Determinants of outcome after intensified therapy of childhood lymphoblastic leukaemia: results from Medical Research Council United Kingdom acute lymphoblastic leukaemia XI protocol

Overview on Aneuploidy in Childhood B-Cell Acute Lymphoblastic Leukemia

Recent years have brought significant progress in the treatment of B-cell acute lymphoblastic leukemia (ALL). This was influenced by both the improved schemes of conventionally used therapy, as well as the development of new forms of treatment. As a consequence, 5-year survival rates have increased and now exceed 90% in pediatric patients. For this reason, it would seem that everything has already been explored in the context of ALL. However, delving into its pathogenesis at the molecular level shows that there are many variations that still need to be analyzed in more detail. One of them is aneuploidy, which is among the most common genetic changes in B-cell ALL. It includes both hyperdiploidy and hypodiploidy. Knowledge of the genetic background is important already at the time of diagnosis, because the first of these forms of aneuploidy is characterized by a good prognosis, in contrast to the second, which is in favor of an unfavorable course. In our work, we will focus on summarizing the current state of knowledge on aneuploidy, along with an indication of all the consequences that may be correlated with it in the context of the treatment of patients with B-cell ALL.

Clinical and Cytogenetic Characteristics of Children With Leukemia 20-Year Retrospective Study

Acute leukemias are the most common malignant diseases in childhood. The aims of this retrospective cohort study were to investigate the frequency of cytogenetic abnormalities in acute pediatric leukemia; the correlation between cytogenetic abnormalities and 5-year survival; and the correlation between cytogenetic abnormalities and clinical and laboratory features. We included 105 patients; acute lymphoblastic leukemia (ALL) had 80.9% patients, B-cell lineage ALL (B-ALL) 84.7% of them, and T-cell lineage (T-ALL) 15.3%. The overall 5-year survival for B-ALL was 85.9% and for T-ALL was 84.6%. The most common cytogenetic abnormalities in patients with B-ALL were t(12;21)(p13.2;q22.1); ETV6-RUNX1 with 22.2% and hyperdiploidy with 19.4%. Our survival analysis showed that t(12;21)(p13.2;q22.1); ETV6-RUNX1 and t(1;19)(q23;p13.3); TCF3-PBX1 had the best 5-year survival with 100% of patients surviving, whereas t(v;11q23.3); KMT2A rearranged had the worst 5-year survival of just 33.3% of patients surviving after 5 years. We found no difference in 5-year survival in B-ALL when comparing clinical features. Acute myelogenous leukemia had 20 patients with 70.6% 5-year survival. The most common cytogenetic abnormality in acute myelogenous leukemia was t(8;21)(q21;q22.1); RUNX1-RUNX1T1 (20%). In conclusion, this study showed the correlation of different cytogenetic abnormalities with 5-year survival in B-ALL patients. Such correlation was not found when comparing clinical features and 5-year survival of patients with B-ALL. This emphasized the significance of cytogenetic analysis in pediatric leukemia.

Survival estimates of childhood malignancies treated at the Mexican telethon pediatric oncology hospital

BACKGROUND

Pediatric cancer incidence in Mexico is ~160/million/year with leukemias making 49.8% of the cases. While survival rates have been reported in various Mexican studies, no data is available from the Telethon Pediatric Oncology Hospital-HITO, a nonprofit private institution specialized exclusively in comprehensive pediatric oncology care in the country that closely follows high-income countries' advanced standards of cancer care.

AIM

To determine overall survival (OS) and relapse-free survival (RFS) in patients treated at HITO between December 2013 and February 2018.

METHODS AND RESULTS

Secondary analysis of data extracted from medical records. It included 286 children aged 0-17 years diagnosed with various cancers grouped into three categories based on location: (1) Acute lymphoblastic leukemia (ALL), (2) tumors within the central nervous system (TWCNS), and (3) tumors outside the CNS (TOCNS). OS and RFS rates for patients who completed 1 (n = 230) and 3 (n = 132) years of follow-up after admission were computed by sex, age, and cancer location, and separately for a subsample (1-year = 191, 3-years = 110) who fulfilled the HITO criteria (no prior treatment, underwent surgery/chemotherapy when indicated, and initiated therapy). TOCNS accounted for 45.1%, but ALL was the most frequent single diagnosis with 28%. Three-year OS for patients with ALL, TWCNS, and TOCNS who fulfilled the HITO criteria were 91.9%, 86.7%, and 79.3%, respectively; for 3-year RFS these were 89.2%, 60%, and 72.4%. Boys showed slightly higher OS and RFS, but no major differences or trends were seen by age group.

CONCLUSION

This study sets a relevant reference in terms of survival and relapse for children with cancer in Mexico treated at a private oncology center that uses a comprehensive and integrated therapeutic model.

A Comprehensive Review of Neuropsychologic Studies Supports the Concept That Adequate Folinic Acid Rescue Prevents Post Methotrexate Neurotoxicity

PURPOSE

To review all studies providing evidence of the correlation between folinic acid (FA) rescue inadequacy and long-term cognitive damage in neuropsychological studies of children with acute lymphoblastic leukemia or osteogenic sarcoma treated under protocols using high-dose methotrexate and FA rescue.

METHODS

A comprehensive literature search was performed of all databases of the Web of Science Citation Index, during 1990-2020, for the terms: neuropsychological, neurocognitive, and cognitive, together with acute lymphoblastic (and lymphocytic) leukemia and osteogenic sarcoma. English-language peer-reviewed articles on neuropsychological assessments of children who had been treated with high-dose methotrexate without irradiation, and which included details of methotrexate and FA schedules, were selected. In addition, a personal database of over 500 reprints of articles from over 130 journals was reviewed on the subjects of methotrexate and FA and their side effects.

RESULTS

Three groups of studies were found and analyzed, with (1) no evidence of cognitive deterioration, (2) evidence of cognitive deterioration, and (3) more than 1 protocol grouped together, preventing separate analysis of any protocols, Protocols without cognitive deterioration reported adequate FA rescue, and those with cognitive deterioration reported inadequate FA rescue.

CONCLUSION

Neuropsychological evaluation supported inadequate FA being the cause of neurocognitive damage after high-dose methotrexate and that adequate FA rescue prevents this complication.

