Intensified therapy for infants with acute lymphoblastic leukemia

Infant Acute Lymphoblastic Leukemia-New Therapeutic Opportunities

Infant acute lymphoblastic leukemia (Infant ALL) is a kind of pediatric ALL, diagnosed in children under 1 year of age and accounts for less than 5% of pediatric ALL. In the infant ALL group, two subtypes can be distinguished: KMT2A-rearranged ALL, known as a more difficult to cure form and KMT2A- non-rearranged ALL with better survival outcomes. As infants with ALL have lesser treatment outcomes compared to older children, it is pivotal to provide novel treatment approaches. Progress in the development of molecularly targeted therapies and immunotherapy presents exciting opportunities for potential improvement. This comprehensive review synthesizes the current literature on the epidemiology, clinical presentation, molecular genetics, and therapeutic approaches specific to ALL in the infant population.

Trends in the Epidemiology of Pneumocystis Pneumonia in Immunocompromised Patients without HIV Infection

The increasing morbidity and mortality of life-threatening Pneumocystis pneumonia (PCP) in immunocompromised people poses a global concern, prompting the World Health Organization to list it as one of the 19 priority invasive fungal diseases, calling for increased research and public health action. In response to this initiative, we provide this review on the epidemiology of PCP in non-HIV patients with various immunodeficient conditions, including the use of immunosuppressive agents, cancer therapies, solid organ and stem cell transplantation, autoimmune and inflammatory diseases, inherited or primary immunodeficiencies, and COVID-19. Special attention is given to the molecular epidemiology of PCP outbreaks in solid organ transplant recipients; the risk of PCP associated with the increasing use of immunodepleting monoclonal antibodies and a wide range of genetic defects causing primary immunodeficiency; the trend of concurrent infection of PCP in COVID-19; the prevalence of colonization; and the rising evidence supporting de novo infection rather than reactivation of latent infection in the pathogenesis of PCP. Additionally, we provide a concise discussion of the varying effects of different immunodeficient conditions on distinct components of the immune system. The objective of this review is to increase awareness and knowledge of PCP in non-HIV patients, thereby improving the early identification and treatment of patients susceptible to PCP.

Relapsed acute lymphoblastic leukaemia after allogeneic stem cell transplantation: a therapeutic dilemma challenging the armamentarium of immunotherapies currently available (case reports)

While survival rates in paediatric acute lymphoblastic leukaemia (ALL) nowadays exceed 90%, systemic ALL relapse, especially after haemopoietic stem cell transplantation (HSCT), is associated with a poor outcome. As there is currently no standardized treatment for this situation, individualized treatment is often pursued. Exemplified by two clinical scenarios, the aim of this article is to highlight the challenge for treating physicians to find a customized treatment strategy integrating the role of conventional chemotherapy, immunotherapeutic approaches and second allogeneic HSCT. Case 1 describes a 2-year-old girl with an early isolated bone marrow relapse of an infant KMT2A-rearranged B-cell precursor ALL after allogeneic HSCT. After bridging chemotherapy and lymphodepleting chemotherapy, chimeric antigen receptor (CAR) T-cells (tisagenlecleucel) were administered for remission induction, followed by a second HSCT from the 9/10 human leukocyte antigen (HLA)-matched mother. Case 2 describes a 16-year-old girl with a late, isolated bone marrow relapse of B-cell precursor ALL after allogeneic HSCT who experienced severe treatment toxicities including stage IV renal insufficiency. After dose-reduced bridging chemotherapy, CAR T-cells (tisagenlecleucel) were administered for remission induction despite a CD19^- clone without prior lymphodepletion due to enhanced persisting toxicity. This was followed by a second allogeneic HSCT from the haploidentical mother. While patient 2 relapsed around Day + 180 after the second HSCT, patient 1 is still in complete remission >360 days after the second HSCT. Both cases demonstrate the challenges associated with systemic ALL relapse after first allogeneic HSCT, including chemotherapy-resistant disease and persisting organ damage inflicted by previous therapy. Immunotherapeutic approaches, such as CAR T-cells, can induce remission and enable a second allogeneic HSCT. However, optimal therapy for systemic ALL relapse after first HSCT remains to be defined.

Presentation acuity, induction mortality, and resource utilization in infants with acute leukemia

BACKGROUND

Treatment of infants with acute leukemia remains challenging, especially for acute lymphocytic leukemia (ALL). Infants have shown markedly higher rates of induction mortality compared with noninfants. There are limited data on presentation acuity and supportive care utilization in this age group.

METHODS

In retrospective analyses of patients treated for new onset ALL or acute myeloid leukemia (AML) at pediatric hospitals contributing to the Pediatric Health Information System, we compared presentation acuity, induction mortality, and resource utilization in infants relative to noninfants less than 10 years at diagnosis.

RESULTS

Analyses included 10 359 children with ALL (405 infants, 9954 noninfants) and 871 AML (189 infants, 682 noninfants). Infants were more likely to present with multisystem organ failure compared to noninfants for both ALL (12% and 1%, PR = 10.8, 95% CI: 7.4, 15.7) and AML (6% vs. 3%; PR = 2.0, 95% CI: 1.0, 3.7). Infants with ALL had higher induction mortality compared to noninfants, even after accounting for differences in anthracycline exposure and presentation acuity (2.7% vs. 0.5%, HR = 2.1, 95% CI: 1.0, 4.8). Conversely, infants and noninfants with AML had similar rates of induction mortality (3.2% vs. 2.1%, HR = 1.2, 95% CI: 0.3, 3.9), which were comparable to rates among infants with ALL. Infants with ALL and AML had greater requirements for blood products, diuretics, supplemental oxygen, and ventilation during induction relative to noninfants.

CONCLUSIONS

Infants with leukemia present with higher acuity compared with noninfants. Induction mortality and supportive care requirements for infants with ALL were similar to all children with AML, and significantly higher than those for noninfants with ALL.

Late Effects in Survivors of Neonatal Cancer

The current 5-year survival rate for cancer in infants is greater than 75% in developed countries. However, survivors of neonatal malignancies have an increased risk of late effects from their tumor or its treatment, which may lead to long-term morbidity and/or early mortality. This article reviews surgical approaches and chemotherapeutic agents commonly used in neonatal malignancies and their associated late effects. It also reviews the increased risk for late effects associated with radiation at a young age and hematopoietic stem cell transplantation at a young age.. It highlights the importance of survivor-specific multidisciplinary care in the long-term management of neonatal cancer survivors.

Hepatic late adverse effects after antineoplastic treatment for childhood cancer

BACKGROUND

Survival rates have greatly improved as a result of more effective treatments for childhood cancer. Unfortunately, the improved prognosis has been accompanied by the occurrence of late, treatment-related complications. Liver complications are common during and soon after treatment for childhood cancer. However, among long-term childhood cancer survivors, the risk of hepatic late adverse effects is largely unknown. To make informed decisions about future cancer treatment and follow-up policies, it is important to know the risk of, and associated risk factors for, hepatic late adverse effects. This review is an update of a previously published Cochrane review.

OBJECTIVES

To evaluate all the existing evidence on the association between antineoplastic treatment (that is, chemotherapy, radiotherapy involving the liver, surgery involving the liver and BMT) for childhood cancer and hepatic late adverse effects.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2018, Issue 1), MEDLINE (1966 to January 2018) and Embase (1980 to January 2018). In addition, we searched reference lists of relevant articles and scanned the conference proceedings of the International Society of Paediatric Oncology (SIOP) (from 2005 to 2017) and American Society of Pediatric Hematology/Oncology (ASPHO) (from 2013 to 2018) electronically.

SELECTION CRITERIA

All studies, except case reports, case series, and studies including fewer than 10 patients that examined the association between antineoplastic treatment for childhood cancer (aged 18 years or less at diagnosis) and hepatic late adverse effects (one year or more after the end of treatment).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection and 'risk of bias' assessment. The 'risk of bias' assessment was based on earlier checklists for observational studies. For the original version of the review, two review authors independently performed data extraction. For the update of the review, the data extraction was performed by one reviewer and checked by another reviewer.

