Marked improvements in outcome with chemotherapy alone in paediatric acute myeloid leukemia: results of the United Kingdom Medical Research Council's 10th AML trial. MRC Childhood Leukaemia Working Party

Gastrointestinal complications in children with acute myeloid leukemia

Gastrointestinal complications in pediatric acute myeloid leukemia (AML) have not been systematically described in the literature. Our objective was to describe complications related to the small and large bowel in children with AML. Literature searches were conducted of Ovid Medline from 1950 to November 2009 and EMBASE from 1980 to November 2009. We included any study design that described gastrointestinal complications in children and/or adults with AML. Common gastrointestinal complications were typhlitis and enterocolitis. Less common complications included appendicitis, pneumatosis intestinalis, and perianal infections. Both leukemia infiltration and intensive chemotherapy likely play a role in the etiology of these conditions. There is a paucity of carefully conducted studies that describe the natural history of typhlitis and enterocolitis and evidence is needed to help guide the management of gastrointestinal complications. Gastrointestinal complications are relatively common in children with AML. Conduction of carefully performed cohort studies is needed to better understand the spectrum of symptoms and expected consequences of gastrointestinal complications. Randomized trials are required to develop evidence-based guidelines for the management of gastrointestinal complications in pediatric AML.

Leukemias and lymphomas: treatment and prophylaxis of the central nervous system

Central nervous system (CNS)-directed therapy is required for many acute leukemia patients and for nearly all aggressive or high-grade non-Hodgkin's lymphoma patients as part of an overall chemotherapy plan for disease eradication. The CNS therapy decisions differ for overt disease treatment versus prophylactic treatment and take into consideration the type of leukemia or lymphoma, the age of the patient, and other prognostic factors. A variety of CNS-directed therapies are used for prevention or treatment of CNS disease in acute leukemias or aggressive lymphomas: intrathecal medications (cytosine arabinoside, methotrexate, or both in combination with hydrocortisone) with or without cranial or craniospinal irradiation, intrathecal medication only with intensive systemic chemotherapy, or high-dose chemotherapy specifically chosen for CNS penetrance. Any type of CNS-directed therapy, whether intrathecal chemotherapy, high-dose systemic chemotherapy, or irradiation, may cause acute or delayed (late) toxicity. Ongoing clinical trial research aims to reduce the risk of toxicity from CNS-directed therapy while preserving or improving treatment efficacy.

A review on allogeneic stem cell transplantation for newly diagnosed pediatric acute myeloid leukemia

Survival of pediatric acute myeloid leukemia (AML) has improved considerably over the past decades. Since 1985, allogeneic stem cell transplantation (allo-SCT) is widely recommended for patients who have a matched sibling donor. However, it remains controversial whether allo-SCT is superior to chemotherapy for children with newly diagnosed AML. This review summarizes phase 3 clinical trials that compared allo-SCT with chemotherapy (including autologous SCT) in pediatric AML, excluding studies that did not use the intention-to-treat analysis or correct for time-to-transplantation. Although allo-SCT might prevent more relapses than chemotherapy, the number needed for transplantation (with allo-SCT) to prevent one relapse is in the order of 10 patients. Moreover, overall survival is similar with both methods in most recent studies, apparently because of increased salvagability of a relapse when initial therapy concerned chemotherapy only, and because of a higher treatment-related mortality with allo-SCT. Because allo-SCT also gives more severe side effects and results more often in secondary malignancies than chemotherapy, we do not recommend allo-SCT in first remission for pediatric AML in general. Further research should focus on the possibility that subgroups might benefit from allo-SCT, aiming at further improvements in the prognosis of pediatric AML.

Acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogeneous group of leukemias that result from clonal transformation of hematopoietic precursors through the acquisition of chromosomal rearrangements and multiple gene mutations. As a result of highly collaborative clinical research by pediatric cooperative cancer groups worldwide, disease-free survival has improved significantly during the past 3 decades. Further improvements in outcomes of children who have AML probably will reflect continued progress in understanding the biology of AML and the concomitant development of new molecularly targeted agents for use in combination with conventional chemotherapy drugs.

Minimal residual disease-directed therapy for childhood acute myeloid leukaemia: results of the AML02 multicentre trial

BACKGROUND

We sought to improve outcome in patients with childhood acute myeloid leukaemia (AML) by applying risk-directed therapy that was based on genetic abnormalities of the leukaemic cells and measurements of minimal residual disease (MRD) done by flow cytometry during treatment.

METHODS

From Oct 13, 2002, to June 19, 2008, 232 patients with de-novo AML (n=206), therapy-related or myelodysplasia-related AML (n=12), or mixed-lineage leukaemia (n=14) were enrolled at eight centres. 230 patients were assigned by block, non-blinded randomisation, stratified by cytogenetic or morphological subtype, to high-dose (18 g/m(2), n=113) or low-dose (2 g/m(2), n=117) cytarabine given with daunorubicin and etoposide (ADE; induction 1). The primary aim of the study was to compare the incidence of MRD positivity of the high-dose group and the low-dose group at day 22 of induction 1. Induction 2 consisted of ADE with or without gemtuzumab ozogamicin (GO anti-CD33 monoclonal antibody); consolidation therapy included three additional courses of chemotherapy or haematopoietic stem-cell transplantation (HSCT). Levels of MRD were used to allocate GO and to determine the timing of induction 2. Both MRD and genetic abnormalities at diagnosis were used to determine the final risk classification. Low-risk patients (n=68) received five courses of chemotherapy, whereas high-risk patients (n=79), and standard-risk patients (n=69) with matched sibling donors, were eligible for HSCT (done for 48 high-risk and eight standard-risk patients). All 230 randomised patients were analysed for the primary endpoint. Other analyses were limited to the 216 patients with AML, excluding those with mixed-lineage leukaemia. This trial is closed to accrual and is registered with ClinicalTrials.gov, number NCT00136084.

FINDINGS

Complete remission was achieved in 80% (173 of 216 patients) after induction 1 and 94% (203 of 216) after induction 2. Induction failures included two deaths from toxic effects and ten cases of resistant leukaemia. The introduction of high-dose versus low-dose cytarabine did not significantly lower the rate of MRD-positivity after induction 1 (34%vs 42%, p=0.17). The 6-month cumulative incidence of grade 3 or higher infection was 79.3% (SE 4.0) for patients in the high-dose group and 75.5% (4.2) for the low-dose group. 3-year event-free survival and overall survival were 63.0% (SE 4.1) and 71.1% (3.8), respectively. 80% (155 of 193) of patients achieved MRD of less than 0.1% after induction 2, and the cumulative incidence of relapse for this group was 17% (SE 3). MRD of 1% or higher after induction 1 was the only significant independent adverse prognostic factor for both event-free (hazard ratio 2.41, 95% CI 1.36-4.26; p=0.003) and overall survival (2.11, 1.09-4.11; p=0.028).