Cytogenetics and Molecular Genetics in Pediatric Acute Lymphoblastic Leukemia (ALL) and Its Correlation with Induction Outcomes

Arathi SrinivasanAims  The aim was to study cytogenetics and molecular genetic profile in pediatric B-acute lymphoblastic leukemia (ALL) and correlate it with induction outcomes. Subjects and Methods  A retrospective study of cytogenetics and molecular genetics of 98 children with B-cell ALL from January 2013 to May 2018 was done. Cytogenetics and molecular genetics were done in the bone marrow using multiplex reverse transcription polymerase chain reaction and G-banded karyotyping, respectively. Minimal residual disease (MRD) assessment was done at the end of induction by flowcytometry. Results  Of the 98 children, 83 (84.6%) had evaluable cytogenetics, with 11 (13.25%) being abnormal karyotypes. Of the 11 abnormal karyotypes, seven children (8.4%) had hyperdiploidy, one had hypodiploidy, and three had miscellaneous findings. In molecular genetics, TEL-AML1 (ETV6/RUNX1)[t(12;21)] was the most common fusion gene abnormality (12.2% [12/98]), followed by E2A-PBX1 [t(1;19)] (5%), BCR/ABL1 [t(9;22)] (3%), and MLL-AF4 [t(4;11)] (1%). All the 98 children attained morphologic remission at the end of induction. All children with hyperdiploidy (7/7) attained remission and MRD negativity, but one expired during maintenance chemotherapy of disseminated tuberculosis. The child with hypodiploidy was MRD-positive. Three (25%) children with t (12;21) were MRD-positive. All children with Ph + ALL, t(1:19), and t(4;11) were MRD-negative. Fifty-two children had no detected abnormalities, six of whom had MRD positivity (11.5%). Conclusion  Cytogenetic and molecular genetic subgrouping prognosticates ALL outcomes. Although 25% of TEL-AML + children had MRD positivity, larger studies are required to validate the same. End-of-induction MRD outcomes did not correlate with chromosomal aberrations.

Clonal heterogeneity and rates of specific chromosome gains are risk predictors in childhood high-hyperdiploid B-cell acute lymphoblastic leukemia

B‐cell acute lymphoblastic leukemia (B‐ALL) is the commonest childhood cancer. High hyperdiploidy (HHD) identifies the most frequent cytogenetic subgroup in childhood B‐ALL. Although hyperdiploidy represents an important prognostic factor in childhood B‐ALL, the specific chromosome gains with prognostic value in HHD‐B‐ALL remain controversial, and the current knowledge about the hierarchy of chromosome gains, clonal heterogeneity and chromosomal instability in HHD‐B‐ALL remains very limited. We applied automated sequential‐iFISH coupled with single‐cell computational modeling to identify the specific chromosomal gains of the eight typically gained chromosomes in a large cohort of 72 primary diagnostic (DX, n = 62) and matched relapse (REL, n = 10) samples from HHD‐B‐ALL patients with either favorable or unfavorable clinical outcome in order to characterize the clonal heterogeneity, specific chromosome gains and clonal evolution. Our data show a high degree of clonal heterogeneity and a hierarchical order of chromosome gains in DX samples of HHD‐B‐ALL. The rates of specific chromosome gains and clonal heterogeneity found in DX samples differ between HHD‐B‐ALL patients with favorable or unfavorable clinical outcome. In fact, our comprehensive analyses at DX using a computationally defined risk predictor revealed low levels of trisomies +18+10 and low levels of clonal heterogeneity as robust relapse risk factors in minimal residual disease (MRD)‐negative childhood HHD‐B‐ALL patients: relapse‐free survival beyond 5 years: 22.1% versus 87.9%, P < 0.0001 and 33.3% versus 80%, P < 0.0001, respectively. Moreover, longitudinal analysis of matched DX‐REL HHD‐B‐ALL samples revealed distinct patterns of clonal evolution at relapse. Our study offers a reliable prognostic sub‐stratification of pediatric MRD‐negative HHD‐B‐ALL patients.

High preharvest donor Foxp3 mRNA level predicts late relapse of acute lymphoblastic leukaemia after haematopoietic stem cell transplantation

OBJECTIVES

The curative effect of allogeneic haematopoietic stem cell transplantation (HSCT) for acute leukaemia is due in part to the donor T cell-mediated graft-versus-leukaemia immune reaction (GvL). Several studies have suggested that donor CD25+CD4+Foxp3+regulator T cells (Tregs) may decrease graft-versus-host disease (GvHD) without abrogating GVL. This notion may need modification in acute lymphoblastic leukaemia (ALL).

METHODS

Foxp3 mRNA level was measured by qPCR in preharvest donor blood CD4+ T cells. The study comprised 45 patients with ALL in 1st or 2nd CR who received myeloablative HSCT using T-replete bone marrow grafts.

RESULTS

Relapse occurred in 17 patients median 363 days after HSCT. The relapse risk was estimated by Cox univariate and multivariate proportional hazard regression. The proportionality assumption was met by analysing the preharvest donor Foxp3 mRNA level as a time-dependent covariate. Early relapse was not modified by the Foxp3 mRNA level. However, a higher Foxp3 mRNA level was associated with a significantly increased relapse risk after day 363 after transplantation, compatible with inhibition of GvL. In contrast, a higher preharvest donor CD4+ T-cell concentration was associated with reduced relapse risk.

CONCLUSION

A higher preharvest donor Foxp3 mRNA level may be predictive of late ALL relapse after HSCT.

Identification of significant risks in pediatric acute lymphoblastic leukemia (ALL) through machine learning (ML) approach

