Intensification of therapy for children with lower-risk acute lymphoblastic leukemia: long-term follow-up of patients treated on Children's Cancer Group Trial 1881

Late isolated central nervous system relapse in childhood B-cell acute lymphoblastic leukemia treated with intensified systemic therapy and delayed reduced dose cranial radiation: A report from the Children's Oncology Group study AALL02P2

BACKGROUND

Patients with late, ≥18 months postdiagnosis, isolated central nervous relapse (iCNS-R) of B-acute lymphoblastic leukemia (ALL) have excellent outcomes with chemotherapy plus cranial radiotherapy, with 5-year overall survival (OS) approaching 80% in POG 9412. Subsequent relapse and radiation-related morbidity remain the causes of treatment failure and long-term sequelae. COG AALL02P2 aimed to maintain outcomes in patients with late iCNS-R using intensified chemotherapy and a decrease in cranial irradiation from 1800 to 1200 cGy.

PROCEDURES

COG AALL02P2 enrolled 118 eligible patients with B-cell ALL (B-ALL) and late iCNS-R who received intensified systemic therapy, triple intrathecal chemotherapy, and 1200 cGy cranial irradiation delivered at 12 months, with maintenance chemotherapy continuing until 104 weeks postdiagnosis.

RESULTS

The 3-year event-free survival (EFS) and OS were 64.3% ± 4.5% and 79.6% ± 3.8%, with 46.1% (18/39) of second relapses including the CNS. Of the 112 patients who completed therapy, 78 received protocol-specified radiation. Study enrollment was closed after interim monitoring analysis showed inferior EFS compared to POG 9412. Patients with initial NCI standard-risk classification fared better than high-risk patients.

CONCLUSIONS

COG AALL02P2 showed inferior EFS but similar OS compared to POG 9412. Limitations included a small sample size, more intensive prior therapies, and a significant number of patients (34/118, 29%) who did not receive protocol-directed radiation due to early relapse prior to 1 year or did not otherwise follow the treatment plan. New approaches are needed to improve outcome for these patients and determine the optimal timing and dose of cranial radiation in the treatment of iCNS-R.

Treatment outcomes for childhood acute lymphoblastic leukemia in low-middle income country before minimal residual disease risk stratification

BACKGROUND

Outcome of childhood acute lymphoblastic leukemia (ALL) in low- and middle-income countries is lagging in many aspects including diagnosis, risk stratification, access to treatment and supportive care.

OBJECTIVE

to report the outcome of childhood ALL at Ain Shams University Children's Hospitals with the use of risk-based protocols before the implementation of minimal residual disease technology and to evaluate the use of double delayed intensification (DDI) in standard risk patients.

METHODS

Two hundred and twenty patients with ALL diagnosed between January 2005 and December 2014 were included in the study. Patients were treated according to a modified CCG 1991 and 1961 for standard and high risk respectively. Patients were stratified into three risk groups: standard risk (SR), high-risk standard arm (HR-SA), and high-risk augmented arm (HR-AA).

RESULTS

Among the whole cohort, the 10-year event-free survival (EFS) and overall survival (OS) were 78.1% and 84.3% respectively. Patients with Pre-B immunophenotype (IPT) had significantly better outcome than T-cell IPT (EFS 82.0% versus 58.6%, p < 0.001; OS 86.9% versus 69%, p = 0.003 for Pre-B and T-cell respectively). Among the SR group, patients treated with single delayed intensification (SDI) had comparable EFS and OS rates when compared to patients treated with DDI with EFS 82.4% versus 87.5%, p = 0.825 and OS 88.2% versus 93.5%, p = 0.638 for SDI and DDI groups, respectively.

CONCLUSION

The use of risk-based protocol with simple laboratory techniques resulted in acceptable survival outcome in resource limited settings. The use of double delayed intensification showed no survival advantage in patients with standard risk.

Acute Complications and Survival Analysis of Childhood Acute Lymphoblastic Leukemia: A 15-year Experience

BACKGROUND

We evaluated the acute complications that occurred during the treatment of childhood acute lymphoblastic leukemia (ALL) and documented the survival rates of children with ALL.

MATERIALS AND METHODS

We retrospectively evaluated 110 children with a diagnosis of ALL treated with the Children's Oncology Group protocol from 1999 to 2014. The demographic, clinical, and laboratory data of 110 patients and acute complications of eligible and evaluable 105 patients were recorded.

RESULTS

Of the 110 patients, 65 were male and 45 were female. The mean age at admission was 8.3 ± 5.2 years. Ninety-seven patients (88.2%) had been diagnosed with pre-B-cell ALL, 11 (10%) with T-cell ALL, 1 (0.9%) with mixed phenotype acute leukemia, and 1 (0.9%) with mature B-cell acute leukemia. Of the 110 patients, 40 (36.3%) were in the standard-risk group and 70 (63.7%) were in high-risk group. Of the 110 patients, 105 had been followed up regularly and evaluated for acute complications. Infection was the most common complication (n = 93; 88.5%), followed by gastrointestinal (n = 29; 27.6%), neurologic (n = 28; 26.6%), metabolic/endocrine (n = 16; 15.2%), drug-related hypersensitivity (n = 16; 15.2%), avascular necrosis (n = 13; 12.3%), thrombotic (n = 11; 10.4%), severe psychiatric (n = 2; 1.9%), and various other (n = 12; 11.4%) complications. Of the 110 patients, 98 were assessed in terms of survival analysis. The 5- and 10-year overall survival rates were both 85.9% (standard error [SE], 3.6%). The relapse-free survival rates at 1, 3, and 5 years were 97.9% (SE, 1.5%), 91.3% (SE, 3%), and 86.3% (SE, 3.7%), respectively.

CONCLUSION

Childhood ALL, although categorized as curable malignancy owing to the improvements in treatment strategies in recent years, can cause acute complications affecting various systems. Thus, patients should be treated and followed up by multidisciplinary medical teams with high expertise.

