Distinct pattern of genomic breakpoints in CML and BCR::ABL1-positive ALL: analysis of 971 patients.

BACKGROUND: The BCR::ABL1 is a hallmark of chronic myeloid leukemia (CML) and is also found in acute lymphoblastic leukemia (ALL). Most genomic breaks on the BCR side occur in two regions - Major and minor - leading to p210 and p190 fusion proteins, respectively. METHODS: By multiplex long-distance PCR or next-generation sequencing technology we characterized the BCR::ABL1 genomic fusion in 971 patients (adults and children, with CML and ALL: pediatric ALL: n = 353; pediatric CML: n = 197; adult ALL: n = 166; adult CML: n = 255 patients) and designed "Break-App" web tool to allow visualization and various analyses of the breakpoints. Pearson's Chi-Squared test, Kolmogorov-Smirnov test and logistic regression were used for statistical analyses. RESULTS: Detailed analysis showed a non-random distribution of breaks in both BCR regions, whereas ABL1 breaks were distributed more evenly. However, we found a significant difference in the distribution of breaks between CML and ALL. We found no association of breakpoints with any type of interspersed repeats or DNA motifs. With a few exceptions, the primary structure of the fusions suggests non-homologous end joining being responsible for the BCR and ABL1 gene fusions. Analysis of reciprocal ABL1::BCR fusions in 453 patients showed mostly balanced translocations without major deletions or duplications. CONCLUSIONS: Taken together, our data suggest that physical colocalization and chromatin accessibility, which change with the developmental stage of the cell (hence the difference between ALL and CML), are more critical factors influencing breakpoint localization than presence of specific DNA motifs.

Whole-genome sequencing facilitates patient-specific quantitative PCR-based minimal residual disease monitoring in acute lymphoblastic leukaemia, neuroblastoma and Ewing sarcoma.

BACKGROUND: Minimal residual disease (MRD) measurement is a cornerstone of contemporary acute lymphoblastic leukaemia (ALL) treatment. The presence of immunoglobulin (Ig) and T cell receptor (TCR) gene recombinations in leukaemic clones allows widespread use of patient-specific, DNA-based MRD assays. In contrast, paediatric solid tumour MRD remains experimental and has focussed on generic assays targeting tumour-specific messenger RNA, methylated DNA or microRNA. METHODS: We examined the feasibility of using whole-genome sequencing (WGS) data to design tumour-specific polymerase chain reaction (PCR)-based MRD tests (WGS-MRD) in 18 children with high-risk relapsed cancer, including ALL, high-risk neuroblastoma (HR-NB) and Ewing sarcoma (EWS) (n = 6 each). RESULTS: Sensitive WGS-MRD assays were generated for each patient and allowed quantitation of 1 tumour cell per 10-4 (0.01%)-10-5 (0.001%) mononuclear cells. In ALL, WGS-MRD and Ig/TCR-MRD were highly concordant. WGS-MRD assays also showed good concordance between quantitative PCR and droplet digital PCR formats. In serial clinical samples, WGS-MRD correlated with disease course. In solid tumours, WGS-MRD assays were more sensitive than RNA-MRD assays. CONCLUSIONS: WGS facilitated the development of patient-specific MRD tests in ALL, HR-NB and EWS with potential clinical utility in monitoring treatment response. WGS data could be used to design patient-specific MRD assays in a broad range of tumours.

Measurable residual disease analysis in paediatric acute lymphoblastic leukaemia patients with ABL-class fusions.

