Validation of a predictive model for identifying an increased risk for thromboembolism in children with acute lymphoblastic leukemia: results of a multicenter cohort study.

Among risk factors for developing thromboembolism (VTE) in children with acute lymphoblastic leukemia were Escherichia coli asparaginase, concomitant steroid use, presence of central venous lines, and thrombophilic abnormalities. Developing a predictive model for determining children at increased risk would be beneficial in targeting interventional studies to high-risk groups (HRGs). Predictive variables were incorporated into a risk assessment model, which was evaluated in 456 children and then validated in 339 patients. VTE risk by score was no greater than 2.5 for low-risk group (LRG) and greater than 2.5 for HRG. VTE rates at 3.5 months (validation cohorts) were 2.5% in LRG and 64.7% in HRG. In multivariate analysis adjusted for age, duration of asparaginase administration, enoxaparin prophylaxis, and T-immunophenotype, the HRG was significantly associated with VTE compared with the LRG (hazard/95% confidence interval [CI], 8.22/1.85-36.53). Model specificity was 96.2% and sensitivity was 63.2%. As secondary objective we investigated the use of enoxaparin for VTE prophylaxis in the HRG. HRG patients without enoxaparin prophylaxis showed a significantly reduced thrombosis-free survival compared with children on low-molecular-weight heparin (LMWH). On the basis of the high specificity, the model may identify children with leukemia at risk of VTE. LMWH may help prevent VTE in the HRG; this warrants assessment in larger cooperative clinical trials.

Isolated congenital asplenia: a French nationwide retrospective survey of 20 cases.

OBJECTIVE: To better describe the natural history, mode of inheritance, and the epidemiological and clinical features of isolated congenital asplenia, a rare and poorly understood primary immunodeficiency. STUDY DESIGN: A French national retrospective survey was conducted in hospital pediatric departments. A definitive diagnosis of ICA was based on the presence of Howell-Jolly bodies, a lack of detectable spleen, and no detectable cardiovascular malformation. RESULTS: The study included 20 patients (12 males and 8 females) from 10 kindreds neither related to each other nor consanguineous. The diagnosis of ICA was certain in 13 cases (65%) and probable in 7 cases (35%). Ten index cases led to diagnosis of 10 additional cases in relatives. Five cases were sporadic and 15 were familial, suggesting autosomal dominant inheritance. Median age was 12 months at first infection (range, 2-516 months), 11 months at diagnosis of asplenia (range, 0-510 months), and 9.9 years at last follow-up (range, 0.7-52 years). Fifteen patients sustained 18 episodes of invasive bacterial infection, caused mainly by Streptococcus pneumoniae (61%). Outcomes were poor, with 9 patients (45%) dying from fulminant infection. CONCLUSIONS: ICA is more common than was previously thought, with an autosomal dominant inheritance in at least some kindreds. Relatives of cases of ICA should be evaluated for ICA, as should children and young adults with invasive infection.

Familial history of cancer and childhood acute leukemia: a French population-based case-control study.

A case-control study was conducted to investigate the role of a familial history of cancer in the etiology of childhood acute leukemia. The history of cancer in the relatives of 472 cases was compared with that of 567 population-based controls. Recruitment was frequency matched on age, sex and region. The familial history of cancer in each child's relatives was reported by the mother in response to a standardized self-administered questionnaire. A familial history of solid tumor in first or second-degree relatives was associated with an increased risk of acute lymphoblastic leukemia (odds ratio (OR)=1.6 [95% confidence interval, 1.2-2.1]), while a familial history of hematopoietic malignancies in first or second-degree relatives was associated with an increased risk of acute myeloid leukemia (OR=4.3 [1.4-13]). The ORs for the histories of cancer increased with the number of relatives with cancer (OR=1.5 [1.1-2.0] for one relative and OR=2.3 [1.3-3.8] for two relatives or more; Ptrend<0.0001). Significant associations between childhood acute leukemia and familial history of genital cancers and brain tumor were also observed (OR=2.7 [1.2-5.8] and OR=10.7 [1.3-86], respectively). This study supports the hypothesis that a familial history of cancer may play a role in the etiology of childhood acute leukemia. It also evidences some specific associations that require further investigation.

Outcome in children with relapsed acute myeloid leukemia after initial treatment with the French Leucemie Aique Myeloide Enfant (LAME) 89/91 protocol of the French Society of Pediatric Hematology and Immunology.