Pediatric acute lymphoblastic leukemia (ALL) through machine learning (ML) technique was analyzed to determine the significance of clinical and phenotypic variables as well as environmental conditions that can identify the underlying causes of child ALL. Fifty pediatric patients (n = 50) included who were diagnosed with acute lymphoblastic leukemia (ALL) according to the inclusion and exclusion criteria. Clinical variables comprised of the blood biochemistry (CBC, LFTs, RFTs) results, and distribution of type of ALL, i.e., T ALL or B ALL. Phenotypic data included the age, sex of the child, and consanguinity, while environmental factors included the habitat, socioeconomic status, and access to filtered drinking water. Fifteen different features/attributes were collected for each case individually. To retrieve most useful discriminating attributes, four different supervised ML algorithms were used including classification and regression trees (CART), random forest (RM), gradient boosted machine (GM), and C5.0 decision tree algorithm. To determine the accuracy of the derived CART algorithm on future data, a ten-fold cross validation was performed on the present data set. The ALL was common in children of age below 5 years in male patients whole belonged to middle class family of rural areas. (B-ALL) was most frequent as compared with T-ALL. The consanguinity was present in 54% of cases. Low levels of platelets and hemoglobin and high levels of white blood cells were reported in child ALL patients. CART provided the best and complete fit for the entire data set yielding a 99.83% model fit accuracy, and a misclassification of 0.17% on the entire sample space, while C5.0 reported 98.6%, random forest 94.44%, and gradient boosted machine resulted in 95.61% fitting. The variable importance of each primary discriminating attribute is platelet 43%, hemoglobin 24%, white blood cells 4%, and sex of the child 4%. An overall accuracy of 87.4% was recorded for the classifier. Platelet count abnormality can be considered as a major factor in predicting pediatric ALL. The machine learning algorithms can be applied efficiently to provide details for the prognosis for better treatment outcome. Graphical Abstract Identification of significant risks in pediatric acute lymphoblastic leukemia (ALL) through machine learning (ML) approach.

Retrospective analysis of 36 fusion genes in 2479 Chinese patients of de novo acute lymphoblastic leukemia

Fusion genes are major molecular biological abnormalities in hematological malignancies. To depict the common recurrent gene-fusion landscape in acute lymphoblastic leukemia (ALL), 36 recurrent fusion genes in hematologic malignancies were assessed using multiplex-nested RT-PCR in 2479 patients with de novo ALL. 17 kinds of distinct fusion genes were detected in 712 (28.72%) cases. Co-occurrence of different fusion genes was observed in 6 (0.24%) patients. Incidence of fusion genes in B-ALL was significantly higher than in T-ALL (31.40% vs. 14.50%, P < 0.001). Pediatric ALL had higher prevalence of ETV6-RUNX1, TCF3-PBX1, and STIL-TAL1, while BCR-ABL1 and SET-NUP214 were more common in adult ALL. BCR-ABL1, TCF3-PBX1, KMT2A-AFF1 and ETV6-RUNX1 were more frequent in B-ALL. On the contrary, KMT2A-MLLT4, SET-NUP214 and STIL-TAL1 were of higher incidence in T-ALL. In comparison with Western cohorts, the incidence of BCR-ABL1 (5.94%) was much higher in our series, while the occurrence of ETV6-RUNX1 (13.19%) was significantly lower in pediatric B-ALL patients in our study than in Western reports. This study provides a genetic landscape of common fusion genes in ALL patients and may serve as a foundation for further improvement of a fusion gene screening panel for clinical applications.

ETV6/RUNX1-positive childhood acute lymphoblastic leukemia (ALL): The spectrum of clonal heterogeneity and its impact on prognosis

The prognostic significance of the ETV6/RUNX1-fusion and of the accompanying aberrations is disputable; whether co-existing sub-clones are responsible for delayed MRD-clearance and thus, moderate outcome, remains to be clarified. We studied, in a paediatric cohort of 119 B-ALLs, the relation between the ETV6/RUNX1 aberration and the co-existing subclones with (a) presenting clinical/biological features, (b) early response to treatment(MRD) and (c) long-term outcome over a 12-year period. Patients were homogeneously treated according to BFM-based-protocols. 27/119 patients (22.7%) were ETV6/RUNX1-positive; 19/27 (70.4%) harbored additional genetic abnormalities while 9/19 (33.3%) presented with clonal heterogeneity. The most common abnormalities were del12p13 (37%), 3-6×21q22 (22.2%), del9p21 (18.5%) and 2-3xETV6/RUNX1 (18.5%). MRDd15-positivity (≥10-3) was detected in 44% of the cohort; the corresponding MRD among patients carrying subclones rises to 88.9%. Common features of all relapses were sub-clonal diversity, FCM-MRDd15-positivity and additional del(9p21) while there were no censored relapses among ETV6/RUNX1-positive patients with sole translocation and absence of additional aberrations, within a median follow-up time of 90 months. In our study, the presence of clonal heterogeneity and impaired FCM-MRD clearance among ETV6/RUNX1-positive patients, ultimately influenced prognosis. Longer follow-up is needed in order to further validate these initial results.

Cytogenetic Profile and FLT3 Gene Mutations of Childhood Acute Lymphoblastic Leukemia

Background:

Childhood acute lymphoblastic leukemia (ALL) is characterized by recurrent genetic aberrations. The identification of those abnormalities is clinically important because they are considered significant risk-stratifying markers.

Aims:

There are insufficient data of cytogenetic profiles in Saudi Arabian patients with childhood ALL leukemia. We have examined a cohort of 110 cases of ALL to determine the cytogenetic profiles and prevalence of FLT3 mutations and analysis of the more frequently observed abnormalities and its correlations to other biologic factors and patient outcomes and to compare our results with previously published results.

Materials and methods:

Patients—We reviewed all cases from 2007 to 2016 with an established diagnosis of childhood ALL. Of the 110 patients, 98 were B-lineage ALL and 12 T-cell ALL. All the patients were treated by UKALL 2003 protocol and risk stratified according previously published criteria. Cytogenetic analysis—Chromosome banding analysis and fluorescence in situ hybridization were used to detect genetic aberrations. Analysis of FLT3 mutations—Bone marrow or blood samples were screened for FLT3 mutations (internal tandem duplications, and point mutations, D835) using polymerase chain reaction methods.

Result:

Cytogenetic analysis showed chromosomal anomalies in 68 out of 102 cases with an overall incidence 66.7%. The most frequent chromosomal anomalies in ALL were hyperdiploidy, t(9;22), t(12;21), and MLL gene rearrangements. Our data are in accordance with those published previously and showed that FLT3 mutations are not common in patients with ALL (4.7%) and have no prognostic relevance in pediatric patients with ALL. On the contrary, t(9;22), MLL gene rearrangements and hypodiploidy were signs of a bad prognosis in childhood ALL with high rate of relapse and shorter overall survival compared with the standard-risk group (P = .031).The event-free survival was also found to be worse (P = .040).

Conclusions:

Our data are in accordance with those published previously, confirming the overall frequency of cytogenetic abnormalities and their prognostic relevance.

