Relapse in teenage and young adult patients treated on a paediatric minimal residual disease stratified ALL treatment protocol is associated with a poor outcome: results from UKALL2003.

Outcomes for teenage and young adult (TYA) patients with acute lymphoblastic leukaemia (ALL) who relapse on contemporary risk-adapted paediatric protocols are largely unknown and there is no consensus on optimal salvage strategies. We assessed the treatment and outcome of TYA patients (aged 16-24 years) recruited to the UKALL2003 trial, who relapsed following attainment of complete morphological remission. Forty-two of 223 patients (18·8%) relapsed, the majority (n = 26, 62%) on treatment. Thirty-eight (90%) patients received salvage treatment, with 22 (58%) achieving second remission (CR2) and 21 patients receiving an allogeneic haematopoietic cell transplant (alloHSCT). Post-relapse outcomes were poor with a 5-year overall survival (OS) of 23% (95% confidence interval; 11-37%). Outcomes for patients relapsing on active treatment were inferior to those relapsing after completing treatment (5-year OS 9% vs. 52%, log-rank P = 0·001). No patient with B cell ALL relapsing on treatment was alive at the end of the study period. TYA patients with ALL who relapse on the UK paediatric protocol, UKALL2003, are largely unsalvageable with conventional approaches aimed at achieving CR2 followed by alloHSCT. Future efforts should be aimed at identifying those patients who are destined to relapse and exploring novel treatment approaches for this high-risk group and for those who do relapse.

Association of Macroeconomic Factors With Nonrelapse Mortality After Allogeneic Hematopoietic Cell Transplantation for Adults With Acute Lymphoblastic Leukemia: An Analysis From the Acute Leukemia Working Party of the EBMT.

PURPOSE: From a global perspective, the rates of allogeneic hematopoietic cell transplantation (alloHCT) are closely related to the economic status of a country. However, a potential association with outcome has not yet been documented. The goal of this study was to evaluate effects of health care expenditure (HCE), Human Development Index (HDI), team density, and center experience on nonrelapse mortality (NRM) after HLA-matched sibling alloHCT for adults with acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: A total of 983 patients treated with myeloablative alloHCT between 2004 and 2008 in 24 European countries were included. RESULTS: In a univariate analysis, the probability of day 100 NRM was increased for countries with lower current HCE (8% vs. 3%; p = .06), countries with lower HDI (8% vs. 3%; p = .02), and centers with less experience (8% vs. 5%; p = .04). In addition, the overall NRM was increased for countries with lower current HCE (21% vs. 17%; p = .09) and HDI (21% vs. 16%; p = .03) and for centers with lower activity (21% vs. 16%; p = .07). In a multivariate analysis, the strongest predictive model for day 100 NRM included current HCE greater than the median (hazard ratio [HR], 0.39; p = .002). The overall NRM was mostly predicted by HDI greater than the median (HR, 0.65; p = .01). Both lower current HCE and HDI were associated with decreased probability of overall survival. CONCLUSION: Both macroeconomic factors and the socioeconomic status of a country strongly influence NRM after alloHCT for adults with ALL. Our findings should be considered when clinical studies in the field of alloHCT are interpreted.

Distinctive genotypes in infants with T-cell acute lymphoblastic leukaemia.

Infant T-cell acute lymphoblastic leukaemia (iT-ALL) is a very rare and poorly defined entity with a poor prognosis. We assembled a unique series of 13 infants with T-ALL, which allowed us to identify genotypic abnormalities and to investigate prenatal origins. Matched samples (diagnosis/remission) were analysed by single nucleotide polymorphism-array to identify genomic losses and gains. In three cases, we identified a recurrent somatic deletion on chromosome 3. These losses result in the complete deletion of MLF1 and have not previously been described in T-ALL. We observed two cases with an 11p13 deletion (LMO2-related), one of which also harboured a deletion of RB1. Another case presented a large 11q14·1-11q23·2 deletion that included ATM and only five patients (38%) showed deletions of CDKN2A/B. Four cases showed NOTCH1 mutations; in one case FBXW7 was the sole mutation and three cases showed alterations in PTEN. KMT2A rearrangements (KMT2A-r) were detected in three out of 13 cases. For three patients, mutations and copy number alterations (including deletion of PTEN) could be backtracked to birth using neonatal blood spot DNA, demonstrating an in utero origin. Overall, our data indicates that iT-ALL has a diverse but distinctive profile of genotypic abnormalities when compared to T-ALL in older children and adults.