BACKGROUND: ABL-class fusions including NUP214-ABL1 and EBF1-PDGFRB occur in high risk acute lymphoblastic leukaemia (ALL) with gene expression patterns similar to BCR-ABL-positive ALL. Our aim was to evaluate new DNA-based measurable residual disease (MRD) tests detecting these fusions and IKZF1-deletions in comparison with conventional immunoglobulin/T-cell receptor (Ig/TCR) markers. METHODS: Precise genomic breakpoints were defined from targeted or whole genome next generation sequencing for ABL-fusions and BCR-ABL1. Quantitative PCR assays were designed and used to re-measure MRD in remission bone marrow samples previously tested using Ig/TCR markers. All MRD testing complied with EuroMRD guidelines. RESULTS: ABL-class patients had 46% 5year event-free survival and 79% 5year overall survival. All had sensitive fusion tests giving high concordance between Ig/TCR and ABL-class fusion results (21 patients, n = 257 samples, r2 = 0.9786, P < 0.0001) and Ig/TCR and IKZF1-deletion results (9 patients, n = 143 samples, r2 = 0.9661, P < 0.0001). In contrast, in BCR-ABL1 patients, Ig/TCR and BCR-ABL1 tests were discordant in 32% (40 patients, n = 346 samples, r2 = 0.4703, P < 0.0001) and IKZF1-deletion results were closer to Ig/TCR (25 patients, n = 176, r2 = 0.8631, P < 0.0001). CONCLUSIONS: MRD monitoring based on patient-specific assays detecting gene fusions or recurrent assays for IKZF1-deletions is feasible and provides good alternatives to Ig/TCR tests to monitor MRD in ABL-class ALL.

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.

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.

Mouse models of high-risk neuroblastoma.

Informative and realistic mouse models of high-risk neuroblastoma are central to understanding mechanisms of tumour initiation, progression, and metastasis. They also play vital roles in validating tumour drivers and drug targets, as platforms for assessment of new therapies and in the generation of drug sensitivity data that can inform treatment decisions for individual patients. This review will describe genetically engineered mouse models of specific subsets of high-risk neuroblastoma, the development of patient-derived xenograft models that more broadly represent the diversity and heterogeneity of the disease, and models of primary and metastatic disease. We discuss the research applications, advantages, and limitations of each model type, the importance of model repositories and data standards for supporting reproducible, high-quality research, and potential future directions for neuroblastoma mouse models.

Determinants of social functioning among adolescents and young adults with cancer: A systematic review.

OBJECTIVES: Survivors of adolescent and young adult (AYA) cancer report deficits in social functioning relative to healthy peers. Identifying factors related to their social functioning is critical to improve their long-term social outcomes. This review addressed: (1) How is social functioning defined and measured among studies of AYAs who have had cancer? (2) What factors have quantitatively/qualitatively are associated with/predictors of social functioning? and (3) What associated factors/predictors of social functioning are modifiable and amenable to intervention? METHODS: A systematic review was conducted to identify publications from 2000 to 2021, meeting these criteria: (1) mean/median age at diagnosis/treatment 13-40, (2) assessed social functioning with a validated measure and included factors associated with/predictive of social functioning and/or qualitatively assessed young people's perceptions of factors related to their social functioning and (3) was peer-reviewed/published in English. RESULTS: Thirty-seven publications were included. Definitions and measures of social functioning varied, and factors related to social functioning varied based on definition. Factors most commonly associated with decreased social functioning included treatment status (receiving or completed treatment), poor physical functioning, depression, negative body image, engaging in social comparisons, social/cultural stigma around cancer, and fatigue. Increased social functioning was most commonly associated with social support and the quality/age-appropriateness of care. CONCLUSIONS: Social functioning is multidimensional construct for AYAs diagnosed with cancer and may not be adequately assessed with measures of adjustment or quality of life. Future studies should clarify how to optimally define and measure social functioning in this population, to ensure their functioning can be protected and promoted long-term.

Outcomes for Australian children with relapsed/refractory acute lymphoblastic leukaemia treated with blinatumomab.

We report on the Australian experience of blinatumomab for treatment of 24 children with relapsed/refractory precursor B-cell acute lymphoblastic leukaemia (B-ALL) and high-risk genetics, resulting in a minimal residual disease (MRD) response rate of 58%, 2-year progression-free survival (PFS) of 39% and 2-year overall survival of 63%. In total, 83% (n = 20/24) proceeded to haematopoietic stem cell transplant, directly after blinatumomab (n = 12) or following additional salvage therapy (n = 8). Four patients successfully received CD19-directed chimeric antigen receptor T-cell therapy despite prior blinatumomab exposure. Inferior 2-year PFS was associated with MRD positivity (20%, n = 15) and in KMT2A-rearranged infants (15%, n = 9). Our findings highlight that not all children with relapsed/refractory B-ALL respond to blinatumomab and factors such as blast genotype may affect prognosis.

CD30 and ALK combination therapy has high therapeutic potency in RANBP2-ALK-rearranged epithelioid inflammatory myofibroblastic sarcoma.

