1,385 research outputs found

    Evidence-Based Guided Interventions in Acute Leukemia

    Get PDF

    Register-based studies on childhood cancer : relapsed childhood acute lymphoblastic leukemia and skeletal adverse events in childhood cancer survivors in the Nordic countries

    Get PDF
    Background: Although cancer is a rare disease in children, it is the leading disease-related cause of death in children and adolescents in developed countries. Currently 80% of patients become long-time survivors but if a relapse occurs the outcome for most patients is still poor. Childhood cancer survivors are also at increased risk of chronic health conditions caused by the cancer treatment. The skeletal system is vulnerable to the toxic effects of cancer treatment during childhood and adolescence. Skeletal adverse events are not life- threatening events but may have a large impact on the quality of life and daily functions of childhood cancer survivors. Aims: The overall aim of this thesis is to explore the use of the unique Nordic registry data to find ways to improve outcomes in childhood cancer. In studies I and II we identified a cohort of patients with relapsed acute lymphoblastic leukemia (ALL) within the NOPHO ALL registry and searched for factors associated with overall survival and treatment-related mortality (TRM). In studies III and IV, we used both the Nordic public health data registries and arthroplasty quality registries to explore the life-time pattern of skeletal late adverse events in a large cohort of childhood cancer survivors and to identify vulnerable subgroups. Results: In study I, we observed an improvement in the 5-year overall survival after relapse of ALL between 1992-2001 and 2002-2011. We identified risk factors independently associated with death: short duration in first remission, bone marrow relapse, age ≄10 years at primary diagnosis, unfavorable cytogenetics and Down syndrome. Our findings indicate that the currently used risk stratification underestimates the risk of second relapses in patients with combined B-precursor relapses. In study II, we identified 52 patients who met criteria for TRM but we did not observe a reduction of TRM over time. Infections, predominantly bacterial infections, were the most common cause of death. Factors associated with TRM were high-risk stratification at relapse, unfavorable cytogenetics and allogeneic HSCT. In study III, we observed a 35% increased hospitalization risk for skeletal adverse events among childhood cancer survivors compared to population comparison subjects. For most of the skeletal adverse events the risk was highest in the years close to the treatment, but an excess risk extended for decades for some of the events. The relative risk was particularly high for osteonecrosis, especially among patients with hematological malignancies and patients diagnosed with cancer between 10-19 years of age. In study IV, we observed an increased risk for hip arthroplasties among survivors of leukemia and lymphoma and for knee arthroplasties among survivors of malignant bone tumors. The rate of arthroplasty operations was highest in early adulthood. Conclusions: Finding ways to balance the treatment intention of inducing and maintaining long-term remission against the potential risk of life-threatening or long-term treatment complications is becoming more difficult. Individualized treatment approaches and novel strategies are therefore needed both to increase survival and improve health in patients with childhood cancer. Despite different study designs and end-points, studies I-IV provide evidence that the Nordic registry data can be used as excellent research tools to increase our knowledge on childhood cancer. The Nordic countries are in a unique position to conduct registry studies on childhood cancer by combining data from public health registries and different quality registries. The design of the registries and the regulatory framework should aim to facilitate research using this valuable source of information