Pitfalls in Diagnosis: JMML versus KMT2A Rearranged Juvenile AML.

Background: Lysine methyltransferase 2A (KMT2A) rearrangements are commonly found in juvenile acute myeloid leukaemia (AML). Although distinct diseases, there is a known clinical overlap between KMT2A-rearranged AML and juvenile myelomonocytic leukaemia (JMML). Both occur in infancy or early childhood and present with abnormal monocytosis. Case Report. We report a case of a 20-month-old girl, who presented with lethargy, recurrent infections, bruising, and marked hepatosplenomegaly. JMML was suspected after initial work-up, revealing an abnormal monocytosis without blast excess on immunophenotyping. The additional cytogenetic and molecular diagnostics, revealing a KMT2A rearrangement, was decisive for the confirmation of AML. Conclusion: This case highlights the challenges of diagnosing KMT2A-rearranged monocytic AML and the importance of careful morphological assessment in partnership with cytogenetic and molecular diagnostics to distinguish between KMT2A-rearranged AML and JMML. Moreover, the emerging role of molecular monitoring in AML is highlighted.

Neosartorya udagawae pulmonary infection requiring a surgical treatment in a paediatric haematopoietic progenitor cell recipient.

Neosartorya udagawae is a known cause of fungal infection in humans and animals. It is found to be more refractory to antifungal treatment in comparison to other Aspergillus species. With this report we present a case of proven invasive infection with Neosartorya udagawae in a child with chronic myeloid leukaemia after haematopoietic stem cell transplant. The patient received several lines of antifungal therapy including dual therapy appropriate to the antifungal susceptibility profile with progression of the invasive fungal disease requiring left lung upper lobe lobectomy. The case emphasizes the importance of early biopsy with antifungal susceptibility testing for targeted therapy and demonstrates the potential requirement for surgical management in addition to appropriate antifungal treatment.

Cytogenetic abnormalities predict survival after allogeneic hematopoietic stem cell transplantation for pediatric acute myeloid leukemia: a PDWP/EBMT study.

Poor-risk (PR) cytogenetic/molecular abnormalities generally direct pediatric patients with acute myeloid leukemia (AML) to allogeneic hematopoietic stem cell transplant (HSCT). We assessed the predictive value of cytogenetic risk classification at diagnosis with respect to post-HSCT outcomes in pediatric patients. Patients younger than 18 years at the time of their first allogeneic HSCT for AML in CR1 between 2005 and 2022 who were reported to the European Society for Blood and Marrow Transplantation registry were subgrouped into four categories. Of the 845 pediatric patients included in this study, 36% had an 11q23 abnormality, 24% had monosomy 7/del7q or monosomy 5/del5q, 24% had a complex or monosomal karyotype, and 16% had other PR cytogenetic abnormalities. In a multivariable model, 11q23 (hazard ratio [HR] = 0.66, P = 0.03) and other PR cytogenetic abnormalities (HR = 0.55, P = 0.02) were associated with significantly better overall survival when compared with monosomy 7/del7q or monosomy 5/del5q. Patients with other PR cytogenetic abnormalities had a lower risk of disease relapse after HSCT (HR = 0.49, P = 0.01) and, hence, better leukemia-free survival (HR = 0.55, P = 0.01). Therefore, we conclude that PR cytogenetic abnormalities at diagnosis predict overall survival after HSCT for AML in pediatric patients.

Gut microbiome immaturity and childhood acute lymphoblastic leukaemia.

Acute lymphoblastic leukaemia (ALL) is the most common cancer of childhood. Here, we map emerging evidence suggesting that children with ALL at the time of diagnosis may have a delayed maturation of the gut microbiome compared with healthy children. This finding may be associated with early-life epidemiological factors previously identified as risk indicators for childhood ALL, including caesarean section birth, diminished breast feeding and paucity of social contacts. The consistently observed deficiency in short-chain fatty-acid-producing bacterial taxa in children with ALL has the potential to promote dysregulated immune responses and to, ultimately, increase the risk of transformation of preleukaemic clones in response to common infectious triggers. These data endorse the concept that a microbiome deficit in early life may contribute to the development of the major subtypes of childhood ALL and encourage the notion of risk-reducing microbiome-targeted intervention in the future.