INTERPRETATION

Our findings suggest that the use of targeted chemotherapy and HSCT, in the context of a comprehensive risk-stratification strategy based on genetic features and MRD findings, can improve outcome in patients with childhood AML.

FUNDING

National Institutes of Health and American Lebanese Syrian Associated Charities (ALSAC).

Hematopoietic stem cell transplantation for leukemia

Leukemia represents the most common pediatric malignancy, accounting for approximately 30% of all cancers in children less than 20 years of age. Most children diagnosed with leukemia are cured without hematopoietic stem cell transplantation (HSCT), but for some high-risk subgroups, allogeneic HSCT plays an important role in their therapeutic approach. The characteristics of these high-risk subgroups and the role of HSCT in childhood leukemias are discussed.

NKAML: a pilot study to determine the safety and feasibility of haploidentical natural killer cell transplantation in childhood acute myeloid leukemia

PURPOSE To conduct a pilot study to determine the safety, feasibility, and engraftment of haploidentical natural killer (NK) cell infusions after an immunosuppressive regimen in children with acute myeloid leukemia (AML). PATIENTS AND METHODS Ten patients (0.7 to 21 years old) who had completed chemotherapy and were in first complete remission of AML were enrolled on the Pilot Study of Haploidentical Natural Killer Cell Transplantation for Acute Myeloid Leukemia (NKAML) study. They received cyclophosphamide (60 mg/kg on day -7) and fludarabine (25 mg/m(2)/d on days -6 through -2), followed by killer immunoglobulin-like receptor-human leukocyte antigen (KIR-HLA) mismatched NK cells (median, 29 x 10(6)/kg NK cells) and six doses of interleukin-2 (1 million U/m(2)). NK cell chimerism, phenotyping, and functional assays were performed on days 2, 7, 14, 21, and 28 after transplantation. Results All patients had transient engraftment for a median of 10 days (range, 2 to 189 days) and a significant expansion of KIR-mismatched NK cells (median, 5,800/mL of blood on day 14). Nonhematologic toxicity was limited, with no graft-versus-host disease. Median length of hospitalization was 2 days. With a median follow-up time of 964 days (range, 569 to 1,162 days), all patients remain in remission. The 2-year event-free survival estimate was 100% (95% CI, 63.1% to 100%). CONCLUSION Low-dose immunosuppression followed by donor-recipient inhibitory KIR-HLA mismatched NK cells is well tolerated by patients and results in successful engraftment. We propose to further investigate the efficacy of KIR-mismatched NK cells in a phase II trial as consolidation therapy to decrease relapse without increasing mortality in children with AML.

Epidemiology of paediatric invasive fungal infections and a case-control study of risk factors in acute leukaemia or post stem cell transplant

Patients aged 0-18 years with confirmed or possible invasive fungal infection were identified by medical record and database searches. Cases with an underlying diagnosis of acute leukaemia or following stem cell transplantation were included in a case control study. Controls included all other children with acute leukaemia or stem cell transplant in the corresponding time period. Variables collected included demographics, underlying disease risk and status, organ impairment, admission to intensive care unit, fungal infection details and certain transplant variables. Risk factors for development of invasive fungal infection were examined using logistic regression. There were 106 cases of invasive fungal infection during the study. The incidence of invasive fungal infection was 21% in acute lymphoblastic leukaemia, 15% in acute myeloid leukaemia and 25% following stem cell transplantation. Sixty per cent were neutropenic at diagnosis and 39% had concomitant bacteremia. High risk acute lymphoblastic leukaemia, relapsed disease, intensive care admission and graft-versus-host disease were significantly associated with development of invasive fungal infection on multivariate analysis. These associations provide new information on paediatric invasive fungal infections and warrant further study; caution should be encouraged when extrapolating from adult studies.

Phase II study of clofarabine in pediatric patients with refractory or relapsed acute myeloid leukemia

PURPOSE

To determine the efficacy and safety of clofarabine in pediatric patients with refractory or relapsed acute myeloid leukemia (AML).

PATIENTS AND METHODS

A phase II, open-label, multicenter study was conducted with single-agent clofarabine in pediatric patients with refractory or relapsed AML. Clofarabine was administered intravenously over 2 hours at the pediatric maximum-tolerated dose (MTD) of 52 mg/m(2) daily for 5 consecutive days. Cycles were repeated every 2 to 6 weeks. Responses determined by an independent response review panel.

RESULTS

The 42 patients treated on the study had a median age of 13 years (range, 2 to 22 years) and had received a median number of two (range, one to five) prior regimens. The response rate was 26% and included one complete response without platelet recovery and 10 partial responses. The median duration of response was 20 weeks (range, 2 to >or= 156 weeks). Six of 28 patients who were refractory to the immediately preceding therapy achieved response. Thirteen patients (31%), including seven responders, proceeded to hematopoietic stem-cell transplantation (HSCT) after treatment with clofarabine and survived between 24 to >or= 160 weeks. Five patients (12%) remain alive post-transplantation at >or= 63, >or= 71, >or= 86, >or= 114, and >or= 130 weeks. The most common grade 3 or greater adverse events without regard to causality were febrile neutropenia, catheter-related infection, epistaxis, hypotension, nausea, and fever. Transient elevation of liver enzymes and hypokalemia occurred frequently. Five patients died within 30 days of clofarabine administration secondary to progressive disease, and another five died as a result of an adverse event.

CONCLUSION

Clofarabine is active in pediatric patients with multiply relapsed or refractory AML. Responses allowed several refractory patients to proceed to HSCT. The toxicity profile was expected in this patient population.

Risk-stratified therapy and the intensive use of cytarabine improves the outcome in childhood acute myeloid leukemia: the AML99 trial from the Japanese Childhood AML Cooperative Study Group

PURPOSE

To improve the prognosis in children with newly diagnosed acute myeloid leukemia (AML) by introducing a dose-dense intensive chemotherapy regimen and an appropriate risk stratification system.

PATIENTS AND METHODS

Two hundred forty children with de novo AML were treated with continuous cytarabine-based induction therapy and stratified to three risk groups based on the initial treatment response, age, and WBC at diagnosis and cytogenetics. All of the patients were treated with intensive consolidation chemotherapy including three or four courses of high-dose cytarabine. Allogeneic hematopoietic stem-cell transplantation (HSCT) was indicated for only the intermediate-risk patients with matched related donors and for all the high-risk subsets.