Neurotoxicity after high-dose methotrexate (MTX) is adequately explained by insufficient folinic acid rescue

PURPOSE

To challenge the view that the dose of folinic acid rescue after high-dose methotrexate (MTX) has no significance in the prevention of neurotoxicity and to present the minority view that neurotoxicity can be prevented by an adequate dose of folinic acid, without compromising treatment results. Several fallacies that led to the misunderstanding of post MTX neurotoxicity are presented.

METHODS

Data mining using search engines was used to find relevant publications, and an e-mail survey of more than 60 authors of articles in this field was performed. All relevant articles identified were read in their entirety.

RESULTS

Examples of clinical studies with neurotoxicity following inadequate rescue are given. Some studies demonstrated no neurotoxicity when adequate doses of folinic acid rescue were started 24-36 h after the start of HDMTX rescue even after mega doses of MTX. Rescue started after 42 h was associated with neurotoxicity except in patients with low serum MTX levels after 24 and 36 h. ALL protocols with neurotoxicity, especially BFM-like protocols, are presented. Protocol is reported in which single protocol changes prevented neurotoxicity.

CONCLUSIONS

From the published data, when folinic acid rescue is given in a sufficiently high enough dose and is started 24-36 h after the beginning of the methotrexate exposure, and virtually all forms of post MTX neurotoxicity can be prevented without compromising therapeutic results.

Mechanism of ETV6-RUNX1 Leukemia

The t(12;21)(p13;q22) translocation is the most frequently occurring single genetic abnormality in pediatric leukemia. This translocation results in the fusion of the ETV6 and RUNX1 genes. Since its discovery in the 1990s, the function of the ETV6-RUNX1 fusion gene has attracted intense interest. In this chapter, we will summarize current knowledge on the clinical significance of ETV6-RUNX1, the experimental models used to unravel its function in leukemogenesis, the identification of co-operating mutations and the mechanisms responsible for their acquisition, the function of the encoded transcription factor and finally, the future therapeutic approaches available to mitigate the associated disease.

Minimal residual disease monitoring in childhood B lymphoblastic leukemia with t(12;21)(p13;q22); ETV6-RUNX1: concordant results using quantitation of fusion transcript and flow cytometry

INTRODUCTION

The translocation t(12;21)(p13;q22) resulting in the fusion gene ETV6-RUNX1, is the most frequent gene fusion in childhood B lymphoblastic leukemia. In the Nordic Society of Paediatric Haematology and Oncology ALL-2008 treatment protocol, treatment stratification in B-lineage ALL is based on results of minimal residual disease (MRD) analysis with fluorescence-activated cell sorting (FACS). In this study, we determined whether RT-qPCR of the ETV6-RUNX1 fusion transcript can be a reliable alternative for MRD analysis.

METHODS

Seventy-eight bone marrow samples from 29 children at diagnosis and day 15, 29, and 78 during treatment were analyzed for MRD with FACS and with quantitative reverse transcription polymerase chain reaction (RT-qPCR). Fusion transcript MRD was defined as the ETV6-RUNX1/GUSB ratio at the follow-up time point (day 15/29/78) divided with the ETV6-RUNX1/GUSB ratio at diagnosis (%).

RESULTS

MRD analysis with FACS and with RT-qPCR of ETV6-RUNX1 fusion transcript showed strong correlation. All cases showed concordant results at the treatment stratifying time points day 29 and day 78, when comparing the two methods with a cutoff set to 0.1%.

CONCLUSION

RT-qPCR is a valuable addition and could also be an alternative to FACS in cases where FACS is not achievable for MRD analysis.

Cytogenetic Profile of De Novo B lineage Acute Lymphoblastic Leukemia: Determination of Frequency, Distribution Pattern and Identification of Rare and Novel Chromosomal Aberrations in Indian Patients

BACKGROUND

Chromosomal aberrations identified in acute lymphoblastic leukemia (ALL) have an important role in disease diagnosis, prognosis and management. Information on karyotype and associated clinical parameters are essential to physicians for planning cancer control interventions in different geographical regions.

MATERIALS AND METHODS

In this study, we present the overall frequency and distribution patterns of chromosomal aberrations in both children and adult de novo B lineage ALL Indian patients using conventional cytogenetics, interphase FISH and multiplex RT-PCR.

RESULTS

Among the 215 subjects, cytogenetic results were achieved in 172 (80%) patients; normal karyotype represented 37.2% and abnormal 62.8% with a distribution as follows: 15.3% hypodiploidy; 10.3% hyperdiploidy; 15.8% t(9;22); 9.8% t(1;19); 3.7% t(12;21); 2.8% t(4;11); 2.8% complex karyotypes. Apart from these, we observed several novel, rare and common chromosomal rearrangements. Also, FISH studies using LSI extra-signal dual-color probes revealed additional structural or numerical changes.

CONCLUSIONS

These results demonstrate cytogenetic heterogeneity of ALL and confirm that the incidence of chromosomal abnormalities varies considerably. To the best of our knowledge, this is one of the largest reported series of cytogenetic investigations in Indian B-lineage ALL cases. In addition, ongoing cytogenetic studies are warranted in larger groups of B-lineage ALL cases to identify newly acquired chromosomal abnormalities that may contribute to disease diagnosis and management.

Risk factors for relapse in childhood acute lymphoblastic leukemia: prediction and prevention

With current treatment regimens, survival rates for acute lymphoblastic leukemia (ALL) have improved dramatically since the 1980s, with current 5-year overall survival rates estimated at greater than 85%. This success was achieved, in part, through the implementation of risk-stratified therapy. Nevertheless, for a subgroup of patients (15-20%) with newly diagnosed ALL who will ultimately relapse, traditional risk assessment remains inadequate. The risk of relapse may be estimated on the basis of diagnostic features or early treatment response findings. Further progress in this field may thus come from refinement of predictive factors for relapse and treatment adaptation and from the identification of biological subsets of ALL patients who could benefit from specific target therapies. This article summarizes the aspects associated with the identification of predictive factors for relapse in childhood ALL and options available for prevention of disease recurrence.