MAIN RESULTS

Thirteen new studies were identified for the update of this review. In total, we included 33 cohort studies including 7876 participants investigating hepatic late adverse effects after antineoplastic treatment (especially chemotherapy and radiotherapy) for different types of childhood cancer, both haematological and solid malignancies. All studies had methodological limitations. The prevalence of hepatic late adverse effects, all defined in a biochemical way, varied widely, between 0% and 84.2%. Selecting studies where the outcome of hepatic late adverse effects was well-defined as alanine aminotransferase (ALT) above the upper limit of normal, indicating cellular liver injury, resulted in eight studies. In this subgroup, the prevalence of hepatic late adverse effects ranged from 5.8% to 52.8%, with median follow-up durations varying from three to 23 years since cancer diagnosis in studies that reported the median follow-up duration. A more stringent selection process using the outcome definition of ALT as above twice the upper limit of normal, resulted in five studies, with a prevalence ranging from 0.9% to 44.8%. One study investigated biliary tract injury, defined as gamma-glutamyltransferase (γGT) above the upper limit of normal and above twice the upper limit of normal and reported a prevalence of 5.3% and 0.9%, respectively. Three studies investigated disturbance in biliary function, defined as bilirubin above the upper limit of normal and reported prevalences ranging from 0% to 8.7%. Two studies showed that treatment with radiotherapy involving the liver (especially after a high percentage of the liver irradiated), higher BMI, and longer follow-up time or older age at evaluation increased the risk of cellular liver injury in multivariable analyses. In addition, there was some suggestion that busulfan, thioguanine, hepatic surgery, chronic viral hepatitis C, metabolic syndrome, use of statins, non-Hispanic white ethnicity, and higher alcohol intake (> 14 units per week) increase the risk of cellular liver injury in multivariable analyses. Chronic viral hepatitis was shown to increase the risk of cellular liver injury in six univariable analyses as well. Moreover, one study showed that treatment with radiotherapy involving the liver, higher BMI, higher alcohol intake (> 14 units per week), longer follow-up time, and older age at cancer diagnosis increased the risk of biliary tract injury in a multivariable analysis.

AUTHORS' CONCLUSIONS

The prevalence of hepatic late adverse effects among studies with an adequate outcome definition varied considerably from 1% to 53%. Evidence suggests that radiotherapy involving the liver, higher BMI, chronic viral hepatitis and longer follow-up time or older age at follow-up increase the risk of hepatic late adverse effects. In addition, there may be a suggestion that busulfan, thioguanine, hepatic surgery, higher alcohol intake (>14 units per week), metabolic syndrome, use of statins, non-Hispanic white ethnicity, and older age at cancer diagnosis increase the risk of hepatic late adverse effects. High-quality studies are needed to evaluate the effects of different therapy doses, time trends, and associated risk factors after antineoplastic treatment for childhood cancer.

Neurocognitive Consequences of Childhood Leukemia and Its Treatment

As survival rates have improved in pediatric patients with leukemia, late side effects from chemotherapeutics and radiotherapy have become important considerations. We investigated these side effects and evaluated their impact on neurocognitive functions. The observational study included 68 patients with acute leukemia who were treated at Eskisehir Osmangazi University Medical Faculty. The study also included 62 of the patients' closest age siblings as a control group. Demographic and clinical data, chemotherapy protocol, use of radiotherapy were recorded, neurological and ophthalmological examinations, cranial imaging, electroencephalography, visual evoked potential, and hearing investigations were performed, and neurocognitive functions were evaluated. At least one or more late effects detected by a neurologic abnormality on physical exam, cranial magnetic resonance imaging, neurological tests, or neurocognitive tests was significantly more likely in the patient group (82.4%) compared to the control group (29%, p < 0.001). A higher rate (82.4%) of delayed neurological and cognitive problems occurred in children who received radiotherapy, intrathecal and/or systemic chemotherapy during leukemia treatment compared to age-matched siblings. Patients being treated for leukemia should be periodically evaluated for treatment-related side effects. Prophylactic interventions such cognitive training and maintenance of academic growth may offer the best hope of preventing late effects.

[Infant acute leukemia]

If acute leukemia is the most frequent cancer in childhood (33%), it remains a very rare diagnosis in infants less than one year old, e.g. less than 5% of cases. At this age, the frequency of acute lymphoblastic leukemia (ALL) (almost all of B-lineage) is quite similar to the one of myeloblastic forms (AML). Infant leukemia frequently presents with high hyperleucocytosis, major tumoral burden and numerous extra-hematological features, especially in central nervous system and skin. Whatever the lineage, the leukemic cell is often very immature cytologically and immunologically. Rearrangements of the Mixed Lineage Leukemia (MLL) gene, located on band 11q23, are the hallmark of these immature leukemias and confer a particular resistance to conventional approaches, corticosteroids and chemotherapy. The immaturity of infants less than 1-year-old is associated to a decrease of the tolerable dose-intensity of some drugs (anthracyclines, alkylating agents) or asks questions about some procedures like radiotherapy or high dose conditioning regimen, responsible of inacceptable acute and late toxicities. The high level of severe infectious diseases and other high-grade side effects limits also the capacity to cure these infants. The survival of infants less than 1-year-old with AML is only 50% but similar to older children. On the other hand, survival of those with ALL is the same, then quite limited comparing the 80% survival in children over one year. Allogeneic stem cell transplantations are indicated in high-risk subgroups of infant ALL (age below 6 months, high hyperleucocytosis >300.10(9)/L, MLL-rearrangement, initial poor prednisone response). However, morbidity and mortality remain very important and these approaches cannot be extended to all cases. During the neonatal period, the dismal prognosis linked to the high number of primary failures or very early relapses and uncertainties about the late toxicities question physicians about ethics. It is an emergency to propose different strategies (targeted therapies) to these infants with acute leukemia as conventional trials failed to improve outcome.

Asparaginase in acute lymphoblastic leukemia

Cure rates in pediatric acute lymphoblastic leukemia have significantly improved over the past decades. Now, almost 90% of children will survive the disease. The cure rates in adolescents, young adults, and adults have not kept pace with the improvements in younger patients, even though almost an equal proportion of adult patients achieve complete remission as their pediatric counterparts. Differences in treatment regimens might be important. Intensive use of asparaginase has been a key component of successful pediatric therapy. In this review, we focus on the use of asparaginase and the potential of optimizing asparaginase use via monitoring to minimize adverse drug events and improve efficacy of the drug.

Intensified chemotherapy without SCT in infant ALL: results from COG P9407 (Cohort 3)

BACKGROUND

Infants with acute lymphoblastic leukemia (ALL) present with aggressive disease and a poor prognosis. Early relapse within 6-9 months of diagnosis is common. Approximately 75% of infants have MLL-rearranged (MLL-R) ALL with event free survival (EFS) ranging from 20% to 30%. Children's Oncology Group (COG) P9407 used shortened (46 weeks), intensified therapy to address early relapse and poor EFS.

PROCEDURE

P9407 therapy was modified three times for induction toxicity resulting in three cohorts of therapy. One hundred forty-seven infants were enrolled in the third cohort.

RESULTS

We report an overall 5-year EFS and OS of 42.3 ± 6% and 52.9 ± 6.5% respectively. Poor prognostic factors included age ≤90 days at diagnosis, MLL-R ALL and white cell count ≥50,000/μl. For infants ≤90 days of age, the 5-year EFS was 15.5 ± 10.1% and 48.5 ± 6.7% for those >90 days (P < 0.0001). Among infants >90 days of age, 5-year EFS rates were 43.8 ± 8% for MLL-R versus 69.1 ± 13.6% for MLL-germline ALL (P < 0.0001).

CONCLUSIONS

Age ≤90 days at diagnosis was the most important prognostic factor. Despite shortened therapy with early intensification, EFS remained less than 50% overall in MLL-R ALL.

Decreased induction morbidity and mortality following modification to induction therapy in infants with acute lymphoblastic leukemia enrolled on AALL0631: a report from the Children's Oncology Group

BACKGROUND

Infants with acute lymphoblastic leukemia (ALL) have a poor prognosis. Intensification of therapy has resulted in fewer relapses but increased early deaths, resulting in failure to improve survival.

PROCEDURE

AALL0631 is a Phase 3 study for infants (<366 days of age) with newly diagnosed ALL. Induction initially (Cohort 1) consisted of 3 weeks of therapy based on COG P9407. Due to excessive early mortality, induction was amended to a less intensive 5 weeks of therapy based on Interfant-99. Additionally, enhanced supportive care guidelines were incorporated with hospitalization during induction until evidence of marrow recovery and recommendations for prevention/treatment of infections (Cohort 2).

