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Bi-allelic inactivating mutations in DOCK8 cause a combined immunodeficiency characterised by severe pathogen infections, eczema, allergies, malignancy and impaired humoral responses. These clinical features result from functional defects in most lymphocyte lineages. Thus, DOCK8 plays a key role in immune cell function. Hematopoietic stem cell transplantation (HSCT) is curative for DOCK8 deficiency. While previous reports have described clinical outcomes for DOCK8 deficiency following HSCT, the effect on lymphocyte reconstitution and function has not been investigated. Our study determined whether defects in lymphocyte differentiation and function in DOCK8-deficient patients were restored following HSCT. DOCK8-deficient T and B lymphocytes exhibited aberrant activation and effector function in vivo and in vitro. Frequencies of αβ T and MAIT cells were reduced while γδT cells were increased in DOCK8-deficient patients. HSCT improved, abnormal lymphocyte function in DOCK8-deficient patients. Elevated total and allergen-specific IgE in DOCK8-deficient patients decreased over time following HSCT. Our results document the extensive catalogue of cellular defects in DOCK8-deficient patients, and the efficacy of HSCT to correct these defects, concurrent with improvements in clinical phenotypes. Overall, our findings provide mechanisms at a functional cellular level for improvements in clinical features of DOCK8 deficiency post-HSCT, identify biomarkers that correlate with improved clinical outcomes, and inform the general dynamics of immune reconstitution in patients with monogenic immune disorders following HSCT.

Background Symptomatic venous thromboembolism (VTE) is an unpredictable and life-threatening toxicity, which occurs early in childhood acute lymphoblastic leukemia (ALL) therapy. Approximately 5% of children will experience VTE which is treated with anticoagulation. Asparaginase and corticosteroids are etiologic factors for VTE, however other clinical factors may modify this risk. Procedure We sought to i) assess published pre-treatment VTE risk factors ii) identify early clinical factors that were associated with VTE and iii) determine whether single nucleotide polymorphisms (SNPs) associated with VTE in non-cancer patients contributed to VTE in children with ALL. We performed a detailed, retrospective analysis of 1021 ALL patients treated between 1998 and 2013. Individual patient records were reviewed to ascertain VTE incidence and document treatment-related clinical variables. Results The incidence of VTE was 5.1%. Extremes of weight at diagnosis ( 95th centile) was an independent risk factor in multivariable analysis, when added to published risk factors of age ≥10 years and mediastinal mass. When factors during induction/consolidation were considered separately: bacteremia, elevated serum gamma-glutamyl transferase and bilirubin were associated with VTE occurrence. None of the SNPs associated with VTE in non-cancer populations were significantly associated with VTE in our cohort. Conclusion We found two known risk factors (age ≥ 10 years and mediastinal mass) in a large cohort of children treated for ALL and identified other factors associated with VTE such as weight extremes at diagnosis, bacteremia, and abnormal liver function which warrant further study. These VTE risk factors may form the basis of future thromboprophylaxis trials.

BACKGROUND: Diffuse Intrinsic Pontine Glioma (DIPG) is a devastating, incurable childhood brain cancer. 80% of patients harbour a genetic lesion to Histone-H3 with a substitution of lysine 27 for a methionine (K27M) (H3F3A/H3.3 and HIST1H3B/H3.1) which results in the loss of methylation, interfering with chromatin function, activating oncogenic transcription. Unfortunately, H3 mutations are not directly targetable. RTK-RAS-PI3Kpathway alterations occur in more than half of these patients (69%), and may represent a more promising therapeutic target. However, PI3K inhibitors have been notoriously ineffective due to their inability to cross the blood-brain-barrier (BBB). Targeting downstream components of the PI3K-AKT-mTOR signalling axis is a promising paradigm for PI3K mutant patients. This project aims to overcome the limitations of targeting downstream effectors of the PI3K pathway by utilising a novel PIK3CA specific, BBB permeable inhibitor, GDC-0084, currently in clinical trials for Glioblastoma (GBM) and DIPG. METHODS: Utilising DIPG patient derived (PDX) cells harboringH3K27M mutations (n=6), and +/- PI3Kmutations, we examined the in-vitroefficacy of GDC-0084 on cell proliferation compared to Rapamycin. Phosphoproteomic profiling is currently underway investigating the role GDC-0084 has on inhibition of downstream oncogenic signalling pathways. Assessment of efficacy in a PDX in-vivo model is currently in progress. RESULTS: GDC-0084 significantly reduced the growth of all DIPG cell lines regardless of whether they harboredPI3K mutations (p=

Approximately one-third of children with acute myeloid leukemia (AML) relapse, requiring re-treatment and allogeneic hematopoietic stem cell transplantation (HSCT). Although achieving second complete remission (CR2) prior to HSCT is desirable, once CR2 is attained, it is unclear if there is any benefit from further chemotherapy prior to HSCT. Moreover, although pre-HSCT minimal residual disease (MRD) has prognostic value in acute lymphoblastic leukemia, the benefit of MRD reduction after achieving CR prior to HSCT is less clear for AML. To address these questions, we analyzed data from pediatric transplant centers in Australia and New Zealand concerning relapsed childhood AML cases occurring between 1998 and 2013. Given the retrospective nature of our analysis and assay data available, we analyzed patients on the basis of measurable residual disease (MeRD) by any methodology, rather than MRD in the conventional sense. We observed improved overall survival (OS) in children receiving two chemotherapy cycles, compared to one cycle or three or more cycles pre-HSCT. Improved OS with two cycles remained significant for patients without MeRD after cycle 1. These data suggest that a second chemotherapy cycle pre-HSCT may improve survival by lowering disease burden. Prospective trials assessing strategies to reduce pre-HSCT MRD in relapsed childhood AML are warranted.

Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive, childhood brainstem cancer with a median overall survival of 10 months post diagnosis. Remarkably, 80–90% of patients harbor recurring point mutation in histone H3, which induces a lysine for methionine substitution at amino acid 27 (H3K27M) in either H3.1 (HIST1H3B ~25%) or H3.3 (H3F3A ~65%) variants. Using the blood-brain barrier (BBB) permeable DRD2 antagonist, ONC201 (in clinical trials for DIPG and H3K27M-mutant gliomas – NCT03416530), we hypothesized that DRD2 antagonism would induce TRAIL expression via indirect inhibition of AKT and ERK signaling, to drive apoptosis in both H3.1K27M and H3.3K27M patient-derived DIPG cell lines alike. For the first time, we reveal that ONC201 shows efficacy in 100% of WT-H3 and H3.1K27M mutant DIPG cell lines (n=5), compared to 50% of H3.3K27M mutant DIPGs (n=6). Investigations to identify the mechanisms of resistance to ONC201, revealed that cell lines with decreased sensitivity upregulated the PI3K/AKT/MTOR signaling axis to drive phosphorylation of AKT and increase metabolic activity. Combined administration of ONC201 and the BBB-permeable PI3K/AKT inhibitor, paxalisib (previously GDC-0084, in clinical trials for newly diagnosed DIPG – NCT03696355), showed synergistic cytotoxicity, reduced PI3K/AKT signaling and metabolic reprogramming to drive apoptosis in all DIPG cell lines tested. This combination was used to treat a 3-year-old DIPG patient, commencing 14 weeks post disease progression, completing 40 weeks of therapy prior to her passing, December 2019. These studies highlight the potential of combined administration of two safe, BBB penetrant, oral targeted therapies and supports testing under clinical trial conditions.

Symptomatic venous thromboembolism (VTE) occurs in five percent of children treated for acute lymphoblastic leukemia (ALL), but whether a genetic predisposition exists across different ALL treatment regimens has not been well studied. Methods: We undertook a genome-wide association study (GWAS) meta-analysis for VTE in consecutively treated children in the Nordic/Baltic acute lymphoblastic leukemia 2008 (ALL2008) cohort and the Australian Evaluation of Risk of ALL Treatment-Related Side-Effects (ERASE) cohort. A total of 92 cases and 1481 controls of European ancestry were included. Results: No SNPs reached genome-wide significance (p &lt, 5 &times, 10&minus, 8) in either cohort. Among the top 34 single-nucleotide polymorphisms (SNPs) (p &lt, 1 &times, 6), two loci had concordant effects in both cohorts: ALOX15B (rs1804772) (MAF: 1%, p = 3.95 &times, 7) that influences arachidonic acid metabolism and thus platelet aggregation, and KALRN (rs570684) (MAF: 1%, p = 4.34 &times, 7) that has been previously associated with risk of ischemic stroke, atherosclerosis, and early-onset coronary artery disease. Conclusion: This represents the largest GWAS meta-analysis conducted to date associating SNPs to VTE in children and adolescents treated on childhood ALL protocols. Validation of these findings is needed and may then lead to patient stratification for VTE preventive interventions. As VTE hemostasis involves multiple pathways, a more powerful GWAS is needed to detect combination of variants associated with VTE.

Identification of recurrent driver mutations in genes encoding tyrosine kinases has resulted in the development of molecularly targeted strategies designed to improve the outcomes for patients diagnosed with acute myeloid leukemia (AML). The receptor tyrosine kinase FLT3, is the most commonly mutated gene in AML, with internal tandem duplications within the juxtamembrane domain (FLT3-ITD) or missense mutations in the tyrosine kinase domain (FLT3-TKD), present in 30%-35% of AML patients at diagnosis. An established driver mutation and marker of poor prognosis, the FLT3 tyrosine kinase has emerged as an attractive therapeutic target, and thus has encouraged the development of FLT3 tyrosine kinase inhibitors (TKIs). However, the therapeutic benefit of FLT3 inhibition, particularly as monotherapy, frequently results in the development of treatment resistance and disease relapse. Commonly, FLT3 inhibitor resistance is induced by the emergence of secondary lesions in the FLT3 gene, particularly in the second tyrosine kinase domain at residue Asp835 (D835) to form a ‘dual mutation’ (ITD-D835). Individual FLT3-ITD and FLT3-TKD mutations influence independent signaling cascades however, currently little is known which divergent signaling pathways are controlled by each of these FLT3 specific mutations, particularly in the context of patients harboring dual ITD-D835 mutations. This review provides a comprehensive analysis of the known discrete and cooperative signaling pathways regulated by each of the FLT3 specific mutations, as well as the therapeutic approaches that hold the most promise for development of more durable and personalized therapeutic approaches targeting mutant FLT3, to improve the treatment of AML.

Many students treated for cancer experience significant challenges in maintaining their education during and beyond cancer treatment. Late effects of cancer treatment combined with prolonged period...

BACKGROUND There is growing impetus for increased genetic screening in childhood cancer survivors. Family history-taking is a critical first step in determining survivors' suitability. However, the family history-taking practices of providers of pediatric oncology survivorship care and the confidence of these providers to discuss cancer risks to relatives are unknown. PROCEDURE Fifty-four providers completed semistructured interviews in total, which included eight tertiary providers representing nine hospitals across two countries (63% male, 63% oncologists, 37% nurses) and 46 primary care providers (PCPs) nominated by a survivor (59% male, 35% regional practice). We used content analysis and descriptive statistics/regression to analyze the data. RESULTS Few tertiary (38%) or primary (35%) providers regularly collected survivors' family histories, often relying on survivors/parents to initiate discussions. Providers mostly took two-generation pedigrees (63% tertiary and 81% primary). Primary providers focused on adult cancers. Lack of time, alternative priorities, and perceived lack of relevance were common barriers. Half of all tertiary providers felt moderately comfortable discussing genetic cancer risk to children of survivors (88% felt similarly discussing risks to other relatives). Most primary providers lacked confidence: 41% felt confident regarding risks to survivors' children and 48% regarding risks to other relatives. CONCLUSIONS While family history-taking will not identify all survivors suitable for genetics assessment, recommendations for regular history-taking are not being implemented in tertiary or primary care. Additional PCP-targeted genetic education is warranted given that they are well placed to review family histories of pediatric cancer survivors.