    Liquid biopsies in pediatric oncology : towards clinical implementation

    Get PDF
    During the last few years, liquid biopsies based on cell-free DNA (cfDNA) have become approved for clinical use in several areas of adult oncology. Due to the minimally invasive nature of this procedure, liquid biopsies could serve many purposes in childhood oncology as well. For instance, the method can provide highly specific biomarkers for molecular diagnostics, enable identification therapeutic targets and, more frequently, be used to assess therapeutic response or disease recurrence. This information could aid clinical decision-making in tailoring treatment and follow-up for each individual patient. However, developing customized assays for children's cancers is demanding for several reasons. First, childhood cancer is rare compared to adult cancers, making it difficult to get the numbers needed for statistically powered studies. Second, children’s cancers generally have few and often private mutations, and display a different mutational landscape than adult counterparts, meaning that generic assays are very challenging to develop. Third, small children mean small liquid biopsy volumes and high risk for subsampling errors, demanding ultrasensitive techniques for disease detection. Due to these circumstances, liquid biopsy assays for children with cancer require some innovative strategies. In this thesis, we describe a few liquid biopsy pilot studies focusing on the two main groups of childhood cancers; acute lymphoblastic leukemia and central nervous system (CNS) tumors. In paper I, we use whole genome sequencing to identify structural variants (SVs) in leukemic cells and use the resulting unique sequences as targets for patient-specific droplet digital PCR (ddPCR) assays. Based on analysis of samples from six children, we show that it is technically feasible to use this approach to accurately quantify measurable residual disease in bone marrow as well as in cfDNA from plasma. The molecular assays also enabled detection of potential low-grade CNSinvolvement in half of patients at diagnosis. In paper II, we use a similar approach analyzing samples from 12 children with medulloblastoma, this time combining single nucleotide variants and SVs in our assays. We show that post-operatively, all tumors that grew in contact with cerebrospinal fluid (CSF) prior to resection, and where imaging supported or could not rule out residual tumor after surgery, molecular signs of the disease were seen in liquid biopsies on at least one occasion within three weeks of surgery. Furthermore, most plasma samples at diagnosis also bore molecular signs of the tumors. In paper III, we analyze cfDNA in CSF from a child with an inoperable brainstem tumor for BRAF V600E/K/R mutations. After confirmation of a BRAF mutation, molecular targeted therapy was initiated with dramatic clinical response during the first nine months of treatment. In paper IV, we used multiomics data to seek a molecular diagnosis for a child born with a large CNS tumor. The data revealed a rare type of glioma, most likely caused by a novel fusion gene; SNRNP70::ALK. Molecular targeted therapy was initiated and four months into treatment, there are clinical and radiological signs of treatment effect. Taken together, the results indicate that our approach to design molecular assays could expand the utility of ddPCR for liquid biopsy analysis. Furthermore, in clinically challenging cases, multiomics can resolve complex diagnoses and liquid biopsies can guide choice of treatment. These studies are the initial efforts of our research group to promote liquid biopsies as a powerful precision diagnostic tool in pediatric oncology. Apart from the 20 patients described in these studies, another 130 children have been included for research and a liquid biopsy biobank of >1800 samples has been established. We have also set up clinical liquid biopsy analysis for BRAF V600 and H3-3A K27M mutations during this period. This was achieved through a close collaboration between the Departments of Clinical Genetics, Pediatric Oncology, Pediatric Neurosurgery, Clinical Pathology and The Swedish Childhood Tumor Biobank

    Diagnosis of Acute Leukemia in Under-Resourced Laboratories

    Get PDF

    Acute Leukemia

    Get PDF
    This book provides a comprehensive overview of he basic mechanisms underlying areas of acute leukemia, current advances, and future directions in management of this disease. The first section discusses the classification of acute leukemia, taking into account diagnoses dependent on techniques that are essential, and thankfully readily available, in the laboratory. The second section concerns recent advances in molecular biology, markers, receptors, and signaling molecules responsible for disease progression, diagnostics based on biochips and other molecular genetic analysis. These advances provide clinicians with important understanding and improved decision making towards the most suitable therapy for acute leukemia. Biochemical, structural, and genetic studies may bring a new era of epigenetic based drugs along with additional molecular targets that will form the basis for novel treatment strategies. Later in the book, pediatric acute leukemia is covered, emphasizing that children are not small adults when it comes to drug development. The last section is a collection of chapters about treatment, as chemotherapy-induced toxicity is still a significant clinical concern. The present challenge lies in reducing the frequency and seriousness of adverse effects while maintaining efficacy and avoiding over-treatment of patients

    How I use measurable residual disease in the clinical management of adult acute lymphoblastic Leukemia

    Get PDF
    Over the last decade the use of measurable residual disease (MRD) diagnostics in adult acute lymphoblastic leukemia (ALL) has expanded from a limited number of study groups in Europe and the United States to a world-wide application. In this review, we summarize the advantages and drawbacks of the current available techniques used for MRD monitoring. Through the use of three representative case studies, we highlight the advances in the use of MRD in clinical decision-making in the management of ALL in adults. We acknowledge discrepancies in MRD monitoring and treatment between different countries, reflecting differing availability, accessibility and affordability

    Multiparametric flow cytometry for MRD monitoring in hematologic malignancies: Clinical applications and new challenges

