Management of patients with diffuse intrinsic pontine glioma in Australia and New Zealand: Australian and New Zealand Children's Haematology/Oncology Group position statement.

INTRODUCTION: The main mission of the Australian and New Zealand Children's Haematology and Oncology Group (ANZCHOG) is to develop and facilitate local access to the world's leading evidence-based clinical trials for all paediatric cancers, including brain tumours, as soon as practically possible. Diffuse intrinsic pontine gliomas (DIPGs) - a subset of a larger group of tumours now termed diffuse midline glioma, H3K27-altered (DMG) - are paediatric brain cancers with less than 10% survival at two years. In the absence of any proven curative therapies, significant recent advancements have been made in pre-clinical and clinical research, leading many to seek integration of novel therapies early into standard practice. Despite these innovative therapeutic approaches, DIPG remains an incurable disease for which novel surgical, imaging, diagnostic, radiation and systemic therapy approaches are needed. MAIN RECOMMENDATIONS: All patients with DIPG should be discussed in multidisciplinary neuro-oncology meetings (including pathologists, neuroradiologists, radiation oncologists, neurosurgeons, medical oncologists) at diagnosis and at relapse or progression. Radiation therapy to the involved field remains the local and international standard of care treatment. Proton therapy does not yield a superior survival outcome compared with photon therapy and patients should undergo radiation therapy with the available modality (photon or proton) at their treatment centre. Patients may receive concurrent chemotherapy or radiation-sensitising agents as part of a clinical trial. Biopsy should be offered to facilitate consideration of experimental therapies and eligibility for clinical trial participation. After radiation therapy, each patient should be managed individually with either observation or considered for enrolment on a clinical trial, if eligible, after full discussion with the family. Re-irradiation can be considered for progressive disease. CHANGES IN MANAGEMENT AS A RESULT OF THE GUIDELINE: Every child diagnosed with DIPG should be offered enrolment on a clinical trial where available. Access to investigational drugs without biological rationale outside the clinical trial setting is not supported. In case of potentially actionable target identification with molecular profiling and absence of a suitable clinical trial, rational targeted therapies can be considered through compassionate access programs.

Minimising Adverse Drug Reactions and Verifying Economic Legitimacy-Pharmacogenomics Implementation in Children (MARVEL- PIC): protocol for a national randomised controlled trial of pharmacogenomics implementation.

INTRODUCTION: DNA-informed prescribing (termed pharmacogenomics, PGx) is the epitome of personalised medicine. Despite international guidelines existing, its implementation in paediatric oncology remains sparse. METHODS AND ANALYSIS: Minimising Adverse Drug Reactions and Verifying Economic Legitimacy-Pharmacogenomics Implementation in Children is a national prospective, multicentre, randomised controlled trial assessing the impact of pre-emptive PGx testing for actionable PGx variants on adverse drug reaction (ADR) incidence in patients with a new cancer diagnosis or proceeding to haematopoetic stem cell transplant. All ADRs will be prospectively collected by surveys completed by parents/patients using the National Cancer Institute Pediatric Patient Reported [Ped-PRO]-Common Terminology Criteria for Adverse Events (CTCAE) (weeks 1, 6 and 12). Pharmacist will assess for causality and severity in semistructured interviews using the CTCAE and Liverpool Causality Assessment Tool. The primary outcome is a reduction in ADRs among patients with actionable PGx variants, where an ADR will be considered as any CTCAE grade 2 and above for non-haematological toxicities and any CTCAE grade 3 and above for haematological toxicities Cost-effectiveness of pre-emptive PGx (secondary outcome) will be compared with standard of care using hospital inpatient and outpatient data along with the validated Childhood Health Utility 9D Instrument. Power and statistics considerations: A sample size of 440 patients (220 per arm) will provide 80% power to detect a 24% relative risk reduction in the primary endpoint of ADRs (two-sided α=5%, 80% vs 61%), allowing for 10% drop-out. ETHICS AND DISSEMINATION: The ethics approval of the trial has been obtained from the Royal Children's Hospital Ethics Committee (HREC/89083/RCHM-2022). The ethics committee of each participating centres nationally has undertaken an assessment of the protocol and governance submission. TRIAL REGISTRATION NUMBER: NCT05667766.

Lessons learnt in the first year of an Australian pediatric cardio oncology clinic.