Pediatric-Inspired Treatment Regimens for Adolescents and Young Adults With Philadelphia Chromosome-Negative Acute Lymphoblastic Leukemia: A Review

Importance

The incidence of acute lymphoblastic leukemia (ALL) and lymphoblastic lymphoma (LBL) in adolescent and young adult (AYA) patients (age range, 15-39 years) in the United States is increasing at a greater rate than in younger or older persons. Their optimal treatment has been increasingly debated as pediatric regimens have become more widely used in the age group. This review compares the basic features of pediatric and adult chemotherapy regimens for ALL and LBL, recognizes and describes the challenges of the pediatric regimen, and suggests strategies to facilitate its adoption for AYAs with ALL and LBL.

Observations

All but 2 of 25 published comparisons of outcomes with pediatric and adult regimens for ALL and LBL in AYAs and 1 meta-analysis favor the pediatric regimen. After more than a half-century of clinical trials of the pediatric regimens, including at least 160 phase 3 trials in the United States, the pediatric regimens have become far more complex than most adult regimens. Asparaginase, a critical component of the pediatric regimens, is more difficult to administer to AYAs (and older patients) but nonetheless has a favorable benefit to toxicity ratio for AYAs. A dramatic reduction in outcome of ALL and LBL during the AYA years (the "survival cliff") is coincident with similar reductions in proportions of AYAs referred to academic centers and enrolled on clinical trials (the "accrual cliff" and "referral cliff").

Conclusions and Relevance

The accumulating data increasingly support treating AYAs with ALL and LBL with a pediatric-inspired regimen or an approved institutional or national clinical trial tailored for this patient group. A need to develop clinical trials specifically for AYAs and to encourage their participation is paramount, with a goal to improve both the quantity and quality of survival.

Intermittent Versus Continuous PEG-Asparaginase to Reduce Asparaginase-Associated Toxicities: A NOPHO ALL2008 Randomized Study

PURPOSE

Asparaginase is an essential drug in childhood acute lymphoblastic leukemia (ALL) therapy and is frequently given for months to obtain continuous asparagine depletion. We randomly assigned patients to continuous versus intermittent pegylated-asparaginase (PEG-asp) treatment, hypothesizing there would be decreased toxicity with unchanged efficacy.

METHODS

Children (median age, 4.2 years) treated for non–high-risk ALL according to the Nordic Society for Pediatric Hematology and Oncology ALL2008 protocol received five intramuscular PEG-asp injections (1,000 IU/m2) every two weeks and were then randomly assigned to additional three doses (6-week intervals [experimental arm], n = 309) versus 10 doses (2-week intervals [standard arm], n = 316). The primary end point was noninferior (6% margin) disease-free survival. Toxicity reduction was a secondary end point. Occurrence of asparaginase-associated hypersensitivity, pancreatitis, osteonecrosis, and thromboembolism were prospectively registered.

RESULTS

After a median follow-up of 4.1 years, the 5-year disease-free survival was 92.2% (95% CI, 88.6 to 95.8) and 90.8% (95% CI, 87.0 to 94.6) in the experimental and standard arms, respectively. The 3-year cumulative incidence of any first asparaginase-associated toxicity (hypersensitivity [n = 13]; osteonecrosis [n = 29]; pancreatitis [n = 24]; thromboembolism [n = 17]) was 9.3% in the experimental arm and 18.1% in the standard arm ( P = .001). Asparaginase-associated toxicity reduction was confirmed in sex- and risk-group–adjusted Cox regression analysis stratified by age (≥ 10 and < 10 years; hazard ratio, 0.48; P = .001). The experimental arm had the lowest incidences of all four toxicities, reaching significance for pancreatitis (6-month risk, 5.8% v 1.3%; P = .002).

CONCLUSION

The excellent cure rates and reduced toxicity risk support the use of intermittent PEG-asp therapy after the first 10 weeks in future childhood ALL trials that apply prolonged PEG-asp therapy.

Burden of Influenza-Related Hospitalizations and Attributable Mortality in Pediatric Acute Lymphoblastic Leukemia

BACKGROUND

Influenza can be severe in patients with underlying malignancy; however, the rate of influenza hospitalizations and attributable mortality in children with cancer is unknown.

METHODS

We performed a retrospective cohort study among 10 698 children with new-onset acute lymphoblastic leukemia (ALL) from 41 US children's hospitals between January 1999 and September 2011. Influenza-related hospitalizations were identified using ICD-9 discharge diagnosis codes, excluding hospitalizations during low-prevalence influenza periods. Follow-up was censored at the earliest of 5 events: end of study period, expected end of chemotherapy, last known hospitalization, hematopoietic stem cell transplant, or death. Data were collected on hospitalization characteristics and resource utilization. Hospitalization rates were calculated using season-adjusted person-time. Crude attributable in-hospital mortality was calculated using baseline mortality for noninfluenza hospitalizations during the same period. Subgroup analysis was performed by time from ALL diagnosis and by age category.

RESULTS

The rate of influenza-related hospitalizations was 618.3 per 100 000 person-months. Rates were similar by time from ALL diagnosis and across age categories. Overall attributable in-hospital mortality was 1.0% (95% confidence interval [CI], 0.3%-2.3%) and was highest for children <6 months from diagnosis (1.6%; 95% CI, 0.4%-4.5%) and children <2 years of age (6.7%; 95% CI, 1.3%-22.7%). Total length of stay, days of broad-spectrum antibiotic exposure, and duration of intensive care were significantly greater for influenza-related hospitalizations compared with noninfluenza hospitalizations.

CONCLUSIONS

The burden of influenza-related hospitalizations in children with ALL is high and associated with significantly increased resource utilization and attributable mortality.

Central nervous system acute lymphoblastic leukemia: role of natural killer cells

Central nervous system acute lymphoblastic leukemia (CNS-ALL) is a major clinical problem. Prophylactic therapy is neurotoxic, and a third of the relapses involve the CNS. Increased expression of interleukin 15 (IL-15) in leukemic blasts is associated with increased risk for CNS-ALL. Using in vivo models for CNS leukemia caused by mouse T-ALL and human xenografts of ALL cells, we demonstrate that expression of IL-15 in leukemic cells is associated with the activation of natural killer (NK) cells. This activation limits the outgrowth of leukemic cells in the periphery, but less in the CNS because NK cells are excluded from the CNS. Depletion of NK cells in NOD/SCID mice enabled combined systemic and CNS leukemia of human pre-B-ALL. The killing of human leukemia lymphoblasts by NK cells depended on the expression of the NKG2D receptor. Analysis of bone marrow (BM) diagnostic samples derived from children with subsequent CNS-ALL revealed a significantly high expression of the NKG2D and NKp44 receptors. We suggest that the CNS may be an immunologic sanctuary protected from NK-cell activity. CNS prophylactic therapy may thus be needed with emerging NK cell-based therapies against hematopoietic malignancies.

