Satoru Takada

Array-based genomic resequencing of human leukemia

To identify oncogenes in leukemias, we performed large-scale resequencing of the leukemia genome using DNA sequence arrays that determine ∼9 Mbp of sequence corresponding to the exons or exon–intron boundaries of 5648 protein-coding genes. Hybridization of genomic DNA from CD34-positive blasts of acute myeloid leukemia (n=19) or myeloproliferative disorder (n=1) with the arrays identified 9148 nonsynonymous nucleotide changes. Subsequent analysis showed that most of these changes were also present in the genomic DNA of the paired controls, with 11 somatic changes identified only in the leukemic blasts. One of these latter changes results in a Met-to-Ile substitution at amino-acid position 511 of Janus kinase 3 (JAK3), and the JAK3(M511I) protein exhibited transforming potential both in vitro and in vivo. Further screening for JAK3 mutations showed novel and known transforming changes in a total of 9 out of 286 cases of leukemia. Our experiments also showed a somatic change responsible for an Arg-to-His substitution at amino-acid position 882 of DNA methyltransferase 3A, which resulted in a loss of DNA methylation activity of >50%. Our data have thus shown a unique profile of gene mutations in human leukemia.

Markedly improved outcomes and acceptable toxicity in adolescents and young adults with acute lymphoblastic leukemia following treatment with a pediatric protocol: a phase II study by the Japan Adult Leukemia Study Group

The superiority of the pediatric protocol for adolescents with acute lymphoblastic leukemia (ALL) has already been demonstrated, however, its efficacy in young adults remains unclear. The ALL202-U protocol was conducted to examine the efficacy and feasibility of a pediatric protocol in adolescents and young adults (AYAs) with BCR–ABL-negative ALL. Patients aged 15–24 years (n=139) were treated with the same protocol used for pediatric B-ALL. The primary objective of this study was to assess the disease-free survival (DFS) rate and its secondary aims were to assess toxicity, the complete remission (CR) rate and the overall survival (OS) rate. The CR rate was 94%. The 5-year DFS and OS rates were 67% (95% confidence interval (CI) 58–75%) and 73% (95% CI 64–80%), respectively. Severe adverse events were observed at a frequency that was similar to or lower than that in children treated with the same protocol. Only insufficient maintenance therapy significantly worsened the DFS (hazard ratio 5.60, P<0.001). These results indicate that this protocol may be a feasible and highly effective treatment for AYA with BCR–ABL-negative ALL.

Lymphoplasmacytic Infiltrate of Regional Lymph Nodes in Küttner's Tumor (Chronic Sclerosing Sialadenitis): A Report of 3 Cases

Regional lymph nodes of Küttners tumor from 3 patients showed reactive follicular hyperplasia and prominent interfollicular plasmacytosis. The patients were 71-, 57-, and 73-year-old Japanese men. The polytypic nature of plasma cells was demonstrated by immunohistochemistry. There were numerous IgG-positive plasma cells with scattered IgA-positive or IgM-positive plasma cells. IgG4-positive cells comprised 25% to 40% of IgG-positive plasma cells. Prominent polyclonal hyperimmunoglobulinemia was demonstrated on laboratory test in 2 cases examined. An elevated serum IgG4 level (16%) was also demonstrated in 1 patient. The present 3 cases indicated that regional lymph node of Küttners tumor may show reactive follicular hyperplasia and prominent interfollicular plasmacytosis and should be differentiated from various benign and malignant lymphoproliferative disorders including systemic rheumatic disease, plasma cell type of Castleman disease, and lymph node involvement of marginal B-cell lymphoma of the mucosa-associated lymphoid tissue type showing prominent plasma cell differentiation.

Clinical significance of granulocytic sarcoma in adult patients with acute myeloid leukemia

