Allogeneic stem cell transplantation for children and adolescents/young adults with de novo blastic phase chronic myeloid leukemia in the tyrosine kinase inhibitor era.

The analysis of 165 children and adolescents/young adults with de novo blastic phase chronic myeloid leukemia showed disease status at hematopoietic stem cell transplantation was a strong prognostic factor and clearly separated the patient outcomes.

Discontinuation of tyrosine kinase inhibitors in pediatric chronic myeloid leukemia.

BACKGROUND: The feasibility of tyrosine kinase inhibitor (TKI) discontinuation in pediatric chronic myeloid leukemia (CML) remains to be fully elucidated. PROCEDURES: TKI was prospectively discontinued in patients who were diagnosed with CML at <20 years of age, treated with TKI for ≥3 years, and sustained molecular response 4.0 (MR4.0) for ≥2 years. Molecular relapse was defined as a single loss of major molecular response (MMR) (BCR-ABL1IS >0.1%). Relapsed patients resumed the same TKI therapy administered before discontinuation. RESULTS: Twenty-two patients with chronic-phase CML were enrolled, and the median ages at diagnosis and at TKI discontinuation were 9 (range: 1-14) years and 16 (5-26) years, respectively. The median follow-up time after TKI discontinuation was 37 months (range: 24-41 months). The median duration of TKI treatment before discontinuation was 100 (42-178) months, and that of MR4.0 was 53.5 (25-148) months. The treatment-free remission (TFR) rate at 12 months was 50.0% (90% confidence interval: 31.7%-65.8%). Eleven patients experienced loss of MMR within 4 months after TKI discontinuation and resumed TKI as originally prescribed. No progression was observed, and all 11 patients regained MR4.0 after TKI resumption. No patient had a withdrawal syndrome. The quality-of-life analysis suggested that successful TFR may improve academic performance in some patients. In patients who discontinued TKI therapy before puberty, the possibility of improvement in growth velocity upon TKI discontinuation was observed. CONCLUSIONS: TKI could be discontinued safely in patients with pediatric CML showing a sustained deep MR.

Sequential use of second-generation tyrosine kinase inhibitors following imatinib therapy in pediatric chronic myeloid leukemia: A report from the Japanese Pediatric Leukemia/Lymphoma Study Group.

BACKGROUND: The details of the sequential use of imatinib for first-line treatment followed by second-generation tyrosine kinase inhibitors (2G-TKIs) for pediatric chronic myeloid leukemia (CML) are still unknown. This study analyzed clinical responses and adverse effects of the use of 2G-TKIs following imatinib in pediatric chronic phase (CP)-CML. PROCEDURES: The Japanese Pediatric Leukemia/Lymphoma Study Group conducted a retrospective study of patients with newly diagnosed CML from 1996 to 2011. A total of 152 cases that received imatinib as first-line therapy were analyzed. RESULTS: Excluding 46 cases treated with hematopoietic stem cell transplantation before nilotinib and dasatinib became available, 31 of 106 patients changed to 2G-TKIs. The primary reason for changing from imatinib was poor response, followed by intolerance, with the main reason for the latter being musculoskeletal events. Switches from imatinib to 2G-TKIs with intolerance occurred significantly earlier than switches with poor response. Sixteen and 15 patients were treated with nilotinib and dasatinib, respectively, following imatinib therapy. After switching to 2G-TKIs, the response status improved in 63% of evaluable patients. The adverse effect profiles of nilotinib and dasatinib tended to be different, with hyperbilirubinemia observed in 33% of nilotinib-treated patients, but in none of the cases with dasatinib. CONCLUSION: This retrospective study represents the first series of children and adolescents in whom sequential use of imatinib followed by 2G-TKIs was reported. These data provide useful insights into the selection of 2G-TKIs as first-line treatment for children and adolescents with CP-CML.

Ph-like acute lymphoblastic leukemia with a novel PAX5-KIDINS220 fusion transcript.