Minimal residual disease (MRD) during early chemotherapy is a powerful predictor of relapse in acute lymphoblastic leukaemia (ALL) and is used in children to determine eligibility for allogeneic haematopoietic stem cell transplantation (HSCT) in first (CR1) or later complete remission (CR2/CR3). Variables affecting HSCT outcome were analysed in 81 children from the ANZCHOG ALL8 trial. The major cause of treatment failure was relapse, with a cumulative incidence of relapse at 5 years (CIR) of 32% and treatment-related mortality of 8%. Leukaemia-free survival (LFS) and overall survival (OS) were similar for HSCT in CR1 (LFS 62%, OS 83%, n = 41) or CR2/CR3 (LFS 60%, OS 72%, n = 40). Patients achieving bone marrow MRD negativity pre-HSCT had better outcomes (LFS 83%, OS 92%) than those with persistent MRD pre-HSCT (LFS 41%, OS 64%, P 0·0001) or post-HSCT (LFS 35%, OS 55%, P 0·0001). Patients with B-other ALL had more relapses (CIR 50%, LFS 41%) than T-ALL and the main precursor-B subtypes including BCR-ABL1, KMT2A (MLL), ETV6-RUNX1 (TEL-AML1) and hyperdiploidy50. A Cox multivariate regression model for LFS retained both B-other ALL subtype (hazard ratio 4·1, P = 0·0062) and MRD persistence post-HSCT (hazard ratio 3·9, P = 0·0070) as independent adverse prognostic variables. Persistent MRD could be used to direct post-HSCT therapy.

We report a retrospective analysis of 53 haematopoietic stem cell transplants for inherited metabolic disorders performed at ANZCHOG transplant centres between 1992 and 2008. Indications for transplant included Hurler syndrome, ALD, and MLD. The majority of transplants utilized unrelated donor stem cells (66%) with 65% of those being unrelated cord blood. Conditioning therapy was largely myeloablative, with Bu plus another cytotoxic agent used in 89% of recipients. Primary graft failure was rare, occurring in three patients, all of whom remain long-term survivors following the second transplant. The CI of grade II-IV and grade III-IV acute GVHD at day +100 was 39% and 14%, respectively. Chronic GVHD occurred in 17% of recipients. TRM was 12% at day +100 and 19% at one yr post-transplant. OS at five yr was 78% for the cohort, 73% for patients with ALD and 83% for patients with Hurler syndrome. There was no statistically significant difference in overall survival between unrelated marrow and unrelated cord blood donor groups. The development of interstitial pneumonitis was an independent variable shown to significantly impact on TRM and OS. In summary, we report a large cohort of patients with inherited metabolic disorders with excellent survival post-allogeneic transplant.

Previous research has suggested positive associations between parental or childhood exposure to pesticides and risk of childhood brain tumors (CBT). This Australian case–control study of CBT investigated whether exposures to pesticides before pregnancy, during pregnancy and during childhood, were associated with an increased risk. Cases were recruited from 10 pediatric oncology centers, and controls by random-digit dialing, frequency matched on age, sex, and State of residence. Exposure data were collected by written questionnaires and telephone interviews. Data were analyzed by unconditional logistic regression. The odds ratios (ORs) for professional pest control treatments in the home in the year before the index pregnancy, during the pregnancy, and after the child’s birth were 1.54 (95 % confidence interval (CI): 1.07, 2.22), 1.52 (95 % CI: 0.99, 2.34) and 1.04 (95 % CI: 0.75, 1.43), respectively. ORs for treatments exclusively before pregnancy and during pregnancy were 1.90 (95 % CI: 1.08, 3.36) and 1.02 (95 % CI: 0.35, 3.00), respectively. The OR for the father being home during the treatment was 1.79 (95 % CI: 0.85, 3.80). The OR for paternal occupational exposure in the year before the child’s conception was 1.36 (95 % CI: 0.66, 2.80). ORs for prenatal home pesticide exposure were elevated for low- and high-grade gliomas; effect estimates for other CBT subtypes varied and lacked precision. These results suggest that preconception pesticide exposure, and possibly exposure during pregnancy, is associated with an increased CBT risk. It may be advisable for both parents to avoid pesticide exposure during this time.

We performed a retrospective analysis on the outcomes of 135 hematopoietic stem cell transplantations (HSCTs) for primary immunodeficiency disorders in Australian and New Zealand Children's Haematology Oncology Group transplantation centers between 1992 and 2008. The most common indications for HSCT were severe combined immunodeficiency, Wiskott-Aldrich syndrome, and chronic granulomatous disease. Five-year overall survival (OS) was 72% for the entire cohort. Disease-specific 5-year OS was 70% for severe combined immunodeficiency, 81% for Wiskott-Aldrich syndrome, and 69% for chronic granulomatous disease. Transplantation-related mortality (TRM) was 10% at day +100. TRM and OS were equivalent in recipients of related and unrelated donor transplants. Source of stem cells had no impact on TRM or OS with outcomes following unrelated umbilical cord blood similar to unrelated bone marrow. The presence of interstitial pneumonitis, active cytomegalovirus infection, or veno-occlusive disease were all independent variables that significantly decreased OS. This large series supports the use of HSCT as curative therapy for a range of primary immunodeficiency disorders, demonstrating excellent survival after both related and unrelated donor transplantation.

Item does not contain fulltext Children with acute lymphoblastic leukemia (ALL) and high minimal residual disease (MRD) levels after initial chemotherapy have a poor clinical outcome. In this prospective, single arm, Phase 2 trial, 111 Dutch and Australian children aged 1-18 years with newly diagnosed, t(9;22)-negative ALL, were identified among 1041 consecutively enrolled patients as high risk (HR) based on clinical features or high MRD. The HR cohort received the AIEOP-BFM (Associazione Italiana di Ematologia ed Oncologia Pediatrica (Italy)-Berlin-Frankfurt-Munster ALL Study Group) 2000 ALL Protocol I, then three novel HR chemotherapy blocks, followed by allogeneic transplant or chemotherapy. Of the 111 HR patients, 91 began HR treatment blocks, while 79 completed the protocol. There were 3 remission failures, 12 relapses, 7 toxic deaths in remission and 10 patients who changed protocol due to toxicity or clinician/parent preference. For the 111 HR patients, 5-year event-free survival (EFS) was 66.8% (+/-5.5) and overall survival (OS) was 75.6% (+/-4.3). The 30 patients treated as HR solely on the basis of high MRD levels had a 5-year EFS of 63% (+/-9.4%). All patients experienced grade 3 or 4 toxicities during HR block therapy. Although cure rates were improved compared with previous studies, high treatment toxicity suggested that novel agents are needed to achieve further improvement.