RESULTS

Two hundred twenty-seven children (94.6%) achieved a complete remission (CR). Four children demonstrated induction death. The median follow-up of the live patients was 55 months (range, 37 to 73 months). The 5-year overall survival of all 240 children was 75.6% (95% CI, 70.3% to 81.4%) and event-free survival was 61.6% (95% CI, 55.8% to 68.1%). The 5-year disease-free survival in each risk group were 71.3% (95% CI, 63.4% to 80.2%) in the low-risk group (n = 112), 59.8% (95% CI, 50.6% to 70.7%) in the intermediate-risk group (n = 92), and 56.5% (95% CI, 39.5% to 80.9%) in the high-risk group (n = 23). Eight children died during the first CR, including four after HSCT.

CONCLUSION

A high survival rate, 75.6% at 5 years, was achieved for childhood with de novo AML in the AML99 trial. The treatment strategy was well tolerated with only 1.7% induction death rate and 3.5% remission death rate. Low-risk children were successfully treated with chemotherapy alone.

Treatment strategies for pediatric acute myeloid leukemia

Therapeutic strategies utilized in recently completed Phase III clinical trials in children with de novo acute myeloid leukemia have led to long-term disease-free survival in 50 - 60% of children. This review describes the contributions from early intensification of therapy and postremission intensification using highly myelosuppressive chemotherapy strategies and discusses the controversial roles of allogeneic bone marrow transplantation, maintenance therapy and CNS irradiation. Current strategies focusing on the identification of critical biologic features and measurements of early response to therapy allow for greatly improved risk group stratification. Future improvements in the treatment of children with acute myeloid leukemia will depend on a better understanding of the biology of the disease, targeted therapeutic approaches directed to specific biologic targets, selective use of allogeneic transplantation and innovative clinical trial designs that will allow for the testing of an increasing number of new agents in increasingly small numbers of patients in defined risk groups.

Incidence and predictors of treatment-related mortality in paediatric acute leukaemia in El Salvador

Survival rates among children with leukaemia in low-income countries are lower than those in high-income countries. This has been attributed in part to higher treatment-related mortality (TRM). We examined the demographics, treatment, and outcomes of paediatric patients in El Salvador with acute lymphoblastic leukaemia (ALL) or acute myeloid leukaemia (AML) to determine the incidence, causes, and risk factors for TRM. Two trained data managers collected data prospectively; no patients were excluded. Biological, socioeconomic and nutritional predictors were examined. A total of 469 patients with ALL and 78 patients with AML were included. The 2-year cumulative incidence of TRM was significantly higher among children with AML (35.4±6.4%) than those with ALL (12.5±1.7%; P<0.0001). However, the proportion of deaths attributable to the toxicity of treatment did not differ significantly between AML (25/47, 53.2%) and ALL (55/107, 51.4%; P=0.98). Among children with ALL, low monthly income (P=0.04) and low parental education (P=0.02) significantly increased the risk of TRM. Among children with AML, biological, socioeconomic, and nutritional variables were not associated with TRM. In this low-income country, toxic death significantly contributes to mortality in both ALL and AML. A better understanding of the effect of socioeconomic status on TRM may suggest specific strategies for patients with ALL.

Comparable outcomes of HLA-matched unrelated and HLA-identical sibling donor bone marrow transplantation for childhood acute myeloid leukemia in first remission

We retrospectively investigated the outcomes of HLA-matched unrelated BMT (MU-BMT, n = 13) and HLA-identical sibling donor BMT (MS-BMT, n = 17) for childhood AML in CR1 between June 2002 and August 2005. Engraftment of neutrophil and platelet did not differ between the two transplant groups. The cumulative incidence of grade II-IV acute GVHD and any chronic GVHD at three yr was not different between MS-BMT and MU-BMT. Of the 30 patients, four patients experienced relapses (three with MS-BMT, one with MU-BMT) and four patients died of transplant-related complications (two with MS-BMT, two with MU-BMT). A total of 23 patients survived with a median follow-up of 43.2 months. The Kaplan-Meier estimates for EFS rates at three yr were 71% and 77% for MS-BMT and MU-BMT, respectively, and the OS rates were 76% and 77% for MS-BMT and MU-BMT, respectively. The outcome of HLA-matched unrelated BMT is comparable to that of HLA-identical sibling BMT for childhood AML in CR1. HLA-matched unrelated BMT may be recommended for patients who have AML in CR1 without an HLA-matched sibling donor.

Combination of cladribine and cytarabine is effective for childhood acute myeloid leukemia: results of the St Jude AML97 trial

Because cladribine can increase cytarabine triphosphate levels, we tested a cladribine—cytarabine combination in the St. Jude AML97, trial in which this combination was administered before standard chemotherapy to 96 children with acute myeloid leukemia (AML) or myelodysplastic syndrome. Patients received a 5-day course of cladribine (9 mg/m²/dose) and cytarabine either as daily 2-hour infusions (500 mg/m²/dose) (arm A) or a continuous infusion (500 mg/m²/day) (arm B). Ara-CTP levels and inhibition of DNA synthesis increased from day 1 to day 2, but were not different between the two arms. In addition, the median blast percentages at day 15 did not differ between arms A and B, but patients treated in arm A had shorter intervals between the initiation of the first and second courses of therapy. Thus, although there were trends towards better CR rates and overall survival for patients treated in arm B, the reduced efficacy of arm A may have been partially compensated by more intense timing of therapy for that group. For all patients, 5-yr event-free survival and overall survival estimates were 44.1% ± 5.4 % and 50.0% ± 5.5%. Our results suggest that cladribine in combination with continuous-infusion cytarabine is effective therapy for childhood AML.

Clinical management of primary non-acute promyelocytic leukemia acute myeloid leukemia: Practice Guidelines by the Italian Society of Hematology, the Italian Society of Experimental Hematology, and the Italian Group for Bone Marrow Transplantation

As many options are now available to treat patients with de novo acute myeloid leukemia, the Italian Society of Hematology and two affiliated societies (SIES and GITMO) commissioned project to an Expert Panel aimed at developing clinical practice guidelines for acute myeloid leukemia treatment. After systematic comprehensive literature review, the Expert Panel formulated recommendations for the management of primary acute myeloid leukemia (with the exception of acute promyelocytic leukemia) and graded them according to the supporting evidence. When evidence was lacking, consensus-based statements have been added. First-line therapy for all newly diagnosed patients eligible for intensive treatment should include one cycle of induction with standard dose cytarabine and an anthracycline. After achieving complete remission, patients aged less than 60 years should receive consolidation therapy including high-dose cytarabine. Myeloablative allogeneic stem cell transplantation from an HLA-compatible sibling should be performed in first complete remission: 1) in children with intermediate-high risk cytogenetics or who achieved first complete remission after the second course of therapy; 2) in adults less than 40 years with an intermediate-risk; in those aged less than 55 years with either high-risk cytogenetics or who achieved first complete remission after the second course of therapy. Stem cell transplantation from an unrelated donor is recommended to be performed in first complete remission in adults 30 years old or younger, and in children with very high-risk disease lacking a sibling donor. Alternative donor stem cell transplantation is an option in high-risk patients without a matched donor who urgently need transplantation. Patients aged less than 60 years, who either are not candidate for allogeneic stem cell transplantation or lack a donor, are candidates for autologous stem cell transplantation. We describe the results of a systematic literature review and an explicit approach to consensus techniques, which resulted in recommendations for the management of primary non-APL acute myeloid leukemia.

