Effective preventive central nervous system therapy with extended triple intrathecal therapy and the modified ALL-BFM 86 chemotherapy program in an enlarged non-high risk group of children and adolescents with non-B-cell acute lymphoblastic leukemia: the Israel National Study report

Poorer outcome of childhood acute lymphoblastic leukemia in the Bedouin population: A report from the Berlin-Frankfurt-Muenster-based Israeli national protocols

BACKGROUND

Therapy outcomes for childhood acute lymphoblastic leukemia (ALL) had substantially improved in the last decades, but variability across racial and ethnic groups was identified in some clinical studies. In this study, we aimed to investigate whether such a difference in outcome is found in the diverse ethnicities in Israel as well.

METHODS

A retrospective study was conducted among 1154 patients (855 Jews, 195 Muslims, 52 Bedouins, 26 Druze, and 26 others) aged 1 to 21 years, who were diagnosed with ALL between 1989 and 2011 and were treated according to the same Berlin-Frankfurt-Muenster-based Israel National Study protocols.

RESULTS

Bedouins had a higher incidence of t(1;19) (16% vs 3% for non-Bedouins) and a lower incidence of high-hyperdiploidy (10% vs 25% for non-Bedouins) (P = 0.01). Five-year event-free survival (EFS) and overall survival (OS) were poorer for the Bedouins (60.3% ± 7.2% and 63.1% ± 7.2%, respectively) compared with the Jews, Muslims, and Druze (80.4% ± 1.4%, 77.3% ± 3.2%, and 84% ± 7.3%, respectively, for EFS [P = 0.02], and 86.3% ± 1.2%, 82.3% ± 2.9%, and 88.3% ± 6.4%, respectively, for OS [P = 0.002]). Adherence to intensive chemotherapy was similar between the Muslims and the Bedouins.

CONCLUSIONS

Our findings suggest that the Bedouins, a highly inbred ethnic Arab people, may be considered a higher risk group that may need more intensive chemotherapy and/or supportive care in order to improve their outcome.

Acute lymphoblastic leukemia in children: correlation of musculoskeletal manifestations and immunophenotypes

PURPOSE

Studies on musculoskeletal manifestations (MSM) of childhood acute lymphoblastic leukemia (ALL) have yielded variable findings with regard to their clinical impact. We investigated the significance for differential diagnosis, treatment and outcome of musculoskeletal complaints as presenting symptoms of ALL, and their correlation with leukemia immunophenotypes, for which data is lacking.

METHODS

Data on 783 children in the national study for childhood ALL between 1984 and 2003 were reviewed retrospectively. Statistical analysis examined possible relationships between MSM at the time of diagnosis and demographic and clinical data, biological features of leukemia (peripheral blood counts, immunophenotype and main cytogenetic aberration), response to initial prednisone treatment, and outcome.

RESULTS

Of 765 children with data on orthopaedic complaints, 240 presented with MSM (31.4%). Among these children, B cell precursor (BCP) was much more common (209/576, 36.3%) than T cell ALL (25/176, 14.2%). Patients with MSM had lower white blood cell counts (WBC) (median of 9 vs. 20 x 10(9)/L, P < 0.001) and percentage of blast cells in the peripheral blood at diagnosis compared to those without (median of 27 vs. 53%, P < 0.001). Hepatomegaly and splenomegaly were less common in MSM group (67 vs. 53% <3 cm, P < 0.001, and 63 vs. 50% <3 cm, P < 0.001, respectively). Poor response to initial treatment with prednisone was recorded in 7.1% of patients with MSM versus 11.5% of those without (P = 0.086). The analysis revealed no independent effect of MSM on event-free survival (EFS), after correcting for differences in EFS related to immunophenotype or initial WBC.

CONCLUSIONS

MSM occur mostly in children with BCP ALL who present with less involvement of extramedullary organs, low peripheral blood blasts and white blood cells counts. These findings highlight the importance of including ALL in the differential diagnosis of MSM even in the presence of an apparently normal peripheral blood count. Our study also suggests that MSM are caused by leukemic cells with enhanced biological propensity to remain relatively confined within the intramedullary bone-marrow space.