The genomic landscape of teenage and young adult T-cell acute lymphoblastic leukemia.

BACKGROUND: Treatment on risk adapted intensive pediatric protocols has improved outcome for teenagers and young adults (TYA) with T-cell acute lymphoblastic leukemia (T-ALL). Understanding the biology of disease in this age group and the genetic basis of relapse is a key goal as patients with relapsed/refractory disease have poor outcomes with conventional chemotherapy and novel molecular targets are required. This study examines the question of whether TYA T-ALL has a specific biological-molecular profile distinct from pediatric or adult T-ALL. METHODS: Genomic characterization was undertaken of a retrospective discovery cohort of 80 patients aged 15-26 years with primary or relapsed T-ALL, using a combination of Genome-Wide Human SNP Array 6.0, targeted gene mutation and promoter methylation analyses. Findings were confirmed by MLPA, real-time quantitative PCR, and FISH. Whole Exome Sequencing was performed in 4 patients with matched presentation and relapse to model clonal evolution. A prevalence analysis was performed on a final data set of 1,792 individual cases to identify genetic lesions with age specific frequency patterns, including 972 pediatric (1-14 years), 439 TYA (15-24 years) and 381 adult (≥25 years) cases. These cases were extracted from 19 publications with comparable genomic data identified through a PubMed search. RESULTS: Genomic characterization of this large cohort of TYA T-ALL patients identified recurrent isochromosome 7q i(7q) in our discovery cohort (n = 3). Prevalence analysis did not identify any age specific genetic abnormalities. Genomic analysis of 6 pairs of matched presentation - relapsed T-ALL established that all relapses were clonally related to the initial leukemia. Whole exome sequencing analysis revealed recurrent, targetable, mutations disrupting NOTCH, PI3K/AKT/mTOR, FLT3, NRAS as well as drug metabolism pathways. CONCLUSIONS: All genetic aberrations in TYA T-ALL occurred with an incidence similar or intermediate to that reported in the pediatric and adult literature, demonstrating that overall TYA T-ALL exhibits a transitional genomic profile. Analysis of matched presentation - relapse supported the hypothesis that relapse is driven by the Darwinian evolution of sub-clones associated with drug resistance (NT5C2 and TP53 mutations) and re-iterative mutation of known key T-ALL drivers, including NOTCH1.

Open-Label, phase 2 study of blinatumomab as second salvage therapy in adults with relapsed/refractory aggressive B-cell non-Hodgkin lymphoma.

The phase 2 portion of this open-label phase 2/3 study assessed the efficacy and safety of blinatumomab as second salvage for aggressive relapsed or refractory (r/r) aggressive B-cell non-Hodgkin lymphoma (B-NHL) following platinum-based first salvage chemotherapy. Forty-one patients with aggressive disease (32% relapsed; 68% refractory) enrolled and received stepwise blinatumomab (9-28-112 µg/day) in a 70-day cycle 1 and an optional 28-day cycle 2; 19 (46%) completed cycle 1 and 3 (7%) completed cycle 2. The overall response rate after 12 weeks was 37%, including 9 (22%) complete metabolic responses. Eight (20%) patients (all responders) subsequently received stem cell transplants. Grade ≥3 adverse events were reported in 29 (71%) patients. Grade 3 cytokine release syndrome occurred in one patient. Grade 3 neurologic events occurred in 10 (24%) patients; all resolved. Blinatumomab monotherapy appears effective as second salvage therapy in patients with r/r aggressive B-NHL. Trial registration: NCT02910063.

The subclonal complexity of STIL-TAL1+ T-cell acute lymphoblastic leukaemia.

