Usefulness of BCOR gene mutation as a prognostic factor in acute myeloid leukemia with intermediate cytogenetic prognosis.

BCOR gene is a transcription regulatory factor that plays an essential role in normal hematopoiesis. The wider introduction of next-generation sequencing technology has led to reports in recent years of mutations in the BCOR gene in acute myeloid leukemia (AML), but the related clinical characteristics and prognosis are not sufficiently understood. We investigated the clinical characteristics and prognosis of 377 de novo AML cases with BCOR or BCORL1 mutation. BCOR or BCORL1 gene mutations were found in 28 cases (7.4%). Among cases aged 65 years or below that were also FLT3-ITD-negative and in the intermediate cytogenetic prognosis group, BCOR or BCORL1 gene mutations were observed in 11% of cases (12 of 111 cases), and this group had significantly lower 5-year overall survival (OS) (13.6% vs. 55.0%, P = 0.0021) and relapse-free survival (RFS) (14.3% vs. 44.5%, P = 0.0168) compared to cases without BCOR or BCORL1 gene mutations. Multivariate analysis demonstrated that BCOR mutations were an independent unfavorable prognostic factor (P = 0.0038, P = 0.0463) for both OS and RFS. In cases of AML that are FLT3-ITD-negative, aged 65 years or below, and in the intermediate cytogenetic prognosis group, which are considered to have relatively favorable prognosis, BCOR gene mutations appear to be an important prognostic factor.

Full-length mutation search of the TP53 gene in acute myeloid leukemia has increased significance as a prognostic factor.

TP53 gene abnormality has been reported to be an unfavorable prognostic factor in acute myeloid leukemia (AML). However, almost all studies of TP53 gene abnormality so far have been limited to mutation searches in the DNA binding domain. As there have been few reports examining both mutation and deletion over the full-length of the TP53 gene, the clinical characteristics of TP53 gene abnormality have not yet been clearly established. In this study, TP53 gene mutation was observed in 7.3% of the total 412 de novo AML cases (33 mutations in 30 cases), with mutation outside the DNA binding domain in eight cases (27%). TP53 gene deletion was observed in 3.1% of 358 cases. All cases had monoallelic deletion with TP53 gene mutation on the opposite allele. Multivariate analysis demonstrated that TP53 gene mutation in the DNA binding domain and outside the DNA binding domain was an independent poor prognostic factor for overall survival and relapse-free survival among the total cohort and it is also an unfavorable prognostic factor in FLT3-ITD-negative AML cases aged 70 years or below with intermediate cytogenetic prognosis. In stratified treatment, full-length search for TP53 gene mutation is therefore very important.

D816 mutation of the KIT gene in core binding factor acute myeloid leukemia is associated with poorer prognosis than other KIT gene mutations.

The clinical impact of KIT mutations in core binding factor acute myeloid leukemia (CBF-AML) is still unclear. In the present study, we analyzed the prognostic significance of each KIT mutation (D816, N822K, and other mutations) in Japanese patients with CBF-AML. We retrospectively analyzed 136 cases of CBF-AML that had gone into complete remission (CR). KIT mutations were found in 61 (45%) of the patients with CBF-AML. D816, N822K, D816 and N822K, and other mutations of the KIT gene were detected in 29 cases (21%), 20 cases (15%), 7 cases (5%), and 5 cases (4%), respectively. The rate of relapse-free survival (RFS) and overall survival (OS) in patients with D816 and with both D816 and N822K mutations was significantly lower than in patients with other or with no KIT mutations (RFS: p < 0.001, OS: p < 0.001). Moreover, stratified analysis of the chromosomal abnormalities t(8;21)(q22;q22) and inv(16)(p13.1q22), t(16;16)(p13.1;q22) showed that D816 mutation was associated with a significantly worse prognosis. In a further multivariate analysis of RFS and OS, D816 mutation was found to be an independent risk factor for significantly poorer prognosis. In the present study, we were able to establish that, of all KIT mutations, D816 mutation alone is an unfavorable prognostic factor.

Clinical characteristics and prognosis of acute myeloid leukemia associated with DNA-methylation regulatory gene mutations.

