Pharmacogenetics of outcome in children with acute lymphoblastic leukemia

Acquired genetic characteristics of acute lymphoblastic leukemia (ALL) cells are used to individualize therapy, whereas germ line genetic characteristics generally are not. We determined whether ALL outcome was related to 16 genetic polymorphisms affecting the pharmacodynamics of antileukemic agents. Of 246 children, 116 were treated on the lower-risk (LR) and 130 on the higher-risk (HR) arms of a St Jude protocol. Patients in the HR group with the glutathione S-transferase (GSTM1) non-null genotype had greater risk of hematologic relapse (P = .03), which was further increased by the thymidylate synthetase (TYMS) 3/3 genotype (P = .03). These genotypes remained predictive in multivariate analyses (P < .001 and .003, respectively). No genotypes were predictive in the LR arm. Expression of these 2 genes in ALL blasts was lower in those with low-activity genotypes. For central nervous system relapse, among the HR group, the vitamin D receptor start site (P = .02) and intron 8 genotypes (P = .04) predisposed, whereas for LR patients the TYMS 3/3 genotype predisposed (P = .04). The GSTM1 non-null and TYMS 3/3 genotypes are plausibly linked to drug resistance. Polymorphisms interact to influence antileukemic outcome and represent determinants of response that can be used to optimize therapy.     

Vincristine pharmacokinetics is related to clinical outcome in children with standard risk acute lymphoblastic leukemia

Vincristine is a key drug in the treatment of childhood and adult acute lymphoblastic leukemia (ALL), and many other childhood malignancies. Despite decades of wide clinical use, no data on the correlation between vincristine pharmacokinetics and long-term clinical outcome have been published. We here report clinical data (median follow-up time 10·5 years, range 7·3–12 years) for 86 children with B-cell precursor ALL, in whom vincristine kinetics were studied on treatment day 1. The median total plasma clearance was 429 and 331 ml/min per m² and the area under the plasma concentration-time curve (AUC) was 4·49 and 5·40 mg/l × min in relapse and non-relapse patients, respectively (not significant). In standard risk patients, where treatment depends more heavily on vincristine than in other subgroups, the relative risk (RR) of relapse was significantly increased for patients with clearance values above median (RR 5·2; P  = 0·036), or AUC values below median (RR 5·8; P  = 0·025). Our data suggest a relationship between the antileukemic effect and the systemic exposure of the drug, which warrants further studies.     

An accurate and rapid flow cytometric diagnosis of BCR-ABL positive acute lymphoblastic leukemia

Tyrosine kinase inhibitors have profoundly modified the treatment and prognosis of chronic myeloid leukemia and Ph⁺ acute lymphoblastic leukemia. A rapid and accurate detection of the BCR-ABL fusion protein is paramount today for an optimal management of Ph⁺ acute lymphoblastic leukemia. We have utilized a recently described and commercialized immunoassay that identifies qualitatively the presence of the BCR-ABL protein in leukemic cell lysates. The BCR-ABL fusion protein is captured and detected by a cytometric bead assay and analyzed by flow cytometry. The assay was applied to 101 primary patient samples (94 acute leukemias and 7 chronic myeloid leukemia blast crisis) and the results of the immunoassay were concordant with those obtained by conventional molecular techniques. The method proved reliable, reproducible, of simple execution and it was successfully completed within four hours. This flow cytometric immunoassay has important implications for perfecting the management of Ph⁺ acute lymphoblastic leukemia patients worldwide.     

Adjuvant tyrosine kinase inhibitor therapy improves outcome for children and adolescents with acute lymphoblastic leukaemia who have an ABL-class fusion

Patients with an ABL-class fusion have a high risk of relapse on standard chemotherapy but are sensitive to tyrosine kinase inhibitors (TKI). In UKALL2011, we screened patients with post-induction MRD ≥1% and positive patients (12%) received adjuvant TKI. As the intervention started during UKALL2011, not all eligible patients were screened prospectively. Retrospective screening of eligible patients allowed the outcome of equivalent ABL-class patients who did and did not receive a TKI in first remission to be compared. ABL-class patients who received a TKI in first remission had a reduced risk of relapse/refractory disease: 0% vs. 63% at four years (P = 0·009).     