Although "paired box 5" (PAX5)-related fusion genes are well documented in childhood B-cell precursor acute lymphoblastic leukemia (ALL), these types of fusion with the exception of PAX5-JAK2 are rarely seen in patients with gene expression profiles similar to those of BCR-ABL1 (Philadelphia)-positive ALL (Ph-like ALL). We report a novel fusion of the genes PAX5 and "kinase D-interacting substrate of 220 kDa" (KIDINS220, also known as ARMS) in a Ph-like ALL. As PAX5 is a master regulator of B-lymphocyte differentiation, PAX5 rearrangements induce a differentiation block in B lymphocytes. KIDINS220 is a mediator of multiple receptor signaling pathways, interacts with both T- and B-cell receptors, and is necessary for sustained extracellular signal-regulated kinase (ERK) signaling. Although functional studies are needed, the PAX5-KIDINS220 fusion protein might not only inhibit wild-type PAX5 function, but also promote sustained activation of the ERK signaling pathway through upregulation of KIDINS220. © 2016 Wiley Periodicals, Inc.

Flow cytometric analysis as an additional predictive tool of treatment response in children with chronic-phase chronic myeloid leukemia treated with imatinib.

Bone marrow samples of newly diagnosed children with chronic-phase chronic myeloid leukemia (CML) were obtained at diagnosis and after imatinib initiation and stained with anti-human CD34, CD38, CD123, CD45RA, cMpl, and lineage antibodies. Flow cytometric analysis revealed that granulocyte macrophage progenitor predominance in CML progenitors at diagnosis and elevated cMpl expression in bone marrow progenitors at 3 months may predict poor outcome in children with chronic-phase CML treated with imatinib. We recommend flow cytometric analysis of bone marrow in the early phase of treatment, as it is a convenient tool that may predict treatment response and guide CML management.

Long-term Results of the Risk-adapted Treatment for Childhood B-Cell Acute Lymphoblastic Leukemia: Report From the Japan Association of Childhood Leukemia Study ALL-97 Trial.

PURPOSE: This study was conducted as the first clinical trial by Japan Association of Childhood Leukemia Study to improve the outcome of B-cell acute lymphoblastic leukemia and explore a less toxic reinduction block. PATIENTS AND METHODS: From 1997 to 2002, 563 patients with B-cell acute lymphoblastic leukemia aged 1 to 15 years were enrolled. The patients were assigned into 4 risk groups (standard, intermediate, high, or extremely high risk) and treated with regimens intensified according to the risk. Two randomized trials were conducted to compare 2 regimens with and without a 3-week reinduction therapy in the standard-risk group, and to compare the efficacy of pirarubicin with daunorubicin in the intermediate-risk and high-risk groups. Prophylactic cranial irradiation was restricted in patients with high or extremely high risk. RESULTS: The event-free survival (EFS) rate at 10 years for all patients was 77.0%. Those in the standard-risk to extremely high-risk groups were 79.3%, 72.5%, 71.7%, and 66.3%, respectively. The 15-week induction/consolidation not followed by reinduction produced 76.4% of the EFS at 10 years comparable with the regimen with reinduction therapy. Pirarubicin at 25 mg/m administered 11 times throughout the treatment produced the EFS comparable with daunorubicin at 30 mg/m. CONCLUSION: The trial produced high survival rates in NCI-HR patients, although the outcomes in NCI-SR patients were not satisfactory possibly due to less intensive central nervous system-directed therapy.

Acute and late toxicities of pirarubicin in the treatment of childhood acute lymphoblastic leukemia: results from a clinical trial by the Japan Association of Childhood Leukemia Study.