PURPOSE: After present first-line therapies for childhood acute myeloid leukemia (AML), nearly 40% of patients still relapse. The goals of this retrospective study were to determine whether these children could be treated successfully with a salvage regimen and to establish the optimal therapeutic strategy. PATIENTS AND METHODS: In the multicentric, prospective, Leucémie Aiquë Myéloïde Enfant 89/91 protocol, 106 of the 308 children enrolled between 1988 and 1998 relapsed. Initial treatment after the first complete remission (CR1) had been allogenic HLA-identical bone marrow transplantation (BMT; n = 21) or chemotherapy (n = 85). Treatment procedures were scheduled according to the choice of each participating institution. RESULTS: When reinduction therapy was attempted, second complete remission (CR2) was obtained in 71% of patients (68 of 96 patients). BMT was performed in 53 (78%) of these 68 patients (autograft, mainly harvested in CR1, n = 25; matched sibling-donor BMT, n = 12; or alternative-donor BMT, n = 16). The 5-year overall survival (OS) rate for all 106 patients was 33%, and the disease-free survival (DFS) rate for children in CR2 was 45%. Multivariate analysis of re-treated children showed that the 5-year OS was higher if the CR1 had been longer than 12 months compared with less than 12 months (54% v 24%, respectively; P =.001) and lower if maintenance therapy had been given after CR1 compared with chemotherapy without maintenance therapy or HLA-identical BMT (12% v 40% v 52%, respectively; P =.002). For patients attaining CR2, the 5-year DFS rate was not significantly different for matched sibling-donor BMT (60%), autograft (47%), or alternative-donor BMT (44%). CONCLUSION: After aggressive first-line therapy, one third of unselected, relapsing AML children could be cured. Further prospective trials are warranted to define the optimal reinduction regimen and megadose chemotherapy and to evaluate the late effects of these therapies.

ZAP-70 tyrosine kinase is constitutively expressed and phosphorylated in B-lineage acute lymphoblastic leukemia cells.

BACKGROUND AND OBJECTIVES: Zeta-associated protein 70 (ZAP-70), a member of the Syk family of protein tyrosine kinases, is normally expressed in T and NK cells. While little is known about ZAP-70 expression in normal human B cells, it has been reported that ZAP-70 is expressed in a subset of patients with chronic lymphocytic leukemia (CLL) with a poor prognosis. In this study, we examined the expression and phosphorylation status of ZAP-70 in B-lineage acute lymphoblastic leukemia (Blin-ALL). DESIGN AND METHODS: First, ZAP-70 protein expression was assessed by Western blotting and flow cytometry and ZAP-70 mRNA transcripts were analyzed by reverse transcription polymerase chain reaction (RT-PCR) on human precursor B cell lines. Experiments were then carried out on cells obtained from 18 patients with Blin-ALL and from normal human bone marrow. RESULTS: ZAP-70 was constitutively expressed and phosphorylated on tyr319 in human precursor Blin-ALL cell lines as well as in primary B leukemic cells from all examined Blin-ALL patients with pro-B, pre-B and B phenotypes, but not in malignant myeloid cells. Importantly, analysis of normal human bone marrow revealed expression of ZAP-70 transcripts only in the CD34+ cell fraction (either CD19-CD10- or CD19+CD10+) but not in the CD34- cell fraction (CD19+sIgM- pre-B cells or CD19+sIgM+ immature B cells). INTERPRETATION AND CONCLUSIONS: ZAP-70 was found to be expressed in the CD34+ normal bone marrow compartment including earlier B-cell progenitors, but not in CD34- pre-B and immature B cells. By contrast, ZAP-70 was consistently expressed and phosphorylated in Blin-ALL cells. Further studies are required to determine whether ZAP-70 may play a pathophysiological role in Blin-ALL.

Cerebral MR imaging in uninfected children born to HIV-seropositive mothers and perinatally exposed to zidovudine.