Successful treatment without cranial radiotherapy of children receiving intensified chemotherapy for acute lymphoblastic leukaemia: results of the risk-stratified randomized central nervous system treatment trial MRC UKALL XI (ISRC TN 16757172)

Concern about late adverse effects of cranial radiotherapy (XRT) has led to alternative approaches to eliminate leukaemia from the central nervous system (CNS) in childhood acute lymphoblastic leukaemia (ALL). The Medical Research Council UKALL XI trial recruited 2090 children with ALL between 1990 and 1997. Median follow-up is 7 years 9 months; event-free survival (EFS) and overall survival were 63.1% and 84.6%, respectively, at 5 years and 59.8% and 79.4% at 10 years. The isolated CNS relapse rate was 7.0% at 10 years. Patients were randomized for CNS-directed therapy within white blood cell (WBC) groups. For WBC <50 x 10(9)/l, high-dose intravenous methotrexate (HDMTX) (6-8 g/m2) with intrathecal methotrexate (ITMTX) was compared with ITMTX alone, and was significantly better at preventing isolated and combined CNS relapse, but non-CNS relapses were similar. There was no significant difference in EFS at 10 years, 64.1% [95% confidence interval (CI) 60.4-67.8] with HDMTX plus ITMTX, and 63.0% (95% CI 59.5-66.5) with ITMTX alone. For WBC >/=50 x 10(9)/l, HDMTX with ITMTX was compared with XRT and a short course of ITMTX. CNS relapses were significantly fewer with XRT, but there was a non-significant increase in non-CNS relapses. EFS was not significantly different, being 55.2% (95% CI 47.8-62.6) at 10 years with XRT and 52.1% (95% CI 44.8-59.4) with HDMTX plus ITMTX.

Germ-lineATM gene alterations are associated with susceptibility to sporadic T-cell acute lymphoblastic leukemia in children

A major feature of ataxia-telangiectasia (A-T) is an increased risk of cancer, particularly of lymphoid malignancies. We studied ATM gene involvement in leukemic cells derived from 39 pediatric T-cell acute lymphoblastic leukemias (ALLs). Two types of sequence changes--truncating and missense--were identified in 8 T-cell ALL samples: 3 truncating changes, all previously identified in A-T (R35X, -30del215, 2284delCT), and 3 missense variants (V410A, F582L, F1463C) were found, none associated with loss of heterozygosity (LOH). In all patients studied, the mutation was present in the germ-line. A-T carriers, defined by the finding of truncating mutations, were found to be 12.9 times more frequent than in the normal population (P = 0.004). A normally ethnically matched population was screened for the 3 missense variants, and their frequency was significantly more prevalent (4.9-fold excess) than in the normal population (P = 0.03). Our data suggest there is some evidence of an association between missense alterations in the ATM gene and T-cell ALL. A significant difference in the mean age at diagnosis of T-cell ALL was noted between patients harboring an ATM sequence change and those with no change, 5.4 years and 9.7 years, respectively (P = 0.001). No ATM alterations were identified in relapse samples, indicating that ATM does not play a role in disease progression. The high prevalence of germ-line truncating and missense ATM gene alterations among children with sporadic T-cell ALL suggests an association with susceptibility to T-cell acute leukemia and supports the model of predisposition to cancer in A-T heterozygotes.

Imatinib in the treatment of Philadelphia chromosome-positive acute lymphoblastic leukaemia: current status and evolving concepts

Until recently, progress in the treatment of patients with Ph(+) acute lymphoblastic leukaemia (ALL) has been limited, and long-term survival, even with high-dose intensified chemotherapy, is rare. Allogeneic stem cell transplantation is potentially curative, but treatment-related mortality and rate of disease recurrence are substantial. With the advent of the ABL-selective tyrosine kinase inhibitor STI571 (imatinib mesylate, Glivec), it has become apparent that the understanding of crucial leukaemogenic pathways at the molecular level can lead to the development of specific and selective agents. In recent clinical trials, imatinib has demonstrated significant anti-leukaemic efficacy in patients with advanced Ph(+) ALL, in conjunction with a remarkably favourable safety profile. Clinical resistance to imatinib develops rapidly, highlighting the limitations of using imatinib as a single agent; however, the value of imatinib as an element of treatment has become apparent. Resistance mechanisms have already been identified that will enable the development of rational strategies to prevent or overcome resistance. On the basis of available clinical results, combinations of imatinib with established anti-leukaemic agents, as well as with novel, molecularly targeted treatment modalities, will need to be evaluated in advanced Ph(+) ALL. Incorporation of imatinib in the first-line treatment of de novo Ph(+) ALL and in the setting of minimal residual disease is a promising therapeutic approach which is currently being studied in clinical trials. Better understanding of targeted therapies, including strategies based on recruitment of host immune functions, as well as the prudent use of active chemotherapy agents, may eventually improve the outlook for patients with Ph(+) ALL.