Treatment outcome of adolescents with acute lymphoblastic leukemia

Despite intensified chemotherapy, adolescents with acute lymphoblastic leukemia (ALL) still have lower rates of survival than younger children. The purpose of our study was to compare the treatment outcome and presenting clinical and laboratory features of adolescent and younger children with newly diagnosed ALL who were treated at our pediatric hematology department. Between April 1991 and February 2000, 42 children up to 18 years of age who were newly diagnosed with ALL and treated adequately with modified ALL Berlin-Frankfurt-Münster (BFM) 90 or 95 protocols were included in this study. The patients were examined in two groups according to their ages: the first group consisted of children who were <14 years old and the second group consisted of adolescents who were >14 years old. The median age of 42 patients was 6.5 years (range: 1-16.5 years); 26% of the patients were adolescents. The results of this study demonstrated that after a median observation time of 6 years the overall survival (OS) and event-free survival (EFS) of patients who were <14 and >14 years of age were 75% vs 49% and 70% vs 40%, respectively. When adolescent and younger patients were compared to each other according to gender, WBC count at administration, French-American-British (FAB) classification, immunophenotypes, risk groups, early deaths, and relapse rates, there were no statistically significant differences. Comparative data from other studies and data from this study indicate that adolescents with ALL still have shorter OS and EFS than younger children and a steady improvement in treatment outcome for adolescents with ALL over time suggests that more intensive therapy favorably influences prognosis.     

Transplantation for children with acute lymphoblastic leukemia

EFS for children with ALL continues to increase and is predicted to reach 90% with current therapy. Better understanding of leukemia cell biology and pharmacogenetics has led to the design of more effective treatment and also refined the prognostic features associated with a poor outcome. ALL characterized by the translocation t(9;22) or t(4;11), or by a hypodiploid karyotype or by an incomplete response to induction therapy is likely to relapse. SCT for ALL is largely used to treat patients failing primary chemotherapy but is selectively included as part of initial therapy for children at high risk for relapse. If SCT is going to become the primary therapy for children with ALL in first remission, the regimen-related mortality must approach 0%, and the risk for severe acute and chronic GVHD should be less than 5%. Salvage therapy after ALL relapse remains the major indication for SCT. The time required to find a suitable match has led to the use of cord blood and haploidentical related donors as stem cell sources. For children who relapse, SCT is likely to remain the principal option to promote survival. Efforts to reduce both the risk of relapse and the transplant regimen toxicity, both immediate and delayed, must continue.     

Time to platelet recovery predicts outcome of patients with de novo acute lymphoblastic leukaemia who have achieved a complete remission

Survival in acute leukaemia depends on the achievement of complete remission (CR). However, CR is not a clear-cut phenomenon and certain variables of its definition could more accurately characterize the quality of the remission. Because platelet recovery > 100 x 10(9)/l is an essential component of CR in acute leukaemia, we hypothesized that time to platelet recovery (TPR) might be predictive of overall survival (OS) or disease-free survival (DFS) in acute lymphoblastic leukaemia (ALL). We analysed TPR in 249 patients with ALL who entered CR after one course of induction chemotherapy and correlated TPR with DFS and OS. TPR was significantly associated with both DFS and OS if it occurred within a maximum of about 60 d from start of therapy. Furthermore, during that time period, the relative risk of death increased with increasing TPR. Although presence of the Philadelphia chromosome was the single most important adverse feature at diagnosis, the effect of TPR on survival continued to be significant within this patient subgroup. This effect was so pronounced that Philadelphia chromosome-positive patients with a TPR of 12 d had a better outcome than Philadelphia chromosome-negative patients with a TPR of 48 d. Thus, a short TPR seems to be able to override adverse characteristics in the outcome of ALL patients treated with chemotherapy. We conclude that a quicker TPR predicts longer DFS and OS in patients with ALL. As platelet counts are obtained almost daily in patients undergoing chemotherapy, TPR can readily be utilized to assess the prognosis of these patients.     

Minimal residual disease in peripheral blood at day 15 identifies a subgroup of childhood B-cell precursor acute lymphoblastic leukemia with superior prognosis

Background

Most minimal residual disease-directed treatment interventions in current treatment protocols for acute lymphoblastic leukemia are based on bone marrow testing, which is a consequence of previous studies showing the superiority of bone marrow over peripheral blood as an investigational material. Those studies typically did not explore the prognostic impact of peripheral blood involvement and lacked samples from very early time points of induction.

Design and Methods

In this study, we employed real-time quantitative polymerase chain reaction analysis to examine minimal residual disease in 398 pairs of blood and bone marrow follow-up samples taken from 95 children with B-cell precursor acute lymphoblastic leukemia treated with the ALL IC-BFM 2002 protocol.