RESULTS

Induction mortality was significantly lower for patients in Cohort 2 (2/123, 1.6%) versus Cohort 1 (4/26, 15.4%; P = 0.009). All induction deaths were infection related except one due to progressive disease (Cohort 2). Sterile site infections were lower for patients in Cohort 2 (24/123, 19.5%) versus Cohort 1 (15/26, 57.7%; P = 0.0002), with a significantly lower rate of Gram positive infections during induction for patients in Cohort 2, P = 0.0002. No clinically significant differences in grades 3-5 non-infectious toxicities were observed between the two cohorts. Higher complete response rates were observed at end induction intensification for Cohort 2 (week 9, 94/100, 94%) versus Cohort 1 (week 7, 17/25, 68%; P = 0.0.0012).

CONCLUSION

De-intensification of induction therapy and enhanced supportive care guidelines significantly decreased induction mortality and sterile site infections, without decreasing complete remission rates.

Allogeneic haematopoietic stem cell transplantation for infant acute lymphoblastic leukaemia with KMT2A (MLL) rearrangements: a retrospective study from the paediatric acute lymphoblastic leukaemia working group of the Japan Society for Haematopoietic Cell Transplantation

Allogeneic haematopoietic stem cell transplantation (HSCT) is still considered to play an important role as a consolidation therapy for high-risk infants with acute lymphoblastic leukaemia (ALL). Here, we retrospectively analysed outcomes of HSCT in infants with ALL based on nationwide registry data of the Japan Society for Haematopoietic Cell Transplantation. A total of 132 allogeneic HSCT for infant ALL with KMT2A (MLL) gene rearrangements, which were performed in first complete remission (CR1), were analysed. The 5-year overall survival rate after transplantation was 67·4 ± 4·5%). Although recent HSCT (after 2004) had a trend toward better survival, no statistical correlation was observed between outcomes and each factor, including age at diagnosis, initial leucocyte count, cytogenetics, donor types or conditioning of HSCT. Myeloablative conditioning with total body irradiation did not provide a better survival (60·7 ± 9·2%) over that with busulfan (BU; 67·8 ± 5·7%). Two of the 28 patients treated with irradiation, but none of the 90 BU-treated patients, developed a secondary malignant neoplasm. In conclusion, allogeneic HSCT using BU was a valuable option for infant ALL with KMT2A rearrangements in CR1.

The evolution of clinical trials for infant acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) in infants has a significantly inferior outcome in comparison with older children. Despite initial improvements in survival of infants with ALL since establishment of the first pediatric cooperative group ALL trials, the poor outcome has plateaued in recent years. Historically, infants were treated on risk-adapted childhood ALL protocols. These studies were pivotal in identifying the need for infant-specific protocols, delineating prognostic categories and the requirement for a more unified approach between study groups to overcome limitations in accrual because of low incidence. This subsequently led to the development of collaborative infant-specific studies. Landmark outcomes have included the elimination of cranial radiotherapy following the discovery of intrathecal and high-dose systemic therapy as a superior and effective treatment strategy for central nervous system disease prophylaxis, with improved neurodevelopmental outcome. Universal prospective identification of independent adverse prognostic factors, including presence of a mixed lineage leukemia rearrangement and young age, has established the basis for risk stratification within current trials. The infant-specific trials have defined limits to which conventional chemotherapeutic agents can be intensified to optimize the balance between treatment efficacy and toxicity. Despite variations in therapeutic intensity, there has been no recent improvement in survival due to the equilibrium between relapse and toxicity. Ultimately, to improve the outcome for infants with ALL, key areas still to be addressed include identification and adaptation of novel prognostic markers and innovative therapies, establishing the role of hematopoietic stem cell transplantation in first complete remission, treatment strategies for relapsed/refractory disease and monitoring and timely intervention of late effects in survivors. This would be best achieved through a single unified international trial.

Essential role of PR-domain protein MDS1-EVI1 in MLL-AF9 leukemia

A subgroup of leukemogenic mixed-lineage leukemia (MLL) fusion proteins (MFPs) including MLL-AF9 activates the Mecom locus and exhibits extremely poor clinical prognosis. Mecom encodes EVI1 and MDS1-EVI1 (ME) proteins via alternative transcription start sites; these differ by the presence of a PRDI-BF1-RIZ1 (PR) domain with histone methyltransferase activity in the ME isoform. Using an ME-deficient mouse, we show that ME is required for MLL-AF9-induced transformation both in vitro and in vivo. And, although Nup98-HOXA9, MEIS1-HOXA9, and E2A-Hlf could transform ME-deficient cells, both MLL-AF9 and MLL-ENL were ineffective, indicating that the ME requirement is specific to MLL fusion leukemia. Further, we show that the PR domain is essential for MFP-induced transformation. These studies clearly indicate an essential role of PR-domain protein ME in MFP leukemia, suggesting that ME may be a novel target for therapeutic intervention for this group of leukemias.

Postinduction dexamethasone and individualized dosing of Escherichia Coli L-asparaginase each improve outcome of children and adolescents with newly diagnosed acute lymphoblastic leukemia: results from a randomized study--Dana-Farber Cancer Institute ALL Consortium Protocol 00-01

PURPOSE

We assessed the toxicity and efficacy of dexamethasone and a novel dosing method of Escherichia coli L-asparaginase (EC-Asnase) in children and adolescents with newly diagnosed acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

Patients achieving complete remission (CR) on Dana-Farber Cancer Institute ALL Consortium Protocol 00-01 were eligible for random assignment to 1) dexamethasone or prednisone, administered as 5-day pulses, every 3 weeks, and 2) weekly EC-Asnase, administered as a 25,000 IU/m(2) fixed dose (FD) or individualized dose (ID) starting at 12,500-IU/m(2), adjusted every 3 weeks based on nadir serum asparaginase activity (NSAA) determinations.

RESULTS

Between 2000 and 2004, 492 evaluable patients (ages 1 to 18 years) enrolled; 473 patients (96%) achieved CR. Four hundred eight patients (86%) participated in the corticosteroid randomization and 384 patients (81%) in the EC-Asnase randomization. With 4.9 years of median follow-up, dexamethasone was associated with superior 5-year event-free survival (EFS; 90% v 81% for prednisone; P = .01) but higher rates of infection (P = .03) and, in older children, higher cumulative incidence of osteonecrosis (P = .02) and fracture (P = .06). ID EC-Asnase had superior 5-year EFS (90% v 82% for FD; P = .04), but did not reduce the frequency of asparaginase-related toxicity. Multivariable analysis identified both dexamethasone and ID EC-Asnase as independent predictors of favorable EFS.

CONCLUSION

There was no overall difference in skeletal toxicity by corticosteroid type; dexamethasone was associated with more infections and, in older children, increased incidence of osteonecrosis and fracture. There was no difference in asparaginase-related toxicity by EC-Asnase dosing method. Dexamethasone and ID EC-Asnase were each associated with superior EFS. Monitoring NSAA during treatment with EC-Asnase may be an effective strategy to improve outcome in pediatric ALL.

Modifications to induction therapy decrease risk of early death in infants with acute lymphoblastic leukemia treated on Children's Oncology Group P9407

BACKGROUND

Infants (<366 days of age) with acute lymphoblastic leukemia (ALL) have a poor prognosis. Most treatment failures occur within 6-9 months of diagnosis, primarily from relapse.

PROCEDURE

The Children's Oncology Group P9407 study was designed to test if early intensified treatment would improve outcome for infants with ALL. Due to a significant number of early deaths (< 90 days from enrollment), Induction therapy was amended three times. Cohorts 1 + 2 (n = 68), received identical Induction therapy except for reduced daunorubicin dose in Cohort 2. Cohort 3 (n = 141) received prednisone (40 mg/m(2)/day) instead of dexamethasone (10 mg/m(2)/day) and short infusion daunorubicin (30 minutes) instead of continuous infusion (48 hours), as well as additional supportive care measures throughout therapy.

RESULTS

Early deaths occurred in 17/68 (25%) infants in Cohorts 1 + 2 and 8/141 (5.7%) infants in Cohort 3 (P < 0.0001). Among infants ≤90 days of age at diagnosis, early death occurred in 10/17 (58.8%) in Cohorts 1 + 2 and 4/27 (14.8%) in Cohort 3 (P = 0.006). Among infants >90 days of age at diagnosis, early death occurred in 7/51 (13.7%) in Cohorts 1 + 2 and 4/114 (3.5%) in Cohort 3 (P = 0.036). Bacterial, viral, and fungal infections were more common in Cohorts 1 + 2 versus Cohort 3.