BACKGROUND: Anthracyclines are used to treat childhood acute lymphoblastic leukemia (ALL). Even when administered at low doses, these agents are reported to cause progressive cardiac dysfunction. We conducted a clinical trial comparing the toxicities of two anthracyclines, pirarubicin (THP) and daunorubicin (DNR), in the treatment of childhood ALL. The results from our study that relate to acute and late toxicities are reported here. METHODS: 276 children with B-ALL were enrolled in the trial from April 1997 to March 2002 and were randomly assigned to receive a regimen including either THP (25 mg/m2 × 11) or DNR (30 mg/m2 × 11). Acute toxicity was prospectively assessed based on the National Cancer Institute Common Toxicity Criteria. Acute hematological toxicity was also examined via some parameters. Patients with event-free survival of >5 years were retrospectively surveyed for cardiac function at 5 and 10 years and at the most recent assessment more than 10 years from the onset of ALL. RESULTS: Acute hematological toxicity in the early phase was more significant in the THP arm. Based on ultrasound cardiography, cardiac function was impaired in both groups during the follow-up period, but there was no significant difference between the groups except for a greater decline in fractional shortening on ultrasound cardiography in the DNR arm. CONCLUSIONS: While acute hematological toxicity was more significant in the THP arm, THP also appeared to be less cardiotoxic. However, the evaluation of late cardiotoxicity was limited because only a few subjects were followed beyond 10 years after ALL onset. Considering that the THP regimen produced an EFS rate comparable with that of the DNR regimen, the efficacy and toxicity of THP at reduced doses should be studied in order to identify potentially safer regimens.

ACTN1 rod domain mutation associated with congenital macrothrombocytopenia.

Mutations in ACTN1, the gene encoding the actin-crosslinking protein α-actinin-1, cause autosomal dominant macrothrombocytopenia. α-Actinin-1 exists as antiparallel dimers, composed of an N-terminal actin-binding domain (ABD), four spectrin-like repeats (SLRs), which form the spacer rod, and a C-terminal calmodulin-like (CaM) domain. All of the previously reported ACTN1 mutations associated with macrothrombocytopenia reside within the ABD and the CaM domain and not within the SLR domain. In this report, we describe a mutation in SLR2 of α-actinin-1 (p.Leu395Gln) associated with familial macrothrombocytopenia. A 3-year-old boy and his mother both had this mutation. They showed a mild form of thrombocytopenia without severe bleeding, accompanied by an elevated mean platelet volume. Consistent with the previous reports of mutations that reside in the ABD or the CaM domain, immunofluorescence examination revealed disorganization of the actin cytoskeleton in Gln395 mutant-transduced Chinese hamster ovary cells. Our findings suggest a novel mechanism for the pathogenesis of ACTN1-related macrothrombocytopenia that does not involve functional domain mutations.

Leukostasis in Children and Adolescents with Chronic Myeloid Leukemia: Japanese Pediatric Leukemia/Lymphoma Study Group.

BACKGROUND: The details of leukostasis in children and adolescents with chronic myeloid leukemia (CML) are unknown. This study determined the characteristics of leukostasis in children and adolescents with CML. PROCEDURE: A total of 256 cases from a retrospective study of patients with CML conducted by the Japanese Pediatric Leukemia/Lymphoma Study Group from 1996 to 2011 were analyzed, and of these, 238 cases were evaluated in this study. RESULTS: Leukostasis was diagnosed in 23 patients (9.7%). The median leukocyte count and spleen size below the left costal margin in cases with leukostasis were significantly higher and larger when compared to those in cases without leukostasis (458.5 × 10(9) /l vs. 151.8 × 10(9) /l (P < 0.01), and 13 vs. 5 cm (P < 0.01), respectively). Leukostasis occurred with ocular symptoms in 14 cases, priapism in four cases, and dyspnea, syncope, headache, knee pain, difficulty hearing, and aseptic necrosis of the femoral head in one case each. One case had two leukostasis symptoms simultaneously. Three cases were diagnosed before imatinib became available. Five cases received special treatment, and in the remaining 15 cases, all of these symptoms resolved after treatment with imatinib. CONCLUSIONS: This retrospective study represents the largest series of children and adolescents in which leukostasis of CML has been reported. Our data provide useful insight into the characteristics of leukostasis in recent cases of children and adolescents with CML.