To investigate the clinical significance of granulocytic sarcoma (GS) in adults with acute myeloid leukemia (AML), 434 consecutive patients with AML were analyzed retrospectively. Forty‐five patients (10.4%) with GS at diagnosis were younger (P < 0.001), presented with higher white blood cell counts (P = 0.03) and were more likely to conform to French–American–British M4 (P = 0.001) and M5 (P = 0.045) classifications than those without GS. In contrast, no significant difference in frequency of cytogenetic abnormalities was found between the GS and non‐GS groups. Treatment outcomes in 260 patients (40 with GS) who underwent intensive chemotherapy, excluding patients with acute promyelocytic leukemia, were investigated. Complete remission rates did not differ significantly between the GS and non‐GS groups (75.0% vs 79.1%; P = 0.192, respectively) or the 5‐year overall survival (OS) rates (39.9% vs 38.7%; P = 0.749, respectively). However, the GS group had a significantly higher relapse rate than the non‐GS group (74.2% vs 55.3%; P = 0.048) and a significantly lower 5‐year disease‐free survival rate (8.2% vs 25.7%, respectively; P = 0.005). When considered together with the results of multivariate analysis, which identified the presence of GS as an independent predictor for disease‐free survival time, these findings indicate that GS might identify a high‐risk subset of patients with AML. (Cancer Sci, doi: 10.1111/j.1349‐7006.2012.02324.x, 2012)

Discrepancy in EBV-DNA load between peripheral blood and cerebrospinal fluid in a patient with isolated CNS post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder (PTLD) is a fatal complication of allogeneic hematopoietic stem cell transplantation (HSCT) that is caused by reactivation of Epstein–Barr virus (EBV). A successful approach, monitoring EBV-DNA load in peripheral blood (PB) accompanied by preemptive rituximab therapy, has recently been reported. Here, we describe a 29-year-old woman who developed isolated central nervous system (CNS) PTLD. She received HSCT against acute myelogenous leukemia from a related human leukocyte antigen-haploidentical donor, following a conditioning regimen that included antithymocyte globulin. Tacrolimus and methylprednisolone were given as prophylaxis for graft-versus-host disease. On day +172, the patient’s consciousness deteriorated. Magnetic resonance imaging showed six ring-enhanced lesions in the cerebral hemispheres. These tumors were diagnosed, via a craniotomy and tumorectomy, as PTLD. EBV-DNA load was elevated in the cerebrospinal fluid (CSF) but not detected in PB. She was treated with whole-brain irradiation and rituximab, and achieved partial remission of the tumors. This case serves as a reminder that vigilance is required regarding the development of isolated CNS PTLD; it is worth examining EBV-DNA replication in CSF for diagnosis even when the EBV-DNA load is negative in PB.

Prognostic factors influencing clinical outcome of allogeneic hematopoietic stem cell transplantation following imatinib-based therapy in BCR–ABL-positive ALL

We investigated prognostic factors for the clinical outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) following imatinib-based therapy. Among 100 adult patients who were prospectively enrolled in the JALSG Ph+ALL202 study, 97 patients obtained complete remission (CR) by imatinib-combined chemotherapy, among whom 60 underwent allo-HSCT in their first CR. The probabilities of overall survival (OS) and disease-free survival (DFS) at 3 years after HSCT were 64% (95% CI, 49–76) and 58% (95% CI, 43–70), respectively. Prognostic factor analysis revealed that the major BCR–ABL transcript was the only unfavorable predictor for OS and DFS after HSCT by both univariate (HR, 3.67 (95% CI 1.49–9.08); P=0.005 and HR, 6.25 (95% CI, 1.88–20.8); P=0.003, respectively) and multivariate analyses (HR, 3.20 (95% CI, 1.21–8.50); P=0.019 and HR, 6.92 (95% CI, 2.09–22.9); P=0.002, respectively). Minimal residual disease status at the time of HSCT had a significant influence on relapse rate (P=0.015). Further study of the BCR–ABL subtype for the clinical impact on outcome of allo-HSCT in Ph+ALL is warranted.

Philadelphia chromosome‐positive mixed phenotype acute leukemia in the imatinib era

Although the introduction of imatinib dramatically improved the outcomes for patients with Philadelphia chromosome‐positive B‐cell precursor acute lymphoblastic leukemia (Ph+BCP‐ALL), the survival benefit of imatinib has not been assessed in the context of Ph+ mixed phenotype acute leukemia (Ph+MPAL). To clarify this important issue, we studied 42 Ph+ acute leukemia (Ph+AL) patients who received intensive chemotherapy and concurrent administration of imatinib. Of the 42 Ph+AL patients, 13 (31%) patients were categorized as Ph+MPAL (positive for both myeloid and B‐cell lineage), 27 (64%) were categorized as Ph+BCP‐ALL, and two (5%) were categorized as Ph+ acute myeloid leukemia. The complete remission rates after the initial induction therapy were not significantly different when comparing Ph+MPAL and Ph+BCP‐ALL patients (100% vs. 85%, respectively, P = 0.14). Likewise, there were no significant differences in the 5‐yr overall survival (OS) or disease‐free survival (DFS) rates when comparing the MPAL and BCP‐ALL groups (OS: 55% vs. 53%, respectively, P = 0.87, DFS: 46% vs. 42%, respectively, P = 0.94). These findings suggest that concurrent imatinib administration with chemotherapy improved the outcomes of Ph+MPAL patients to the level seen in Ph+BCP‐ALL patients and should, therefore, be considered as the standard therapy for these patients.