CONCLUSIONS

Early morbidity and mortality for infants with ALL were reduced by substitution of prednisone (40 mg/m(2)/day) for dexamethasone (10 mg/m(2)/day), the delivery of daunorubicin over 30 minutes instead of a continuous infusion for 48 hours, and the provision of more specific supportive care measures.

Hepatic late adverse effects after antineoplastic treatment for childhood cancer

BACKGROUND

Survival rates have greatly improved as a result of more effective treatments for childhood cancer. Unfortunately the improved prognosis has resulted in the occurrence of late, treatment-related complications. Liver complications are common during and soon after treatment for childhood cancer. However, among long-term childhood cancer survivors the risk of hepatic late adverse effects is largely unknown. To make informed decisions about future cancer treatment and follow-up policies it is important to know the risk of, and associated risk factors for, hepatic late adverse effects.

OBJECTIVES

To evaluate the existing evidence on the association between antineoplastic treatment for childhood cancer and hepatic late adverse effects.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, Issue 2), MEDLINE (1966 to June 2009) and EMBASE (1980 to June 2009). In addition, we searched reference lists of relevant articles and conference proceedings.

SELECTION CRITERIA

All studies except case reports, case series and studies including less than 10 patients that examined the association between antineoplastic treatment for childhood cancer (aged 18 years or less at diagnosis) and hepatic late adverse effects (one year or more after the end of treatment).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, risk of bias assessment and data extraction.

MAIN RESULTS

We identified 20 cohort studies investigating hepatic late adverse effects after antineoplastic treatment for childhood cancer. All studies had methodological limitations. The prevalence of hepatic late adverse effects varied widely, between 0% and 84.2%. Selecting studies where the outcome of hepatic late adverse effects was well defined as alanine aminotransferase (ALT) above the upper limit of normal resulted in five studies. In this subgroup the prevalence of hepatic late adverse effects ranged from 8.0% to 52.8%, with follow-up durations varying from one to 27 years after the end of treatment. A more stringent selection process using the outcome definition of ALT as above twice the upper limit of normal resulted in three studies, with a prevalence ranging from 7.9% to 44.8%. Chronic viral hepatitis was identified as a risk factor for hepatic late adverse effects in univariate analyses. It is unclear which specific antineoplastic treatments increase the risk of hepatic late adverse effects

AUTHORS' CONCLUSIONS

The prevalence of hepatic late adverse effects ranged from 7.9% to 52.8% when selecting studies with an adequate outcome definition. It has not been established which childhood cancer treatments result in hepatic late adverse effects. There is a suggestion that chronic viral hepatitis increases the risk of hepatic late adverse effects. More well-designed studies are needed to reliably evaluate the prevalence of, and risk factors for, hepatic late adverse effects after antineoplastic treatment for childhood cancer.

Erwinia asparaginase after allergy to E. coli asparaginase in children with acute lymphoblastic leukemia

BACKGROUND

Escherichia coli asparaginase is an important component of treatment for childhood acute lymphoblastic leukemia (ALL); however, hypersensitivity develops in up to 30% of patients. We assessed the nadir enzyme activity and tolerability of Erwinia asparaginase, an alternative preparation, in E. coli asparaginase-allergic patients.

PATIENTS AND METHODS

Between 2000 and 2002, 215 children with newly diagnosed ALL were enrolled on Dana-Farber Cancer Institute ALL Consortium Protocol 00-01 and were to receive 30 weekly doses of intramuscular E. coli asparaginase. If E. coli asparaginase allergy developed, patients were switched to twice-weekly intramuscular Erwinia asparaginase (25,000 IU/m(2)). Nadir serum asparaginase activity (NSAA) was measured every 3 weeks.

RESULTS

Forty-two patients (20%) developed E. coli asparaginase allergy and switched to Erwinia. Of 38 patients with evaluable samples, 34 (89%) Erwinia-treated patients had at least one therapeutic NSAA (> or =0.1 IU/ml). The median NSAA was 0.247 IU/ml 3 days and 0.077 IU/ml 4 days after an Erwinia dose. Associated toxicities included allergy in 14 (33%) and pancreatitis in 3 patients (7%). At a median follow-up of 5.4 years, event-free survival (+/-standard error) of the 42 patients who switched to Erwinia was 86 +/- 5% compared with 81 +/- 3% for the 170 patients without E. coli asparaginase allergy (P = 0.55).

CONCLUSIONS

Twice-weekly Erwinia asparaginase was well tolerated and achieved a therapeutically effective NSAA in most E. coli asparaginase-allergic patients. Development of E. coli allergy and subsequent treatment with twice-weekly Erwinia did not adversely impact event-free survival. Erwinia asparaginase should be considered for E. coli asparaginase-allergic patients.

Long-term results of Dana-Farber Cancer Institute ALL Consortium protocols for children with newly diagnosed acute lymphoblastic leukemia (1985-2000)

The Dana-Farber Cancer Institute (DFCI) ALL Consortium has been conducting multi-institutional clinical trials in childhood ALL since 1981. The treatment backbone has included 20–30 consecutive weeks of asparaginase during intensification and frequent vincristine/corticosteroid pulses during the continuation phase. Between 1985–2000, 1457 children aged 0–18 years were treated on four consecutive protocols: 85-01 (1985–7), 87-01 (1987–91), 91-01 (1991–5) and 95-01 (1996–2000). The 10-year event-free survival (EFS) ± standard error by protocol was 77.9 ± 2.8% (85-01), 74.2± 2.3 (87-01), 80.8 ± 2.1% (91-01) and 80.5 ± 1.8% (95-01). Approximately 82% of patients treated in the 1980s and 88% treated in the 1990s were long-term survivors. Both EFS and overall survival (OS) rates were significantly higher for patients treated in the 1990s compared with the 1980s (p=0.05 and 0.01, respectively). On the two protocols conducted in the 1990s, EFS was 79–85% for T-ALL patients and 75–78% for adolescents (age 10–18 years). Results of randomized studies revealed that dexrazoxane prevented acute cardiac injury without adversely impacting EFS or OS in high-risk patients and frequently-dosed intrathecal chemotherapy was an effective substitute for cranial radiation in standard-risk patients. Current studies continue to focus on improving efficacy while minimizing acute and late toxicities.

Outcome of congenital acute lymphoblastic leukemia treated on the Interfant-99 protocol

Acute lymphoblastic leukemia (ALL) diagnosed in the first month of life (congenital ALL) is very rare. Although congenital ALL is often assumed to be fatal, no studies have been published on outcome except for case reports. The present study reports the outcome of 30 patients with congenital ALL treated with the uniform Interfant-99 protocol, a hybrid regimen combining ALL treatment with elements designed for treatment of acute myeloid leukemia. Congenital ALL was characterized by a higher white blood cell count and a strong trend for higher incidence of MLL rearrangements and CD10-negative B-lineage ALL compared with older infants. Induction failure rate was 13% and not significantly different from that in older infants (7%, P = .14), but relapse rate was significantly higher in congenital ALL patients (2-year cumulative incidence [SE] was 60.0 [9.3] vs 34.2 [2.3], P < .001). Two-year event-free survival and survival of congenital ALL patients treated with this protocol was 20% (SE 9.1%). Early death in complete remission and treatment delays resulting from toxicity were not different. The survival of 17% after last follow-up, combined with a toxicity profile comparable with that in older infants, justifies treating congenital ALL with curative intent. This trial was registered at www.clinicaltrials.gov as no. NCT 00015873, and at www.controlled-trials.com as no. ISRCTN24251487.

Outcome of recurrent or refractory acute lymphoblastic leukemia in infants with MLL gene rearrangements: A report from the Japan Infant Leukemia Study Group

BACKGROUND

Despite the poor outcome of recurrent or refractory acute lymphoblastic leukemia (ALL) in infants with MLL gene rearrangement, few studies have focused on this specific group. We conducted a retrospective analysis of infants with recurrent or refractory ALL from two previous consecutive Japanese studies to clarify the characteristics and prognostic factors among these patients

PROCEDURE

All recurrent or refractory ALL infants with MLL gene rearrangement (MLL-R) who were registered in two consecutive Japanese nation-wide multicentric trials (MLL96 and MLL98; between 1995 and 2001) were eligible for the study.

