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.

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.

The genetic basis of leukemogenesis in adults with B-cell acute lymphoblastic leukemia (B-ALL) is largely unclear and its clinical outcome remains unsatisfactory. This study aimed to advance the understanding of biological characteristics, improve disease stratification, and identify molecular targets of adult B-ALL. Adolescents and young adults (AYA; 15-39 years old, n = 193) and adults (40-64 years old, n = 161) with Philadelphia chromosome-negative B-ALL were included in this study. Integrated transcriptomic and genetic analyses were used to classify the cohort into defined subtypes. Of the 323 cases included in the RNA sequencing analysis, 278 (86.1%) were classified into 18 subtypes. The ZNF384 subtype (22.6%) was the most prevalent, with two novel subtypes (CDX2-high and IDH1/2-mut) identified among cases not assigned to the established subtypes. The CDX2-high subtype (3.4%) was characterized by high expression of CDX2 and recurrent gain of chromosome 1q. The IDH1/2-mut subtype (1.9%) was defined by IDH1 R132C or IDH2 R140Q mutations with specific transcriptional and high-methylation profiles. Both subtypes showed poor prognosis and were considered inferior prognostic factors independent of clinical parameters. Comparison with a previously reported pediatric B-ALL cohort (n = 1003) showed that the frequencies of these subtypes were significantly higher in AYA/adults than in children. We delineated the genetic and transcriptomic landscape of adult B-ALL and identified two novel subtypes that predict poor disease outcomes. Our findings highlight the age-dependent distribution of subtypes, which partially accounts for the prognostic differences between adult and pediatric B-ALL.

Regional lymph nodes of Küttner's 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 Küttner's 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.

No abstract

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.

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 2012; 103: 1513-1517 G ranulocytic sarcoma (GS), a rare extramedullary tumor composed of malignant granulocytic precursor cells that affects 3-9% of patients diagnosed with acute myeloid leukemia (AML), (1)(2)(3) occurs concomitantly with or after a diagnosis of AML. Granulocytic sarcoma can occur in any organ and common sites are bones, lymph nodes, soft tissues and skin. (4) Other organs, including the brain, (5,6) orbit (7,8) and genitourinary system, (9,10) are infrequently affected by GS. Such variation in its site of occurrence complicates accurate diagnosis of GS, and, moreover, the low incidence of GS has impeded establishment of the clinical characteristics of patients with GS. Several studies have reported that specific factors, including French-American-British (FAB) M4 and M5 classification (11,12) and the expression of CD56 (13,14) or T-cell antigens (CD2, CD4 and CD7) (15,16) on leukemia cells, are associated with GS, while others have identified an association between GS and t(8;21) (17,18) or inv(16). (19,20) Establishment of the clinical characteristics of GS has been further impeded by the mixed results obtained by several studies that investigated the prognosis of GS in limited subpopulations of AML patients. Byrd et al. (21) found that GS was associated with unfavorable outcomes and a shorter survival time (median 5.4 months with GS vs 59.5 months without GS) among AML patients carrying t(8;21), whereas Felice et al. (22) argued that GS had no adverse prognostic impact on AML patients carrying t(8;21). In light of these discrepant findings, this study aimed to clarify the clinical significance of GS...

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.