BACKGROUND AND PURPOSE: Mitochondrial dysfunction has been reported in HIV-negative children perinatally exposed to zidovudine, a drug often used in HIV-seropositive mothers during pregnancy. The purpose of this study was to determine the incidence of cerebral MR imaging findings in HIV-uninfected children exposed to zidovudine who present with unexplained neurologic symptoms. METHODS: Two expert groups conducted a systematic, retrospective review of all cerebral MR images available in a multicentric, nationwide French prospective cohort of children born to HIV-seropositive mothers to identify imaging abnormalities. Experts were blinded to each others' interpretations, to the children's neurologic symptoms, and to laboratory evidence of mitochondrial dysfunction. The incidence of abnormalities was determined and compared with the neurologic presentation and laboratory evidence of mitochondrial dysfunction. RESULTS: MR images from 49 HIV-uninfected children (mean age, 26 months) were available for study. All children were perinatally exposed to zidovudine. Twenty-two had probable or established mitochondrial dysfunction according to their symptoms and laboratory data. Twenty-seven children without mitochondrial dysfunction presented with unexplained neurologic symptoms (n = 14) or nonneurologic symptoms (n = 7), and six were asymptomatic. Sixteen of 22 MR images in children with mitochondriopathy were considered abnormal in both independent analyses. Diffuse hyperintensity in the supratentorial white matter (n = 9) and in the tegmentum pons (n = 9) were the most frequent anomalies. Imaging abnormalities were often multifocal (n = 10) and sometimes associated with necrotic areas (n = 3) and volume loss (n = 8). Although 19 of 27 MR images of children without mitochondrial dysfunction were mainly normal, abnormal images were observed in five of 14 children with unexplained neurologic symptoms and in three of six asymptomatic children. CONCLUSION: Images observed in children with antiretroviral-induced mitochondrial dysfunction are similar to those observed in congenital mitochondrial diseases. These images were also observed in symptomatic or asymptomatic children without evidence of systemic mitochondrial dysfunction.

French "real life" experience of clofarabine in children with refractory or relapsed acute lymphoblastic leukaemia.

BACKGROUND: Clofarabine alone or in combination with cyclophosphamide and etoposide has shown a good efficacy and a tolerable toxicity profile in previous studies of children with relapsed or refractory leukaemia. This report describes a retrospective study of 38 French patients who received clofarabine as a monotherapy or in combination for relapsed or refractory acute lymphoblastic leukaemia (ALL) outside of clinical trials after marketing authorization. METHODS: We retrospectively analysed data for 38 patients, up to 21 years old, attending 17 French centres. Thirty patients received clofarabine alone or in combination for a bone marrow relapse of acute lymphoblastic leukaemia (ALL) or refractory disease and eight patients for a high level of minimal residual disease (MRD). Survival and response durations were estimated by the Kaplan-Meier method. RESULTS: For the 30 patients who received clofarabine for a bone marrow relapse of ALL (number of relapse, 1-3; median, 1), the overall remission rate (ORR) was 37%: eight complete remission (CR) and three complete remission without platelet recovery (CRp). Ten of the 11 responding patients subsequently underwent haematopoietic stem cell transplantation (HSCT).Only four of the eight patients who received clofarabine while in remission for a high level of MRD, showed a moderate improvement of MRD. Seven of these eight patients received HSCT and six of them were alive at the end of the study. One other patient was alive without receiving HSCT.However, clofarabine treatment was associated with a high risk of infection and hepatotoxicity. Febrile neutropenia grade ≥ 3 was reported in 79% of patients and documented infections grade ≥ 3 occurred in nine patients (24%). Hepatotoxicity grade 3 was reported in nine patients (24%). We observed four deaths related to treatment. CONCLUSION: In our experience, the efficacy of clofarabine is poorer than previously reported. Its toxicity is high and can be life threatening. Prospective studies on clofarabine used during earlier phases of the disease may help to define how best this new drug can be exploited for childhood and adolescent ALL.

Prognostic factors for leukemic induction failure in children with acute lymphoblastic leukemia and outcome after salvage therapy: the FRALLE 93 study.