RESULTS

Among 80 MLL-R ALL infants, 34 cases of recurrence and 5 induction failures occurred. The median duration of first remission was 5 months (range, 0-28 months). All patients underwent various salvage chemotherapies; remission was achieved in 40.5% (15/37). A total of 23 patients received subsequent hematopoietic stem cell transplantations (HSCT): 9 in remission, 12 without remission, and 2 with unknown status. With median follow-up period of 5.5 years, the 5-year overall survival (OS) rate after the second-line treatment was 25.6% +/- 6.9%. Young age (<3 months) and central nervous system involvement at initial diagnosis were associated with poor outcome; however, failure to achieve remission after salvage therapy was the sole independent poor prognostic factor in multivariate analysis (P = 0.01).

CONCLUSIONS

The prognosis of infants with recurrent or refractory MLL-R ALL is extremely poor despite alternative treatments including HSCT; therefore, it is necessary to develop novel treatment strategies.

Analysis of infectious complications in infants with acute lymphoblastic leukemia treated on the Children's Cancer Group Protocol 1953: a report from the Children's Oncology Group

Infants with acute lymphoblastic leukemia have a poor prognosis. The Children's Cancer Group (CCG) 1953 protocol tested the hypothesis that intensification of therapy would improve outcome for these patients. This intensified therapy resulted in better disease control, but resulted in greater toxicity. In this paper, we report the infectious complications associated with this intensified therapy. We retrospectively analyzed the infectious complications reported on the case report forms of all 115 patients enrolled on CCG 1953. Overall 495 infectious complications were identified in 115 patients. Bacterial infections occurred most frequently (74%), followed by viral (13%), fungal (11%), and protozoan (1%). Infection related mortality disproportionately occurred with viral (31%) and fungal (19%) infections. Twenty-three percent (n=26) of patients died of infectious complications, with the majority occurring during induction/intensification. Lower respiratory infections contributed to death in 12 patients and were most commonly viral (n=6) and fungal (n=3). Intensification of therapy resulted in increased infectious complications and deaths compared with previous studies. Future studies will need to focus on: (1) decreasing intensification during the first month of therapy, (2) developing targeted therapies, and (3) improving measures designed to prevent, quickly diagnose, and appropriately treat infections.

Neurodevelopmental sequelae of pediatric acute lymphoblastic leukemia and its treatment

This review will describe the neurocognitive outcomes associated with pediatric acute lymphoblastic leukemia (ALL) and its treatment. The literature is reviewed with the aim of addressing methodological issues, treatment factors, risks and moderators, special populations, relationship to neuroimaging findings, and directions for future research. It is concluded that neurocognitive outcomes for the majority of children with standard-risk ALL treated according to current chemotherapy protocols is relatively good, but subgroups of children are more significantly compromised. As medical treatments advance and survival rates continue to improve, neurocognitive outcomes and other quality of life indicators will become increasingly important. Preventing or ameliorating treatment-related neuropsychological sequelae represents the next major challenge in pediatric ALL.

Ornithine decarboxylase prevents methotrexate-induced apoptosis by reducing intracellular reactive oxygen species production

Methotrexate (MTX), a folate antagonist, was developed for the treatment of malignancies, and is currently used in rheumatoid arthritis (RA) and other chronic inflammatory disorders. It has been proven in short-term and long-term prospective studies that low doses of MTX (0.75 mg/Kg/week) are effective in controlling the inflammatory manifestations of RA. Low-concentrations of MTX achieve apoptosis and clonal deletion of activated peripheral T cells. One of the mechanisms of the anti-inflammatory and immunosuppressive effects may be the production of reactive oxygen species (ROS). However, the drug resistance of MTX in malignancies remains poorly understood. Ornithine decarboxylase (ODC) plays an important role in diverse biological functions, including cell development, differentiation, transformation, growth and apoptosis. In our previous studies, ODC overexpression was shown to prevent TNFalpha-induced apoptosis via reducing ROS. Here, we also investigated one mechanism of MTX-induced apoptosis and of drug resistance as to the anti-apoptotic effects of ODC during MTX treatment. We found MTX could induce caspase-dependent apoptosis and promote ROS generation together with disrupting the mitochondrial membrane potential (DeltaPsim) of HL-60 and Jurkat T cells. Putrescine and ROS scavengers could reduce MTX-induced apoptosis, which leads to the loss of DeltaPsim, through reducing intracellular ROS. Overexpression of ODC in parental cells had the same effects as putrescine and the ROS scavengers. Moreover, ODC overexpression prevented the decline of Bcl-2 that maintains DeltaPsim, the cytochrome c release and activations of caspase 9 and 3 following MTX treatment. The results demonstrate that MTX-induced apoptosis is ROS-dependent and occurs along a mitochondria-mediated pathway. Overexpressed ODC cells are resistant to MTX-induced apoptosis by reducing intracellular ROS production.

Acute lymphoblastic leukemia in infancy

Infant ALL is uncommon, biologically distinctive from the disease in older children, and associated with a relatively poor prognosis. Adverse prognostic factors include the presence of an MLL gene rearrangement (observed in up to 80% of infants with ALL), younger age at diagnosis, high presenting leukocyte counts, and slow early response to therapy. The role of stem cell transplant in first remission remains controversial. Current research efforts to improve the outcome of MLL-rearranged ALL in infants include clinical trials testing cytarabine-intensive regimens and translational investigations of novel, targeted therapies, such as FLT3-inhibitors.

Insights from clinical studies into the role of the MLL gene in infant and childhood leukemia

Translocations involving the Mixed Lineage Leukemia (MLL) gene at 11q23 are found in both acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML), but have different prognostic implications depending on the phenotype of the leukemia in de novo pediatric cases. The majority of MLL gene rearrangements are associated with infant ALL, and their presence predicts a poor prognosis which worsens with earlier age of presentation. Rearrangements of the MLL gene are found in most cases of infant AML and regardless of age confer an intermediate risk. The treatment of MLL-rearranged ALL in children involves increased intensification of chemotherapy, and infants with ALL are treated with an intensive regimen of ALL- and AML-like chemotherapy, with the proportion of MLL-rearranged cases being responsible for the poor outcome in this age group. The use of DNA microarray analysis to distinguish a particular gene signature for MLL-rearranged leukemias is shedding light on the molecular mechanisms and potential therapeutic targets of these leukemias. It may also prove to have a useful role in both diagnosis and prognosis. This review considers recent advances in our understanding of the role of MLL gene rearrangements in pediatric clinical practice.

Outcome of risk-based therapy for infant acute lymphoblastic leukemia with or without an MLL gene rearrangement, with emphasis on late effects: a final report of two consecutive studies, MLL96 and MLL98, of the Japan Infant Leukemia Study Group

We evaluated the efficacy of a treatment strategy in which infants with acute lymphoblastic leukemia (ALL) were stratified by their MLL gene status and then assigned to different risk-based therapies. A total of 102 patients were registered on two consecutive multicenter trials, designated MLL96 and MLL98, between 1995 and 2001. Those with a rearranged MLL gene (MLL-R, n=80) were assigned to receive intensive chemotherapy followed by hematopoietic stem cell transplantation (HSCT), while those with germline MLL (MLL-G, n=22) were treated with chemotherapy alone. The 5-year event-free survival (EFS) rate for all 102 infants was 50.9% (95% confidence interval, 41.0-60.8%). The most prominent late effect was growth impairment, observed in 58.9% of all evaluable patients in the MLL-R group. This plan of risk-based therapy appears to have improved the overall prognosis for infants with ALL, compared with previously reported results. However, over half the events in patients with MLL rearrangement occurred before the instigation of HSCT, and that HSCT-related toxic events comprised 36.3% (8/22) of post-transplantation events, suggesting that further stratification within the MLL-R group and the development of more effective early-phase intensification chemotherapy will be needed before the full potential of this strategy is realized.

A treatment protocol for infants younger than 1 year with acute lymphoblastic leukaemia (Interfant-99): an observational study and a multicentre randomised trial

BACKGROUND

Acute lymphoblastic leukaemia in infants younger than 1 year is rare, and infants with the disease have worse outcomes than do older children. We initiated an international study to investigate the effects of a new hybrid treatment protocol with elements designed to treat both acute lymphoblastic leukaemia and acute myeloid leukaemia, and to identify any prognostic factors for outcome in infants. We also did a randomised trial to establish the value of a late intensification course.