Optimal management for pediatric chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is rare among childhood leukemias. Its incidence increases with age, from 0.09/100 000 at ≤15 years old to 7.88/100 000 at ≥75 years old. There are several biological and clinical differences between pediatric and adult CML. Markedly increased leukocyte count and a higher incidence of splenomegaly are characteristic features at diagnosis in pediatric patients. The therapeutic approach to CML has changed since the introduction of the tyrosine kinase inhibitor (TKI) imatinib, followed by dasatinib and nilotinib. Given the efficacy of TKI in adult CML, TKI are regarded as the established first-line treatment in adult patients. In 2011, a prospective phase IV study in pediatric patients showed the excellent efficacy and safety of imatinib. Imatinib is also accepted as a first-line option for childhood chronic phase CML. Although the efficacy of dasatinib and nilotinib reported in adult studies seems very attractive for pediatric patients, neither drug has been prospectively investigated in a large pediatric cohort. TKI are designed to inhibit BCR-ABL1 kinase, but they have unfavorable effects, so-called "off-target" complications, such as growth impairment. Long-term morbidity due to TKI is unknown. Furthermore, the adverse effects on growing children have not been clearly elucidated, even though the exposure period to imatinib is relatively short. To establish the standard therapeutic management for pediatric CML, it is important to prospectively confirm the attractive outcomes obtained in adult studies via pediatric clinical trials with a careful monitoring system for TKI-induced adverse effects, especially in growing children.

A case of retinoblastoma metastasizing to the mandible and review of literature.

OBJECTIVES: The aim of this case report and review was to determine the characteristics of retinoblastoma. METHODS: One case report was introduced along with previous reports on retinoblastoma metastasizing to the mandible. RESULTS: Sixteen cases from 14 reports were included in this study. Including the present case, 11 of 16 patients died within 8 months. DISCUSSION: Retinoblastoma rarely metastasizes to the mandible. However, metastasis to other organs should be considered, and specialists should be consulted if retinoblastoma metastasis to the mandible is observed. Moreover, it is necessary to follow up patients after multidisciplinary therapy is completed, because subsequent complications of the teeth and jawbones associated with therapy could occur.

Serial changes of (18)F-FDG PET/CT findings in ischiopubic synchondrosis: comparison with contrast-enhanced MRI.

UNLABELLED: A 3 years old female patient underwent resection and chemotherapy for a yolk sac tumor of the retroperitoneum. Two years later, fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) showed high uptake in the right ischiopubic synchondrosis (IPS), which had a radiolucent structure on CT. The structure showed contrast enhancement on magnetic resonance imaging (MRI), which was a non-specific finding. Six weeks later, a follow-up (18)F-FDG PET/CT scan was performed which showed no abnormal uptake in the IPS. The disappearance of (18)F-FDG uptake preceded that of contrast enhancement on MRI, which was seen 7 months after the initial (18)F-FDG PET/CT scan. CONCLUSION: This is the first report showing serial changes of (18)F-FDG uptake in IPS, in comparison to MRI findings.

Paroxysmal cold hemoglobinuria caused by an IgM-class Donath-Landsteiner antibody.

We report on a 4-year-old boy who developed paroxysmal cold hemoglobinuria (PCH) following the first dose of a seven-valent pneumococcal conjugate vaccine. He was admitted because of dark urine after exposure to cold air. Laboratory tests indicated anemia, increased serum indirect bilirubin and lactate dehydrogenase, and decreased serum haptoglobin. Donath-Landsteiner (D-L) test was positive. The D-L antibody belonged to the IgM class and exhibited anti-P specificity. Symptoms and signs subsided after supportive care without any medication. Although PCH is often associated with viral or bacterial infection and is caused by IgG-class D-L antibodies with anti-P specificity, this case was unique because a D-L antibody of the IgM class with anti-P specificity caused PCH after immunization with a pneumococcal vaccine.

Fatigue in survivors of childhood acute lymphoblastic and myeloid leukemia in Japan.

BACKGROUND: Fatigue in cancer survivors is a serious problem in pediatric oncology, but reports on this issue are limited, especially in Asian countries. METHODS: Sixty-three patients with acute lymphoblastic leukemia and 18 patients with acute myeloid leukemia who attended a follow-up outpatient clinic were enrolled. Participants were required to be >8 years of age, in remission, and without any cancer treatment for at least the previous 1 year. A control group consisted of 243 subjects whose age and gender were matched with the patient group. A questionnaire consisting of 12 items was devised for fatigue measurement. RESULTS: Principal factor analysis identified three dimensions, defined as physical fatigue, decreased function, and altered mood. The mean total and the three fatigue dimension scores tended to be higher in the control group, but significant differences between the scores were seen only in the total and physical fatigue scores. Multiple regression analysis indicated an association of present older age or shorter duration after completion of treatment with total and physical fatigue, and an association of presence of total body irradiation with decreased function. CONCLUSION: Pediatric leukemia survivors in Japan experience equal or less fatigue compared with that of controls in different fatigue dimensions. Elucidation of underlying mechanisms of cancer-related fatigue including the differences of cultural background among different countries is necessary for future study of this issue.