In recent years, it has been reported that the frequency of DNA-methylation regulatory gene mutations - mutations of the genes that regulate gene expression through DNA methylation - is high in acute myeloid leukemia. The objective of the present study was to elucidate the clinical characteristics and prognosis of acute myeloid leukemia with associated DNA-methylation regulatory gene mutation. We studied 308 patients with acute myeloid leukemia. DNA-methylation regulatory gene mutations were observed in 135 of the 308 cases (43.8%). Acute myeloid leukemia associated with a DNA-methylation regulatory gene mutation was more frequent in older patients (P<0.0001) and in patients with intermediate cytogenetic risk (P<0.0001) accompanied by a high white blood cell count (P=0.0032). DNA-methylation regulatory gene mutation was an unfavorable prognostic factor for overall survival in the whole cohort (P=0.0018), in patients aged ≤70 years, in patients with intermediate cytogenetic risk, and in FLT3-ITD-negative patients (P=0.0409). Among the patients with DNA-methylation regulatory gene mutations, 26.7% were found to have two or more such mutations and prognosis worsened with increasing number of mutations. In multivariate analysis DNA-methylation regulatory gene mutation was an independent unfavorable prognostic factor for overall survival (P=0.0424). However, patients with a DNA-methylation regulatory gene mutation who underwent allogeneic stem cell transplantation in first remission had a significantly better prognosis than those who did not undergo such transplantation (P=0.0254). Our study establishes that DNA-methylation regulatory gene mutation is an important unfavorable prognostic factor in acute myeloid leukemia.

Importance of maintaining the relative dose intensity of CHOP-like regimens combined with rituximab in patients with diffuse large B-cell lymphoma.

CHOP-like regimen combined with rituximab is a standard chemotherapy for diffuse large B-cell lymphoma (DLBCL). The relative dose intensity (RDI) was proposed as an index of the dose and administration interval of agents. Previous studies reported that the maintenance of the RDI during CHOP therapy improved the treatment results. However, few studies regarding RDI have reviewed patients receiving combination therapy with CHOP and rituximab. We investigated the influence of RDI maintenance, involving combination therapy with rituximab, on therapeutic effects in patients with DLBCL. We retrospectively examined 152 DLBCL patients who were treated with CHOP-like regimen combined with rituximab in whom the RDI could be followed up. Multivariate analysis revealed that international prognosis index (IPI) high intermediate-high (HI-H) (p = 0.005) and RDI of less than 70% (p = 0.007) were independent prognostic factors for low progression free survival. Concerning overall survival, IPI HI-H (p = 0.027) and an RDI of less than 70% (p = 0.002) were involved in an unfavorable prognosis. In addition, age over 60 years (p = 0.003), R-THPCOP (p = 0.034), or the presence of febrile neutropenia (p = 0.004) made RDI maintenance difficult, and prophylactic G-CSF therapy (p = 0.026) was useful for maintaining the RDI. Maintaining the RDI is important even in the era of rituximab-combined chemotherapy for DLBCL.

[Successful treatment with reduced-intensity stem cell transplantation for primary myelofibrosis].

A 60-year-old man was found to have anemia and leukocytosis from a health examination, and diagnosed with primary myelofibrosis (PMF). He was treated with low-dose melphalan but required frequent transfusions of red blood cells, and his splenomegaly enlarged. He received reduced-intensity stem cell transplantation (RIST)from an HLA-identical unrelated donor. The recovery of hematopoiesis was delayed due to the small number of transplanted cells (0.4 x 10(8)/kg). Splenomegaly and myelofibrosis gradually improved, and transfusion was not necessary 6 months later. He died of pneumonia about 1 year after transplantation. However, this case suggests that RIST is an effective treatment for PMF with giant splenomegaly.

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

To clarify the clinical features of adult patients with acute leukemia (AL) with 11q23 abnormalities, we performed a retrospective analysis of data from 58 adult Japanese patients: 51 with acute myeloid leukemia (AML), and 7 with acute lymphoblastic leukemia (ALL). The incidences according to fusion partners in AML were: t(9;11), 31.3%; t(11;19), 27.4%; t(6;11), 21.5%. The incidence of patients with t(11;19) was higher than those in the US and Europe, and the incidence of t(4;11) was lower than that in childhood. The results indicated the poor prognosis of AML with 11q23 abnormalities regardless of the fusion partners. AML patients with 11q23 aged <60 years in the first CR who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) showed a more favorable outcome than those treated without allo-HSCT, although the differences were not statistically significant (P = 0.322 for DFS, P = 0.138 for OS). This result suggests that treatment strategies including allo-HSCT may be considered in the first CR in cases of AML with 11q23 abnormalities. However, further studies involving a large number of cases are required to assess the effect of allo-HSCT on adult AL with 11q23 abnormalities.