Purpose To develop an evidence-based guideline for the empiric management of pediatric fever and neutropenia (FN). Methods The International Pediatric Fever and Neutropenia Guideline Panel is a multidisciplinary and multinational group composed of experts in pediatric oncology and infectious disease as well as a patient advocate. The Panel was convened for the purpose of creating this guideline. We followed previously validated procedures for creating evidence-based guidelines. Working groups focused on initial presentation, ongoing management, and empiric antifungal therapy. Each working group developed key clinical questions, conducted systematic reviews of the published literature, and compiled evidence summaries. The Grades of Recommendation Assessment, Development, and Evaluation approach was used to generate summaries, and evidence was classified as high, moderate, low, or very low based on methodologic considerations. Results Recommendations were made related to initial presentation (risk stratification, initial evaluation, and treatment), ongoing management (modification and cessation of empiric antibiotics), and empiric antifungal treatment (risk stratification, evaluation, and treatment) of pediatric FN. For each recommendation, the strength of the recommendation and level of evidence are presented. Conclusion This guideline represents an evidence-based approach to FN specific to children with cancer. Although some recommendations are similar to adult-based guidelines, there are key distinctions in multiple areas. Implementation will require adaptation to the local context.

In patients with XLP, a primary immunodeficiency caused by mutations in SH2D1A, EBV infection can lead to somatic reversion of the disease-causing mutation selectively in effector memory CD8 T cells; reverted CD8 cells are better able to respond to and kill EBV-infected cells., Patients with the primary immunodeficiency X-linked lymphoproliferative disease (XLP), which is caused by mutations in SH2D1A, are highly susceptible to Epstein-Barr virus (EBV) infection. Nonetheless, some XLP patients demonstrate less severe clinical manifestations after primary infection. SH2D1A encodes the adaptor molecule SLAM-associated protein (SAP), which is expressed in T and natural killer cells and is required for cytotoxicity against B cells, the reservoir for EBV. It is not known why the clinical presentation of XLP is so variable. In this study, we report for the first time the occurrence of somatic reversion in XLP. Reverted SAP-expressing cells resided exclusively within the CD8+ T cell subset, displayed a CD45RA−CCR7− effector memory phenotype, and were maintained at a stable level over time. Importantly, revertant CD8+ SAP+ T cells, but not SAP− cells, proliferated in response to EBV and killed EBV-infected B cells. As somatic reversion correlated with EBV infection, we propose that the virus exerts a selective pressure on the reverted cells, resulting in their expansion in vivo and host protection against ongoing infection.

Objective: To describe wellbeing and nutrition-related side effects in a group of paediatric oncology patients undergoing chemotherapy, and to examine associations with nutritional status, disease and treatment-related factors. Methods: Cross-sectional survey of patients attending the Sydney (n = 41) or John Hunter Children’s Hospitals (n = 13). Wellbeing was assessed using the Multi-attribute Health Status Classification Scheme (MHSCS) and the Play Performance Scale (PPS). Disease and treatment details were obtained through patient and parent interviews and audit of medical records. Nutritional status was assessed using anthropometric and biochemical measurements. Results: Twenty-four per cent and 33% scored maximum points on the MHSCS and PPS, respectively. Advanced stage of solid tumour or lymphoma was associated with worse MHSCS scores, P = 0.008. Longer time on treatment correlated negatively with PPS scores (r = −0.35; P = 0.030). The most frequent side effects were nausea, decreased appetite, vomiting and changes in taste. While 67% experienced five or more side effects concurrently, the number increased with length of time on treatment (r = 0.38; P = 0.006). Of the 23 patients experiencing five or more side effects, only two had been seen by a dietitian in the previous two months. Conclusion: Nutrition-related side effects are common in children undergoing chemotherapy, with the number of side effects not decreasing over time. While wellbeing scores were generally satisfactory, those with advanced stage of solid tumour or lymphoma, or with longer time on treatment, reported lower scores. We recommend that all paediatric oncology patients are referred for dietetic review, even those in the later stages of treatment, in order to optimise nutritional status and wellbeing.

The objective of this study was to assess the efficacy of the VETOPEC regimen, a regimen of vincristine and etoposide with escalating doses of cyclophosphamide (CPA), in pediatric patients with high-risk brain tumors. Three consecutive studies by the Australia and New Zealand Children’s Cancer Study Group—VETOPEC I, Baby Brain 91, and VETOPEC II—have used a specific chemotherapy regimen of vincristine (VCR), etoposide (VP-16) and escalating CPA in patients with relapsed, refractory, or high-risk solid tumors. Patients in the VETOPEC II cohort were treated with very high dose CPA with peripheral blood stem cell (PBSC) rescue. We analyzed the subset of patients with high-risk brain tumors treated with these intensive VETOPEC-based protocols to assess the response, toxicity, and survival. We also assessed whether the use of very high dose chemotherapy with stem cell rescue improved the response rate or affected toxicity. Seventy-one brain tumor patients were treated with VETOPEC-based protocols. Of the 54 patients evaluable for tumor response, 17 had a complete response (CR) and 20 a partial response (PR) to treatment, which yielded an overall response rate of 69%. The CR + PR was 83% (19/23) for medulloblastomas, 56% (5/9) for primitive neuroectodermal tumors, 55% (6/11) for grade 3 and 4 astrocytomas, and 80% (6/8) for ependymomas. At a median follow-up of 36 months, overall survival for the entire cohort of 71 patients was 32%, with event-free survival of 13%. There were no toxic deaths within the PBSC-supported VETOPEC II cohort, despite higher CPA doses, compared with 7% among the non-PBSC patients. This regimen produces high response rates in a variety of very poor prognosis pediatric brain tumors. The maximum tolerated dose of CPA was not reached. Higher escalation in doses of CPA did not deliver a further improvement in response. With PBSC rescue in the VETOPEC II study, hematologic toxicity was no longer a limiting factor. The response rates observed support further development of this chemotherapy regimen.