The negative impact of being underweight and weight loss on survival of children with acute lymphoblastic leukemia

Body mass index and change in body mass index during treatment may influence treatment outcome of pediatric patients with acute lymphoblastic leukemia. However, previous studies in pediatric acute lymphoblastic leukemia reported contradictory results. We prospectively collected data on body composition from a cohort of newly diagnosed Dutch pediatric patients with acute lymphoblastic leukemia (n=762, age 2-17 years). Patients were treated from 1997-2004 and the median follow-up was 9 years (range, 0-10). Body mass index at diagnosis was expressed as age- and gender-matched standard deviation scores and on the basis of these scores the patients were categorized as being underweight, of normal weight or overweight. Multivariate analyses showed that patients who were underweight (8%) had a higher risk of relapse [hazard ratio: 1.88, 95% confidence interval (1.13-3.13)], but similar overall survival and event-free survival as patients who had a normal weight or who were overweight. Patients with loss of body mass index during the first 32 weeks of treatment had a similar risk of relapse and event-free survival, but decreased overall survival [hazard ratio: 2.10, 95% confidence interval (1.14-3.87)] compared to patients without a loss of body mass index. In addition, dual X-ray absorptiometry scans were performed in a nested, single-center cohort. Data from these scans revealed that a loss of body mass consisted mainly of a loss of lean body mass, while there was a gain in the percentage of fat. In conclusion, being underweight at diagnosis is a risk factor for relapse, and a decrease in body mass index early during treatment is associated with decreased survival. In addition, loss of body mass during treatment seems to consist mainly of a loss of lean body mass. This study was approved by the Medical Ethical Committee in 1996 (trial number NTR460/SNWLK-ALL-9).

Clinical characteristics and treatment outcome of childhood acute lymphoblastic leukemia in Saudi Arabia: a multi-institutional retrospective national collaborative study

BACKGROUND

Treatment of childhood acute lymphoblastic leukemia (ALL) has been available in Saudi Arabia (SA) for over 30 years; however, only limited data have been published from there. This study was conducted to establish processes for collaborative data collection and provide clinical characteristics and outcome of children with ALL in SA.

PROCEDURE

Clinical data for patients diagnosed from 2004 to 2008 were retrospectively collected at eight institutions and entered remotely into a custom-built database. Statistics regarding clinical and genetic characteristics and treatment outcome were calculated.

RESULTS

The 594 evaluable patients had a median age of 4.37 years and 56.4% were boys. Majority of patients had B-precursor ALL while 10.7% had T-ALL. CNS leukemia was present in 5.2% of patients. The distribution of common genetic abnormalities was similar to that reported from western populations, with 24.6% hyperdiploidy, 21% RUNX1-ETV6 positivity, 4.2% BCR-ABL1 positivity, and 2.5% with MLL gene rearrangement. Patients received risk-adapted therapy according to various protocols, although treatment strategies for the majority were similar. Five-year OS, RFS and EFS were 86.9%, 79.1%, and 73.3%, respectively. The OS for patients with pre-B ALL was significantly higher than for T-ALL (88.0% vs. 71.8%; P = 0.019, Log-Rank test). Patients with pre-B ALL categorized as low-risk by NCI/Rome criteria and those with hyperdiploidy had OS of 93.4% and 95.8%, respectively.

CONCLUSIONS

The characteristics of childhood ALL in SA are similar to those observed in developed countries. Future prospective studies utilizing unified national protocols are needed to further improve the outcome of our patients.

Late effects of childhood cancer treatment: severe hypertriglyceridaemia, central obesity, non alcoholic fatty liver disease and diabetes as complications of childhood total body irradiation

BACKGROUND

Childhood cancer survivors may develop a number of endocrine complications linked to organ failure, such as hypogonadism, diabetes and growth hormone deficiency. However, increasing evidence now suggests that total body irradiation treatment, specifically, is linked with future risk of insulin resistance, hepatic steatosis and dyslipidaemia, possibly because total body irradiation affects adipocyte differentiation and impairs subcutaneous adipose tissue depot expansion during times of positive energy balance.

CASE REPORT

We describe a 20-year-old woman who developed pancreatitis with severe hypertriglyceridaemia (serum triglycerides > 300 mmol/l) that required plasmapheresis. She had received total body irradiation prior to her bone marrow transplant at age 6 years for relapsed acute lymphoblastic leukaemia. She developed ovarian failure at age 12 years. At age 15 years she was noted to have hyperglycaemia, increased blood pressure, hepatic steatosis and mild hypertriglyceridaemia. She presented with severe hypertriglyceridaemia and eruptive xanthoma, and developed pancreatitis 12 h after admission. She was treated with plasmapheresis and intravenous insulin and made an excellent recovery. We implicate and discuss total body irradiation as the major contributing factor to her severe hypertriglyceridaemia, compounded by worsening glycaemic control, oestrogen deficiency and a changing adult lifestyle.

CONCLUSION

Children who have received total body irradiation are at risk of diabetes and an exaggerated form of the metabolic syndrome with hypertriglyceridaemia, which can be life-threatening. We suggest that survivors of total body irradiation treatment require careful lifelong monitoring of their metabolic status.

Absolute lymphocyte counts refine minimal residual disease-based risk stratification in childhood acute lymphoblastic leukemia

BACKGROUND

Several studies have demonstrated the prognostic utility of absolute lymphocyte count (ALC) during therapy for a range of malignancies, with low ALC associated with adverse outcome. Here we investigated whether ALC retained independent prognostic significance with respect to minimal residual disease (MRD) status in children with acute lymphoblastic leukemia (ALL).

PROCEDURE

We reviewed 171 cases of pediatric ALL treated on the Children's Oncology Group P9900 series of treatment trials. Variables analyzed included ALC at several time points during Induction, age at diagnosis, cytogenetics, initial white blood cell count, and MRD status at Day 29 of Induction (MRD-29).

RESULTS

We found high ALC at Induction Day 29 (ALC-29) to be an independent, clinically significant predictor of improved relapse-free and overall survival (OS). Patients with ALC-29 >1,500 cells/µl had a superior 6-year relapse-free survival (80 ± 4% vs. 62 ± 8%, P = 0.018) and overall survival (96 ± 2% vs. 74 ± 8%, P = 0.001). Moreover, ALC-29 identified distinct prognostic subgroups within cases stratified by MRD-29. In subjects with >0.01% MRD, ALC-29 > or <1,500 cells/µl had a significant 51% difference in 6-year OS (92 ± 7% vs. 41 ± 16%, P = 0.0001).

CONCLUSIONS

ALC, a readily obtainable test, constitutes a significant and independent prognostic factor in childhood ALL that may refine current MRD-based risk stratification algorithms and provide key prognostic information in settings where MRD determination is not feasible.