Prognostic impact of low allelic ratio FLT3-ITD and NPM1 mutation in acute myeloid leukemia.

In the opinion of the European LeukemiaNet (ELN), nucleophosmin member 1 gene mutation (NPM1 mut)-positive acute myeloid leukemia (AML) with an fms-like kinase 3-internal tandem duplication (FLT3-ITD) allele ratio (AR) <0.5 (low AR) has a favorable prognosis, and allogeneic hematopoietic stem cell transplant (allo-HSCT) in the first complete remission (CR1) period is not actively recommended. We studied 147 patients with FLT3-ITD gene mutation-positive AML, dividing them into those with low AR and those with AR of ≥0.5 (high AR), and examined the prognostic impact according to allo-HSCT in CR1. Although FLT3-ITD AR and NPM1 mut are used in the prognostic stratification, we found that NPM1 mut-positive AML with FLT3-ITD low AR was not associated with favorable outcome (overall survival [OS], 41.3%). Moreover, patients in this group who underwent allo-HSCT in CR1 had a significantly more favorable outcome than those who did not (relapse-free survival [RFS] P = .013; OS P = .003). Multivariate analysis identified allo-HSCT in CR1 as the sole favorable prognostic factor (RFS P < .001; OS P < .001). The present study found that prognosis was unfavorable in NPM1 mut-positive AML with FLT3-ITD low AR when allo-HSCT was not carried out in CR1.

Clinical features of Japanese polycythemia vera and essential thrombocythemia patients harboring CALR, JAK2V617F, JAK2Ex12del, and MPLW515L/K mutations.

The risk of complication of polycythemia vera (PV) and essential thrombocythemia (ET) by thrombosis in Japanese patients is clearly lower than in western populations, suggesting that genetic background such as race may influence the clinical features. This study aimed to clarify the relationship between genetic mutations and haplotypes and clinical features in Japanese patients with PV and ET. Clinical features were assessed prospectively among 74 PV and 303 ET patients. There were no clinical differences, including JAK2V617F allele burden, between PV patients harboring the various genetic mutations. However, CALR mutation-positive ET patients had a significantly lower WBC count, Hb value, Ht value, and neutrophil alkaline phosphatase score (NAP), and significantly more platelets, relative to JAK2V617F-positive ET patients and ET patients with no mutations. Compared to normal controls, the frequency of the JAK246/1 haplotype was significantly higher among patients with JAK2V617F, JAK2Ex12del, or MPL mutations, whereas no significant difference was found among CALR mutation-positive patients. CALR mutation-positive patients had a lower incidence of thrombosis relative to JAK2V617F-positive patients. Our findings suggest that JAK2V617F-positive ET patients and CALR mutation-positive patients have different mechanisms of occurrence and clinical features of ET, suggesting the potential need for therapy stratification in the future.

Analysis of triglyceride value in the diagnosis and treatment response of secondary hemophagocytic syndrome.

BACKGROUND/AIMS: Secondary hemophagocytic syndrome (hemophagocytic lymphohistiocytosis, HLH) follows viral infection, malignant disorders, and autoimmune disease. Criteria for HLH diagnosis, which were proposed in 2004, include hypertriglyceridemia. However, some studies reported the absence of hypertriglyceridemia in patients with secondary HLH, differing from those with primary HLH. SUBJECTS AND METHODS: In this study, we investigated the presence or absence of hypertriglyceridemia in 28 patients who were diagnosed with secondary HLH between 1997 and 2007 retrospectively. There were no patients undergoing treatment for those with a history of hyperlipidemia. RESULTS: The subjects consisted of 14 patients with lymphoma-associated HLH, 11 with virus-associated HLH, 2 with autoimmune disease-associated HLH, and 1 with post transplantation HLH. In 19 patients (68%), hypertriglyceridemia was noted on diagnosis or during the disease period (mean: 242 mg/dL). Furthermore, the triglyceride (TG) level decreased with the treatment-related amelioration of HLH (mean level before and after treatment: 297 and 136 mg/dL, respectively, p=0.0001). CONCLUSION: These results suggest that the TG level is useful for diagnosing HLH and evaluating the treatment response. TG measurement is simple and inexpensive; therefore, this parameter can be determined several times to evaluate the treatment response.