Background and Purpose Improved radiotherapy techniques in pediatric craniospinal therapy (CSRT) strive to reduce risks of late morbidity. Using a pediatric anthropomorphic phantom, this research correlated measured target and normal tissue dose to that predicted from a 3D planning system (3D-RTP). Patients and Methods A pediatric anthropomorphic phantom was planned following French Society of Pediatric Oncology (SFOP) protocols. Thermoluminescent detectors (TLDs) were used to perform dosimetric measurements during treatment. 4 and 6 MV photon fields with multi leaf collimation (MLC) or custom blocks were compared to 3D-RTP computer (ADAC Pinnacle) predictions for cranial fields. Spinal dosimetry was studied using photons (4 and 6 MV) and electrons (9 and 12 MeV). Results 3D-RTP predictions generally concurred with dose received in cranial and spinal sites. The measured dose was over-predicted significantly by the 3D-RTP in the anterior cranial fossa. Normal tissue doses were reduced when treating the spine using megavoltage electron beams instead of photons. Conclusions Treating the spinal field with electrons minimises the risk of pulmonary sequelae, however electron energy selection is critical to achieve adequate spinal field coverage. Despite adhering to a major trial protocol guideline, dose at the floor of the anterior cranial fossa remains a potential clinical problem and 3D-RTP do not predict this well.

Background: The aim of the present study was to evaluate the usefulness of the elastase 1 (E1) enzyme-linked immunosorbent assay (ELISA) in the diagnosis of acute pancreatitis. This is the first Australian evaluation of the E1 ELISA. Methods: Three groups of patients were prospectively assessed: control patients, patients with acute pancreatitis, and patients with acute non-pancreatitic abdominal pain. Serum was collected on all patients on admission and the sensitivity, specificity and diagnostic accuracy of serum elastase, amylase and lipase was determined. Results: Twenty-nine patients with 30 episodes of pancreatitis, 38 patients with acute non-pancreatitic abdominal pain and 121 control patients were studied. For all patient episodes E1 ELISA at a cut-off of 3.5 ng/mL had a sensitivity of 80%, specificity of 96% and an efficiency of 94% in the diagnosis of acute pancreatitis. For episodes more than 48 h after onset of symptoms, sensitivity was 100%, specificity was 96% and diagnostic efficiency was 96%. This performance was equivalent to amylase but inferior to lipase. Conclusion: Of the biochemical markers for pancreatitis currently available, lipase is the most useful. The relatively inferior sensitivity and problematic reference range for the ELISA E1, together with its limitations in measuring total elastase, currently prevent its widespread use.

Venous thromboembolism (VTE) is an unpredictable and life-threatening toxicity that occurs early in acute lymphoblastic leukemia (ALL) therapy. The incidence is approximately 5% in children diagnosed with ALL [Caruso et al. Blood. 2006;108(7):2216-22], which is higher than in other pediatric cancer types [Athale et al. Pediatric Blood & Cancer. 2008;51(6):792-7]. Clinical risk factors for VTE in children during ALL therapy include older age and the use of asparaginase. We hypothesized that there may be additional risk factors that can modify VTE risk, beyond those previously reported [Mitchell et al. Blood. 2010;115(24):4999-5004]. We sought to define early predictive clinical factors that could select a group of children at highest risk of VTE, with possible utility in an interventional trial of prophylactic anticoagulation. We conducted a retrospective study of 1021 Australian children, aged 1-18 years, treated between 1998-2013 on successive BFM-based ALL therapies. Patient records were reviewed to ascertain incidence of VTE; and to systematically document clinical variables present at diagnosis and during induction/consolidation phases of therapy. The CTCAE v4.03 system was used for grading of VTE events. Multivariate logistic and cox regression were used to determine significant clinical risk factors associated with VTE (SPSS v23.0). All P values were 2-tailed, significance level The incidence of on-treatment VTE was 5.09% [96% ≥Grade 2 (CTCAE v4.0)]. Age ≥10 years [P =.048, HR 1.96 (95% confidence interval= 1.01-3.82)], positive blood culture in induction/consolidation [ P =.009, HR 2.35 (1.24-4.46)], extreme weight at diagnosis 95th centile [ P =.028, HR 2.14 (1.09-4.20)] and elevated peak gamma-glutamyl transferase (GGT) >5 x upper limit normal in induction/consolidation [ P =.018, HR 2.24 (1.15-4.36)] were significantly associated with VTE in multivariate cox regression modeling. The cumulative incidence of VTE, if all 4 clinical risk factors in our model were present, was 33.33%, which is significantly greater than the incidence of VTE for a patient without any risk factors (1.62%, P These 4 clinical factors could be used as a basis for assigning thromboprophylaxis in children with ALL. Our model detected 80% (42/52) of all VTE events by incorporating one or more risk factors. An equal proportion of patients eventually developing VTE could be predicted by weight and age ≥10 years; or later bacteremia and elevated GGT. Bacteremia, when present as a risk factor, preceded VTE in 80% of cases (20/25 cases) at a median of 29 days before VTE (range 3-668 days). The negative predictive value (NPV), specificity and sensitivity for the 4 risk factor model were 98.38%, 98.70% and 28.57% respectively. If 3 specified risk factors were included in the algorithm, such as 2 baseline and one treatment-related variable, the incidence of VTE was ≥25%, NPV 98.38%, specificity ≥96.19% and sensitivity 80%. The high NPV and high specificity mean the model can successfully exclude children who are not at increased risk of VTE. The challenge is to balance unnecessary exposure to anticoagulation against the risk of development of VTE. We have identified novel clinical risk factors in induction/consolidation - positive blood culture, hepatic enzymatic elevation and extreme weight at diagnosis- that may highlight risk mechanisms related to VTE pathogenesis. Our predictive model can define a group at highest risk of VTE who may benefit from randomized trials of prophylactic anticoagulation in childhood ALL therapy. Acknowledgments: The authors acknowledge support from the Kids Cancer Alliance (a Translational Cancer Research Centre of Cancer Institute NSW), Cancer Institute New South Wales, Royal Australasian College of Physicians - Kids Cancer Project Research Entry Scholarship, Cancer Therapeutics CRC (CTx) PhD Clinician Research Top-Up Scholarship, The Kids Cancer Project, Australian and New Zealand Children's Haematology Oncology Group, ASSET study members, data managers and clinical research associates at each site. Disclosures No relevant conflicts of interest to declare.