BACKGROUND: Epithelioid inflammatory myofibroblastic sarcoma (eIMS) is characterised by perinuclear ALK localisation, CD30 expression and early relapse despite crizotinib treatment. We aimed to identify therapies to prevent and/or treat ALK inhibitor resistance. METHODS: Malignant ascites, from an eIMS patient at diagnosis and following multiple relapses, were used to generate matched diagnosis and relapse xenografts. RESULTS: Xenografts were validated by confirmation of RANBP2-ALK rearrangement, perinuclear ALK localisation and CD30 expression. Although brentuximab-vedotin (BV) demonstrated single-agent activity, tumours regrew during BV therapy. BV resistance was associated with reduced CD30 expression and induction of ABCB1. BV resistance was reversed in vitro by tariquidar, but combination BV and tariquidar treatment only briefly slowed xenograft growth compared with BV alone. Combining BV with either crizotinib or ceritinib resulted in marked tumour shrinkage in both xenograft models, and resulted in prolonged tumour-free survival in the diagnosis compared with the relapse xenograft. CONCLUSIONS: CD30 is a therapeutic target in eIMS. BV efficacy is limited by the rapid emergence of resistance. Prolonged survival with combination ALK and CD30-targeted-therapy in the diagnosis model provides the rationale to trial this combination in eIMS patients at diagnosis. This combination could also be considered for other CD30-positive, ALK-rearranged malignancies.

Accelerating development of high-risk neuroblastoma patient-derived xenograft models for preclinical testing and personalised therapy.

BACKGROUND: Predictive preclinical models play an important role in the assessment of new treatment strategies and as avatar models for personalised medicine; however, reliable and timely model generation is challenging. We investigated the feasibility of establishing patient-derived xenograft (PDX) models of high-risk neuroblastoma from a range of tumour-bearing patient materials and assessed approaches to improve engraftment efficiency. METHODS: PDX model development was attempted in NSG mice by using tumour materials from 12 patients, including primary and metastatic solid tumour samples, bone marrow, pleural fluid and residual cells from cytogenetic analysis. Subcutaneous, intramuscular and orthotopic engraftment were directly compared for three patients. RESULTS: PDX models were established for 44% (4/9) of patients at diagnosis and 100% (5/5) at relapse. In one case, attempted engraftment from pleural fluid resulted in an EBV-associated atypical lymphoid proliferation. Xenogeneic graft versus host disease was observed with attempted engraftment from lymph node and bone marrow tumour samples but could be prevented by T-cell depletion. Orthotopic engraftment was more efficient than subcutaneous or intramuscular engraftment. CONCLUSIONS: High-risk neuroblastoma PDX models can be reliably established from diverse sample types. Orthotopic implantation allows more rapid model development, increasing the likelihood of developing an avatar model within a clinically useful timeframe.

Enrolment in paediatric oncology early-phase clinical trials: The health-care professionals' perspective.

AIM: Approximately 20-30% of children/adolescents with cancer will not respond to standard therapies. These children are usually offered experimental treatment in the form of an early-phase clinical trial. We examined the perspectives of health-care professionals (HCPs) regarding obtaining informed consent for early-phase trials in paediatric oncology. METHODS: We collected survey data from 87 HCPs working in paediatric cancer centres across Australia and New Zealand. RESULTS: HCPs were, on average, 44 years old (range = 25-74), with 15.8 years' experience in paediatric oncology (range = 1-40). Few HCPs (17.4%) received training for early-phase trial consent; however, most were willing to attend training (77.9%). HCPs (61.6%) reported that they informed families about early-phase trials without any attempt to influence their decision. However, 23.3% of HCPs reported that they informed families that their child would benefit. HCPs' main obstacle in obtaining consent was their perception of parents' eagerness to 'try anything' (52.3%). HCPs perceived that many parents misunderstood key clinical trials concepts, with 25.2% of HCPs believing that not being given clear information influenced parents' decisions. Physicians were more likely than social workers/nurses to inform families that other children will benefit from enrolment in the study. Social workers/nurses appeared to rate the chance of benefits for the patient higher than physicians. CONCLUSIONS: HCPs may experience difficulty conducting early-phase trial consultations and obtaining valid informed consent. Our study highlights the need for formal training for HCPs and additional patient education tools.