Prediction of methotrexate CNS distribution in different species - influence of disease conditions

Children and adults with malignant diseases have a high risk of prevalence of the tumor in the central nervous system (CNS). As prophylaxis treatment methotrexate is often given. In order to monitor methotrexate exposure in the CNS, cerebrospinal fluid (CSF) concentrations are often measured. However, the question is in how far we can rely on CSF concentrations of methotrexate as appropriate surrogate for brain target site concentrations, especially under disease conditions. In this study, we have investigated the spatial distribution of unbound methotrexate in healthy rat brain by parallel microdialysis, with or without inhibition of Mrp/Oat/Oatp-mediated active transport processes by a co-administration of probenecid. Specifically, we have focused on the relationship between brain extracellular fluid (brainECF) and CSF concentrations. The data were used to develop a systems-based pharmacokinetic (SBPK) brain distribution model for methotrexate. This model was subsequently applied on literature data on methotrexate brain distribution in other healthy and diseased rats (brainECF), healthy dogs (CSF) and diseased children (CSF) and adults (brainECF and CSF). Important differences between brainECF and CSF kinetics were found, but we have found that inhibition of Mrp/Oat/Oatp-mediated active transport processes does not significantly influence the relationship between brainECF and CSF fluid methotrexate concentrations. It is concluded that in parallel obtained data on unbound brainECF, CSF and plasma concentrations, under dynamic conditions, combined with advanced mathematical modeling is a most valid approach to develop SBPK models that allow for revealing the mechanisms underlying the relationship between brainECF and CSF concentrations in health and disease.

Outcome of childhood acute Lymphoblastic leukemia in Egyptian children: a challenge for limited health resource countries

In childhood acute lymphoblastic leukemia (ALL) the reported 5-year event-free survival (EFS) rates are as high as 80%. Since 2004, multiple Egyptian centers shifted protocol of therapy of ALL to the CCG 1991 (the single delayed intensification arm) and CCG 1961 protocol for standard risk and high-risk ALL therapy, respectively, being cost effective. We aimed to evaluate the efficacy and safety of the CCG protocol in treatment of childhood ALL in Ain Shams and Menoufeya University hospitals.

METHODS

Fifty-two ALL patients, aged 1-17 years, treated according to the modified CCG protocol in both centers and registered from November 2004 to December 2005 were included. They were classified into three risk groups, standard risk (SR), high-risk standard arm (HR-SA), and high-risk augmented arm (HR-AA).

RESULTS

The mean age at diagnosis was 5.9 + 3.3 years, male/female ratio of 1.6:1, and central nervous system leukemia represented 6%. The 5-year overall survival (OS) and EFS were 84.6% and 67%, respectively. The 5-year OS and EFS were 92.6% and 70% in SR, 68.8% and 55% in HR-SA, 88.9% and 80% in HR-AA patients, respectively. Six patients had grade 3-4 adverse events.

CONCLUSION

The outcome of HR-SA protocol was inferior to the other two groups, necessitating shift to a more intensified arm with double delayed intensification. The use of minimal residual disease for better risk classification of childhood ALL is recommended in our centers.

Pharmacogenetic analysis of pediatric patients with acute lymphoblastic leukemia: a possible association between survival rate and ITPA polymorphism

Genetic polymorphisms are important factors in the effects and toxicity of chemotherapeutics. To analyze the pharmacogenetic and ethnic differences in chemotherapeutics, major genes implicated in the treatment of acute lymphoblastic leukemia (ALL) were analyzed. Eighteen loci of 16 genes in 100 patients with ALL were analyzed. The distribution of variant alleles were CYP3A4*1B (0%), CYP3A5*3 (0%), GSTM1 (21%), GSTP1 (21%), GSTT1 (16%), MDR1 exon 21 (77%), MDR1 exon 26 (61%), MTHFR 677 (63%), MTHFR 1298 (29%), NR3C1 1088 (0%), RFC1 80 (68%), TPMT combined genotype (7%), VDR intron 8 (11%), VDR FokI (83%), TYMS enhancer repeat (22%) and ITPA 94 (30%). The frequencies of single nucleotide polymorphisms (SNPs) of 10 loci were statistically different from those in Western Caucasians. Dose percents (actual/planned dose) or toxicity of mercaptopurine and methotrexate were not related to any SNPs. Event free survival (EFS) rate was lower in ITPA variants, and ITPA 94 AC/AA variant genotypes were the only independent risk factor for lower EFS in multivariate analysis, which was a different pharmacogenetic implication from Western studies. This study is the first pharmacogenetic study in Korean pediatric ALL. Our result suggests that there are other possible pharmacogenetic factors besides TPMT or ITPA polymorphisms which influence the metabolism of mercaptopurine in Asian populations.

Ancestry and pharmacogenomics of relapse in acute lymphoblastic leukemia

Although five-year survival rates for childhood acute lymphoblastic leukemia (ALL) are now over 80% in most industrialized countries, not all children have benefited equally from this progress. Ethnic differences in survival after childhood ALL have been reported in many clinical studies, with poorer survival observed among African Americans or those with Hispanic ethnicity when compared with European Americans or Asians. The causes of ethnic differences remain uncertain, although both genetic and non-genetic factors are likely important. Interrogating genome-wide germline SNP genotypes in an unselected large cohort of children with ALL, we observed that the component of genomic variation that co-segregated with Native American ancestry was associated with risk of relapse (P = 0.0029) even after adjusting for known prognostic factors (P = 0.017). Ancestry-related differences in relapse risk were abrogated by the addition of a single extra phase of chemotherapy, indicating that modifications to therapy can mitigate the ancestry-related risk of relapse.