Analysis of ZAP70 expression in adult acute lymphoblastic leukaemia by real time quantitative PCR

Background

ZAP70 gene expression is associated with poor prognosis in B-cell lymphoproliferative disorders especially chronic lymphocytic leukaemia (CLL) but its role in adult B-ALL has not been established. On diagnostic samples from 76 patients with adult ALL (65 with B-ALL and 11 with T-ALL) ZAP70 mRNA expression levels were studied by real time-quantitative PCR (RT-qPCR) analysis.

Findings

A broad distribution of ZAP70 expression was observed in ALL, ranging from 0.002 to 5.3 fold that of the ZAP70 positive Jurkat reference cell line. No association was observed between expression levels and the presence of specific cytogenetic abnormalities. Five cases, including one case of T-ALL, had ZAP70 expression above the level of the Jurkat reference cell line.

Conclusions

Our results confirm the frequent expression of ZAP70 in adult ALL. Limited comparisons made did highlight poor-risk patients with high ZAP70 expression, but due to lack of clinical information on patient samples we were unable to directly assess the impact on disease prognosis. ZAP-70 may be an important laboratory assay in adult ALL and further studies are warranted to study a potential correlation with cytogenetic and other genetic markers.

Mechanisms of defective erythropoiesis and anemia in pediatric acute lymphoblastic leukemia (ALL)

Anemia frequently accompanies the diagnosis of acute lymphoblastic leukemia (ALL) in children and is considered to be one of the most common clinical complications of the disease. In addition, a low hemoglobin (Hb) level is often responsible for fatigue and other associated symptoms that cause a decline in the quality of life of these children. Traditionally, a number of contributing factors such as overcrowding of the marrow, coexisting infections, and nutritional deficits have been used to explain this phenomenon. However, recent advances in in vivo modeling and real-time ultrastructural analytical techniques have enabled researchers to examine leukemic bone marrow (BM) microenvironment more closely and helped to build mechanistic models of this process. Importantly, data from these studies show that in the majority of cases, the required stem cell populations and the erythropoietic growth mechanisms remain intact in leukemia. In this report, we aim to review the current state of knowledge regarding the cellular and molecular mechanisms implicated in the altered erythropoiesis at the time of diagnosis of leukemia. We propose that further understanding of the mechanisms of anemia in leukemia may help to manage some of its clinical consequences more effectively as well as to yield key insight into the process of leukemogenesis itself.

Newly diagnosed acute lymphoblastic leukemia in China (I): abnormal genetic patterns in 1346 childhood and adult cases and their comparison with the reports from Western countries

It has been generally acknowledged that the diagnosis, treatment and prognosis evaluation of leukemia largely rely on an adequate identification of genetic abnormalities. A systemic analysis of genetic aberrations was performed in a cohort of 1346 patients with newly diagnosed acute lymphoblastic leukemia (ALL) in China. The pediatric patients had higher incidence of hyperdiploidy and t(12;21) (p13;q22)/ETV6-RUNX1 than adults (P<0.0001); in contrast, the occurrence of Ph and Ik6 variant of IKZF1 gene was much more frequent in adult patients (all P<0.0001). In B-ALL, the existence of Ik6 and that of BCR-ABL were statistically correlated (P<0.0001). In comparison with Western cohorts, the incidence of t(9;22) (q34;q11)/BCR-ABL (14.60%) in B-ALL and HOX11 expression in T-ALL (25.24%) seemed to be much higher in our group, while the incidence of t(12;21) (p13;q22)/ETV6-RUNX1 (15.34%) seemed to be lower in Chinese pediatric patients. The occurrence of hyperdiploidy was much lower either in pediatric (10.61% vs 20-38%) or adult patients (2.36% vs 6.77-12%) in our study than in Western reports. In addition, the frequencies of HOX11L2 in adult patients were much higher in our cohort than in Western countries (20.69% vs 4-11%). In general, it seems that Chinese ALL patients bear more adverse prognostic factors than their Western counterparts do.

Balancing high accrual and ethical recruitment in paediatric oncology: a qualitative study of the 'look and feel' of clinical trial discussions

Background

High accrual to clinical trials enables new treatment strategies to be tested rapidly, accurately and with generalisability. Ethical standards also must be high so that participation is voluntary and informed. However, this can be difficult to achieve in trials with complex designs and in those which are closely embedded in clinical practice. Optimal recruitment requires a balance of both ethical and accrual considerations. In the context of a trial of stratified treatments for children with acute lymphoblastic leukaemia (UKALL2003) we examined how recruitment looked to an observer and how it felt to the parents, to identify how doctors' communication could promote or inhibit optimal recruitment.

Methods

We audio-recorded, transcribed and analysed routine doctor-patient consultations (n = 20) and interviews between researchers and parents (n = 30 parents) across six UK treatment centres. Analysis was informed by the constant comparative method. For consultation transcripts, analysis focussed on how doctors presented the trial. We compared this with analysis of the interview transcripts which focussed on parents' perceptions and understanding of the trial.

Results

Parents and doctors discussed the trial in most consultations, even those that did not involve a decision about randomisation. Doctors used language allying them both with the trial and with the parent, indicating that they were both an 'investigator' and a 'clinician'. They presented the trial both as an empirical study with a scientific imperative and also as offering personalisation of treatment for the child. Parents appeared to understand that trial involvement was voluntary, that it was different from routine care and that they could withdraw from the trial at any time. Some were confused about the significance of the MRD test and the personalisation of treatment.

Conclusions

Doctors communicated in ways that generally promoted optimal recruitment, indicating that trials can be embedded into clinical practice. However, parents were unclear about some details of the trial's rationale, suggesting that recruitment to trials with complicated designs, such as those involving stratified treatments, might need enhanced explanation.

A unique complex translocation involving six different chromosomes in a case of childhood acute lymphoblastic leukemia with the Philadelphia chromosome and adverse prognosis

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy. Approximately 84% of cases of ALL are classified as B-precursor ALL, 14% of cases are T-cell and 2% of cases are B-cell (B-)ALL. About one third of B-ALL cases show an abnormal karyotype. Combining data obtained by immunophenotyping, karyotyping and molecular cytogenetic analyses allows for a better understanding of this heterogeneous disease. This study reports an exceptional B-ALL case with a poor prognosis and unique complex chromosomal aberrations not previously observed, i.e., a translocation involving the six chromosomal regions 1q42, 4q21, 4q24, 4q35 (twice), 8q22 and 10p15.3 besides 9q34 and 22q11.2.