Introduction: While remission rates for childhood acute lymphoblastic leukemia (ALL) now exceed 80%, relapsed ALL remains the leading cause of non-traumatic death in children. Recently, a high-risk group of B-progenitor ALL patients has been identified. Such cases exhibit a gene expression profile similar to that of BCR-ABL1 positive (Ph+) ALL but are BCR-ABL1 negative, and also experience poor treatment outcomes. This subset, termed Ph-like ALL, is characterised by a range of genetic alterations that activate cytokine receptor and kinase signalling, allowing potential targeting by available tyrosine kinase inhibitors (TKI). The frequency of Ph-like ALL in the Australian community and the prognosis in the setting of the first MRD (minimal residual disease) intervention trial by the Australian and New Zealand Children's Haematology/Oncology Group (ANZCHOG ALL8) is unknown. Method: We retrospectively screened 250 unselected samples that were available from children diagnosed with B-ALL, for Ph-like ALL. The children, aged between 1 and 18 years, were enrolled on the ANZCHOG ALL8 trial and recruited from 2002-2011. The criteria for stratification to the high-risk group, based upon Berlin-Frankfurt-Munster (BFM) protocols, were BCR-ABL1 or MLL t(4;11) translocation; poor prednisolone response at day 8; failure to achieve remission by day 33 or high MRD (>5 x10-4) at day 79. MRD was measured by RQ-PCR for patient-specific immunoglobulin and T-cell receptor rearrangements. All patients received a standard BFM four drug induction chemotherapy regimen including a prednisolone pre-phase and intrathecal methotrexate. High-risk patients received a further three novel intensive blocks of chemotherapy followed by transplant in most cases. Patients were screened for Ph-like ALL using a custom Taqman Low Density Array (TLDA) based upon previous reports. Fusions were then confirmed by RT-PCR for 30 known fusions, Sanger sequencing, mRNA sequencing and/or FISH. Results: Ten percent (25/250) of children in this cohort were identified as having Ph-like ALL, with most fusions converging on kinase activating pathways (Table 1). Three Ph-like ALL patients were considered high-risk, the remaining 22 (88%) were medium risk. Five children with Ph-like ALL, that did not have a fusion identified by RT-PCR, are currently under further investigation. Furthermore, 15 of the 20 (75%) of rearrangements involved CRLF2 with 10 (66%) of these children relapsing. Strikingly, 56% (14/25) of children in the ALL8 cohort who were identified as Ph-like subsequently relapsed compared to 16% (36/225) who were not, with significantly worse event free survival (p Conclusion: Here we demonstrate a significantly higher frequency of relapse amongst Australian children with Ph-like ALL compared to non Ph-like disease despite a MRD-adjusted intensification regimen. In this cohort, these children should be classified as high-risk due to high treatment failure rates with standard/medium risk regimens. Importantly, rapid identification of these patients may guide future intervention with targeted therapies, such as TKI, matched to the causative genetic lesion in this high-risk group. Figure 1. Fusions identified in Ph-like ALL from ANZCHOG ALL8 cohort. Figure 1. Fusions identified in Ph-like ALL from ANZCHOG ALL8 cohort. Figure 2. Kaplan-Meier estimates of event free survival for patients with Ph-like ALL and non Ph-like ALL (all risk groups). Figure 2. Kaplan-Meier estimates of event free survival for patients with Ph-like ALL and non Ph-like ALL (all risk groups). Disclosures Hughes: ARIAD: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Mullighan:Incyte: Consultancy, Honoraria; Cancer Science Institute: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Speakers Bureau; Loxo Oncology: Research Funding. White:Novartis: Honoraria, Research Funding; BMS: Honoraria, Research Funding.

After publication, it was noted by the authors that the dataset used for the analyses of occupational exposures in this study accidentally used incomplete occupational histories collected for 94 control fathers and 104 control mothers recruited in 2006, and these control parents were all treated as unexposed to occupational pesticides. Results in Tables 1–3 and Supplemental Tables 1 and 2 (and the first three rows of Supplemental Table 3) of our published paper were unaffected by this error as they concerned household, rather than occupational pesticide exposure. The conclusions regarding the association with household exposure to professional pest control treatments are consequently unchanged. However, for occupational exposure, 18 control fathers and 2 control mothers were mistakenly classified as being unexposed to pesticides when they should have been classified as exposed (any time before the child’s birth). The analyses presented in Table 4 and parts of Supplemental Table 3 in the published manuscript were re-run using the full dataset to ensure correct exposure assignment (5 case fathers and 4 control fathers were additionally excluded from revised occupational analysis due to genuinely missing data). The updated Table 4 and Supplemental Table 3 (occupational estimates only) are presented in this erratum. The online version of the original article can be found under doi:10. 1007/s10552-013-0205-1.