Improved outcome in childhood ALL with intensive consolidation and hematopoietic stem cell transplant

Background

Despite advances in chemotherapy, the prognosis of relapsed acute lymphoblastic leukemia (ALL) remains poor. Few studies on relapsed ALL have reported the importance of intensive consolidation followed with or without allogeneic hematopoietic stem cell transplantation (HSCT).

Methods

We evaluated the post-relapse outcomes in 47 Korean children with a first marrow relapse, and analyzed the prognostic factors.

Results

A second complete remission (CR) was achieved in 40 patients (85.1%), and at the time of this study, second CR was maintained in 12 of these patients. The estimated 3-yr event-free survival (EFS) rate after the first marrow relapse was 29.8±6.7%, and the overall survival (OS) rate was 45.3±7.5%. We found that second remission, consolidation of pediatric oncology group chemotherapy regimen (POG 9411), and HSCT significantly affected the outcome of the disease after relapse (P<0.001; P=0.004; P=0.05).

Conclusion

The results of our study revealed that an intensified POG 9411 consolidation chemotherapy regimen followed by HSCT can improve the outcome of patients with relapsed ALL.

Twenty-five years of treatment for childhood acute lymphoblastic leukaemia in Western Australia: how do we compare?

OBJECTIVES

To compare survival among the subgroup of children with acute lymphoblastic leukaemia (ALL) who were treated at Princess Margaret Hospital for Children (PMH) in Perth, Western Australia, over 25 years under 15 consecutive protocols of the Children's Cancer Group (CCG) with survival for the entire cohort of children in multiple centres treated under CCG protocols in that period; and to highlight the benefits of membership of a large cooperative research group conducting multicentre randomised controlled trials.

DESIGN, PARTICIPANTS AND SETTING

Retrospective review of the outcomes of all 311 children with newly diagnosed ALL treated at PMH between 1983 and 2008.

MAIN OUTCOME MEASURES

4-year event-free survival; and 10-year overall survival.

RESULTS

Four-year event-free survival for the entire PMH cohort increased from 66% (SE, 6%) for 1983-1987 to 88% (SE, 6%) for 2002-2005, while overall survival over the same period improved from 78% (SE, 5%) to 94% (SE, 4%). Comparisons of outcomes of children treated at PMH with those of the entire CCG cohort, protocol by protocol, revealed similar outcomes.

CONCLUSION

Outcomes of children treated at PMH over the 25-year period are equivalent to those of the larger CCG cohort.

Randomized trial to compare LSA2L2-type maintenance therapy to daily 6-mercaptopurine and weekly methotrexate with vincristine and dexamethasone pulse for children with acute lymphoblastic leukemia

BACKGROUND

A total of 201 pediatric cases of acute lymphoblastic leukemia were treated with the ALL-96 protocol by the Kyushu-Yamaguchi Children's Cancer Study Group.

PROCEDURE

Risk stratification was based on white cell counts, immunophenotype, the presence of central nervous system disease at diagnosis, organomegaly, and early treatment response (day 14 bone marrow status). All of the patients were classified into standard-risk (SR) or high-risk (HR) groups and were randomly assigned to receive maintenance therapy with either LSA2L2-type or 6-mercaptopurine (6-MP)/methotrexate (MTX) with vincristine (VCR) and dexamethasone (DEX) pulse in both risk groups.

RESULTS

The 7-year event-free survival (EFS) and overall survival (OS) rates in the entire study population were 72.1% (95% CI: 68.0-76.2%) and 84.8% (95% CI: 79.7-89.9%), respectively, and the EFS of the SR patients (85.3% [95% CI: 78.2-92.4%]) was significantly better than HR patients (62.4% [95% CI: 52.2-72.6%]) (P = 0.0007).

CONCLUSIONS

There were no differences in the EFS between the different maintenance therapies in each risk group; however, grade IV liver toxicity occurred more often in the patients receiving 6-MP/MTX with VCR and DEX therapy than in patients receiving LSA2L2.

Central nervous system prophylaxis in adults with acute lymphoblastic leukemia: current and emerging therapies

Central nervous system (CNS) recurrence continues to be a significant complication in the treatment of adult patients with acute lymphoblastic leukemia (ALL). Preventing CNS recurrence has been a therapeutic challenge and has not been addressed critically in many clinical trials. Adult studies modeled on childhood ALL studies have used multiple treatment modalities, including radiation therapy, systemic therapy, intrathecal therapy, and combinations thereof. Cranial irradiation is effective but is offset by substantial toxicity, including neurologic sequelae. Systemic chemotherapy, especially with cytarabine (AraC) and methotrexate, has demonstrated promise in decreasing CNS recurrence, but therapeutic levels of drugs in the cerebrospinal fluid (CSF) are not maintained. Intrathecal chemotherapy with or without high-dose systemic therapy is the most common approach to CNS prophylaxis. Liposomal AraC recently has become available and confers prolonged levels of free AraC in the CSF, a critical requirement for CNS prophylactic therapy. This review discusses the various modalities used for CNS prophylaxis in patients with ALL and the emerging trends, with specific emphasis on the outcome in terms of event-free survival and toxicity.

Evaluation of conceptual framework for recruitment of African American patients with breast cancer

PURPOSE/OBJECTIVES

To describe the Heiney-Adams Recruitment Framework (H-ARF); to delineate a recruitment plan for a randomized, behavioral trial (RBT) based on H-ARF; and to provide evaluation data on its implementation.

DATA SOURCES

All data for this investigation originated from a recruitment database created for an RBT designed to test the effectiveness of a therapeutic group convened via teleconference for African American women with breast cancer.

DATA SYNTHESIS

Major H-ARF concepts include social marketing and relationship building. The majority of social marketing strategies yielded 100% participant recruitment. Greater absolute numbers were recruited via Health Insurance Portability and Accountability Act waivers. Using H-ARF yielded a high recruitment rate (66%).

CONCLUSIONS

Application of H-ARF led to successful recruitment in an RBT. The findings highlight three areas that researchers should consider when devising recruitment plans: absolute numbers versus recruitment rate, cost, and efficiency with institutional review board-approved access to protected health information.