METHODS

Patients aged 0-12 months were enrolled by 17 study groups in 22 countries between 1999 and 2005. Eligible patients were stratified for risk according to their peripheral blood response to a 7-day prednisone prophase, and then given a hybrid regimen based on the standard protocol for acute lymphoblastic leukaemia, with some elements designed for treatment of acute myeloid leukaemia. Before the maintenance phase, a subset of patients in complete remission were randomly assigned to receive either standard treatment or a more intensive chemotherapy course with high-dose cytarabine and methotrexate. The primary outcomes were event-free survival (EFS) for the initial cohort of patients and disease-free survival (DFS) for the patients randomly assigned to a treatment group. Data were analysed on an intention-to-treat basis. This trial was registered with ClinicalTrials.gov, number NCT 00015873, and at controlled-trials.com, number ISRCTN24251487.

FINDINGS

In the 482 enrolled patients who underwent hybrid treatment, 260 (58%) were in complete remission at a median follow-up of 38 (range 1-78) months, and EFS at 4 years was 47.0% (SE 2.6, 95% CI 41.9-52.1). Of 445 patients in complete remission after 5 weeks of induction treatment, 191 were randomised: 95 patients to receive a late intensification course, and 96 to a control group. At a median follow-up of 42 (range 1-73) months, 60 patients in the treatment group and 57 controls were disease-free. DFS at 4 years did not differ between the two groups (60.9% [SE 5.2] for treatment group vs 57.0% [5.5] for controls; p=0.81). During the intensification phase, of 71 patients randomly assigned to the treatment group, and for whom toxicity data were available, 35 (49%) had infections, 21 (30%) patients had mucositis, 22 (31%) patients had toxic effects on the liver, and 2 (3%) had neurotoxicity. All types of rearrangements in the (mixed lineage leukaemia) MLL gene, very high white blood cell count, age of younger than 6 months, and a poor response to the prednisone prophase were independently associated with inferior outcomes.

INTERPRETATION

Patients treated with our hybrid protocol, and especially those who responded poorly to prednisone, had higher EFS than most reported outcomes for treatment of infant ALL. Delayed intensification of chemotherapy did not benefit patients.

Allogeneic bone marrow transplantation in first remission for children with ultra-high-risk features of acute lymphoblastic leukemia: A children's oncology group study report

The prognosis for childhood acute lymphoblastic leukemia (ALL) has improved dramatically over the past quarter of a century. Despite improvements in the treatment of childhood ALL, relapse still occurs in 20%-30% of patients. Although many of these relapses occur in the "standard-risk" patients, approximately 10% of these patients present at diagnosis with clinical and biological features that identify them as having a very high risk of relapse. Children (2 months to 21 years) with > or =1 ultra-high-risk feature (UHRF) of ALL in first remission treated on a frontline Children's Cancer Group (CCG) ALL study with a matched family allogeneic donor were eligible for study entry onto CCG-1921 and an allogeneic bone marrow transplant (AlloBMT). Each patient received fractionated total body irradiation (1200 cGy) and cyclophosphamide (120 mg/kg) conditioning therapy followed by unmobilized BM from a matched family donor. Graft-versus-host disease (GVHD) prophylaxis consisted of methotrexate and cyclosporin. Twenty-nine patients with a median age of 8.7 years with UHRF ALL in first complete remission (CR1) received an AlloBMT from a family member. The incidence of grade II-IV acute GVHD was 20.7% and the incidence of chronic GVHD was 3.7%. AlloBMT conditioning regimen was well tolerated and only 1 patient (3%) had treatment-related mortality. Ten patients (35%) died due to progressive disease. The 5-year event-free survival (EFS) for all patients was 58.6% and patients without cytogenetic abnormalities had a 5-year EFS of 77.8%. The 5-year EFS rates for infants and non-infants were 20.0% and 66.7% (log-rank test, P = .01), respectively. Patients with Philadelphia chromosome-positive ALL had a 5-year EFS of 66.7%. The children with UHRF of ALL may benefit from AlloBMT in CR1, especially patients with primary induction failure and Philadelphia chromosome-positive ALL. Randomized prospective cooperative group studies are required to establish the role of allogeneic hematopoietic stem cell transplantation versus intensive chemotherapy in children with UHRF ALL in CR1.

Results of the Dana-Farber Cancer Institute ALL Consortium Protocol 95-01 for children with acute lymphoblastic leukemia

The Dana-Farber Cancer Institute (DFCI) Childhood ALL Consortium Protocol 95-01 was designed to minimize therapy-related morbidity for children with newly diagnosed ALL without compromising efficacy. Patients participated in randomized comparisons of (1) doxorubicin given with or without dexrazoxane, a cardioprotectant (high-risk patients), (2) intensive intrathecal chemotherapy and cranial radiation (standard-risk patients), and (3) Erwinia and Escherichia coli asparaginase (all patients). Between 1996 and 2000, 491 patients (aged 0-18 years) were enrolled (272 standard risk and 219 high risk). With a median of 5.7 years of follow-up, the estimated 5-year event-free survival (EFS) for all patients was 82%+/-2%. Dexrazoxane did not have a significant impact on the 5-year EFS of high-risk patients (P=.99), and there was no significant difference in outcome of standard-risk patients based on type of central nervous system (CNS) treatment (P=.26). Compared with E coli asparaginase, Erwinia asparaginase was associated with a lower incidence of toxicity (10% versus 24%), but also an inferior 5-year EFS (78%+/-4% versus 89%+/-3%, P=.01). We conclude that (1) dexrazoxane does not interfere with the antileukemic effect of doxorubicin, (2) intensive intrathecal chemotherapy is as effective as cranial radiation in preventing CNS relapse in standard-risk patients, and (3) once-weekly Erwinia is less toxic than E coli asparaginase, but also less efficacious.

Favorable outcome for infant acute lymphoblastic leukemia after hematopoietic stem cell transplantation

Infants with acute lymphoblastic leukemia (ALL) have a poor prognosis when treated with standard chemotherapy. A subset of these infants, particularly those with mixed-lineage leukemia (MLL) rearrangements, has a high likelihood of relapse. Hematopoietic stem cell transplantation (HSCT) performed early in first remission may improve outcome. We present the results of 16 patients with infant ALL who were treated with HSCT in first remission. Six patients were < or =6 months of age at diagnosis, 11 had an initial white blood cell count of >50000/microL, and all patients with determinable cytogenetics had a high-risk karyotype [t(4:11) abnormality or other MLL rearrangement]. All patients received 150 cGy of total body irradiation for 8 doses (1200 cGy). Fifteen of 16 patients received etoposide at 1000 mg/m(2) as a continuous infusion over 24 hours and cyclophosphamide at 60 mg/kg/d for 3 days. Eight patients received HSCT from an HLA-identical sibling, and 8, from unrelated cord blood. Twelve (75%) patients remain long-term survivors (median follow-up, 4.7 years). Two patients, 1 of whom had minimal residual disease at HSCT, died after relapse following HSCT. Two patients died of transplant-related causes. The HSCT was well tolerated; 15 patients achieved neutrophil engraftment at a median of 16 days. Acute and chronic graft-versus-host disease were minimal in these patients. These results support the use of HSCT in the treatment of infant ALL, especially when used as consolidation in first remission. The risk of relapse seems to be decreased with this approach. Further work is being performed to determine the long-term effects from this therapy.

Comparable Long-Term Survival After Unrelated and HLA-Matched Sibling Donor Hematopoietic Stem Cell Transplantations for Acute Leukemia in Children Younger Than 18 Months

Purpose

To describe outcomes after unrelated donor stem cell transplantation (HCT) in children (< 18 months at diagnosis) with acute leukemia and compare these with outcomes after human leukocyte antigen (HLA)-matched sibling donor HCT.

Patients and Methods

We compared the results of unrelated donor HCT with bone marrow (n = 85) or cord blood grafts (n = 81) and HLA-matched sibling donor HCT with bone marrow grafts (n = 101) for acute myeloid or acute lymphoblastic leukemia using Cox proportional hazards models. Unrelated donor HCT recipients were younger, more likely to have MLL gene rearrangement, to have advanced leukemia, and to receive irradiation before HCT.