X-linked lymphoproliferative disease (XLP) is an immunodeficiency resulting from mutations in SH2D1A, which encodes signalling lymphocytic activation molecule (SLAM)-associated protein (SAP). In addition to SLAM, SAP associates with several other cell-surface receptors including 2B4 (CD244), Ly9 (CD229), CD84 and NTB-A. SAP contains a single src-homology-2 domain and acts as an intracellular adaptor protein by recruiting the protein tyrosine kinase FynT to the cytoplasmic domains of some of these receptors, which results in the initiation of specific downstream signal transduction pathways. XLP is likely to result from perturbed signalling through one or more of these SAP-associating receptors. In this study, we identified missense (Y54C, I84T and F87S) and insertion (fs82 --> X103) mutations in four different kindreds affected by XLP. Each mutation dramatically reduced the half-life of SAP, thus diminishing its expression in primary lymphocytes as well as in transfected cell lines. Interestingly, although the Y54C and F87S mutations compromised the ability of SAP to associate with different receptors, the I84T mutation had no effect on the ability of SAP to bind SLAM, CD84 or 2B4. However, signalling downstream of SLAM was reduced in the presence of SAP bearing the I84T mutation. These findings indicate that, irrespective of the type of mutation, signalling through SAP-associating receptors in XLP can be impaired by reducing the expression of SAP, the ability of SAP to bind surface receptors and/or its ability to activate signal transduction downstream of the SLAM-SAP complex.

The objective of this study was to assess the efficacy of the VETOPEC regimen, a regimen of vincristine and etoposide with escalating doses of cyclophosphamide (CPA), in pediatric patients with high-risk brain tumors. Three consecutive studies by the Australia and New Zealand Children's Cancer Study Group--VETOPEC I, Baby Brain 91, and VETOPEC II--have used a specific chemotherapy regimen of vincristine (VCR), etoposide (VP-16) and escalating CPA in patients with relapsed, refractory, or high-risk solid tumors. Patients in the VETOPEC II cohort were treated with very high dose CPA with peripheral blood stem cell (PBSC) rescue. We analyzed the subset of patients with high-risk brain tumors treated with these intensive VETOPEC-based protocols to assess the response, toxicity, and survival. We also assessed whether the use of very high dose chemotherapy with stem cell rescue improved the response rate or affected toxicity. Seventy-one brain tumor patients were treated with VETOPEC-based protocols. Of the 54 patients evaluable for tumor response, 17 had a complete response (CR) and 20 a partial response (PR) to treatment, which yielded an overall response rate of 69%. The CR + PR was 83% (19/23) for medulloblastomas, 56% (5/9) for primitive neuroectodermal tumors, 55% (6/11) for grade 3 and 4 astrocytomas, and 80% (6/8) for ependymomas. At a median follow-up of 36 months, overall survival for the entire cohort of 71 patients was 32%, with event-free survival of 13%. There were no toxic deaths within the PBSC-supported VETOPEC II cohort, despite higher CPA doses, compared with 7% among the non-PBSC patients. This regimen produces high response rates in a variety of very poor prognosis pediatric brain tumors. The maximum tolerated dose of CPA was not reached. Higher escalation in doses of CPA did not deliver a further improvement in response. With PBSC rescue in the VETOPEC II study, hematologic toxicity was no longer a limiting factor. The response rates observed support further development of this chemotherapy regimen.

Objectives: Febrile neutropenia post-chemotherapy continues to impose a burden of morbidity and mortality on patients and families affected by childhood cancer, whereas these unplanned hospital admissions increase the financial cost of treating paediatric malignancies. There are currently no published national guidelines. This study comprises the first audit of current therapeutic practice in Australasia. Methods: Information was sought prospectively from the 12 paediatric oncology tertiary referral centres in Australia and New Zealand regarding treatment of febrile neutropenia episodes commencing between 11 March and 10 May 2002. Results: Data were returned on 127 episodes by nine centres. The median length of stay was 6 days and 18 different antibiotic regimens were implemented as first-line therapy. The median neutrophil count at the beginning and end of the febrile neutropenic episode was 0.0 × 109/L (range 0.0 to 2.3 × 109/L) and 0.7 × 109/L (range 0.0 to 25.4 × 109/L), respectively. Thirty per cent of episodes had positive blood cultures. Of these, 81% occurred in patients with tunnelled central venous catheters. The initial antimicrobial combination was changed in 61% of episodes. Outpatient antibiotics were used in 21% episodes after initial intravenous antimicrobial therapy. Conclusions: The current practice in Australasia is consistent with international guidelines, although changes are made more frequently to first-line therapy than in previous published studies. The central venous catheters are associated with a much higher risk of bacteraemia and consideration should be given to increased use of implanted port systems.

An unusual presentation of acute lymphoblastic leukaemia (ALL) in a 6-year-old girl is reported. She presented with unilateral cervical lymphadenopathy, a mixed obstructive/cholestatic jaundice and a progressive pancytopenia. Ultrasound examination revealed an obstructed common bile duct with gross thickening of the wall of the duct and intrahepatic bile duct dilatation. The jaundice resolved with high dose intravenous (i.v.) methylprednisolone. It is postulated that this was due to infiltration of the common bile duct, given the failure to demonstrate any other cause for the bile duct pathology.

Objective: To correlate clinical presentation and therapeutic outcomes in children with a diagnosis of juvenile myelomonocytic leukaemia. Methods: The medical records of 14 children who fulfilled the International Juvenile Myelomonocytic Leukaemia Working Group Criteria for a diagnosis of juvenile myelomonocytic leukaemia (JMML) presenting to a single institution were reviewed, and their clinical status at September 2000 was documented. Results: The most common presenting features were hepatosplenomegaly and lymphadenopathy. Fifty per cent of cases presented in the first year of life. Nine of 14 patients initially received chemotherapy otherwise used in the treatment of acute myeloid or lymphoblastic leukaemia with no apparent benefit. All six patients who received conditioning therapy with chemotherapy alone, followed by allogeneic bone marrow transplant (BMT), are in complete remission at a median follow-up duration of 12 months (range 5–91 months). Five of six patients surviving post-allogeneic BMT received marrow from an unrelated donor. Only one of seven patients who did not receive BMT survived long-term. Conclusion: Children with a diagnosis of JMML should be treated with allogeneic BMT as soon as a suitable donor is found. The role of anti-leukaemic therapy in this disease, prior to BMT, requires further investigation in the context of a multicentre clinical trial.

