristics of five patients with mediastinal emphysema (ME) and bilateral pneumothoraces (BP) caused by chronic lung GVHD after allo-SCT. Four of these patients had undergone unrelated SCT, and three had had HLA-identical unrelated donors. All patients received total body irradiation (TBI) during conditioning. Immunosuppressive agents were administered as GHVD prophylaxis, but two patients developed acute GVHD and all the five developed chronic GVHD. The onset of lung complications was 99-1915 days (median, 202 days) after SCT. The onset of ME and BP was 6-48 days (median, 23 days) after the onset of lung complications. Immunosuppressive agents were initially beneficial on the lung complications, but the patients later showed no response to therapy, and all died from respiratory failure 7-195 days (median, 28 days) after the development of ME and BP. The results suggest that these complications progress rapidly, are resistant to treatment, and have a poor prognosis. It is therefore important to start prophylaxis and treatment as early as possible.

A prospective multicenter Phase II study was performed to examine the efficacy and safety of imatinib therapy in newly diagnosed Japanese patients with chronic‐phase CML. Patients were scheduled to receive imatinib 400 mg daily. Plasma imatinib concentrations were measured by liquid chromatography–tandem mass spectrometry. In 481 evaluable patients, estimated 7‐year overall survival (OS) and event‐free survival (EFS) at a median follow‐up of 65 months were 93% and 87%, respectively. Because imatinib dosage was reduced in many patients due mainly to adverse events, subgroup analysis was performed according to the mean daily dose during the first 24 months of treatment: ≥360 mg (400‐mg group; n = 294), 270–359 mg (300‐mg group; n = 90) and <270 mg (200‐mg group; n = 67). There were no significant differences in OS and EFS between the 300‐ and 400‐mg groups; however, cumulative rates of complete cytogenetic and major molecular responses differed significantly between the two groups. There were no significant differences in mean imatinib trough levels between these two groups for the patients in whom trough levels had been measured. Survival and efficacy in the 200‐mg group were markedly inferior to the former two groups. These results suggest that, although a daily dose of 400 mg imatinib is associated with better outcomes, 300 mg imatinib may be adequate for a considerable number of Japanese patients who are intolerant to 400 mg imatinib. Blood level monitoring would be useful to determine the optimal dose of imatinib. (Cancer Sci 2012; 103: 1071–1078)