BFM-oriented treatment for children with acute lymphoblastic leukemia without cranial irradiation and treatment reduction for standard risk patients: results of DCLSG protocol ALL-8 (1991-1996)

Modern treatment strategies, consisting of intensive chemotherapy and cranial irradiation, have remarkably improved the prognosis for children with acute lymphoblastic leukemia. However, patients with a potential for cure are at risk of severe acute and late adverse effects of treatment. Furthermore, in 25-30% of patients treatment still fails. The objectives of the DCLSG study ALL 8 were to decrease the toxicity and to increase the effectivity of BFM-oriented treatment. Decrease of toxicity was aimed at by confirmation of the results of the previous DCLSG study ALL-7, showing that the majority (94%) of children with ALL can successfully be treated with BFM-oriented therapy without cranial irradiation, and by reduction of treatment for standard risk (SRG) patients. To increase the cure rate in medium risk (MRG) patients the efficacy of high doses of intravenous 6-mercaptopurine (HD-6MP) during protocol M and in SRG patients the efficacy of high doses of L-asparaginase (HD-L-ASP) during maintenance treatment was studied in randomized studies. Patient stratification and treatment were identical to protocol ALL-BFM90, with the following differences: no prophylactic cranial irradiation, SRG patients received only phase 1 of protocol I. Four hundred and sixty-seven patients entered the protocol: 170 SRG, 241 MRG and 56 HRG patients. The 5 years event-free survival rate for all patients was 73% (s.e. 2%); for SRG, MRG and HRG patients 85% (s.e. 3%), 73% (s.e. 3%) and 39% (s.e. 7%), respectively. In patients >1 year of age at diagnosis unfavorable prognostic factors were male sex, >25% blasts in the bone marrow at day 15 and initial white blood cell count (WBC) >50 x 10(9)/l. The cumulative risk of CNS relapse rate was 5% (s.e. 1%) at 5 years. These results confirm that the omission of cranial irradiation in BFM-oriented treatment does not jeopardize the overall good treatment results, nor does early reduction of chemotherapy in SRG patients. No benefit was observed from treatment intensification with HD-L-ASP in SRG patients, nor from HD-6MP in MRG patients.

Prophylactic therapy with enoxaparin during L-asparaginase treatment in children with acute lymphoblastic leukemia

Forty-one consecutive children with acute lymphoblastic leukemia (ALL) received prophylaxis therapy with the low molecular weight heparin (LMWH) enoxaparin during L-asparaginase treatment. Enoxaparin was given every 24 h subcutaneously at a median dose of 0.84 mg/kg per day (range, 0.45-1.33 mg/kg per day) starting at the first dose of L-asparaginase until 1 week after the last dose. Molecular analysis for thrombophilic polymorphisms documented prothrombin G20210A mutation in 3/27 (11%), homozygosity for MTHFR C677T mutation in 5/27 (18.5%, and heterozygosity for factor V Leiden mutation in 5/27 (18.5%) children. There were no thrombotic events during 76 courses of L-asparaginase in 41 patients who had received enoxaparin. One patient suffered brain infarct 7 days after enoxaparin was stopped. There were no bleeding episodes. In a historical control group of 50 ALL children who had not received prophylactic enoxaparin during L-asparaginase treatment, two had thromboembolisms (one deep vein thrombosis and one pulmonary embolism). Enoxaparin is safe and seems to be effective in prevention of thromboembolism in ALL patients during L-asparaginase therapy. This study provides pilot data for a future randomized trial of the use of LMWH during ALL therapy for the prevention of asparaginase-associated thrombotic events.