Severe Maroteaux-Lamy syndrome is usually fatal in teenage or early adult life. Until recently, allogeneic bone marrow transplantation was the only form of enzyme replacement. We report the first successful transplant using CD34 selected, mobilised allogeneic blood cells for an inborn error of metabolism. A busulphan, cyclophosphamide, melphalan and antithymocyte globulin conditioning regimen was used as myeloablative therapy. Allogeneic CD34 selected granulocyte colony-stimulating factor (G-CSF)-mobilised blood cells from a HLA-identical sibling were used for the transplant. Haemopoietic reconstitution occurred on day 10 post-transplant with normal N-acetylgalactosamine-4-sulphatase levels. Infectious and graft-versus-host disease (GVHD) complications were minimal. We suggest that CD34 selected, mobilised allogeneic blood cells are a safe form of enzyme replacement therapy in Maroteaux-Lamy syndrome and should be considered in other metabolic diseases where the benefits of haemopoietic transplantation are proven.

Abstract 1517 Purpose: Decitabine, a deoxycytidine nucleoside derivative, is an inhibitor of DNA-methyltransferases indicated for treatment of myelodysplastic syndrome (MDS) including previously treated and untreated, de novo or secondary MDS of all French-American-British (FAB) subtypes, Intermediate-1, Intermediate-2, and High-Risk International Prognostic Scoring System (IPSS) groups. Laboratory evidence shows that pretreatment of AML cell lines can sensitize leukemia cells to chemotherapy as well as inhibit clonogenic potential. The purpose of this study is to evaluate the safety, pharmacokinetics, and efficacy of decitabine when used as priming before induction therapy in children with newly diagnosed AML. Exploratory analyses of genomic methylation and RNA expression patterns and minimal residual disease (MRD) are embedded correlative studies. Methods: This multicenter, randomized, two-arm, open-label study enrolls pediatric pts ages 1–16 with newly diagnosed AML to either Arm A: daunorubicin, cytarabine, etoposide (D-ADE) preceded by a 5-day course of decitabine (experimental arm) or Arm B: daunorubicin, cytarabine, etoposide (ADE; control arm). Following completion of induction on study, post-induction therapy is at the treating physician's discretion. To date, 20 pts, 10 in each arm (1–16 yrs, median 9.4 yrs in both arms) have been enrolled. Results: At the protocol-specified bone marrow sampling time 3 weeks post-induction, there were 2 CRs, 6 CRi (CR with incomplete hematopoietic recovery), 1 leukemia not in remission and 1 pt who discontinued due to an AE in Arm A. In Arm B, 6 CRs, 2CRi, 1 PR and 1 pt with marrow aplasia have been confirmed. Decitabine PK in all arm A pts (100%) were characterized by mean+SD Cmax, 297+109 ng/mL, AUC0-t, 216+73.7 ng*h/mL, CL, 136+93.9L/h, Vdss 93.1+70.7 L, t1/2 0.456+0.073 h, and median tmax0.925 h. All pts had at least one AE. Grade 3 and 4 non-hematologic AEs in Arm A that were not seen in Arm B were caecitis in 2 (20%), anorexia in 3 (30%), and hypophosphatemia in 2 (20%) of pts. All pts experienced neutropenia and thrombocytopenia as expected. One pt in Arm A had appendicitis and colon perforation on Day 6 that led to study discontinuation, later determined to have been leukemic infiltrate. Two pts have died to date (both in Arm A), one of necrotic bowel, Pseudomonas sepsis and multisystem organ failure 6 months after completing study induction therapy. One pt died 5 months following study treatment from multisystem organ failure after stem cell transplant. Epigenetic changes associated with decitabine pretreatment were analyzed and will be presented. Conclusions: Decitabine in combination with ADE chemotherapy is well tolerated in children with newly diagnosed AML. There were no AEs that had not been previously identified in adults with MDS or AML. No differences have been observed between treatment arms in hematologic toxicities based on the current sample size. To date, the decitabine-treated pts in this study may have more gastrointestinal toxicity and hypophosphatemia. Decitabine-treated pts achieved PK exposures that were similar to those observed in adults treated with decitabine. Preliminary responses by CR/CRi were similar between treatment arms; expected adverse events of neutropenia and thrombocytopenia were similar between both Arms. Molecular changes associated with decitabine pretreatment may be important in the sensitization of clonogenic AML cells. Total accrual of 40 subjects is planned. Disclosures: Off Label Use: AC220 in relapsed/refractory pediatric acute leukemia. Tarassoff:Eisai, Inc.: Employment. Jones:Eisai Inc: Employment.

X-linked lymphoproliferative disease (XLP) is a rare immunodeficiency caused by mutations in SH2D1A which encodes SAP (SLAM-associated protein). SAP functions as an adaptor protein downstream of the SLAM family of cell surface receptors, thereby contributing to lymphocyte activation. The major defects in patients with XLP are exquisite sensitivity to infection with Epstein–Barr virus (EBV) due to dysfunctional CD8 + T cells and NK cells, and impaired antibody responses due to an inability of CD4 + T cells to provide ‘help’ to B cells for their differentiation into antibody secreting plasma cells. We have been investigating the molecular basis underlying these defects in XLP using a combination of approaches: by studying the viral specificity of CD8 + T cells from XLP patients as well as female carriers of XLP, and by studying the breakdown in CD4 + T cell help to B cells in an animal model of XLP (i.e., sap -deficient mice). Results from these studies highlight a critical role for interactions between SAP-associating receptors on T cells and appropriate antigen-presenting cells for the generation of effector CD4 + and CD8 + T cells and that this process is severely compromised in the presence of loss-of-function mutations in SH2D1A .

Socio-technical approaches to health information systems evaluation are particularly relevant to the study of Computerised Provider Order Entry (CPOE) systems. Pathology services are made up of a number of departments each with unique and complex tasks and requirements. These different components of pathology have received very little research attention. This study used qualitative methods to identify key organisational and work process along with repercussions of the implementation of CPOE through a comparison of the Haematology and Clinical Chemistry departments of a hospital pathology service. The results focus attention on areas where the departments face similar challenges along with those areas where work practices diverged. This underlined the key importance of understanding the context and setting of pathology laboratories. The study also draws attention to the importance of cross departmental and multi-disciplinary negotiation in the implementation process and highlights the potential for technology to affect and be affected by the organisational context in which it is placed.