Impact of disease risk on efficacy of matched related bone marrow transplantation for pediatric acute myeloid leukemia: the Children's Oncology Group

PURPOSE

There is considerable variation in the use of HLA-matched related bone marrow transplantation (BMT) for the treatment of pediatric patients with newly diagnosed acute myeloid leukemia (AML). Some oncologists have argued that BMT should be offered to most patients in first complete remission (CR). Others have maintained that transplantation in first remission should be reserved for patients with high-risk disease. We performed this study to determine how disease risk influences the efficacy of BMT.

METHODS

We combined data from four cooperative group clinical trials: Pediatric Oncology Group 8821, Children's Cancer Group (CCG) 2891, CCG 2961, and Medical Research Council 10. Using cytogenetics and the percentage of marrow blasts after the first course of chemotherapy, patients were stratified into favorable, intermediate, and poor-risk disease groups. Patients who could not be risk classified were analyzed separately. Outcomes for patients assigned to BMT and for patients assigned to chemotherapy alone were compared.

RESULTS

The data set included 1,373 pediatric patients with AML in first CR. In the intermediate-risk group, the estimated disease-free survival at 8 years for patients who did not undergo transplantation was 39% +/- 5% (2 SE), whereas it was 58% +/- 7% for BMT patients. The estimated overall survival for patients who did not undergo transplantation was 51% +/- 5%, whereas it was 62% +/- 7% for BMT patients. Both differences were significant (P < .01). There were no significant differences for survival in the other two risk groups or in the non-risk-stratified patients.

CONCLUSION

Our study indicates that HLA-matched related BMT is an effective treatment for pediatric patients with intermediate-risk AML in first CR.

Recent advances in management of acute myeloid leukemia (AML)

Acute myeloid leukemia (AML) is the most common childhood malignancy. AML has therapeutically been difficult to treat. In 2001, the World Health Organization (WHO), in conjunction with the Society for Hematopathology and the European Association of Hematopathology, published a new classification for myeloid neoplasms. A number of chromosomal abnormalities are used to predict outcome and stratify therapeutic risk groups in children with AML. Recently, alterations in receptor tyrosine kinases, tyrosine phosphatases and in oncogenes such as RAS have been implicated in the pathogenesis of AML. This article aims to review the recent development in diagnosis, treatment and monitoring of AML. Better understanding of the molecular pathogenesis of AML has led to the development of target-specific therapies. Some of the new classes of drugs include monoclonal antibody directed against the CD33 antigen, farnesyltransferase inhibitors (FTI), and FMSlike tyrosine kinase 3 (FLT3) inhibitors. The role of allogenic SCT, particularly whether it should be done during first CR or reserved for second remission, remains the most controversial issue in pediatric AML. There is a need of collaboration with international pediatric cooperative oncology groups and definitive clinical trials in order to establish use of these newer molecules in pediatric populations.

Indications and donor selections for allogeneic stem cell transplantation in children with hematologic malignancies

Allogeneic stem cell transplantation (SCT) is the only curative approach for many patients with advanced or high-risk leukemia. Advances in supportive care and management of graft-versus-host disease have resulted in improvements in outcomes of related and unrelated donor SCT, creating controversies as to which strategy might be the optimal therapy for individual patients. This article discusses the indications and donor selection strategies for SCT in patients with malignant hematologic disease.

Acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogeneous group of leukemias that result from clonal transformation of hematopoietic precursors through the acquisition of chromosomal rearrangements and multiple gene mutations. As a result of highly collaborative clinical research by pediatric cooperative cancer groups worldwide, disease-free survival has improved significantly during the past 3 decades. Further improvements in outcomes of children who have AML probably will reflect continued progress in understanding the biology of AML and the concomitant development of new molecularly targeted agents for use in combination with conventional chemotherapy drugs.

The development of a novel protocol for the treatment of de novo childhood acute myeloid leukemia in a single institution in Taiwan

From November 1, 1995 to July 31, 2004, 49 children with de novo acute myeloid leukemia (AML) were treated at our institution. One patient who was treated by a different protocol was excluded. In total, 48 patients with de novo AML were enrolled in this study. Forty-two patients with AML other than acute promyelocytic leukemia (non-APL) were treated consecutively with 2 novel protocols: Mackay Memorial Hospital (MMH)-AML-96, designed as a pilot phase, and Taiwan Pediatric Oncology Group (TPOG)-AML-97A, on the basis of MMH-AML-96 with minor modifications. Six patients with APL were treated consecutively with 2 protocols, TPOG-APL-97 and APL-2001. As of July 31, 2006, the remission rates were 79%, 92%, and 98% after 1, 2, and 3 courses of induction therapy, respectively. The 5-year overall survival was 64%+/-6.9% (SE), and the 5-year event-free survival was 60%+/-7.1%; for non-APL AML, the rates were 62%+/-7.5% and 59%+/-7.6%; for APL, 83+/-15.2 and 67+/-19.3%. Among the factors analyzed, a complete remission achieved after 1 course of induction therapy, lactate dehydrogenase <500 IU/L at diagnosis, patients without invasive fungal infection during chemotherapy, and male sex were associated with a favorable outcome.

Childhood central nervous system leukemia: historical perspectives, current therapy, and acute neurological sequelae

INTRODUCTION

During the past three decades, improvements in the treatment of childhood leukemia have resulted in high cure rates, particularly for acute lymphoblastic leukemia (ALL). Unfortunately, successful therapy has come with a price, as significant morbidity can result from neurological affects which harm the brain and spinal cord. The expectation and hope is that chemotherapy, as a primary means of CNS therapy, will result in acceptable disease control with less CNS morbidity than has been observed with combinations of chemotherapy and radiotherapy over the past several decades.

METHODS AND RESULTS

In this review we discuss the poignant, historical aspects of CNS leukemia therapy, outline current methods of systemic and CNS leukemia therapy, and present imaging findings we have encountered in childhood leukemia patients with a variety of acute neurological conditions. A major objective of our research is to understand the neuroimaging correlates of acute and chronic effects of cancer and therapy. Specific features related to CNS leukemia and associated short-term toxicities, both disease- and therapy-related, are emphasized in this review with the specific neuroimaging findings. Specific CNS findings are similarly important when treating acute myelogenous leukemia (AML), and details of leukemic involvement and toxicities are also presented in this entity.