IMPLICATIONS FOR NURSING

H-ARF may be applied to any clinical or population-based research setting because it provides direction for researchers to develop a recruitment plan based on the target audience and cultural attributes that may hinder or help recruitment.

Long-term results of the pediatric oncology group studies for childhood acute lymphoblastic leukemia 1984-2001: a report from the children's oncology group

From 1984 to 2001, the Pediatric Oncology Group (POG) conducted 12 acute lymphoblastic leukemia (ALL) studies. Ten-year event-free survival (EFS) for patients >12 months of age with B-precursor ALL on acute leukemia in children 14, 15 and 16 series were 66.7+/-1.2%, 68.1+/-1.4% and 73.2+/-2.1%, respectively. Intermediate dose methotrexate (ID MTX; 1 g/m(2)) improved outcomes for standard risk patients (10-year EFS 77.5+/-2.7% vs 66.3+/-3.1% for oral MTX). Neither MTX intensification (2.5 g/m(2)) nor addition of cytosine arabinoside/daunomycin/teniposide improved outcomes for higher risk patients. Intermediate dose mercaptopurine (1 g/m(2)) failed to improve outcomes for either group. Ten-year EFS for patients with T-cell ALL, POG 8704 and 9404 were 49.1+/-3.1% and 72.2+/-4.7%, respectively. Intensive asparaginase (10-year EFS 61.8 vs 42.7%) and high-dose MTX (5 g/m(2)) (10-year EFS 78.0 vs 65.8%) improved outcomes. There was a non-significant improvement in EFS for infants (10-year EFS 17.7+/-7.2-31.9+/-8.3%). Prognostic indicators for B-precursor ALL were age and WBC at diagnosis, gender, central nervous system disease, DNA index and cytogenetic abnormalities. Only gender was prognostic in T-cell ALL. In infants, WBC and MLL translocation were linked to inferior outcome.

Long-term results of the children's cancer group studies for childhood acute lymphoblastic leukemia 1983-2002: a Children's Oncology Group Report

The Children's Cancer Group enrolled 13 298 young people age <21 years on 1 of 16 protocols between 1983 and 2002. Outcomes were examined in three time periods, 1983-1988, 1989-1995, 1996-2002. Over the three intervals, 10-year event-free survival (EFS) for Rome/National Cancer Institute standard risk (SR) and higher risk (HR) B-precursor patients was 68 and 58%, 77 and 63%, and 78 and 67%, respectively, whereas for SR and HR T-cell patients, EFS was 65 and 56%, 78 and 68%, and 70 and 72%, respectively. Five-year EFS for infants was 36, 38, and 43%, respectively. Seminal randomized studies led to a number of important findings. Stronger post-induction intensification improved outcome for both SR and HR patients. With improved systemic therapy, additional intrathecal (IT) methotrexate effectively replaced cranial radiation. For SR patients receiving three-drug induction, iso-toxic substitution of dexamethasone for prednisone improved EFS. Pegylated asparaginase safely and effectively replaced native asparaginase. Thus, rational therapy modifications yielded better outcomes for both SR and HR patients. These trials provide the platforms for current Children's Oncology Group trials.

Risk-adapted treatment of pediatric acute lymphoblastic leukemia

Optimal use of antileukemic agents and stringent application of risk-directed therapy in clinical trials have resulted in steady improvement in the outcome of children with acute lymphoblastic leukemia, with current cure rates exceeding 80% in developed countries. The intensity of treatment varies substantially among subsets of patients, as therapy is designed to reduce acute and long-term toxicity in low-risk groups while improving outcomes in poor risk groups by treatment intensification. Recent advances in genome-wide screening techniques, pharmacogenomic studies, and development of molecular therapeutics are ushering in an era of more refined personalized therapy.

Genome-wide analysis of small RNA and novel MicroRNA discovery in human acute lymphoblastic leukemia based on extensive sequencing approach

BACKGROUND

MicroRNAs (miRNAs) have been proved to play an important role in various cellular processes and function as tumor suppressors or oncogenes in cancers including leukemia. The identification of a large number of novel miRNAs and other small regulatory RNAs will provide valuable insights into the roles they play in tumorgenesis.

METHODOLOGY/PRINCIPAL FINDINGS

To gain further understanding of the role of miRNAs relevant to acute lymphoblastic leukemia (ALL), we employed the sequencing-by-synthesis (SBS) strategy to sequence small RNA libraries prepared from ALL patients and normal donors. In total we identified 159 novel miRNAs and 116 novel miRNA*s from both libraries. Among the 159 novel miRNAs, 42 were identified with high stringency in our data set. Furthermore, we demonstrated the different expression patterns of 20 newly identified and several known miRNAs between ALL patients and normal donors, suggesting these miRNAs may be associated with ALL and could constitute an ALL-specific miRNA signature. Interestingly, GO "biological process" classifications revealed that a set of significantly abnormally expressed miRNAs are associated with disease relapse, which implies that these dysregulated miRNAs might promote the progression of ALL by regulating genes involved in the pathway of the disease development.

CONCLUSION/SIGNIFICANCE

The study presents a comprehensive picture of the expression of small RNAs in human acute lymphoblastic leukemia and highlights novel and known miRNAs differentially expressed between ALL patients and normal donors. To our knowledge, this is the first study to look at genome-wide known and novel miRNA expression patterns in in human acute lymphoblastic leukemia. Our data revealed that these deregulated miRNAs may be associated with ALL or the onset of relapse.

Stem cell transplant in the treatment of childhood biphenotypic acute leukemia

BACKGROUND

Many studies have found that biphenotypic acute leukemia (BAL) is associated with a poor outcome.

METHODS

We retrospectively reviewed the medical records and analyzed clinicopathological data on 25 children with BAL, and correlated outcomes with prognostic factors.