PURPOSE: To identify prognostic factors and to evaluate the outcome of children with acute lymphoblastic leukemia (ALL) failure after induction therapy. PATIENTS AND METHODS: Between June 1993 and December 1999, 1,395 leukemic children were included in the French Acute Lymphoblastic Leukemia 93 study. RESULTS: Fifty-three patients (3.8%) had a leukemic induction failure (LIF) after three- or four-drug induction therapy. In univariate analysis, high WBC count (P = .001), mediastinal mass (P = .017), T-cell phenotype (T-ALL; P = .001), t(9;22) translocation (P = .001), and a slow early response (at day 8 and/or on day 21, P = .001) were predictive of LIF. The following three prognostic groups for LIF were identified by multivariate analysis: a low-risk group with B-cell progenitor (BCP) ALL without t(9;22) (odds ratio [OR] = 1), an intermediate-risk group with T-ALL and a mediastinal mass (OR = 7.4, P < .0001), and a high-risk group with BCP-ALL and t(9;22) or T-ALL without a mediastinal mass (OR = 28.4, P < .0001). Complete remission (CR) was subsequently obtained in 43 patients (81%). The 5-year overall survival (OS) rate of the 53 patients was 30% +/- 6%. The 5-year OS rate among allogeneic graft recipients, autologous graft recipients, and after chemotherapy were 30.4% +/- 9.6% (50% +/- 26% after genoidentical transplantation), 50% +/- 17.7%, and 41.7% +/- 14.2%, respectively (P = .18). Fourteen patients (26%) were still in first CR after a median of 83 months (range, 53 to 117 months). CONCLUSION: Three risk categories for LIF in children with ALL were identified. Approximately one third of patients with LIF can be successfully treated with salvage therapy overall. Subsequent CR after LIF is mandatory for cure.

Multicenter randomized trial of chewing gum for preventing oral mucositis in children receiving chemotherapy.

The properties of saliva led us to hypothesize that the salivary flow increase induced by gum chewing might protect the oral mucosa from lesions due to cancer chemotherapy. We conducted a multicenter randomized trial to evaluate the efficacy of chewing gum in preventing oral mucositis in 145 children receiving chemotherapy regimens expected to induce WHO grade 3-4 oral mucositis in at least 30% of patients. Patients were allocated at random to standard oral care with or without 5 gum pieces per day. No overall reduction in severe oral mucositis occurred in the gum arm (51%) compared with the standard arm (44%). VIDE, COPADM, and multidrug intensive chemotherapy caused severe oral mucositis in 75% of patients in both arms. In patients receiving less toxic regimens, a decrease in WHO grade 1-4 oral mucositis was noted in the gum arm compared with the standard arm (49% vs. 72%, P=0.03). In the multivariate analysis, the risk of oral mucositis was related only to the type of chemotherapy regimen, suggesting that further strategies for preventing oral mucositis could be mainly based on these criteria.

Economic evaluation of recombinant human granulocyte colony-stimulating factor in very high-risk childhood acute lymphoblastic leukemia.

PURPOSE: In a previous randomized study, the authors reported that granulocyte colony-stimulating factor (G-CSF) increased the chemotherapy dose-intensity delivered during the consolidation therapy of high-risk childhood acute lymphoblastic leukemia (ALL). The aim of the current study was to perform an economic evaluation in the same cohort. METHODS: In this open-label multicenter randomized trial, prophylactic G-CSF was administered after consolidation therapy courses. Economic data were retrospectively quantified for each patient: hospital stays, drugs, and blood products. RESULTS: Sixty-seven children were enrolled in the very high-risk branch of the FRALLE 93 protocol. Chemotherapy dose-intensity was significantly increased (105 +/- 5% in the G-CSF group vs. 91 +/- 4% in the non-G-CSF group, P < 0.001). The mean total costs per child were not statistically different: 32,309 dollars in the G-CSF group versus 31,569 dollars in the non-G-CSF group. Further analysis per child and per course (R3 or COPADM) demonstrated that the mean cost of hospitalization and the mean cost of intravenous antibiotics were significantly decreased in the G-CSF group after R3 courses (3,857 dollars vs. 4,993.80 dollars, P < 0.001; 171.40 dollars vs. 306.20 dollars, P = 0.029, respectively), but the cost of platelet transfusion was significantly increased (P = 0.03). Conversely, post-COPADM costs were similar. Finally, mean costs per course in the two randomized groups were not significantly different: 5,848.80 dollars versus 6,181 dollars and 7,388.10 dollars versus 6,475.70 dollars for R3 and COPADM, respectively. The 3-year probability of event-free survival between the two groups was not different. CONCLUSIONS: G-CSF can increase chemotherapy dose-intensity in very high-risk ALL without raising costs, but event-free survival was not improved. The cost benefit of prophylactic treatment by G-CSF relies on the chemotherapeutic regimen given prior to G-CSF administration.