Results

We confirmed the previously published poor correlation between minimal residual disease in blood and marrow at early treatment time points, with levels in bone marrow being higher than in blood in most samples (median 7.9-fold, range 0.04–8,293-fold). A greater involvement of peripheral blood at diagnosis was associated with a higher white blood cell count at diagnosis (P=0.003) and with enlargement of the spleen (P=0.0004) and liver (P=0.05). At day 15, a level of minimal residual disease in blood lower than 10⁻⁴ was associated with an excellent 5-year relapse-free survival in 78 investigated patients (100% versus 69±7%; P=0.0003). Subgroups defined by the level of minimal residual disease in blood at day 15 (high-risk: ≥10⁻², intermediate-risk: <10⁻² and ≥10⁻⁴, standard-risk: <10⁻⁴) partially correlated with bone marrow-based stratification described previously, but the risk groups did not match completely. No other time point analyses were predictive of outcome in peripheral blood, except for a weak association at day 8.

Conclusions

Minimal residual disease in peripheral blood at day 15 identified a large group of patients with an excellent prognosis and added prognostic information to the risk stratification based on minimal residual disease at day 33 and week 12.     

Prognostic significance and modalities of flow cytometric minimal residual disease detection in childhood acute lymphoblastic leukemia

Detection of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL) predicts outcome. Previous studies were invariably based on relative quantification and did not investigate sample-inherent parameters that influence test accuracy, which makes comparisons and clinical conclusions cumbersome. Hence, we conducted a prospective, population-based MRD study in 108 sequentially recruited children with ALL uniformly treated with the ALL-Berlin-Frankfurt-Münster (ALL-BFM) 95 protocol in Austria (median follow-up of 40 months). Using sensitive, limited antibody panel flow cytometry applicable to 97% of patients, we investigated 329 bone marrow samples from 4 treatment time points. MRD was quantified by blast percentages among nucleated cells (NCs) and by absolute counts (per microliter). Covariables such as NC count, normal B cells, and an estimate of the test sensitivity were also recorded. Presence and distinct levels of MRD correlated with a high probability of early relapse at each of the time points studied. Sequential monitoring at day 33 and week 12 was most useful for predicting outcome independently from clinical risk groups: patients with persistent disease (> or =1 blast/microL) had a 100% probability of relapse, compared to 6% in all others. Absolute MRD quantification was more appropriate than relative, due to considerable variations in total NC counts between samples. Regeneration of normal immature B cells after periods of rest from treatment limited the test sensitivity. In conclusion, MRD detection by flow cytometry is a strong and independent outcome indicator in childhood ALL. Standardization regarding absolute quantification on the basis of NCs and assessment during periods of continuous treatment promise to increase the accuracy, simplicity, and cost efficiency of the approach.     

Oral health status in children with acute lymphoblastic leukemia

Leukemia is a malignancy of the bone marrow. Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy and accounts for nearly 75% of all newly diagnosed leukemias and 25% of all malignancies in childhood. The aim of the present study was to review the oral health status in children with ALL. Databases were explored using various combinations of the following keywords: "acute lymphoblastic leukemia", "children", "inflammation", "pediatric", "periodontal disease" and "periodontitis". Oral inflammatory conditions including chelitis, gingivitis, herpetic gingivostomatitis, mucositis, oral candidiasis, periodontitis and ulcerations are common manifestations in children with ALL. RESULTS: Periodontal inflammatory conditions and oral mucositis were reported to be significantly higher in children with ALL as compared to healthy controls. Tooth morphological disorders including agenesis, microdontia, short roots and developmental defects in the enamel and dentin were more often observed in children with ALL as compared to healthy controls. Children with ALL have a reduced salivary flow rate, which makes them more susceptible to dental caries as compared to healthy children. Malocclusion due to microdontia may also trigger temporomandibular joint disorders in children with ALL; however, this relationship needs further investigations. CONCLUSION: Oral inflammatory conditions including mucositis and gingivitis are common in children with ALL as compared to healthy children. Tooth morphological disorders including microdontia and enamel and dentin are common manifestations in children with ALL.     

Cytogenetic study of 105 children with acute lymphoblastic leukemia

Cytogenetic analysis was performed on 105 children with acute lymphoblastic leukemia (ALL). Adequate mitoses for study were obtained in 79 of the cases (71%). A normal karyotype was found in 18 patients (23%), while clonal chromosomal abnormalities were detected in 61 patients (77%). The karyotypes fell into five categories according to modal number: normal (18 patients), pseudodiploid (27 patients), hypodiploid (3 patients), hyperdiploid with 47-50 chromosomes (11 patients), and hyperdiploid with greater than or equal to 51 chromosomes (20 patients). Structural chromosome changes were found in 50 patients (63%); translocations were encountered in 15 of these patients (19%). The chromosome most often participating in translocations was number 19. Modal number was found to be an independent prognostic factor. Modal numbers 47-50 were associated with the poorest prognosis. The hyperdiploid clone with more than 50 chromosomes and the normal karyotype had the best prognosis.     