A risk score including microdeletions improves relapse prediction for standard and medium risk precursor B-cell acute lymphoblastic leukaemia in children.

To prevent relapse, high risk paediatric acute lymphoblastic leukaemia (ALL) is treated very intensively. However, most patients who eventually relapse have standard or medium risk ALL with low minimal residual disease (MRD) levels. We analysed recurrent microdeletions and other clinical prognostic factors in a cohort of 475 uniformly treated non-high risk precursor B-cell ALL patients with the aim of better predicting relapse and refining risk stratification. Lower relapse-free survival at 7 years (RFS) was associated with IKZF1 intragenic deletions (P < 0·0001); P2RY8-CRLF2 gene fusion (P < 0·0004); Day 33 MRD>5 × 10-5 (P < 0·0001) and High National Cancer Institute (NCI) risk (P < 0·0001). We created a predictive model based on a risk score (RS) for deletions, MRD and NCI risk, extending from an RS of 0 (RS0) for patients with no unfavourable factors to RS2 +  for patients with 2 or 3 high risk factors. RS0, RS1, and RS2 +  groups had RFS of 93%, 78% and 49%, respectively, and overall survival (OS) of 99%, 91% and 71%. The RS provided greater discrimination than MRD-based risk stratification into standard (89% RFS, 96% OS) and medium risk groups (79% RFS, 91% OS). We conclude that this RS may enable better early therapeutic stratification and thus improve cure rates for childhood ALL.

Alectinib is effective, safe and tolerable in an adolescent with stage IVB ALK-rearranged adenocarcinoma of the lung.

Anaplastic lymphoma kinase (ALK) inhibitors such as crizotinib and alectinib have been shown to have significant activity in ALK-rearranged non-small cell lung cancers (NSCLC). There are no data for alectinib's safety or efficacy in younger patients, though it is superior to crizotinib in adult trials. We present a 14-year old girl diagnosed with stage IV-B ALK-positive adenocarcinoma of the lung after presenting with cough and fever. She was commenced on alectinib at adult dose and has had sustained complete metabolic remission for 9 months. She is the youngest patient with lung adenocarcinoma to be treated with alectinib.

Persistent MRD before and after allogeneic BMT predicts relapse in children with acute lymphoblastic leukaemia.

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 hyperdiploidy >50. 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.

Social Anxiety Symptoms in Adolescents and Young Adults Recently Diagnosed with Cancer.

Purpose: Social anxiety disorder (SAD) remains an understudied potential link between the cancer experience and adolescent and young adult (AYA) cancer survivors' poor psychosocial outcomes. We investigated the frequency and duration of, as well as factors associated with, symptoms of SAD among AYAs with cancer. Methods: This longitudinal, mixed-methods study involved online surveys (including a validated screening tool for SAD) at recruitment and 6 months later, and a structured clinical interview. Results: Twenty-eight AYAs (aged 12-30 years, <1-year postdiagnosis, 50% male) completed the first survey (M = 6 months postdiagnosis). About 32% reported clinically significant SAD symptoms. Fourteen completed the follow-up survey (M = 12 months postdiagnosis), of which 9 (62%) reported persistent or worse symptoms of SAD significantly associated with emotional distress, physical appearance concerns, negative social cognitions, and depression. Conclusion: A subset of AYAs with cancer may experience clinically significant SAD symptoms that can affect their psychosocial well-being. Further work on how to best identify and support AYAs with SAD is needed.

Guidelines for Caring for the Social Well-Being of Adolescents and Young Adults with Cancer in Australia.