CONCLUSION

Despite contemporary treatment approaches which favor the use of chemotherapy (including intrathecal therapy) over radiotherapy in the treatment of CNS leukemia, children still occasionally experience morbid neurotoxicity. Standard neuroimaging is sufficient to identify a variety of neurotoxic sequelae in children, and often suggest specific etiologies. Specific neuroimaging findings frequently indicate a need to alter antileukemia therapy. It is important to appreciate that intrathecal and high doses of systemic chemotherapy are not innocuous and are associated with acute, specific, recognizable, and often serious neurological consequences.

Early pediatric anthracycline cardiotoxicity: managed by serial heart and bone marrow transplantation

We report a favorable outcome in a child who underwent cardiac transplantation for severe early post-anthracycline-induced cardiomyopathy, 9 months after completion of treatment for acute myeloid leukemia (AML). The child suffered a relapse of AML 2 months after cardiac transplantation and then underwent a successful bone marrow transplant. This case is unique in the literature. We believe it offers an alternative strategy for children with hematologic malignancies, where severe early post-anthracycline cardiotoxicity might preclude bone marrow transplantation.

Repetitive cycles of high-dose cytarabine are effective for childhood acute myeloid leukemia: long-term outcome of the children with AML treated on two consecutive trials of Tokyo Children's Cancer Study Group

BACKGROUND

Various methods of intensive chemotherapy have contributed to an improved survival in pediatric acute myeloid leukemia (AML). We here report the long-term results of the two consecutive trials of Tokyo Children's Cancer Study Group (TCCSG), incorporating repetitive use of high-dose cytarabine (HD-Ara-C) based combination chemotherapy in post-remission phase.

PROCEDURE

A total of 216 eligible children with newly diagnosed AML were treated in the two consecutive multi-center trials of TCCSG, M91-13 and M96-14, from August 1991 to September 1998. In M91-13 trial, patients received eight courses of intensive post-remission chemotherapy, including six HD-Ara-C containing courses, after remission-induction therapy. Autologous hematopoietic stem cell transplantation (HSCT) could be selected by physician's choice, and allogeneic HSCT was allocated if donor was available. In M96-14 trial, the last two HD-Ara-C courses were omitted from the chemotherapy arm.

RESULTS

The remission-induction rate was 88.8% and probability of 5-year Overall survival (OS) and event-free survival (EFS) were 62% (56-69% with 95% Confidence intervals (CIs)) and 56% (49-62%), respectively. Treatment-related mortality (TRM) was 7.8%. Among patients without Down syndrome (DS) or acute promyelocytic leukemia (APL), the presence of t(8;21) or inv(16) was a significant good prognostic factor both in the univariate and multivariate analyses. Children with DS (N = 10) and APL (N = 14) also showed a good survival exceeding 70% in 5 years.

CONCLUSIONS

These results suggest that repetitive use of HD-Ara-C was effective and safe for childhood AML. However, further optimization of AML therapy is required.

Microbiologically documented infections and infection-related mortality in children with acute myeloid leukemia

The primary objective was to describe the prevalence and characteristics of microbiologically defined infections and infection-related mortality (IRM) in 492 children with acute myeloid leukemia enrolled on CCG 2961. Secondary objectives were to determine the relationship between demographic, disease-related, and therapeutic variables, and infections and IRM. Institutions documented infections prospectively. Age, ethnicity, body mass index, leukemia karyotype, treatment, and institutional size were examined for association with infection outcomes. More than 60% of children experienced such infections in each of 3 phases of chemotherapy. There were 58 infectious deaths; cumulative incidence of IRM was 11% plus or minus 2%. Thirty-one percent of infectious deaths were associated with Aspergillus, 25.9% with Candida, and 15.5% with alpha hemolytic streptococci. Age older than 16 years (hazard ratio [HR], 3.32; 95% confidence interval [CI], 1.87-5.89; P < .001), nonwhite ethnicity (HR, 1.85; 95% CI, 1.10-3.09; P = .02), and underweight status (HR, 3.06; 95% CI, 1.51-6.22; P = .002) were associated with IRM, while size of the treating institution was not. Thus, age, ethnicity, and BMI were important contributors to IRM. Fungi and Gram-positive cocci were the most common organisms associated with IRM and, in particular, Aspergillus species was the largest contributor to infectious deaths.

HLA-identical haematopoietic stem cell transplantation for acute leukaemia in children: less relapse with higher biologically effective dose of TBI

To examine relapse, survival and transplant-related complications in relationship to disease- and pre-treatment-related characteristics, we evaluated 132 children, who consecutively received an allogeneic HLA-identical SCT for acute leukaemia in our centre: ALL in first remission (n=24), ALL in second remission (n=53) and AML in first remission (n=55). The source of the stem cells was bone marrow in all but three cases. Most patients (89%) were pre-treated with cyclophosphamide and an age-related dose of TBI. Initially, GVHD prophylaxis consisted of long-course MTX only (n=24), later short-course MTX and CsA (n=102) was given. All patients were nursed in strictly protective isolation and received total gut decontamination to suppress their potentially pathogenic enteric microflora. The 5-year probability of overall survival was 63, 53 and 74% for ALL1, ALL2 and AML1, respectively (median follow-up: 10.6 years). The overall transplant-related mortality was 6%. The incidence of acute GVHD was 17%; 6% was grades II-IV. A higher total biologically effective TBI dose (BED) resulted in a decreased relapse frequency (P=0.034) and increased overall survival. AML patients with acute GVHD got no relapse (P=0.02); this was not the case in ALL patients. Fractionated TBI regimens with higher BED should be evaluated in prospective studies.

Longitudinal evaluation of early and late anthracycline cardiotoxicity in children with AML

BACKGROUND

Anthracyclines are effective antineoplastic drugs in acute myelogenous leukemia (AML). However, their use is limited by cardiomyopathy, which occurs in children already at cumulative doses of 300 mg/m(2) (given as daunorubicin equivalent).

PROCEDURE

To evaluate anthracycline-associated cardiomyopathy in pediatric AML-patients, the incidence of early and late (>1 year after intensive AML chemotherapy) clinical and subclinical cardiotoxicity was analyzed out of a total of 1,207 patients <18 years treated between 1993 and 2003 in trials AML-BFM93/98: 1,010 protocol patients with de novo AML, 121 with Down syndrome (DS)-AML, and 76 with secondary AML. The cumulative dose of anthracyclines was generally risk-adapted: 300-450 mg/m(2) using 1-4-hr infusions of anthracyclines with the assumed lowest cardiotoxic potential. Eight hundred eighty-five patients (73%) were eligible for the analysis of early and 547 (45%) of late cardiotoxicity (1,399 follow-up data).