Suppressed neutrophil function in children with acute lymphoblastic leukemia

Infection is a major obstacle in cancer chemotherapy. Neutropenia has been considered to be the most important risk factor for severe infection; however, other factors, such as impaired neutrophil function, may be involved in susceptibility to infection in patients undergoing chemotherapy. In this study, we analyzed neutrophil function in children with acute lymphoblastic leukemia (ALL). Whole blood samples were obtained from 16 children with ALL at diagnosis, after induction chemotherapy, and after consolidation chemotherapy. Oxidative burst and phagocytic activity of neutrophils were analyzed by flow cytometry. Oxidative burst of neutrophils was impaired in ALL patients. The percentage of neutrophils with normal oxidative burst after PMA stimulation was 59.0 ± 13.2 or 70.0 ± 21.0% at diagnosis or after induction chemotherapy, respectively, which was significantly lower compared with 93.8 ± 6.1% in healthy control subjects (P = 0.00004, or 0.002, respectively); however, this value was normal after consolidation chemotherapy. No significant differences were noted in phagocytic activity in children with ALL compared with healthy control subjects. Impaired oxidative burst of neutrophils may be one risk factor for infections in children with ALL, especially in the initial periods of treatment.     

Assessment of megakaryopoiesis in children with acute lymphoblastic leukemia

The effect of the underlying disease and chemotherapy on megakaryopoiesis has not been extensively studied in children with acute lymphoblastic leukemia (ALL) during and at the end of therapy. Using a serum-free assay, we assessed the megakaryocyte (Mk) colony formation in vitro from bone marrow mononuclear cells of 25 children with ALL during chemotherapy and shortly after the cessation of it. Twelve children with solid tumors without bone marrow involvement and cord blood from 10 full-term normal vaginal deliveries were used as controls. A significant reduction in the number of Mk colonies was observed at diagnosis of ALL, and Mk colony formation remained lower than controls throughout the different phases of leukemia treatment. Our study suggests that defects in megakaryopoiesis of children with ALL in long-term remission may persist during chemotherapy and at least shortly after the end of it.     

Characteristics of children with acute lymphoblastic leukemia presenting with arthropathy

Clinical Rheumatology - Acute lymphoblastic leukemia (ALL) is the most common childhood neoplasia and may present with arthralgia and arthritis, with the risk of misdiagnosis and diagnostic delay....     

Factors associated with outcome after unrelated marrow transplantation for treatment of acute lymphoblastic leukemia in children

Acute lymphoblastic leukemia (ALL) is the most common indication for transplantation of marrow from unrelated donors in children. We analyzed results of this procedure in children with ALL treated according to a standard protocol to determine risk factors for outcome. From January 1987 to 1999, 88 consecutively seen patients with ALL who were younger than 18 years received a marrow transplant from an HLA-matched (n = 56) or partly matched (n = 32) unrelated donor during first complete remission (CR1; n = 10), second remission (CR2; n = 34), third remission (CR3; n = 10), or relapse (n = 34). Patients received cyclophosphamide and fractionated total-body irradiation as conditioning treatment and were given methotrexate and cyclosporine for graft-versus-host disease (GVHD) prophylaxis. Three-year rates of leukemia-free survival (LFS) according to phase of disease were 70% for CR1, 46% for CR2, 20% for CR3, and 9% for relapse (P <.0001). Three-year cumulative relapse rates were 10%, 33%, 20%, and 50%, respectively, and 3-year cumulative rates of death not due to relapse were 20%, 22%, 60%, and 41%, respectively, for patients with CR1, CR2, CR3, and relapse. Grades III to IV acute GVHD occurred in 43% of patients given HLA-matched transplants and in 59% given partly matched transplants (P =.10); clinical extensive chronic GVHD occurred in 32% and 38%, respectively (P =.23). LFS rates were lower in patients with advanced disease (P <.0001), age 10 years or older (P =.002), or short duration of CR1 (P =.007). Thus, in addition to phase of disease, age and duration of CR1 were predictors of outcome after unrelated-donor transplantation for treatment of ALL in children. Outcome was particularly favorable in younger patients with early phases of the disease.