Results

Treatment-related mortality rates were 6%, 15%, and 31% after matched sibling, unrelated donor bone marrow, and cord blood HCT, respectively. Risks of relapse, overall and leukemia-free survival were significantly associated with disease status at transplantation. Though leukemia recurrence was lowest after unrelated donor HCT in first clinical remission (CR), overall survival, and leukemia-free survival rates were similar after matched sibling and unrelated donor HCT, after adjustment for disease status. Relapse, overall and leukemia-free survival did not differ by graft type (bone marrow v cord blood) or type of leukemia. Three-year probabilities of leukemia-free survival were 49% and 54% after HLA-matched sibling and unrelated donor transplantation in first CR, respectively. Corresponding rates for those with advanced leukemia were 20% and 30%.

Conclusion

Unrelated donor HCT should be considered for infants with acute leukemia in first CR using the same eligibility criteria as are currently used for those with HLA matched sibling donors.

Allogeneic hematopoietic cell transplantation for infants with acute lymphoblastic leukemia

The role of transplantation in infants with acute lymphoblastic leukemia (ALL) is not defined. We analyzed results of 40 infants diagnosed before age 12 months who received a hematopoietic cell transplant (HCT) between July 1982 and February 2003 in first complete remission (CR1; n = 17), CR2/3 (n = 7), or relapse (n = 16). Patients were conditioned with cyclophosphamide with total body irradiation (n = 39) or busulfan (n = 1). Donors were matched related (n = 8), mismatched related (n = 16), or unrelated (n = 16). Graft-versus-host disease (GVHD) prophylaxis was methotrexate or cyclosporine (n = 7) or methotrexate plus cyclosporine (n = 33). Thirty-nine patients engrafted, 20 developed acute GVHD, and 7 developed chronic GVHD. Sixteen patients relapsed and 7 died of other causes. Patients in CR1 had disease-free survival (DFS) of 76% compared with 45% for CR2/CR3 and 8% for relapse (P < .001). Of 33 patients with cytogenetic data, 26 (79%) had MLL gene rearrangement. Fourteen of these 26 were in CR1 and 11 survive in remission. Outcome was associated with phase of disease, but having the MLL gene was not a factor predictive of outcome. Late effects included growth and other hormone deficiencies. These data demonstrate that infants with ALL and MLL gene have excellent DFS when they received transplants in CR1, and consideration for transplantation in CR1 is warranted.

MLL-rearranged leukemias: insights from gene expression profiling

Gene expression analysis of human leukemias has provided insight into disease classification and mechanisms of oncogenesis. Its success is particularly evident for acute leukemias with rearrangement of the mixed lineage leukemia (MLL) gene on chromosome 11q23. Unlike most other recurrent translocations, MLL rearrangements are found in leukemias classified as acute myelogenous leukemia (AML) or acute lymphoblastic leukemia (ALL). In addition, MLL-rearranged leukemias often express both myeloid- and lymphoid-associated genes. These unusual characteristics have generated much interest in the cell of origin and the mechanism of transformation by MLL rearrangements. Here we review insights gained from characterization of MLL-rearranged human leukemias by genome-wide expression profiling and compare these to data from model systems.

In vitro drug-resistance profile in infant acute lymphoblastic leukemia in relation to age, MLL rearrangements and immunophenotype

Acute lymphoblastic leukemia (ALL) in infants under 1 year is strongly associated with translocations involving 11q23 (MLL gene), CD10-negative B-lineage (proB) immunophenotype, and poor outcome. The present study analyses the relationship between age, MLL rearrangements, proB-lineage, and in vitro drug resistance determined using the MTT assay. Compared to 425 children aged over 1 year with common/preB (c/preB) ALL, the 44 infants were highly resistant to steroids (for prednisolone (PRED) more than 580-fold, P=0.001) and L-asparaginase (L-ASP) (12-fold, P=0.001), but more sensitive to cytarabine (AraC) (1.9-fold, P=0.001) and 2-chlorodeoxyadenosine (2-CdA) (1.7-fold, P<0.001). No differences were found for vincristine, anthracyclines, thiopurines, epipodophyllotoxines, or 4-hydroperoxy (HOO)-ifosfamide. ProB ALL of all ages had a profile similar to infant ALL when compared with the group of c/preB ALL: relatively more resistant to L-ASP and PRED (and in addition thiopurines), and more sensitive to AraC and 2-CdA. Age was not related to cellular drug resistance within the proB ALL group (<1 year, n=32, vs >/=1 year, n=19), nor within the MLL-rearranged ALL (<1 year, n=34, vs >/=1 year, n=8). The translocation t(4;11)(q21;q23)-positive ALL cases were more resistant to PRED (>7.4-fold, P=0.033) and 4-HOO-ifosfamide (4.4-fold, P=0.006) than those with other 11q23 abnormalities. The expression of P-glycoprotein, multidrug-resistance protein, and lung-resistance protein (LRP) was not higher in infants compared to older c/preB ALL patients, but LRP was higher in proB ALL and MLL-rearranged ALL of all ages. In conclusion, infants with ALL appear to have a distinct in vitro resistance profile with the proB immunophenotype being of importance. The role of MLL cannot be excluded, with the t(4;11) being of special significance, while age appears to play a smaller role.

Fetal and neonatal leukemia

The biological and clinical characteristics of perinatal leukemia differ significantly from those of leukemia in older children, and the prognosis is generally bleak. Once complete remission is achieved, neonates with acute myelocytic leukemia (AML) fare much better than those with acute lymphocytic leukemia (ALL). The results of this study suggest that age, sex, type of leukemia, and cytogenetic findings have a strong influence on outcome. Neonates, particularly females, with pre-B ALL have a much worse prognosis than neonates and older children with this disease. Transient leukemia in the Down syndrome neonate is associated with significant morbidity; close follow-up is recommended for at least the first 3 years of life because of the potential of developing acute leukemia, particularly AMKL (M7). The purpose of this review is to focus on the fetus and neonate in an attempt to determine the various ways leukemia differs clinically and morphologically from the disease occurring in older infants and children and to demonstrate that certain types of leukemia have a poor prognosis compared with those occurring in older children.

Clinical heterogeneity in childhood acute lymphoblastic leukemia with 11q23 rearrangements

To assess the clinical heterogeneity among patients with acute lymphoblastic leukemia (ALL) and various 11q23 abnormalities, we analyzed data on 497 infants, children and young adults treated between 1983 and 1995 by 11 cooperative groups and single institutions. The substantial sample size allowed separate analyses according to age younger or older than 12 months for the various cytogenetic subsets. Infants with t(4;11) ALL had an especially dismal prognosis when their disease was characterized by a poor early response to prednisone (P=0.0005 for overall comparison; 5-year event-free survival (EFS), 0 vs 23+/-+/-12% s.e. for those with good response), or age less than 3 months (P=0.0003, 5-year EFS, 5+/-+/-5% vs 23.4+/-+/-4% for those over 3 months). A poor prednisone response also appeared to confer a worse outcome for older children with t(4;11) ALL. Hematopoietic stem cell transplantation failed to improve outcome in either age group. Among patients with t(11;19) ALL, those with a T-lineage immunophenotype, who were all over 1 year of age, had a better outcome than patients over 1 year of age with B-lineage ALL (overall comparison, P=0.065; 5-year EFS, 88+/-+/-13 vs 46+/-14%). In the heterogeneous subgroup with del(11)(q23), National Cancer Institute-Rome risk criteria based on age and leukocyte count had prognostic significance (P=0.04 for overall comparison; 5-year EFS, 64+/-+/-8% (high risk) vs 83+/-+/-6% (standard risk)). This study illustrates the marked clinical heterogeneity among and within subgroups of infants or older children with ALL and specific 11q23 abnormalities, and identifies patients at particularly high risk of failure who may benefit from innovative therapy.

Inhibition of FLT3 in MLL. Validation of a therapeutic target identified by gene expression based classification

We recently found that MLL-rearranged acute lymphoblastic leukemias (MLL) have a unique gene expression profile including high level expression of the receptor tyrosine kinase FLT3. We hypothesized that FLT3 might be a therapeutic target in MLL and found that 5 of 30 MLLs contain mutations in the activation loop of FLT3 that result in constitutive activation. Three are a newly described deletion of I836 and the others are D835 mutations. The recently described FLT3 inhibitor PKC412 proved cytotoxic to Ba/F3 cells dependent upon activated FLT3 containing either mutation. PKC412 is also differentially cytotoxic to leukemia cells with MLL translocations and FLT3 that is activated by either overexpression of the wild-type receptor or mutation. Finally, we developed a mouse model of MLL and used bioluminescent imaging to determine that PKC412 is active against MLL in vivo.