Single-cell genetics were used to interrogate clonal complexity and the sequence of mutational events in STIL-TAL1+ T-ALL. Single-cell multicolour FISH was used to demonstrate that the earliest detectable leukaemia subclone contained the STIL-TAL1 fusion and copy number loss of 9p21.3 (CDKN2A/CDKN2B locus), with other copy number alterations including loss of PTEN occurring as secondary subclonal events. In three cases, multiplex qPCR and phylogenetic analysis were used to produce branching evolutionary trees recapitulating the snapshot history of T-ALL evolution in this leukaemia subtype, which confirmed that mutations in key T-ALL drivers, including NOTCH1 and PTEN, were subclonal and reiterative in distinct subclones. Xenografting confirmed that self-renewing or propagating cells were genetically diverse. These data suggest that the STIL-TAL1 fusion is a likely founder or truncal event. Therapies targeting the TAL1 auto-regulatory complex are worthy of further investigation in T-ALL.

Cancer Patient Experience in the Teenage Young Adult Population- Key Issues and Trends Over Time: An Analysis of the United Kingdom National Cancer Patient Experience Surveys 2010-2014.

Improving outcomes for teenagers and young adults (TYA) with cancer is a key element of the national cancer strategy in England. Recognition of the unique needs of this group has led to the development of recommendations for specific models of care and delivery of this care through the provision of dedicated clinical units in principal treatment centers (PTCs) across the United Kingdom. The aim of this study was to understand the current cancer patient experience for this patient group. We aimed to determine whether treatment experience is influenced by place of treatment and whether it has changed over time using patient-reported data from national cancer patient experience surveys. This study highlights that a prolonged pathway to diagnosis remains an issue for the TYA group and identifies areas on which quality improvement measures for TYA services should focus, including communication and involvement of the patient in treatment decisions. Positive experiences for the TYA group such as involvement in research were also highlighted. Treatment within a TYA PTC was associated with positive patient perception in a number of key areas highlighting the need for future studies to fully elucidate the impact of the full range of TYA services now available in the United Kingdom on both patient experience and outcome.

Expression of extremely low levels of thymidine kinase from an acyclovir-resistant herpes simplex virus mutant supports reactivation from latently infected mouse trigeminal ganglia.

A single-cytosine-deletion in the herpes simplex virus gene encoding thymidine kinase (TK) was previously found in an acyclovir-resistant clinical isolate. A laboratory strain engineered to carry this mutation did not generate sufficient TK activity for detection by plaque autoradiography, which detected 0.25% wild-type activity. However, a drug sensitivity assay suggested that extremely low levels of TK are generated by this virus. The virus was estimated to express 0.09% of wild-type TK activity via a ribosomal frameshift 24 nucleotides upstream of the mutation. Remarkably, this appeared to be sufficient active TK to support a low level of reactivation from latently infected mouse trigeminal ganglia.

Low-level expression and reversion both contribute to reactivation of herpes simplex virus drug-resistant mutants with mutations on homopolymeric sequences in thymidine kinase.

Many acyclovir-resistant herpes simplex virus isolates from patients contain insertions or deletions in homopolymeric sequences in the thymidine kinase (TK) gene (tk). Viruses that have one (G8) or two (G9) base insertions in a run of seven G's (G string) synthesize low levels of active TK (TK-low phenotype), evidently via ribosomal frameshifting. These levels of TK can suffice to permit reactivation from latently infected mouse ganglia, but in a majority of ganglia, especially with the G9 virus, reactivation of virus that has reverted to the TK-positive phenotype predominates. To help address the relative contributions of translational mechanisms and reversion in reactivation, we generated viruses with a base either inserted or deleted just downstream of the G string. Both of these viruses had a TK-low phenotype similar to that of the G8 and G9 viruses but with less reversion. Both of these viruses reactivated from latently infected trigeminal ganglia, albeit inefficiently, and most viruses that reactivated had a uniformly TK-low phenotype. We also generated viruses that have one insertion in a run of six C's or one deletion in a run of five C's. These viruses lack measurable TK activity. However, they reactivated from latently infected ganglia, albeit inefficiently, with the reactivating viruses having reverted to the wild-type TK phenotype. Therefore, for G-string mutants, levels of active TK as low as 0.25% generated by translational mechanisms can suffice for reactivation, but reversion can also contribute. For viruses that lack TK activity due to mutations on other homopolymeric sequences, reactivation can occur via reversion.