Prognostic Factors for Outcomes of Allogeneic HSCT for Children and Adolescents/Young Adults With CML in the TKI Era.

The breakthrough effects of tyrosine kinase inhibitors (TKIs) have lessened indications for allogeneic hematopoietic stem cell transplantation (HSCT) in chronic myeloid leukemia (CML). However, HSCT is still attractive for children and adolescents/young adults (AYAs) requiring lifelong TKI therapy. Nevertheless, little has been reported on the outcomes of large clinical studies of HSCT targeting these age groups. This study aimed to identify prognostic factors for the outcomes of HSCT, including reduced-intensity conditioning (RIC)-HSCT, for children and AYAs with CML in the TKI era. We performed a registry analysis for 200 patients with CML aged <30 years who underwent pretransplant TKI therapy from the observational nationwide database established by the Japanese Society for Transplantation and Cellular Therapy. The patients received bone marrow (BM), peripheral blood (PB), or cord blood (CB) from either related or unrelated donors. The indication for HSCT for individual patients was determined by the institution according to European LeukemiaNet recommendations and other guidelines. The 5-year overall survival (OS) rates for patients with chronic phase (CP) (n = 124), accelerated phase (AP) (n = 23), and blastic phase (BP) (n = 53) at diagnosis were 82.8%, 71.1%, and 73.3%, respectively, with no significant difference (P =.3293). The strongest predictor of engraftment was transplant source, with CB (hazard ratio [HR], 0.33) and PB (HR, 2.00) (compared with BM) being independent unfavorable and favorable predictors, respectively. Transplant source was also an independent predictor of chronic GVHD, with PB (HR, 1.81) and CB (HR, 0.39) (compared with BM) being unfavorable and favorable predictors, respectively. The strongest predictor of OS rate for patients with CP at diagnosis was disease phase at HSCT, with second or greater CP, AP, or BP (HR, 2.81) (compared with first CP [CP1]) being an unfavorable predictor. In addition, patients with CP at diagnosis who had major and complete molecular responses at HSCT had excellent outcomes, with 5-year OS rates of 100% and 94.4%, respectively. The 5-year OS rate was compared between RIC (n = 31) and myeloablative conditioning (MAC) (n = 58) in patients with CP1, both of which were 89.3%, with no significant difference (P = .9440). On univariate analysis for the RIC cohort with CP at diagnosis, the age at HSCT (HR, 1.27) (increase per year) and the time from diagnosis to HSCT (HR, 1.83) (increase per year) were significant predictors for OS. Our study demonstrates that RIC may be an appropriate alternative to MAC for children and AYAs with CP1. As for the transplant source, we recommend first selecting BM because of a higher engraftment rate compared to CB and a lower incidence of chronic GVHD compared to PB. Although HSCT in the status of a major molecular response is desirable, it is not advisable to continue TKI pointlessly long because age at HSCT and timing of HSCT are prognostic factors that determine survival. The decision to perform RIC-HSCT instead of continuing TKI should be carefully made, considering the possibility of transplant-related complications.

Distinct impact of imatinib on growth at prepubertal and pubertal ages of children with chronic myeloid leukemia.