BACKGROUND: Modern oncological therapies together with chemotherapy and radiotherapy have broadened the agents that can cause cardiac sequelae, which can manifest for pediatric oncology patients while on active treatment. Recommendations for high-risk patients who should be monitored in a pediatric cardio-oncology clinic have previously been developed by expert Delphi consensus by our group. In 2022 we opened our first multidisciplinary pediatric cardio-oncology clinic adhering to these recommendations in surveillance and management. OBJECTIVES: Our pediatric cardio-oncology clinic aimed to: (i) Document cardiovascular toxicities observed within a pediatric cardio-oncology clinic and. (ii) Evaluate the applicability of the Australian and New Zealand Pediatric Cardio-Oncology recommendations. METHODS: Monthly multidisciplinary cardio-oncology clinics were conducted in an Australian tertiary pediatric hospital. Structured standardised approaches to assessment were built into the electronic medical record (EMR). All patients underwent baseline echocardiogram and electrocardiogram assessment together with vital signs in conjunction with standard history and examination. RESULTS: Nineteen (54%) individuals had a documented cardiovascular toxicity or pre-existing risk factor prior to referral. The two most common cardiovascular toxicities documented during clinic review included Left Ventricular Dysfunction (LVD) and hypertension. Of note 3 (8.1%) patients had CTCAE grade III LVD. An additional 10 (27%) patients reviewed in clinic had CTCAE grade I hypertension. None of these patients had hypertension noted within their referral. Cascade testing for cardiac history was warranted in 2 (5.4%) of patients. CONCLUSIONS: Pediatric cardio-oncology clinics are likely beneficial to documenting previously unrecognised cardiotoxicity and relevant cardiac family histories, whilst providing an opportunity to address lifestyle risk factors.

Hopes, concerns, satisfaction and regret in a precision medicine trial for childhood cancer: a mixed-methods study of parent and patient perspectives.

BACKGROUND: Paediatric precision oncology aims to match therapeutic agents to driver gene targets. We investigated whether parents and patients regret participation in precision medicine trials, particularly when their hopes are unfulfilled. METHODS: Parents and adolescent patients completed questionnaires at trial enrolment (T0) and after receiving results (T1). Parents opted-in to an interview at T1. Bereaved parents completed a questionnaire 6-months post-bereavement (T1B). We analysed quantitative data with R and qualitative data thematically with NVivo, before integrating all data for interpretation. RESULTS: 182 parents and 23 patients completed T0; 108/182 parents and 8/23 patients completed T1; 27/98 bereaved parents completed T1B; and 45/108 parents were interviewed. At enrolment, participants held concurrent hopes that precision medicine would benefit future children and their child. Participants expressed concern regarding wait-times for receipt of results. Most participants found the trial beneficial and not burdensome, including bereaved parents. Participants reported high trial satisfaction (median scores: parents: 93/100; patients: 80/100). Participants expressed few regrets (parent median scores: parents: 10/100; bereaved parents: 15/100; patient regret: 2/8 expressed minimal regret). CONCLUSIONS: Even when trial outcomes did not match their hopes, parents and patients rarely regretted participating in a childhood cancer precision medicine trial. These data are critical for integrating participants' views into future precision medicine delivery.

Physician-defined severe toxicities occurring during and after cancer treatment: Modified consensus definitions and clinical applicability in the evaluation of cancer treatment.

Overall survival after cancer is increasing for the majority of cancer types, but survivors can be burdened lifelong by treatment-related severe toxicities. Integration of long-term toxicities in treatment evaluation is not least important for children and young adults with cancers with high survival probability. We present modified consensus definitions of 21 previously published physician-defined Severe Toxicities (STs), each reflecting the most serious long-term treatment-related toxicities and representing an unacceptable price for cure. Applying the Severe Toxicity (ST) concept to real-world data required careful adjustments of the original consensus definitions, translating them into standardized endpoints for evaluating treatment-related outcomes to ensure that (1) the STs can be classified uniformly and prospectively across different cohorts, and (2) the ST definitions allow for valid statistical analyses. The current paper presents the resulting modified consensus definitions of the 21 STs proposed to be included in outcome reporting of cancer treatment.

A novel transcriptional signature identifies T-cell infiltration in high-risk paediatric cancer.