Methylation status of fragile histidine triad (FHIT) gene and its clinical impact on prognosis of patients with multiple myeloma

Abstract:  Aberrant methylation of tumor suppressor genes (TSG) has been studied in multiple myeloma (MM). We determined the methylation status of the FHIT (fragile histidine triad) gene, a putative TSG, in 48 patients with MM. Clinical association with its methylation status was then analyzed. The FHIT gene methylation was observed in 21 of the 48 patients (44%). No association between FHIT gene methylation and clinical variables such as age, gender and clinical stage was found. However, the estimated 50% survival time of the methylated group was significantly shorter than that of the unmethylated group (18.2 vs. 45.1 months, P < 0.05). Univariate analysis revealed adverse prognostic factors: FHIT gene methylation (P = 0.028), poor performance status (I to IV, P = 0.002), anemia (≤8.5 g/dL, P = 0.007), hypoalbuminemia (≤3.5 g/dL, P < 0.002), high serum C‐reactive protein levels (>0.5 mg/dL, P = 0.002), elevated beta‐2‐microglobulin serum levels (>6.5 mg/L, P < 0.001), and treatments not including autologous peripheral blood stem cell transplantation (auto‐PBSCT) (P = 0.007). Multivariate analysis identified FHIT gene methylation [hazard ratio (HR) 1.722, 95% confidence interval (CI) 1.150–2.603, P = 0.009], elevated beta‐2‐microglobulin serum levels (>6.5 mg/L, HR 2.005, 95% CI 1.035–3.937, P = 0.004), and treatments not including auto‐PBSCT are independent predictive variables. These findings indicate that aberrant methylation of the FHIT gene is an independent adverse prognostic factor in MM.

Clinical evaluation of WT1 mRNA expression levels in peripheral blood and bone marrow in patients with myelodysplastic syndromes.

Abstract A study to evaluate WT1 mRNA expression levels in peripheral blood (PB) and bone marrow aspirate (BM) was conducted in 172 patients, including 115 with myelodysplastic syndromes (MDS), in Japan. The level of WT1 mRNA expression was evaluated according to the French–American–British (FAB) and World Health Organization (WHO) classifications (2001, 2008) and using the International Prognostic Scoring System and the WHO Prognostic Scoring System scales. WT1 mRNA expression levels in PB and BM were well correlated (r = 0.85), and they tended to increase with disease stage progression and in those at higher risk of leukemic transformation. WT1 mRNA expression can be a useful marker for the diagnosis and risk evaluation of MDS.

Prevalence of extramedullary relapses is higher after allogeneic stem cell transplantation than after chemotherapy in adult patients with acute myeloid leukemia

Although studies have demonstrated a high prevalence of extramedullary (EM) relapse after allogeneic stem cell transplantation (allo-SCT) in patients with acute myeloid leukemia (AML), the prevalence of EM relapse has not been compared with that after chemotherapy. This study investigated the prevalence of EM relapse among 498 adult AML patients (median age, 57 years; range, 15-82 years) who underwent intensive chemotherapy. A total of 281 relapses occurred in 210 patients (36 after allo-SCT; 245 after chemotherapy), and 33 relapses (11.7%) were accompanied by EM disease. Among these relapses, EM disease was more frequently observed at relapse after allo-SCT than after chemotherapy (25% vs. 9%, respectively; p=0.008). Eight of 33 relapses after the first allo-SCT had EM disease, and only presence of extensive chronic graft-versus-host disease (GVHD) was identified as a predisposing factor for EM relapse. Additionally, the 1-year overall survival rate after relapse was not significantly different when comparing those with EM relapse and those with BM relapse (38% vs. 16%, respectively; p=0.279). These data suggest that AML patients undergoing allo-SCT should be closely followed for signs of EM relapse, especially those with extensive chronic GVHD.