RESULTS

Thirty-eight patients (4.3%), including 3 DS-AML and 1 secondary AML, suffered from early cardiomyopathy. After 5 years, four patients showed temporarily or persistently a reduced shortening fraction, which led to death in one DS-AML patient. Including these 4 patients, late cardiomyopathy was seen in 16 patients (cumulative incidence after 11 years: 5% +/- 1%). Nine patients (2.5 +/- 1%) showed clinical symptoms, five of them had persistent abnormal shortening fraction. Late subclinical cardiomyopathy occurred temporarily in seven patients. Late clinical cardiomyopathy mainly affected patients with a second anthracycline therapy (secondary malignancy) and those with early cardiotoxicity.

CONCLUSION

In spite of a highly intensive and effective treatment, the frequency of anthracycline-associated cardiomyopathy was low in the AML-BFM studies.

Prognostic factors and risk-based therapy in pediatric acute myeloid leukemia

Acute myeloid leukemia (AML) has posed significant therapeutic challenges to pediatric oncologists. Despite intensive therapy, half of the children with AML relapse and die from their disease. Efforts to identify risk factors in AML are directed toward defining populations who may benefit from alternative therapies. Patients at lower risk for relapse may benefit from treatment de-escalation, sparing them adverse side effects. Management of high-risk patients may prove more difficult, as the nearly myeloablative nature of AML therapy leaves little room for therapy escalation short of stem cell transplantation. This review evaluates prognostic factors in pediatric AML and discusses the feasibility of using these factors in risk-adapted therapy regimens.

Improved outcome in childhood acute myeloid leukemia in Singapore with the MRC AML 10 protocol

BACKGROUND

The introduction of the United Kingdom Medical Research Council's 10th AML trial (MRC AML 10) protocol incorporating high-dose anthracycline therapy has improved outcome of children with acute myeloid leukemia (AML). In this study, we review the results of childhood AML therapy in a Singapore university hospital over the last 17 years emphasizing toxicity and outcome.

PROCEDURE

Retrospective analysis revealed 34 children with AML between 1988 and 2003. Prior to September 1996, therapy consisted of: POG-8498 (n = 10), others (n = 9). From September 1996, all but one of 15 children received MRC AML 10 treatment.

RESULTS

At the time of analysis, 17 had died from disease, and 17 patients were alive among whom 2 had relapsed. MRC AML 10-treated patients (n = 14) had significantly better 3-year overall, event-free, and disease-free survival (74% vs. 35%, 77% vs. 20%, 83% vs. 31%; P = 0.019, P = 0.002, and P = 0.010, respectively) and were likelier to achieve complete remission (CR) than non-MRC AML 10 patients (P = 0.102). Among patients who achieved CR, MRC AML 10-treated patients were significantly more likely to achieve CR after only one cycle of chemotherapy (P = 0.016). Hematologic toxicity was similar among the different regimens (P = 0.9).

CONCLUSIONS

These findings suggest that MRC AML 10 treatment results in significantly superior survival, without excess toxicity. Future studies should attempt to elucidate the relative importance of individual MRC AML 10 components and reduce the high cumulative anthracycline dose without compromising outcome.

The role of cytotoxic therapy with hematopoietic stem cell transplantation in the therapy of acute myeloid leukemia in children: an evidence-based review

Clinical research examining the role of hematopoietic stem cell transplantation (SCT) in the therapy of acute myeloid leukemia (AML) in children is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are presented in the table entitled "Summary of Treatment Recommendations Made by the Expert Panel for Pediatric Acute Myeloid Leukemia" and were reached unanimously by a panel of experts in AML. The identified priority areas of needed future research in pediatric AML include: What is the role of risk group stratification, including the role of cytogenetics, in selection of patients for allogeneic SCT, especially those in first CR? What is the appropriate timing and use of alternative donor SCT, given that matched unrelated donor SCT appears to yield outcomes equivalent to matched related donor SCT? What is the role of reduced intensity SCT (including the use of fludarabine-based preparative regimens) and/or other immunomodulatory approaches to maximize the graft-versus-leukemic effect? and What is the role of biologically targeted agents (ie, tyrosine kinase inhibitors, farnesyl transferase inhibitors, Flt-3 inhibitors, etc) in the treatment of AML, including induction, consolidation, conditioning regimens, and after SCT?

Less toxicity by optimizing chemotherapy, but not by addition of granulocyte colony-stimulating factor in children and adolescents with acute myeloid leukemia: results of AML-BFM 98

PURPOSE

To improve prognosis in children with acute myeloid leukemia (AML) by randomized comparisons of (1) two short consolidation cycles versus the Berlin-Frankfurt-Muenster (BFM) -type biphasic 6-week consolidation and (2) the prophylactic administration of granulocyte colony-stimulating factor (G-CSF) versus no G-CSF. Further, therapy for standard risk patients was intensified by addition of a second induction, HAM (high-dose cytarabine and mitoxantrone).

PATIENTS AND METHODS

Four hundred seventy-three patients younger than 18 years with de novo AML were enrolled in trial AML-BFM 98. Patients received five courses of intensive chemotherapy, cranial irradiation, and 1-year maintenance therapy.

RESULTS

Four hundred eighteen patients (88%) achieved remission. Compared with trial AML-BFM 93, early deaths decreased from 7.4 to 3.2% (P = .005), and 5-year overall survival increased from 58% to 62% (log-rank P = .03). Both types of consolidation therapy led to similar outcome (event-free survival, 51% v 50%), but in the two-cycle arm, treatment duration was shorter (median duration, 15 days), and treatment related mortality was lower (five v nine patients). G-CSF shortened neutropenia, but did not reduce the rate of severe infections. Intensification of induction therapy did not improve prognosis of standard-risk patients (event-free survival, 62% v 67%).

CONCLUSION

Overall results were improved by neither the administration of G-CSF nor by cycle therapy; however, the latter was easier to perform. Compared with study AML-BFM 93, therapy intensification with HAM in standard-risk patients did not result in improved prognosis. Future treatment designs have to balance intensification of treatment with higher toxicity, improve supportive care, and to consider alternative treatment strategies.

Emergence of antitumor cytolytic T cells is associated with maintenance of hematologic remission in children with acute myeloid leukemia

Although the graft-versus-leukemia effect of allogeneic bone marrow transplantation (BMT) is of paramount importance in the maintenance of disease remission, the role played by the autologous T-cell response in antitumor immune surveillance is less defined. We evaluated the emergence of antileukemia cytotoxic T-lymphocyte precursors (CTLp's) and the correlation of this phenomenon with maintenance of hematologic remission in 16 children with acute myeloid leukemia (AML), treated with either chemotherapy alone (5 patients) or with autologous BMT (A-BMT, 11 patients). Antileukemia CTLp's were detectable in 8 patients in remission after induction chemotherapy; none of them subsequently had a relapse. Of the 8 patients who did not show detectable CTLp frequency while in remission after induction chemotherapy, 7 subsequently experienced leukemia relapse. In patients undergoing A-BMT, molecular fingerprinting of the TCR-Vbeta repertoire, performed on antileukemia lines, demonstrated that selected antileukemia T-cell clonotypes, detectable in bone marrow before transplantation, survived ex vivo pharmacologic purging and were found in the recipient after A-BMT. These data provide evidence for an active role of autologous T cells in the maintenance of hematologic remission and also suggest that quantification of antileukemia CTLp frequency may be a useful tool to identify patients at high risk for relapse, thus potentially benefiting from an allogeneic antitumor effect.