BACKGROUND: Molecular profiling of the tumour immune microenvironment (TIME) has enabled the rational choice of immunotherapies in some adult cancers. In contrast, the TIME of paediatric cancers is relatively unexplored. We speculated that a more refined appreciation of the TIME in childhood cancers, rather than a reliance on commonly used biomarkers such as tumour mutation burden (TMB), neoantigen load and PD-L1 expression, is an essential prerequisite for improved immunotherapies in childhood solid cancers. METHODS: We combined immunohistochemistry (IHC) with RNA sequencing and whole-genome sequencing across a diverse spectrum of high-risk paediatric cancers to develop an alternative, expression-based signature associated with CD8+ T-cell infiltration of the TIME. Furthermore, we explored transcriptional features of immune archetypes and T-cell receptor sequencing diversity, assessed the relationship between CD8+ and CD4+ abundance by IHC and deconvolution predictions and assessed the common adult biomarkers such as neoantigen load and TMB. RESULTS: A novel 15-gene immune signature, Immune Paediatric Signature Score (IPASS), was identified. Using this signature, we estimate up to 31% of high-risk cancers harbour infiltrating T-cells. In addition, we showed that PD-L1 protein expression is poorly correlated with PD-L1 RNA expression and TMB and neoantigen load are not predictive of T-cell infiltration in paediatrics. Furthermore, deconvolution algorithms are only weakly correlated with IHC measurements of T-cells. CONCLUSIONS: Our data provides new insights into the variable immune-suppressive mechanisms dampening responses in paediatric solid cancers. Effective immune-based interventions in high-risk paediatric cancer will require individualised analysis of the TIME.

Prospective longitudinal evaluation of treatment-related toxicity and health-related quality of life during the first year of treatment for pediatric acute lymphoblastic leukemia.

BACKGROUND: Pediatric acute lymphoblastic leukemia (ALL) therapy is accompanied by treatment-related toxicities (TRTs) and impaired quality of life. In Australia and New Zealand, children with ALL are treated with either Children's Oncology Group (COG) or international Berlin-Frankfurt-Munster (iBFM) Study Group-based therapy. We conducted a prospective registry study to document symptomatic TRTs (venous thrombosis, neurotoxicity, pancreatitis and bone toxicity), compare TRT outcomes to retrospective TRT data, and measure the impact of TRTs on children's general and cancer-related health-related quality of life (HRQoL) and parents' emotional well-being. METHODS: Parents of children with newly diagnosed ALL were invited to participate in the ASSET (Acute Lymphoblastic Leukaemia Subtypes and Side Effects from Treatment) study and a prospective, longitudinal HRQoL study. TRTs were reported prospectively and families completed questionnaires for general (Healthy Utility Index Mark 3) and cancer specific (Pediatric Quality of Life Inventory (PedsQL)-Cancer Module) health related quality of life as well the Emotion Thermometer to assess emotional well-being. RESULTS: Beginning in 2016, 260 pediatric patients with ALL were enrolled on the TRT registry with a median age at diagnosis of 59 months (range 1-213 months), 144 males (55.4%), majority with Pre-B cell immunophenotype, n = 226 (86.9%), 173 patients (66.5%) treated according to COG platform with relatively equal distribution across risk classification sub-groups. From 2018, 79 families participated in the HRQoL study through the first year of treatment. There were 74 TRT recorded, reflecting a 28.5% risk of developing a TRT. Individual TRT incidence was consistent with previous studies, being 7.7% for symptomatic VTE, 11.9% neurotoxicity, 5.4% bone toxicity and 5.0% pancreatitis. Children's HRQoL was significantly lower than population norms throughout the first year of treatment. An improvement in general HRQoL, measured by the HUI3, contrasted with the lack of improvement in cancer-related HRQoL measured by the PedsQL Cancer Module over the first 12 months. There were no persisting differences in the HRQoL impact of COG compared to iBFM therapy. CONCLUSIONS: It is feasible to prospectively monitor TRT incidence and longitudinal HRQoL impacts during ALL therapy. Early phases of ALL therapy, regardless of treatment platform, result in prolonged reductions in cancer-related HRQoL.

Acute central nervous system toxicity during treatment of pediatric acute lymphoblastic leukemia: phenotypes, risk factors and genotypes.