Risk-directed treatment of infant acute lymphoblastic leukaemia based on early assessment of MLL gene status: results of the Japan Infant Leukaemia Study (MLL96)

We studied the effectiveness of risk-directed therapy for infants younger than 13 months of age with acute lymphoblastic leukaemia (ALL). Fifty-five infants were assigned to different treatment programs (from December 1995 to December 1998) on the basis of their MLL gene status at diagnosis. Forty-two cases (76.3%) had a rearranged MLL gene (MLL+) and were treated with remission induction therapy followed by sequential intensive chemotherapy, including multiple genotoxic agents (MLL9601 protocol). Haematopoietic stem cell transplantation (HSCT) was attempted if suitable donors were available. Thirteen infants (23.7%) were classified as MLL- and treated for 2.5 years with intensive chemotherapy for high-risk B-ALL (MLL9602 protocol). Complete remission was induced in 38 of the 42 infants (90.5%) with MLL+ ALL and in all 13 patients (100%) with MLL- disease. In the MLL+ subgroup, the estimated event-free survival (EFS) rate at 3 years post diagnosis was 34.0% +/- 7.5%, compared with 92.3% +/- 7.4% in the MLL- subgroup (overall comparison, P = 0.001 by log-rank analysis). Both age less than 6 months (hazard ratio = 6.87, 95% CI = 0.91-52.3; P = 0.013) and central nervous system (CNS) involvement at diagnosis (hazard ratio = 2.92 95% CI = 1.29-6.63; P = 0.015) were significant independent predictors of an inferior outcome. These findings indicate a strategic advantage in classifying infant ALL as either MLL+ or MLL- early in the clinical course and selecting therapy accordingly. Standard chemotherapy for high-risk B-lineage ALL appeared adequate for MLL- cases. Novel therapeutic initiatives are warranted for infants with MLL+ disease, particularly those with initial CNS leukaemic involvement or age less than 6 months, or both.

Infant acute lymphoblastic leukemia - combined cytogenetic, immunophenotypical and molecular analysis of 77 cases

We used karyotyping, fluorescence in situ hybridization (FISH), Southern blotting, and RT-PCR in order to analyze prospectively 77 infants (less than 1 year of age) with acute lymphoblastic leukemia for the occurrence of 11q23/MLL rearrangements and/or other cytogenetic abnormalities. Out of the 69 informative samples we found an 11q23/MLL rearrangement in 42 cases (61%). Regarding only pro-B ALL cases, the incidence of 11q23/MLL rearranged cases, however, reached more than 90% The infants were treated within the therapy studies ALL-BFM90, ALL-BFM95 and CoALL-05-92. For patients with an adequate follow-up of 4 years the event-free survival of the 11q23/MLL-positive and 11q23/MLL-negative group was 0.2 or 0.64, respectively (P = 0.024). The monoclonal antibody 7.1. (moab 7.1) does not react with normal hematopoetic precursors or mature blood cells but was shown to specifically react with leukemic cells bearing a rearrangement of chromosome 11q23 or the MLL gene, respectively. We, therefore, specifically addressed the question whether the reactivity of moab 7.1, as determined by flow cytometry, may substitute for molecular testing of an 11q23/MLL rearrangement in this cohort of infant ALLs. Reactivity of moab 7.1 indicated a 11q23/MLL rearrangement with a specificity of 100%. However, five of the 11q23/MLL-positive cases did not react with moab 7.1 indicating a sensitivity of 84% only. Three of these five moab 7.1-negative but 11q23/MLL-positive cases could be identified by their unique expression pattern of CD65s and/or CD15. Thus, 95% of all 11q23/MLL-positive ALL cases in infancy may be identified by flow cytometry based on their expression of CD15, CD65s and/or moab 7.1.

Outcome of treatment in childhood acute lymphoblastic leukaemia with rearrangements of the 11q23 chromosomal region

BACKGROUND

The prognosis and optimum treatment of childhood acute lymphoblastic leukaemia (ALL) with abnormalities of chromosomal band 11q23 are controversial. We aimed to identify prognostic factors that might help in planning future therapy, and to assess the effectiveness of haemopoietic stem-cell transplantation in patients with the t(4;11) translocation, which is associated with a particularly poor outcome.

METHODS

We reviewed data on 497 children and young adults who had ALL with various 11q23 abnormalities, including the translocations t(4;11), t(9;11), and t(11;19). All patients were treated with intensive chemotherapy, with or without haemopoietic stem-cell transplantation in first complete remission, by 11 study groups and single institutions from 1983 to 1995.

FINDINGS

Age was the most important prognostic factor. In a Cox's proportional-hazard model stratified by 11q23 abnormalities, infants younger than 1 year fared significantly worse than patients 1 year of age or older (hazard ratio for event-free survival 1 84 [95% CI 1 38-2 47], p=0 0001). Among infants, any category of 11q23 abnormality conferred a dismal outcome, whereas in older patients, t(4;11) and t(9;11) were associated with a worse outcome than were other 11q23 changes. In the largest subgroup--256 patients with t(4;11)--any type of transplantation was associated with significantly worse disease-free survival (1 61 [1 10-2 35], p=0 014) and overall survival (1 76 [1 08-2 45], p=0 004) compared with chemotherapy only. Even transplantation with stem cells from HLA-matched related or HLA-matched unrelated donors tended to be associated with a worse outcome than chemotherapy alone.

INTERPRETATION

The prognosis of acute lymphoblastic leukaemia with an 11q23 abnormality is particularly dismal in infants. Allogeneic transplantation with haemopoietic stem cells from an HLA-matched related donor does not seem to improve the clinical outcome in patients with t(4;11)-positive leukaemia.

Central nervous system-directed therapy in the treatment of childhood acute lymphoblastic leukemia and studies of neurobehavioral outcome: Children's Cancer Group trials

Long-term survival rates in childhood acute lymphoblastic leukemia (ALL) have improved due, in part, to the introduction and subsequent refinements in central nervous system (CNS)-directed therapy. Studies of cognitive, motor, and behavioral functioning, which characterize the patterns and severity of CNS sequelae, are being used increasingly as measurable treatment endpoints. This paper summarizes the advances in CNS-directed therapy derived from Children's Cancer Group randomized therapeutic trials. Results from neurobehavioral outcome studies built upon these trials are also presented. A section of this review is focused on CNS-directed treatments and the neurodevelopmental outcomes of infants diagnosed with ALL, an especially high-risk patient subset. Future studies of neurobehavioral outcome are briefly elaborated in the context of current chemotherapy approaches used in the treatment of childhood ALL.

Treatment of childhood acute lymphoblastic leukemia: results of Dana-Farber ALL Consortium Protocol 87-01

PURPOSE

To improve efficacy and reduce toxicity of treatment for children with acute lymphoblastic leukemia.

PATIENTS AND METHODS

Patients from all risk groups, including infants and those with T-cell disease, were treated between 1987 and 1991. Standard-risk (SR) patients did not receive cranial irradiation, whereas high-risk (HR) and very high-risk (VHR) patients participated in a randomized comparison of 18 Gy of cranial irradiation conventionally fractionated versus two fractions per day (hyperfractionated).

RESULTS

At a median follow-up of 9.2 years, the 9-year event-free survival (EFS +/- SE) was 75% +/- 2% for all 369 patients, 77% +/- 4% for the 142 SR patients, and 73% +/- 3% for the 227 HR/VHR patients (P =.37 comparing SR and HR/VHR). The CNS, with or without concomitant bone marrow involvement, was the first site of relapse in 19 (13%) of the 142 SR patients: 16 (20%) of 79 SR boys and three (5%) of 63 SR girls. This high incidence of relapses necessitated a recall of SR boys for additional therapy. CNS relapse occurred in only two (1%) of 227 HR and VHR patients. There were no outcome differences found among randomized treatment groups. Nine-year overall survival was 84% +/- 2% for the entire population, 93% +/- 2% for SR children, and 79% +/- 3% for HR and VHR children (P <.01 comparing SR and HR/VHR).

CONCLUSION

A high overall survival outcome was obtained for SR patients despite the high risk of CNS relapse for SR boys, which was presumed to be associated with eliminating cranial radiation without intensifying systemic or intrathecal chemotherapy. For HR/VHR patients, inability to salvage after relapse (nearly all of which were in the bone marrow) remains a significant clinical problem.