RESULTS

BAL constituted 4.4% of all acute childhood leukemia cases. In terms of immunophenotype, 14 patients had leukemia with myeloid plus B-lymphoid (M + B) marker, 7 with myeloid plus T-lymphoid (M + T) marker, and 4 with myeloid plus B-lymphoid and T-lymphoid (M + B + T) markers. Overall survival was superior in patients with the M + B immunophenotype (P = 0.004). Hematopoietic stem cell transplantation (HSCT) did not improve either overall survival or event-free survival compared to chemotherapy alone (hazard ratio 0.98, 95% CI 0.35-2.76, P = 0.966; hazard ratio 1.07, 95% CI 0.41-2.78, P = 0.88). Each of four patients with high-hyperdiploidy (>50 chromosomes) displayed a good treatment response and long-term overall survival even though these patients were treated with chemotherapy alone.

CONCLUSIONS

Treatment outcomes in childhood BAL patients differed by immunophenotype and cytogenetics. HSCT did not offer a significantly greater survival advantage compared to chemotherapy. While these data suggest that treatment should be individualized and stratified according to biologic characteristics and prognostic factors in BAL, prospective trial data are still needed.

Factors influencing survival after relapse from acute lymphoblastic leukemia: a Children's Oncology Group study

Despite great progress in curing childhood acute lymphoblastic leukemia (ALL), survival after relapse remains poor. We analyzed survival after relapse among 9585 pediatric patients enrolled on Children's Oncology Group clinical trials between 1988 and 2002. A total of 1961 patients (20.5%) experienced relapse at any site. The primary end point was survival. Patients were subcategorized by the site of relapse and timing of relapse from initial diagnosis. Time to relapse remains the strongest predictor of survival. Patients experiencing early relapse less than 18 months from initial diagnosis had a particularly poor outcome with a 5-year survival estimate of 21.0+/-1.8%. Standard risk patients who relapsed had improved survival compared with their higher risk counterparts; differences in survival for the two risk groups was most pronounced for patients relapsing after 18 months. Adjusting for both time and relapse site, multivariate analysis showed that age (10+ years) and the presence of central nervous system disease at diagnosis, male gender, and T-cell disease were significant predictors of inferior post-relapse survival. It can be noted that there was no difference in survival rates for relapsed patients in earlier vs later era trials. New therapeutic strategies are urgently needed for children with relapsed ALL and efforts should focus on discovering the biological pathways that mediate drug resistance.

Allogeneic hematopoietic cell transplantation in children with relapsed acute lymphoblastic leukemia isolated to the central nervous system

Allogeneic hematopoietic cell transplantation (HCT) is the standard of care for pediatric patients with early medullary relapse of acute lymphoblastic leukemia (ALL). Most patients with isolated central nervous system (CNS) relapse have good outcomes when treated with intrathecal and systemic chemotherapy followed by irradiation to the neuroaxis. However, the role of HCT remains unclear for those patients with early isolated CNS relapse (<18 months) or who had high risk disease at diagnosis. We therefore compared the HCT outcomes of 116 children treated at the University of Minnesota from 1991 to 2006 with relapsed ALL involving the CNS alone (CNS, n = 14), the bone marrow alone (BM, n = 85), or both bone marrow and CNS (BM + CNS, n = 17). There were no significant differences among groups in age at diagnosis or transplant, length of first complete remission (CR1), remission status (CR2 versus >or=CR3), graft source, or preparative regimen. The incidence of acute GVHD was similar between groups. Patients with isolated CNS relapse had the lowest cumulative incidence of mortality following transplant (CNS: 0%, BM: 19%, BM + CNS: 29%, P = .03) and relapse (CNS: 0% BM: 30%, BM + CNS: 12%, at 2 years, P = .01) and highest leukemia-free survival (CNS: 91%, BM: 35%, BM + CNS: 46%, P < .01) at 5 years. Risk factors for poor survival were: T cell leukemia or BCR-ABL gene rearrangement, history of marrow relapse, and receipt of HLA-mismatched marrow. These data support the use of allogeneic HCT in the treatment of children with poor prognosis isolated CNS relapse.

Acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia, a malignant disorder of lymphoid progenitor cells, affects both children and adults, with peak prevalence between the ages of 2 and 5 years. Steady progress in development of effective treatments has led to a cure rate of more than 80% in children, creating opportunities for innovative approaches that would preserve past gains in leukaemia-free survival while reducing the toxic side-effects of current intensive regimens. Advances in our understanding of the pathobiology of acute lymphoblastic leukaemia, fuelled by emerging molecular technologies, suggest that drugs specifically targeting the genetic defects of leukaemic cells could revolutionise management of this disease. Meanwhile, studies are underway to ascertain the precise events that take place in the genesis of acute lymphoblastic leukaemia, to enhance the clinical application of known risk factors and antileukaemic agents, and to identify treatment regimens that might boost the generally low cure rates in adults and subgroups of children with high-risk leukaemia.

Antimetabolite therapy for lesser-risk B-lineage acute lymphoblastic leukemia of childhood: a report from Children's Oncology Group Study P9201

Pediatric Oncology Group (POG) protocol 9201 enrolled children with lesser-risk B-lineage acute lymphoblastic leukemia (ALL) defined by age (1-9), white blood cell count (WBC) less than 50 x 10(9)/L (50,000/microL), DNA findings of trisomies 4 and 10 (or DNA index > 1.16), and lack of overt central nervous system (CNS) leukemia. After vincristine, prednisone, and asparaginase induction, 650 of 653 eligible patients attained remission (3 induction deaths) and received 6 courses of intravenous methotrexate (1 g/m(2)) with daily mercaptopurine. Weekly intramuscular methotrexate was added during maintenance; pulses of vincristine and prednisone were administered with periodic intrathecal chemotherapy. Treatment duration was 2.5 years. No alkylators, epipodophylotoxins, anthracyclines, or radiation were given. The 6-year event-free survival (EFS) was 86.6% with overall survival (OS) of 97.2%. Patients with less than 5% marrow blasts on induction day 15 had superior EFS. A difference not reaching conventional statistical significance (P = .068) was noted for superior outcomes in patients with trisomies of chromosomes 4 and 10 versus those lacking double trisomies. Sex, ethnicity, CNS status, and WBC were not predictive. This indicates the great majority of children with lesser-risk B-lineage ALL are curable without agents with substantial late effects.