Central nervous system (CNS) toxicity is common at diagnosis and during treatment of pediatric acute lymphoblastic leukemia (ALL). We studied CNS toxicity in 1,464 children aged 1.0-17.9 years, diagnosed with ALL and treated according to the Nordic Society of Pediatric Hematology and Oncology ALL2008 protocol. Genome-wide association studies, and a candidate single-nucleotide polymorphism (SNP; n=19) study were performed in 1,166 patients. Findings were validated in an independent Australian cohort of children with ALL (n=797) in whom two phenotypes were evaluated: diverse CNS toxicities (n=103) and methotrexate-related CNS toxicity (n=48). In total, 135/1,464 (9.2%) patients experienced CNS toxicity for a cumulative incidence of 8.7% (95% confidence interval: 7.31-10.20) at 12 months from diagnosis. Patients aged ≥10 years had a higher risk of CNS toxicity than had younger patients (16.3% vs. 7.4%; P<0.001). The most common CNS toxicities were posterior reversible encephalopathy syndrome (n=52, 43 with seizures), sinus venous thrombosis (n=28, 9 with seizures), and isolated seizures (n=16). The most significant SNP identified by the genome-wide association studies did not reach genomic significance (lowest P-value: 1.11x10-6), but several were annotated in genes regulating neuronal functions. In candidate SNP analysis, ATXN1 rs68082256, related to epilepsy, was associated with seizures in patients <10 years (P=0.01). ATXN1 rs68082256 was validated in the Australian cohort with diverse CNS toxicities (P=0.04). The role of ATXN1 as well as the novel SNP in neurotoxicity in pediatric ALL should be further explored.

Methotrexate-related central neurotoxicity: clinical characteristics, risk factors and genome-wide association study in children treated for acute lymphoblastic leukemia.

Symptomatic methotrexate-related central neurotoxicity (MTX neurotoxicity) is a severe toxicity experienced during acute lymphoblastic leukemia (ALL) therapy with potential long-term neurologic complications. Risk factors and long-term outcomes require further study. We conducted a systematic, retrospective review of 1,251 consecutive Australian children enrolled on Berlin-Frankfurt-Münster or Children's Oncology Group-based protocols between 1998-2013. Clinical risk predictors for MTX neurotoxicity were analyzed using regression. A genome-wide association study (GWAS) was performed on 48 cases and 537 controls. The incidence of MTX neurotoxicity was 7.6% (n=95 of 1,251), at a median of 4 months from ALL diagnosis and 8 days after intravenous or intrathecal MTX. Grade 3 elevation of serum aspartate aminotransferase (P=0.005, odds ratio 2.31 [range, 1.28-4.16]) in induction/consolidation was associated with MTX neurotoxicity, after accounting for the only established risk factor, age ≥10 years. Cumulative incidence of CNS relapse was increased in children where intrathecal MTX was omitted following symptomatic MTX neurotoxicity (n=48) compared to where intrathecal MTX was continued throughout therapy (n=1,174) (P=0.047). Five-year central nervous system relapse-free survival was 89.2 4.6% when intrathecal MTX was ceased compared to 95.4 0.6% when intrathecal MTX was continued. Recurrence of MTX neurotoxicity was low (12.9%) for patients whose intrathecal MTX was continued after their first episode. The GWAS identified single-nucletide polymorphism associated with MTX neurotoxicity near genes regulating neuronal growth, neuronal differentiation and cytoskeletal organization (P<1x10-6). In conclusion, increased serum aspartate aminotransferase and age ≥10 years at diagnosis were independent risk factors for MTX neurotoxicity. Our data do not support cessation of intrathecal MTX after a first MTX neurotoxicity event.

A cost-effective approach to increasing participation in patient-reported outcomes research in cancer: A randomized trial of video invitations.

Maximizing participation in cancer research is important to improve the validity and generalizability of research findings. We conducted a four-arm randomized controlled trial to test the impact of a novel video invitation on participant response. We invited childhood cancer survivors and parents of survivors <16 years to complete questionnaires. We compared response rates to an invitation letter (control) vs receiving the letter plus a video invitation on a flash drive presented by a childhood cancer survivor, a pediatric oncologist or a researcher. We explored factors associated with viewing the video and examined the impact of enclosing the USB on study costs. Overall 54% (634/1176) of questionnaires were returned. Participants who received a video invitation on a USB were more likely to return the questionnaire than those who did not (58% vs 47%, P < .001). Participation rate did not significantly differ by video presenter. Forty-seven percent of participants who received a USB reported watching the video, of whom 48% reported that the video influenced their decision to participate. Participants with a lower income (OR = 0.43, 95% CI = 0.25-0.74, P = .002) were more likely to report watching the video. Participants who received a video invitation required significantly fewer reminder calls than those who only received a written invitation (mean = 1.6 vs 1.1 calls, P < .001), resulting in a 25% recruitment cost-saving for the study. Adding a USB with a video study invitation to recruitment packages is a cost-effective way of improving study participation. This is important in an era of declining study participation and underrepresentation of vulnerable populations in research.