    Get PDF
    In hematologic cancers, Minimal Residual Disease (MRD) monitoring, using either molecular (PCR) or immunophenotypic (MFC) diagnostics, allows the identification of rare cancer cells, readily detectable either in the bone marrow or in the peripheral blood at very low levels, far below the limit of classic microscopy. In this paper, we outlined the state-of-the-art of MFC-based MRD detection in different hematologic settings, highlighting main recommendations and new challenges for using such a method in patients with acute leukemias or chronic hematologic neoplasms. The combination of new molecular technologies with advanced flow cytometry is progressively allowing clinicians to design a personalized therapeutic path, proportionate to the biological aggressiveness of the disease, in particular by using novel immunotherapies, in view of a modern decision-making process, based on precision medicine. Along with the evolution of immunophenotypic and molecular diagnostics, the assessment of Minimal Residual Disease (MRD) has progressively become a keystone in the clinical management of hematologic malignancies, enabling valuable post-therapy risk stratifications and guiding risk-adapted therapeutic approaches. However, specific prognostic values of MRD in different hematological settings, as well as its appropriate clinical uses (basically, when to measure it and how to deal with different MRD levels), still need further investigations, aiming to improve standardization and harmonization of MRD monitoring protocols and MRD-driven therapeutic strategies. Currently, MRD measurement in hematological neoplasms with bone marrow involvement is based on advanced highly sensitive methods, able to detect either specific genetic abnormalities (by PCRbased techniques and next-generation sequencing) or tumor-associated immunophenotypic profiles (by multiparametric flow cytometry, MFC). In this review, we focus on the growing clinical role for MFC-MRD diagnostics in hematological malignancies-from acute myeloid and lymphoblastic leukemias (AML, B-ALL and T-ALL), to chronic lymphocytic leukemia (CLL) and multiple myeloma (MM)-providing a comparative overview on technical aspects, clinical implications, advantages and pitfalls of MFC-MRD monitoring in different clinical settings

    Optimization of the indications for allogeneic stem cell transplantation in Acute Myeloid Leukemia based on interactive diagnostic strategies

    Get PDF
    The indications for allogeneic stem cell transplantation (SCT) in Acute Myeloid Leukemia (AML) represent a real challenge due to the clinical and genetic heterogeneity of the disorder. Therefore, an optimized indication for SCT in AML first requires the determination of the individual relapse risk based on diverse chromosomal and molecular prognosis-defining aberrations. A broad panel of diagnostic methods is needed to allow such subclassification and prognostic stratification: cytomorphology, cytogenetics, molecular genetics, and immunophenotyping by multiparameter flow cytometry. These methods should not be seen as isolated techniques but as parts of an integral network with hierarchies and interactions. Examples for a poor risk constellation as a clear indication for allogeneic SCT are provided by anomalies of chromosome 7, complex aberrations, or FLT3-length mutations. In contrast, the favorable reciprocal translocations such as the t(15;17)/PML-RARA or t(8;21)/AML1-ETO are not indications for SCT in first remission due to the rather good prognosis after standard therapy. Further, the indication for SCT should include the results of minimal residual disease (MRD) diagnostics by polymerase chain reaction (PCR) or flow cytometry. New aspects for a safe and fast risk stratification as basis for an optimized indication for SCT in AML might be provided by novel technologies such as microarray-based gene expression profiling. Keywords: Acute Myeloid Leukemia (AML), Allogeneic Stem Cell Transplantation (SCT), Indication, Cytogenetics, Polymerase Chain Reaction (PCR

    Using whole-exome sequencing data in an exome-wide association study approach to identify genetic risk factors influencing acute lymphoblastic leukemia response : a focus on asparaginase complications & vincristine-induced peripheral neuropathy