Prognostic effect of chromosomal abnormalities in childhood B-cell precursor acute lymphoblastic leukaemia: results from the UK Medical Research Council ALL97/99 randomised trial

BACKGROUND

Chromosomal abnormalities in childhood acute lymphoblastic leukaemia are well established disease markers and indicators of outcomes. However, the long-term prognosis and independent prognostic effect of some abnormalities has been questioned. Also, little is known about the association between cytogenetics and the characteristics of relapse (eg, time and site of relapse) that are known to predict outcome after relapse.

METHODS

We analysed cytogenetic data from 1725 children with B-cell precursor acute lymphoblastic leukaemia who were included in the UK Medical Research Council ALL97/99 study and followed up for a median time of 8.2 years. Univariate and multivariate analysis were done to examine risk of relapse, event-free survival, and overall survival associated with 21 chromosomal abnormalities and three cytogenetic risk groups constructed from these data.

FINDINGS

Two chromosomal abnormalities were associated with a significantly better outcome (ETV6-RUNX1, hazard ratio [HR] 0.51, 95% CI 0.38-0.70 and high hyperdiploidy, 0.60, 0.47-0.78), whereas five abnormalities were associated with an increased risk of relapse (intrachromosomal amplification of chromosome 21 [iAMP21], 6.04, 3.90-9.35; t(9;22), 3.55, 2.21-5.72; MLL translocations, 2.98, 1.71-5.20; abnormal 17p, 2.09, 1.30-3.37; and loss of 13q, 1.87, 1.09-3.20). Multivariate analysis incorporating age, white-cell count, and treatment parameters showed that six cytogenetic abnormalities (ETV6-RUNX1, high hyperdiploidy, iAMP21, t(9;22), loss of 13q, and abnormal 17p) retained their significance for effect on relapse risk. Based on these data, patients were classified into good, intermediate, and poor cytogenetic risk groups. Slow early treatment response correlated with cytogenetic risk group: 34 of 460 (7%) in the good-risk group, 22 of 211 (10%) in the intermediate-risk group, and 27 of 95 (28%) in the poor-risk group had a slow response (p<0.0001). Additionally, the proportion of patients with a very early (<18 months) relapse varied by cytogenetic risk group: eight of 129 (6%) patients in the good-risk group had a very early relapse, compared with 24 of 98 (24%) in the intermediate-risk group, and 37 of 82 (45%) in the poor-risk group (p<0.0001). However, there was no difference in the site of relapse by cytogenetic risk group.

INTERPRETATION

Individual chromosomal abnormalities are strong independent indicators of outcome, especially risk of relapse. Diagnostic cytogenetics identifies patients with a higher rate of relapse and those who are likely to have a high-risk relapse.

FUNDING

Leukaemia and Lymphoma Research (LLR).

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.

Temporal changes in the incidence and pattern of central nervous system relapses in children with acute lymphoblastic leukaemia treated on four consecutive Medical Research Council trials, 1985-2001

Despite the success of contemporary treatment protocols in childhood acute lymphoblastic leukaemia (ALL), relapse within the central nervous system (CNS) remains a challenge. To better understand this phenomenon, we have analysed the changes in incidence and pattern of CNS relapses in 5564 children enrolled on four successive MRC-ALL trials between 1985 and 2001. Changes in the incidence and pattern of CNS relapses were examined and the relationship with patient characteristics assessed. Factors affecting post-relapse outcome were determined. Overall, relapses declined by 49%. Decreases occurred primarily in non-CNS and combined relapses with a progressive shift towards later (≥30 months from diagnosis) relapses (p<0·0001). Although isolated CNS relapses declined, the proportional incidence and timing of relapse remained unchanged. Age and presenting white cell count were risk factors for CNS relapse. On multivariate analysis, the time to relapse and the trial period influenced post-relapse outcomes. Relapse trends differed within biological subtypes. In ETV6-RUNX1 ALL, relapse patterns mirrored overall trends while in High Hyperdiploidy ALL, these appear to have plateaued over the latter two trial periods. Intensive systemic and intrathecal chemotherapy have decreased the overall CNS relapse rates and changed the patterns of recurrence. The heterogeneity of therapeutic response in the biological subtypes suggests room for further optimisation using currently available chemotherapy.

Non-classical karyotypic features in relapsed childhood B-cell precursor acute lymphoblastic leukemia

Karyotype analysis of acute lymphoblastic leukemia (ALL) at diagnosis has provided valuable prognostic markers for treatment stratification. However, reports of cytogenetic studies of relapsed ALL samples are limited. We compared the karyotypes from 436 nonselected B-cell precursor ALL patients at initial diagnosis and of 76 patients at first relapse. We noticed a relative increase of karyotypes that did not fall into the classic ALL cytogenetic subgroups (high hyperdiploidy, t(12;21), t(9;22), 11q23, t(1;19), <45 chromosomes) in a group of 29 patients at relapse (38%) compared to 130 patients at presentation (30%). Non-classical cytogenetic aberrations in these 29 patients were mostly found on chromosomes 1, 2, 7, 9, 13, 14, and 17. We also describe six rare reciprocal translocations, three of which involved 14q32. The most frequent abnormalities were found in 9p (12/29 cases) and were associated with a marked decrease in the duration of the second remission, but not of the probability of 10-year event-free survival after relapse treatment. From 29 patients with non-classical cytogenetic aberrations, only 8 (28%) had been stratified to a high risk-arm on the first treatment protocol, suggesting that this subgroup might benefit from the identification of new prognostic markers in future studies.

ETV6/RUNX1 fusion lacking prognostic effect in pediatric patients with acute lymphoblastic leukemia

A Brazilian sample of 58 patients with acute lymphoblastic leukemia has been prospectively followed up with the objective of evaluating evolution of disease. Age ranged from 6 months to 16 years. Of the 58 patients, 11 were positive and 47 were negative for the ETV6/RUNX1 fusion (previously known as TEL/AML1). After a minimum follow-up period of 57 months, 2 of the ETV6/RUNX1(+) patients had died and 11 of the ETV6/RUNX1(-), for an overall survival of 77.6%. Among the 11 ETV6/RUNX1(+) patients (age range, 2 years to 13 years 7 months), all achieved a complete remission; the average overall survival was 64.2 months and the average event-free survival was 61.7 months. Among the 47 ETV6/RUNX1(-) patients, 4 did not have a complete remission; the average overall survival was of 60.8 months and the average event-free survival was 57.2 months. No significant difference was observed between overall survival and event-free survival, nor in any of the other data comparatively analyzed. The patients had a cure rate similar to that described in literature. In this small sample population, the presence of the ETV6/RUNX1 fusion did not identify statistical difference in prognosis.