Genome-Wide Association Meta-Analysis of Single-Nucleotide Polymorphisms and Symptomatic Venous Thromboembolism during Therapy for Acute Lymphoblastic Leukemia and Lymphoma in Caucasian Children.

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 < 5 × 10-8) in either cohort. Among the top 34 single-nucleotide polymorphisms (SNPs) (p < 1 × 10-6), two loci had concordant effects in both cohorts: ALOX15B (rs1804772) (MAF: 1%; p = 3.95 × 10-7) that influences arachidonic acid metabolism and thus platelet aggregation, and KALRN (rs570684) (MAF: 1%; p = 4.34 × 10-7) 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.

Down syndrome and leukemia: insights into leukemogenesis and translational targets.

Children with Down syndrome (DS) have a significantly increased risk of childhood leukemia, in particular acute megakaryoblastic leukemia (AMKL) and acute lymphoblastic leukemia (DS-ALL). A pre-leukemia, called transient myeloproliferative disorder (TMD), characterised by a GATA binding protein 1 (GATA1) mutation, affects up to 30% of newborns with DS. In most cases, the pre-leukemia regresses spontaneously, however one-quarter of these children will go on to develop AMKL or myelodysplastic syndrome (MDS) . AMKL and MDS occurring in young children with DS and a GATA1 somatic mutation are collectively termed myeloid leukemia of Down syndrome (ML-DS). This model represents an important multi-step process of leukemogenesis, and further study is required to identify therapeutic targets to potentially prevent development of leukemia. DS-ALL is a high-risk leukemia and mutations in the JAK-STAT pathway are frequently observed. JAK inhibitors may improve outcome for this type of leukemia. Genetic and epigenetic studies have revealed likely candidate drivers involved in development of ML-DS and DS-ALL. Overall this review aims to identify potential impacts of new research on how we manage children with DS, pre-leukemia and leukemia.

The prenatal origins of cancer.

The concept that some childhood malignancies arise from postnatally persistent embryonal cells has a long history. Recent research has strengthened the links between driver mutations and embryonal and early postnatal development. This evidence, coupled with much greater detail on the cell of origin and the initial steps in embryonal cancer initiation, has identified important therapeutic targets and provided renewed interest in strategies for the early detection and prevention of childhood cancer.

Transplant-related mortality following allogeneic hematopoeitic stem cell transplantation for pediatric acute lymphoblastic leukemia: 25-year retrospective review.

BACKGROUND: Over the last 25 years, donor source, conditioning, graft-versus-host disease prevention and supportive care for children undergoing hematopoeitic stem cell transplantation (HSCT) have changed dramatically. HSCT indications for acute lymphoblastic leukemia (ALL) now include high-risk patients in first and subsequent remission. There is a large burden of infectious and pre-HSCT morbidities, due to myelosuppressive therapy required for remission induction. We hypothesized that, despite these trends, overall survival (OS) had increased. PROCEDURE: A retrospective audit of allogeneic pediatric HSCT for ALL was performed in our institution over 25 years. Outcomes for 136 HSCTs were analyzed in three consecutive 8-year periods (Period 1: 1/1/1984-31/8/1992, Period 2: 1/9/1992-30/4/2001, Period 3: 1/5/2001-31/12/2009). RESULTS: Despite a significant increase in unrelated donor HSCT, event-free and OS over 25 years improved significantly. (EFS 31.6-64.8%, P = 0.0027; OS 41.8-78.9%, P < 0.0001) Concurrently, TRM dropped from 33% to 5% (P = 0.0004) whilst relapse rate was static (P = 0.07). TRM reduced significantly for matched sibling and unrelated cord blood transplantation (UCT) in Period 3 compared with earlier periods (P = 0.036, P = 0.0098, respectively). Factors leading to improved survival in patients undergoing UCT include better matching, higher total nucleated cell doses, and significantly faster neutrophil engraftment. Length of initial HSCT admission was similar over time. CONCLUSION: EFS and OS have increased significantly despite heightened HSCT complexity. This survival gain was due to TRM reduction. Contemporary patients have benefited from refined donor selection and improved supportive care. Overall rates of leukemic relapse post-HSCT are unchanged, and remain the focus for improvement.