Impact of age on outcome of pediatric acute myeloid leukemia: a report from 2 institutions

BACKGROUND

The prognostic significance of age among pediatric patients with acute myeloid leukemia (AML) was investigated.

METHODS

The authors reviewed the outcome of 424 patients who were <or=21 years of age at the time of diagnosis of AML (excluding acute promyelocytic leukemia) between 1983 and 2002 at St. Jude Children's Research Hospital (n=288) or the M. D. Anderson Cancer Center (n=136). Two treatment eras (1983-1989 and 1990-2002) were examined because of the greater intensity of treatment during the recent era.

RESULTS

After controlling for the effects of cytogenetics, white blood cell (WBC) count, French-American-British (FAB) subtype, and treatment era, they observed that age and treatment era interacted significantly in relation to event-free survival (EFS) (P=.033). Patients 10 years of age or older were at greater risk of an adverse event than younger patients in the recent era (hazard ratio=1.8; 95% confidence interval [CI]: 1.3-2.6; P=.005) but not in the early era. The rate of adverse events (death or recurrence) increased significantly with each year of age in the recent era (4.3%/year; 95% CI: 1.9-6.8%; P=.001) but not in the early era. The rate of death increased significantly with each year of age in both eras (4.4%/year; 95% CI: 2.3-6.5%; P<.001). EFS and survival showed no association with study site, and the effects of age were similar at the 2 sites.

CONCLUSIONS

These results suggest that age is an independent prognostic factor in childhood AML and that children younger than 10 years benefit more than older children from newer intensive therapies.

Ethnicity and survival in childhood acute myeloid leukemia: a report from the Children's Oncology Group

We evaluated differences in outcome by ethnicity among children with acute myeloid leukemia (AML). We analyzed 791 children in the CCG 2891 trial and confirmed positive findings in 850 children in the CCG 2961 trial. Hispanic and black children treated with chemotherapy in CCG 2891 had significantly inferior overall survival (OS) from study entry compared with white children (37%+/- 9% vs 48%+/- 4% [P = .016] and 34% +/- 10% vs 48% +/- 4%, [P = .007], respectively). Significantly fewer black children had related donors. Analyses of CCG 2961 confirmed that black children had significantly decreased OS rates compared with white children (45% +/- 12% vs 60% +/- 4%; P = .007) The difference in OS rates between Hispanic and white children approached statistical significance (51% +/- 8% vs 60% +/- 4%; P = .065) Only 7.5% of black children on CCG 2961 had an available family donor. In conclusion, Hispanic and black children with AML have worse survival than white children. Access to chemotherapy, differences in supportive care or leukemia phenotype, and reduced compliance are unlikely explanations for this difference because therapy was given intravenously according to CCG protocols. Fewer black children than expected had an available family marrow donor.

Efficacy and tolerability of gemtuzumab ozogamicin (anti-CD33 monoclonal antibody, CMA-676, Mylotarg) in children with relapsed/refractory myeloid leukemia

BACKGROUND

Gemtuzumab ozogamicin (GO) is a cytotoxic anti-CD33 monoclonal antibody that has given promising preliminary results in adult myeloid CD33+ AML. We conducted a retrospective multicenter study of 12 children treated with GO on a compassionate basis (median age 5.5 y). Three patients (2 MDS/AML, 1 JMML) were refractory to first-line treatment, 8 patients with de novo AML were in refractory first relapse, and one patient with de novo AML was in 2nd relapse after stem cell transplantation (SCT). CD33 expression exceeded 20% in all cases.

METHODS

GO was administered alone, at a unit dose of 3-9 mg/m2, once (3 patients), twice (3 patients), three (5 patients) or five times (1 patient). Mean follow-up was 128 days (8-585 d).

RESULTS

There were three complete responses (25%) leading to further curative treatment (SCT). Treatment failed in the other nine patients, and only one patient was alive at the end of follow-up. NCI-CTC grade III/IV adverse events comprised hematological toxicity (n = 12), hypertransaminasemia (n = 2), allergy and hyperbilirubinemia (1 case each). There was only one major adverse event (grade IV allergy). No case of sinusoidal obstruction syndrome occurred.

CONCLUSION

These results warrant a prospective trial of GO in a larger population of children with AML.

Curing childhood acute myeloid leukemia (AML) at the half-way point: promises to keep and miles to go before we sleep

Childhood and adolescent acute myeloid leukemia (AML) is traditionally one of the hardest childhood cancers to successfully treat and had an overall survival well under 10% in the 1960s. Initial progress was made by three major events: (1) active chemotherapeutic agents were identified which led to remissions for the first time in this disease; (2) cooperative groups were instituted leading to important clinical trials; and (3) several single institutions began experimenting with the role of allogeneic matched sibling donor (MSD) BMT as effective intensification. Over the last 25 years, the cure rate has improved from <20% to 50% or higher. Most of the clinical research during this time of great advancement focused on two major themes: (1) the role of aggressive induction therapy in not only improving CR rates but in post-remission outcomes; and (2) the role of aggressive post-remission therapy in further improving survival, with an emphasis on high-dose Ara C-based chemotherapy, BMT, and supportive care. But we have "miles to go before we sleep." Some of the challenges that will lead to ongoing reduction of population-based mortality for AML through young adulthood include: (1) improving access of adolescents to pediatric AML therapy; (2) stratification by prognostic factors; (3) individualized therapy based on individual genetics and leukemia cell biology; (4) and the use of novel therapies including targeted immuno-conjugates and "small molecules" which disrupt abnormal signal transduction pathways. This brief review looks at both the advances over the last three decades as well as discusses the challenges moving forward for ultimately curing all children with this disease.

High WT1 expression after induction therapy predicts high risk of relapse and death in pediatric acute myeloid leukemia

PURPOSE

To determine whether minimal residual disease (MRD) measured by Wilms' tumor gene 1 (WT1) expression is a prognostic marker in pediatric acute myeloid leukemia (AML), we quantified WT1 transcript by real-time quantitative-polymerase chain reaction in 92 AML at diagnosis and during follow-up.