A comprehensive analysis of the CDKN2A gene in childhood acute lymphoblastic leukemia reveals genomic deletion, copy number neutral loss of heterozygosity, and association with specific cytogenetic subgroups

Inactivation of the tumor suppressor gene, CDKN2A, can occur by deletion, methylation, or mutation. We assessed the principal mode of inactivation in childhood acute lymphoblastic leukemia (ALL) and frequency in biologically relevant subgroups. Mutation or methylation was rare, whereas genomic deletion occurred in 21% of B-cell precursor ALL and 50% of T-ALL patients. Single nucleotide polymorphism arrays revealed copy number neutral (CNN) loss of heterozygosity (LOH) in 8% of patients. Array-based comparative genomic hybridization demonstrated that the mean size of deletions was 14.8 Mb and biallelic deletions composed a large and small deletion (mean sizes, 23.3 Mb and 1.4 Mb). Among 86 patients, only 2 small deletions were below the resolution of detection by fluorescence in situ hybridization. Patients with high hyperdiploidy, ETV6-RUNX1, or 11q23/MLL rearrangements had low rates of deletion (11%, 15%, 13%), whereas patients with t(9;22), t(1;19), TLX3, or TLX1 rearrangements had higher frequencies (61%, 42%, 78%, and 89%). In conclusion, CDKN2A deletion is a significant secondary abnormality in childhood ALL strongly correlated with phenotype and genotype. The variation in the incidence of CDKN2A deletions by cytogenetic subgroup may explain its inconsistent association with outcome. CNN LOH without apparent CDKN2A inactivation suggests the presence of other relevant genes in this region.

Molecular cytogenetic characterization of TCF3 (E2A)/19p13.3 rearrangements in B-cell precursor acute lymphoblastic leukemia

The t(1;19)(q23;p13.3) is one of the most common chromosomal abnormalities in B-cell precursor acute lymphoblastic leukemia (BCP-ALL) and usually gives rise to the TCF3-PBX1 fusion gene. Additional rare, and sometimes cytogenetically cryptic, translocations involving the TCF3 gene have also been described. Using a dual color split-signal fluorescence in situ hybridization (FISH) probe, we have investigated the involvement of this gene in a series of BCP-ALLs harboring 19p13 translocations, as well as an unselected patient cohort. The TCF3 gene was shown to be involved in the majority of cases with a cytogenetically visible t(1;19) translocation, while the remaining TCF3-negative ALLs demonstrated breakpoint heterogeneity. Although most "other" 19p13 translocations did not produce a split-signal FISH pattern, a novel t(13;19)(q14;p13) involving TCF3 was discovered. A prospective screen of 161 children with BCP-ALL revealed a cryptic t(12;19)(p13;p13), another novel TCF3 rearrangement, and a series of patients with submicroscopic deletions of TCF3. These results demonstrate the utility of a split-signal FISH strategy in confirming the involvement of the TCF3 gene in 19p13 rearrangements and in identifying novel and cryptic TCF3 translocations. In addition to its role as a fusion partner gene, we propose that TCF3 can also act as a tumor suppressor gene in BCP-ALL.

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.

Adolescents with acute lymphoblastic leukaemia: outcome on UK national paediatric (ALL97) and adult (UKALLXII/E2993) trials

BACKGROUND

Adolescents with acute lymphoblastic leukaemia (ALL) have languished in the shadow of success of the outcome of therapy in childhood ALL. Their treatment has always been incorporated into either paediatric or adult clinical trials depending on the mode of referral and hence there is a need to address an age and risk specific strategy for improving the outcome of this neglected group of patients. This article has summarised the recent and updated retrospective comparative analysis of adolescents treated on the Medical Research Council (MRC) trials. This analysis adds further emphasis to the treatment approach and the merits and limitations of treatment of adolescents on paediatric and adult trials.

METHODS

A retrospective comparative analysis of adolescents aged 15-17 years, treated on either MRC ALL97/revised 99 (n = 61), a randomised paediatric trial or UKALLXII/E2993 (n = 67), an adult trial, between 1997 and 2002 was undertaken.

RESULT

Results suggest a trend towards a superior outcome on paediatric trials. The 5-year EFS on ALL97 was 65% (95% CI = 52-78%) and on UKALLXII/E2993 was 49% (95% CI = 37-61%; P = 0.01). Multivariate analysis allowing for age and Ph status, diminished the EFS difference, but confirmed a reduced rate of death in remission in patients managed on the paediatric protocol.

CONCLUSIONS

Despite limitations in the methodology, comparative studies including our MRC study suggest a consistent advantage for adolescents managed intensively on paediatric trials. Redefining age limits with risk-based strategy and multi-centre collaboration should be considered to improve the survival of young adults.

Genome complexity in acute lymphoblastic leukemia is revealed by array-based comparative genomic hybridization

Chromosomal abnormalities are important for the classification and risk stratification of patients with acute lymphoblastic leukemia (ALL). However, approximately 30% of childhood and 50% of adult patients lack abnormalities with clinical relevance. Here, we describe the use of array-based comparative genomic hybridization (aCGH) to identify copy number alterations (CNA) in 58 ALL patients. CNA were identified in 83% of cases, and most frequently involved chromosomes 21 (n=42), 9 (n=21), 6 (n=16), 12 (n=11), 15 (n=11), 8 (n=10) and 17 (n=10). Deletions of 6q (del(6q)) were heterogeneous in size, in agreement with previous data, demonstrating the sensitivity of aCGH to measure CNA. Although 9p deletions showed considerable variability in both the extent and location, all encompassed the CDKN2A locus. Six patients showed del(12p), with a common region encompassing the ETV6 gene. Complex CNA were observed involving chromosomes 6 (n=2), 15 (n=2) and 21 (n=11) with multiple regions of loss and gain along each chromosome. Chromosome 21 CNA shared a common region of gain, with associated subtelomeric deletions. Other recurrent findings included dim(13q), dim(16q) and enh(17q). This is the first report of genome-wide detection of CNA in ALL patients using aCGH, and it has demonstrated a higher level of karyotype complexity than anticipated from conventional cytogenetic analysis.