Obesity and Outcome in Pediatric Acute Lymphoblastic Leukemia

Purpose

To evaluate the effect of obesity (defined as a body mass index > 95th percentile for age and sex at diagnosis) on outcome of pediatric acute lymphoblastic leukemia (ALL).

Patients and Methods

We retrospectively analyzed data from 4,260 patients with newly diagnosed ALL enrolled from 1988 to 1995 onto five concurrent Children's Cancer Group studies. Results were verified in a second cohort of 1,733 patients enrolled onto a sixth study from 1996 to 2002.

Results

The 1988 to 1995 cohort included 343 obese and 3,971 nonobese patients. The 5-year event-free survival rate and risk of relapse in obese versus nonobese patients were 72% ± 2.4% v 77% ± 0.6% (P = .02) and 26 ± 2.4 v 20 ± 0.6 (P = .02), respectively. After adjusting for other prognostic variables, obesity's hazard ratios (HRs) of events and relapses were 1.36 (95% CI, 1.04 to 1.77; P = .021) and 1.29 (95% CI, 1.02 to 1.56; P = .04), respectively. The effect of obesity was prominent in the 1,003 patients ≥ 10 years old at diagnosis; in this subset, obesity's adjusted HRs of events and relapses were 1.5 (95% CI, 1.1 to 2.1; P = .009) and 1.5 (95% CI, 1.2 to 2.1; P = .013), respectively. In a second cohort of 1,160 patients ≥ 10 years old, obesity's adjusted HRs of events and relapses were 1.42 (95% CI, 1.03 to 1.96; P = .032) and 1.65 (95% CI, 1.13 to 2.41; P = .009), respectively. The effect of obesity on outcome was unrelated to changes in chemotherapy doses, length of intervals between chemotherapy cycles, or incidence and severity of therapy-related toxicity.

Conclusion

Obesity at diagnosis independently predicts likelihood of relapse and cure in preteenagers and adolescents with ALL.

Favorable Outcome for Adolescents With Acute Lymphoblastic Leukemia Treated on Dana-Farber Cancer Institute Acute Lymphoblastic Leukemia Consortium Protocols

Purpose

Historically, adolescents with acute lymphoblastic leukemia (ALL) have had inferior outcomes when compared with younger children. We report the outcome of adolescents treated on Dana-Farber Cancer Institute (DFCI; Boston, MA) ALL Consortium Protocols conducted between 1991 and 2000.

Patients and Methods

A total of 844 patients aged 1 to 18 years, with newly diagnosed ALL were enrolled onto two consecutive DFCI-ALL Consortium Protocols. We compared outcomes in three age groups: children aged 1 to 10 years (n = 685), young adolescents aged 10 to 15 years (n = 108), and older adolescents aged 15 to 18 years (n = 51).

Results

With a median follow-up of 6.5 years, the 5-year event-free survival (EFS) for those aged 1 to 10 years was 85% (SE, 1%), compared with 77% (SE, 4%) for those aged 10 to 15 years, and 78% (SE, 6%) for those aged 15 to 18 years (P = .09). Adolescents were more likely to present with T-cell phenotype (P < .001) and less likely to have the TEL-AML1 fusion (P = .05). The incidence of pancreatitis and thromboembolic complications, but not asparaginase allergy, was higher in patients ≥ 10 years of age compared with those younger than 10 years. However, there was no difference in the rate of treatment-related complications between the 10- to 15-year and 15- to 18-year age groups.

Conclusion

Adolescents were more likely to present at diagnosis with biologically higher risk disease (T-cell phenotype and absence of the TEL-AML1 fusion) and more likely to experience treatment-related complications than younger children. However, the 5-year EFS for older adolescents was 78% ± 6%, which is superior to published outcomes for similarly aged patients treated with other pediatric and adult ALL regimens. Based on this experience, we currently are piloting our regimen in patients aged 18 to 50 years.

Low prevalence of complications in severe neutropenic children with cancer in the unprotected environment of an overnight camp

BACKGROUND

The high risk of infection and other complications in severely neutropenic pediatric oncology patients receiving chemotherapy has led to development of a variety of preventive measures including isolation and diet restrictions. In order to examine the potential impact of these measures, we evaluated the outcomes of such patients attending a recreational summer camp.

METHODS

We collected data on all children who attended an overnight summer camp for children with cancer during the years 1999-2004, and who were either severely neutropenic or at a high-intensity phase of chemotherapy. Outcome measures included fever, bleeding, hospitalization, and clinical or laboratory evidence of infection. The observation period included both, the 2-week camp experience and 30 days post-camp.

RESULTS

The study group was comprised of 34 patients. Although nine (24%) were hospitalized for management of fever and neutropenia, only one patient had clinical or culture-positive evidence of an invasive infectious agent. No bleeding episode was recorded and most patients attended all camp activities.

CONCLUSIONS

Our results support the safety and feasibility of severely neutropenic patients with cancer to attend the non-isolated, non-sterile environment of a summer camp. These findings may be applicable to school and other social settings.

Risk- and response-based classification of childhood B-precursor acute lymphoblastic leukemia: a combined analysis of prognostic markers from the Pediatric Oncology Group (POG) and Children's Cancer Group (CCG)

The Children's Cancer Group (CCG) and the Pediatric Oncology Group (POG) joined to form the Children's Oncology Group (COG) in 2000. This merger allowed analysis of clinical, biologic, and early response data predictive of event-free survival (EFS) in acute lymphoblastic leukemia (ALL) to develop a new classification system and treatment algorithm. From 11 779 children (age, 1 to 21.99 years) with newly diagnosed B-precursor ALL consecutively enrolled by the CCG (December 1988 to August 1995, n=4986) and POG (January 1986 to November 1999, n=6793), we retrospectively analyzed 6238 patients (CCG, 1182; POG, 5056) with informative cytogenetic data. Four risk groups were defined as very high risk (VHR; 5-year EFS, 45% or below), lower risk (5-year EFS, at least 85%), and standard and high risk (those remaining in the respective National Cancer Institute [NCI] risk groups). VHR criteria included extreme hypodiploidy (fewer than 44 chromosomes), t(9;22) and/or BCR/ABL, and induction failure. Lower-risk patients were NCI standard risk with either t(12;21) (TEL/AML1) or simultaneous trisomies of chromosomes 4, 10, and 17. Even with treatment differences, there was high concordance between the CCG and POG analyses. The COG risk classification scheme is being used for division of B-precursor ALL into lower- (27%), standard- (32%), high- (37%), and very-high- (4%) risk groups based on age, white blood cell (WBC) count, cytogenetics, day-14 marrow response, and end induction minimal residual disease (MRD) by flow cytometry in COG trials.