More than 1000 Australian adolescents and young adults (AYAs) are diagnosed with cancer annually. Many report unmet social well-being needs, which impact their mental health. Australian AYA cancer care providers lack guidance to address these needs well. We aimed to develop guidelines for caring for the social well-being of AYAs with cancer in Australia. Following the Australian National Health and Medical Research Council guidance, we formed a multidisciplinary working group (n = 4 psychosocial researchers, n = 4 psychologists, n = 4 AYA cancer survivors, n = 2 oncologists, n = 2 nurses, and n = 2 social workers), defined the scope of the guidelines, gathered evidence via a systematic review, graded the evidence, and surveyed AYA cancer care providers about the feasibility and acceptability of the guidelines. The guidelines recommend which AYAs should have their social well-being assessed, who should lead that assessment, when assessment should occur with which tools/measures, and how clinicians can address AYAs' social well-being concerns. A key clinician, who is knowledgeable about AYAs' developmental needs, should lead the assessment of social well-being during and after cancer treatment. The AYA Psycho-Oncology Screening Tool is recommended to screen for social well-being needs. The HEADSSS Assessment (Home, Education/Employment, Eating/Exercise, Activities/Peer Relationships, Drug use, Sexuality, Suicidality/Depression, Safety/Spirituality Assessment) can be used for in-depth assessment of social well-being, while the Social Phobia Inventory can be used to assess social anxiety. AYA cancer care providers rated the guidelines as highly acceptable, but discussed many feasibility barriers. These guidelines provide an optimal care pathway for the social well-being of AYAs with cancer. Future research addressing implementation is critical to meet AYAs' social well-being needs.

Precision-guided treatment in high-risk pediatric cancers.

Recent research showed that precision medicine can identify new treatment strategies for patients with childhood cancers. However, it is unclear which patients will benefit most from precision-guided treatment (PGT). Here we report consecutive data from 384 patients with high-risk pediatric cancer (with an expected cure rate of less than 30%) who had at least 18 months of follow-up on the ZERO Childhood Cancer Precision Medicine Program PRecISion Medicine for Children with Cancer (PRISM) trial. A total of 256 (67%) patients received PGT recommendations and 110 (29%) received a recommended treatment. PGT resulted in a 36% objective response rate and improved 2-year progression-free survival compared with standard of care (26% versus 12%; P = 0.049) or targeted agents not guided by molecular findings (26% versus 5.2%; P = 0.003). PGT based on tier 1 evidence, PGT targeting fusions or commenced before disease progression had the greatest clinical benefit. Our data show that PGT informed by comprehensive molecular profiling significantly improves outcomes for children with high-risk cancers. ClinicalTrials.gov registration: NCT03336931.

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.

Precision Medicine Is Changing the Roles of Healthcare Professionals, Scientists, and Research Staff: Learnings from a Childhood Cancer Precision Medicine Trial.

Precision medicine programs aim to utilize novel technologies to identify personalized treatments for children with cancer. Delivering these programs requires interdisciplinary efforts, yet the many groups involved are understudied. This study explored the experiences of a broad range of professionals delivering Australia's first precision medicine trial for children with poor-prognosis cancer: the PRecISion Medicine for Children with Cancer (PRISM) national clinical trial of the Zero Childhood Cancer Program. We conducted semi-structured interviews with 85 PRISM professionals from eight professional groups, including oncologists, surgeons, clinical research associates, scientists, genetic professionals, pathologists, animal care technicians, and nurses. We analyzed interviews thematically. Professionals shared that precision medicine can add complexity to their role and result in less certain outcomes for families. Although many participants described experiencing a greater emotional impact from their work, most expressed very positive views about the impact of precision medicine on their profession and its future potential. Most reported navigating precision medicine without formal training. Each group described unique challenges involved in adapting to precision medicine in their profession. Addressing training gaps and meeting the specific needs of many professional groups involved in precision medicine will be essential to ensure the successful implementation of standard care.

Memory of stochastic single-cell apoptotic signaling promotes chemoresistance in neuroblastoma.

Gene expression noise is known to promote stochastic drug resistance through the elevated expression of individual genes in rare cancer cells. However, we now demonstrate that chemoresistant neuroblastoma cells emerge at a much higher frequency when the influence of noise is integrated across multiple components of an apoptotic signaling network. Using a JNK activity biosensor with longitudinal high-content and in vivo intravital imaging, we identify a population of stochastic, JNK-impaired, chemoresistant cells that exist because of noise within this signaling network. Furthermore, we reveal that the memory of this initially random state is retained following chemotherapy treatment across a series of in vitro, in vivo, and patient models. Using matched PDX models established at diagnosis and relapse from individual patients, we show that HDAC inhibitor priming cannot erase the memory of this resistant state within relapsed neuroblastomas but improves response in the first-line setting by restoring drug-induced JNK activity within the chemoresistant population of treatment-naïve tumors.