PATIENTS AND METHODS

Patients (median age, 6 years; cytogenetics, favorable 27%, intermediate 59%, poor 13%) were treated between 1995 and 2002 and enrolled in Leucémie aiguë Myéloblastique Enfant (LAME) 89/91, LAME 99 pilot study and Acute Promyelocytic Leukemia French collaborative protocols. With a median follow-up of 26 months, event-free survival was 56% with a standard deviation (SD) of 5% and overall survival of 62.5% with an SD of 6%. WT1 copy number was normalized by TATA box binding protein gene transcripts and expressed as WT1/TBP x 1,000 ratio. Median WT1 ratio in normal patient controls was 12 (range, 0 to 57). A level over two SD than normal bone marrow controls (ie, WT1 ratio > 50), was considered as significant overexpression.

RESULTS

At diagnosis, WT1 overexpression was detected in 78% of patients (72 of 92 patients; median copy ratio, 2231). The WT1 values were significantly higher (P = .01) in favorable cytogenetics and lower (P < .0001) in M5-FAB subtype, 11q23 rearrangements (P < .001), and infants (P = .003) and demonstrate a strong correlation with fusion transcript AML1-ETO, PML-RARalpha expression. After induction treatment, WT1 ratio was analyzed in 46 of 72 patients and found above 50 in nine of 36 patients and five of 25 patients at D35-50 and 3 to 5 months, respectively. WT1 ratio > 50 after induction is an independent prognostic risk factor of relapse (P = .002) and death (P = .02).

CONCLUSION

WT1 quantification is an informative molecular marker for MRD in pediatric AML and is now performed as prospective analysis in ELAM02 protocol.

Treatment of childhood acute myeloid leukemia

Childhood acute myeloid leukemia is rare, but accounts for a significant number of malignancy-related deaths in this age group. However, the prognosis has improved over past decades, and survival rates of 60% and above have been reported. Still, this implies that more than a third of children and adolescents die from this disease. Moreover, treatment is intensive, and quality of life and late effects are worrying issues. Therefore, there is a need for further improved treatment of pediatric acute myeloid leukemia. This review describes several important developments in this respect, such as improved diagnostics, prognostic factors, subgroup-directed and tailored treatment, and targeted therapy. In addition, background information is provided and current treatment strategies are described, as well as the late effects of treatment. Most groups now have risk-group adapted protocols, with allogeneic stem cell transplantation often being reserved for the higher risk group. Even in these cases, the benefit of stem cell transplantation has not been demonstrated beyond reasonable doubt with current high-intensive chemotherapy. Similarly, the use of cranial irradiation for CNS prophylaxis and maintenance treatment does not seem to be indicated in general. Subgroup-directed treatment has become a reality for acute myeloid leukemia in young children with Down's syndrome and in acute promyelocytic leukemia. In addition to tailoring therapy according to biologic features and especially monitoring treatment by measurements of minimal residual disease, targeted therapy for subgroups with activating mutations in receptor tyrosine kinases will further optimize the treatment of pediatric acute myeloid leukemia. Together with the development of many novel agents that have different mechanisms of action than the currently available anticancer agents, and improved supportive care, it is realistic that the prognosis of acute myeloid leukemia in children and adolescents will improve further in the next 5-10 years.

Antimetabolite-based therapy in childhood T-cell acute lymphoblastic leukemia: a report of POG study 9296

PURPOSE

A previous Pediatric Oncology Group (POG) study showed high incidence of secondary acute myelogenous leukemia (AML) in children treated for T-cell acute lymphoblastic leukemia (T-ALL) or higher-stage lymphoblastic lymphoma. To prevent secondary neoplasms, induce prolonged asparagine depletion, and maintain high event-free survival (EFS) in children with newly diagnosed T-ALL or higher-stage non-Hodgkins lymphoma (NHL), we designed this pilot study to determine feasibility and safety of substituting methotrexate/mercaptopurine for teniposide/cytarabine and PEG-asparaginase for native asparaginase.

PATIENTS AND METHODS

Forty-five patients were entered, 29 with T-ALL and 16 with higher-stage NHL. Forty-two of 45 patients achieved complete remission (CR), and 27 completed the therapy in continuous CR. Treatment consisted of 4-week induction then 6 weeks consolidation and ten 9-week maintenance cycles. Therapy primarily comprised antimetabolites, anthracyclines, alkylating agents, and asparaginase. Expected chemotherapy duration was 100 weeks.

RESULTS

Forty-two of 45 patients achieved CR, and 27 completed therapy. The most common toxicities were Grade 3 or 4 myelosuppression after cyclophosphamide/cytarabine and allergic reactions to asparaginase. Two died of sepsis early in maintenance. Five-year EFS was 68.5% (SE 9.1%) for T-ALL and 81.3% (SE 9.8%) for NHL. Five-year EFS was 73.1% (SE 6.8%) for the entire cohort. No patients treated entirely on this study developed secondary neoplasms. One patient taken off study for asparaginase toxicity was treated with multiagent therapy that contained teniposide, and died from secondary myelodysplasia (sMDS)/AML.

CONCLUSION

Substituting methotrexate/mercaptopurine for teniposide/cytarabine and PEG-asparaginase for native asparaginase in a dose-intensive regimen was feasible in children and young adults with newly diagnosed T-ALL or higher-stage NHL. EFS was not compromised and secondary neoplasms were decreased.

Treatment of childhood acute myeloblastic leukemia: dose intensification improves outcome and maintenance therapy is of no benefit--multicenter studies of the French LAME (Leucémie Aiguë Myéloblastique Enfant) Cooperative Group

From 1989 to 1998, 341 children were included in the French multicentric LAME (Leucémie Aiguë Myéloblastique Enfant) trials. A total of 309 children were registered in the LAME 89/91 protocol. This intensive regimen included an induction phase (mitoxantrone plus cytarabine), two consolidation courses, one containing timed-sequential high-dose cytarabine, asparaginase and amsacrine; 276 (90%) achieved a CR. The 5-year overall survival (OS) and event-free survival (EFS) were 60+/-4 and 48+/-4%, respectively. From 1997, timed-sequencing of the LAME SP induction chemotherapy led to an unacceptable frequency of consolidation delay; future improvements are unlikely to come from further increases in intensity. The role of allogenic bone-marrow transplantation from an HLA-identical sibling in CR1 was examined. The disease-free survival (DFS) was 52+/-4% for non-allografted patients and 57+/-7% for allografted patients (P=NS); a better OS for allografted patients was shown and could be related either to allo-BMT early in CR1 or to a second allo-BMT in CR2. For the complete responders after consolidation therapy, the 5-year OS was significantly better in patients randomized for no maintenance therapy (MT-) than in patients randomized for MT (77.6+/-8 vs 59+/-8%; P=0.05), while the 5-year DFS was not significantly different. Exposure to low-dose MT might contribute to clinical drug resistance and treatment failure in relapsing patients.