Intrathecal triple therapy decreases central nervous system relapse but fails to improve event-free survival when compared with intrathecal methotrexate: results of the Children's Cancer Group (CCG) 1952 study for standard-risk acute lymphoblastic leukemia, reported by the Children's Oncology Group

The Children's Cancer Group (CCG) 1952 clinical trial for children with standard-risk acute lymphoblastic leukemia (SR-ALL) compared intrathecal (IT) methotrexate (MTX) with IT triples (ITT) (MTX, cytarabine, and hydrocortisone sodium succinate [HSS]) as presymptomatic central nervous system (CNS) treatment. Following remission induction, 1018 patients were randomized to receive IT MTX and 1009 ITT. Multivariate analysis identified male sex, hepatomegaly, CNS-2 status, and age younger than 2 or older than 6 years as significant predictors of isolated CNS (iCNS) relapse. The 6-year cumulative incidence estimates of iCNS relapse are 3.4% +/- 1.0% for ITT and 5.9% +/- 1.2% for IT MTX; P = .004. Significantly more relapses occurred in bone marrow (BM) and testicles with ITT than IT MTX, particularly among patients with T-cell phenotype or day 14 BM aspirate containing 5% to 25% blasts. Thus, the estimated 6-year event-free survivals (EFS) with ITT or IT MTX are equivalent at 80.7% +/- 1.9% and 82.5% +/- 1.8%, respectively (P = .3). Because the salvage rate after BM relapse is inferior to that after CNS relapse, the 6-year overall survival (OS) for ITT is 90.3% +/- 1.5% versus 94.4% +/- 1.1% for IT MTX (P = .01). It appears that ITT improves presymptomatic CNS treatment but does not improve overall outcome.

Central Nervous System Disease in Acute Lymphoblastic Leukemia: Prophylaxis and Treatment

Improved treatment for acute lymphoblastic leukemia (ALL) has virtually eliminated testicular relapse. However, the control of central nervous system (CNS) leukemia remains a therapeutic challenge in childhood ALL, partly because of the late complications arising from cranial irradiation. In most current pediatric protocols, cranial irradiation (12 to 18 Gy) is given to 5% to 25% of patients—those with T-cell ALL, overt CNS disease (CNS3 status) or high-risk cytogenetics. CNS control is a less urgent concern in adults with ALL, in whom systemic relapse remains the major problem. With current approaches, approximately 2% to 10% of patients can be expected to develop CNS relapse. Children with B-cell precursor ALL who have a late CNS relapse (after an initial remission of 18 months or more) and did not receive cranial irradiation have an excellent outcome after retrieval therapy, with a 5-year event-free survival (EFS) rate approaching that in newly diagnosed patients. Innovative treatment options are needed for children who develop CNS relapses after a short initial remission or after receiving cranial irradiation, and in any adults with CNS leukemia at diagnosis or relapse.

RAS oncogene mutations and outcome of therapy for childhood acute lymphoblastic leukemia

Activating mutations in the RAS oncogenes are among the most common genetic alterations in human cancers, including patients with acute lymphoblastic leukemia (ALL). We sought to define the frequency and spectrum, and possible prognostic importance, of N- and K-RAS mutations in children with ALL treated with contemporary therapy. Leukemic blast DNA from 870 children was analyzed for the presence of activating mutations in the N- or K-RAS oncogenes using a sensitive mutation detection algorithm. RAS mutations were present in the blasts of 131 (15.1%) pediatric ALL patients. The spectrum of mutations included 81 (9.3%) mutations of codons 12/13 of N-RAS, 12 (1.4%) mutations of codon 61 of N-RAS, 39 (4.5%) mutations of codons 12/13 of K-RAS, and 2 (0.2%) mutations of codon 61 of K-RAS. The presence of N- or K-RAS mutations was not associated with white blood cell count at diagnosis, sex, race, extramedullary testicular involvement, central nervous system disease, or NCI/CTEP ALL Risk Group. Patients with an exon 1 K-RAS mutation (codons 12/13) were significantly younger at diagnosis (P=0.001) and less frequently B-lineage phenotype (P=0.01). RAS mutation status did not predict overall survival, event-free survival and disease-free survival. While N- and K-RAS mutations can be identified in 15% of children with newly diagnosed ALL, they do not represent a significant risk factor for outcome using contemporary chemotherapy regimens.

Deletion of 7p or monosomy 7 in pediatric acute lymphoblastic leukemia is an adverse prognostic factor: a report from the Children's Cancer Group

Monosomy 7 or deletions of 7q are associated with many myeloid disorders; however, the significance of such abnormalities in childhood acute lymphoblastic leukemia (ALL) is unknown. Among 1880 children with ALL, 75 (4%) had losses involving chromosome 7, 16 (21%) with monosomy 7, 41 (55%) with losses of 7p (del(7p)), 16 (21%) with losses of 7q (del(7q)), and two (3%) with losses involving both arms. Patients with losses involving chromosome 7 were more likely to be > or =10 years old, National Cancer Institute (NCI) poor risk, and hypodiploid than patients lacking this abnormality. Patients with or without these abnormalities had similar early response to induction therapy. Event-free survival (EFS) and survival for patients with monosomy 7 (P<0.0001 and P=0.0007, respectively) or del(7p) (P<0.0001 and P=0.0001, respectively), but not of patients with del(7q), were significantly worse than those of patients lacking these abnormalities. The poorer EFS was maintained after adjustment for a Philadelphia (Ph) chromosome, NCI risk status, ploidy, or an abnormal 9p. However, the impact on survival was not maintained for monosomy 7 after adjustment for a Ph. These results indicate that the critical region of loss of chromosome 7 in pediatric ALL may be on the p-arm.