OBJECTIVE: To determine the extent of growth impairment resulting from imatinib treatment in children with chronic myeloid leukemia (CML). STUDY DESIGN: Clinical records of 48 chronic-phase CML children administered imatinib as the first-line therapy between 2001 and 2006 were analyzed retrospectively. Cumulative change in height was assessed using the height height-SDS and converted height data from age- and sex-adjusted Japanese norms. RESULTS: A decrease in height-SDS was observed in 72.9% of children, with a median maximum reduction in height-SDS of 0.61 during imatinib treatment. Median follow-up time was 34 months (range, 10-88 months). Growth impairment was seen predominantly in children who started imatinib at a prepubertal age compared with those who started at pubertal age. Growth velocity tended to recuperate in prepubertal children with growth impairment, as they reached pubertal age, suggesting that imatinib had little impact on growth during puberty. CONCLUSIONS: Growth impairment was a major adverse effect of long-term imatinib treatment in children with CML. We report the distinct inhibitory effect of imatinib on growth in prepubertal and pubertal children with CML. We should be aware of growth deceleration in children, especially in young children given imatinib before puberty and subjected to prolonged exposure.

Outcome of 125 children with chronic myelogenous leukemia who received transplants from unrelated donors: the Japan Marrow Donor Program.

Because of a small number of patients, only a few studies have addressed the outcome of bone marrow transplantation (BMT) in children with Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML), who receive graft from a volunteer-unrelated donor (VUD), especially after practical application of imatinib mesylate. The outcomes of BMT from a VUD in 125 children with Ph+ CML were retrospectively reviewed. Patients were identified through the Japan Marrow Donor Program as having undergone BMT between 1993 and 2005 and were aged 1-19 years at the time of transplant (median age, 14 years). The probabilities of 5-year overall survival (OS) and leukemia-free survival (LFS) were 59.3% and 55.5%, respectively. Multivariate analysis identified the following unfavorable survival factors: infused total nucleated cell dose<314 x 10(6) /kg (relative risk [RR]=2.43; 95% confidence interval [CI]=1.33-4.44; P=.004), advanced phase (RR=2.43; 95% CI=1.37-4.31; P=.004), and no major cytogenetic response (MCyR) at the time of BMT (RR=6.55; 95% CI=1.98-21.6; P=.002). Of the 17 patients treated with imatinib, 15 (88%) achieved MCyR at the time of BMT, and this group had an excellent 5-year OS of 81.9%. Disease phase, infused total nucleated cell dose, and cytogenetic response were independent risk factors for survival of unrelated BMT. These findings provide important information for assessing the indications for and improving outcome in unrelated BMT for the treatment of pediatric CML.

Outcome of childhood acute lymphoblastic leukemia with induction failure treated by the Japan Association of Childhood Leukemia study (JACLS) ALL F-protocol.

BACKGROUND: Children with acute lymphoblastic leukemia (ALL) who fail to achieve complete remission (CR) after induction therapy (induction failure: IF) have a poor prognosis; however, there have been few prospective studies in patients with IF. PATIENTS AND METHODS: Between April 1997 and March 2005, 27 of 1,237 leukemic patients (2.2%) failed to achieve CR after four- or five-drug induction therapy. Twenty-three of these patients entered the F-protocol study, which mainly consisted of acute-myeloid-leukemia-oriented chemotherapy followed by scheduled hematopoietic cell transplantation (HCT). RESULTS: Seventeen (73.9%) of the 23 patients responded to re-induction chemotherapy with CR. Of note, 15 (93.8%) of 16 patients with Philadelphia-chromosome-negative (non-Ph(+)) ALL achieved CR; in contrast, only 2 (28.6%) of 7 Ph(+) patients achieved CR. Fourteen (82.4%) of 17 patients remained in CR (CCR) until their scheduled HCT, 12 of the 14 with CCR underwent HCT as scheduled, and 6 patients remain in first CR after a median of 78 months (range, 49-107 months). The 5-year overall survival (OS) rates of 16 patients with non-Ph(+) and 7 patients with Ph(+) were 43.8 +/- 12.4% and 14.3 +/- 13.2%, respectively (P = 0.012). The 5-year OS rate of the 17 patients who obtained CR by re-induction therapy and the 6 who did not were 47.1 +/- 12.1% and 0%, respectively (P < 0.001). CONCLUSION: Acute-myeloid-leukemia-oriented chemotherapy followed by scheduled HCT is a promising treatment strategy for non-Ph(+) ALL patients with IF.