    Full text link
    Le traitement de la leucĂ©mie lymphoblastique aiguĂ« (LLA) de l’enfant, une affection d'origine maligne des cellules progĂ©nitrices lymphoĂŻdes, s’est considĂ©rablement amĂ©liorĂ© au cours des derniĂšres dĂ©cennies. En effet, le taux de succĂšs du traitement a dĂ©passĂ© 90% dans des conditions favorables. Cependant, des toxicitĂ©s liĂ©es au traitement peuvent ĂȘtre fatales et entrainer l’interruption ou la cessation du traitement. L'allergie, la pancrĂ©atite et la thrombose sont des complications frĂ©quentes du traitement de la LLA et sont associĂ©es Ă  l'utilisation de l'asparaginase (ASNase), tandis qu’une toxicitĂ© frĂ©quente due Ă  la vincristine (VCR) induit la neuropathie pĂ©riphĂ©rique (VIPN). Étant donnĂ© que l’ajustement du schĂ©ma posologique afin d’augmenter l'efficacitĂ© et diminuer la toxicitĂ© est un processus sensible, ceci demeure un dĂ©fi majeur dans plusieurs protocoles de traitement. La pharmacogĂ©nĂ©tique Ă©tudie comment des altĂ©rations de la composante gĂ©nĂ©tique peuvent influer sur la variabilitĂ© interindividuelle observĂ©e dans la rĂ©ponse au traitement. Une meilleure comprĂ©hension de la base molĂ©culaire de cette variabilitĂ© pourrait amĂ©liorer considĂ©rablement les rĂ©sultats du traitement, en permettant la personnalisation de ce dernier en fonction du profil gĂ©nĂ©tique du patient. Des Ă©tudes rĂ©centes suggĂšrent l’avantage d’appliquer l’analyse de l’exome Ă  la dĂ©couverte de variants associĂ©s Ă  des traits humains complexes ainsi qu’à des phĂ©notypes de rĂ©actions mĂ©dicamenteuses. L'objectif de notre travail Ă©tait d'utiliser les donnĂ©es de sĂ©quençage pour rĂ©aliser des Ă©tudes d'association Ă  l'Ă©chelle de l'exome, y compris des Ă©tapes de filtrage et de validation, afin d'identifier de nouveaux variants gĂ©nĂ©tiques susceptibles de moduler le risque de dĂ©velopper des complications associĂ©es Ă  ASNase et Ă  VIPN. Douze SNP Ă©taient associĂ©s Ă  des complications due Ă  l’ASNase dans la cohorte initiale, dont 3 Ă©taient associĂ©s Ă  une allergie, 3 Ă  une pancrĂ©atite et 6 Ă  une thrombose. Parmi ceux-ci, les variants rs3809849, rs11556218 et rs34708521 des gĂšnes MYBBP1A, IL16 et SPEF2 respectivement ont Ă©tĂ© associĂ©s Ă  des complications multiples et leur association Ă  une pancrĂ©atite a Ă©tĂ© rĂ©pliquĂ©e dans une cohorte de validation indĂ©pendante. En ce qui concerne la VCR, trois variantes ont Ă©tĂ© associĂ©es Ă  la modulation du risque de VIPN: rs2781377 dans SYNE2, rs10513762 dans MRPL47 et rs3803357 dans BAHD1. Nous dĂ©montrons Ă©galement le puissant effet combinĂ© de la prĂ©sence de plusieurs variants de risque pour chacune des toxicitĂ©s Ă©tudiĂ©es et fournissons des modĂšles de prĂ©diction du risque pour la pancrĂ©atite et le VIPN basĂ©s sur la mĂ©thode d’évaluation du risque gĂ©nĂ©tique pondĂ©rĂ©e et qui ont Ă©tĂ© validĂ©s Ă  l’interne. De plus, Ă©tant donnĂ© une association du polymorphisme du gĂšne MYBBP1A avec de multiples issus de traitement, nous avons cherchĂ© Ă  comprendre comment cette altĂ©ration gĂ©nĂ©tique se traduit par des variabilitĂ©s de rĂ©ponse aux traitements Ă  l’ASNase. En utilisant la technique CRISPR-CAS9 pour induire l'inactivation de gĂšnes dans des lignĂ©es cellulaires cancĂ©reuses PANC1 (pancrĂ©atiques) nous avons testĂ© la diffĂ©rence de viabilitĂ© entre les cellules inactivĂ©es et les cellules du type sauvage Ă  la suite de la suppression du gĂšne et du traitement par ASNase. Nos rĂ©sultats suggĂšrent un rĂŽle fonctionnel de ce gĂšne dans la modulation de la viabilitĂ©, de la capacitĂ© de prolifĂ©ration et de la morphologie des cellules knock-out, ainsi que dans leur sensibilitĂ© Ă  l'ASNase, et plaident en outre pour que le gĂšne influence l’issus du traitement de la LLA par ASNase. Le prĂ©sent travail dĂ©montre que l’utilisation de l’approche de sĂ©quençage de l’exome entier dans le contexte d’une Ă©tude d’association Ă  l’échelle de l’exome est une stratĂ©gie valide « sans hypothĂšse » pour identifier de nouveaux marqueurs gĂ©nĂ©tiques modulant l’effet du traitement de la LLA de l’enfant, et souligne l’importance de l'effet synergique de la combinaison des locus Ă  risque.Treatment of childhood acute lymphoblastic leukemia (ALL), a malignant disorder of lymphoid progenitor cells has improved significantly over the past decades and treatment success rates have surpassed 90% in favorable settings. However, treatment-related toxicities can be life-threatening and cause treatment interruption or cessation. Allergy, pancreatitis and thrombosis are common complications of ALL treatment associated with the use of asparaginase (ASNase), while vincristine-induced peripheral neuropathy (VIPN) is a frequent toxicity of vincristine (VCR). It is a sensitive process and a constant struggle to adjust the dosing regimen to ensure maximum efficacy and minimum toxicity. Pharmacogenetics studies show alterations in the genetic component between individuals can influence the observed variability in treatment response. A better understanding of the molecular basis of this variability in drug effect could significantly improve treatment outcome by allowing the personalization of ALL treatment based on the genetic profile of the patient. Emerging reports suggest the benefit of applying exome analysis to uncover variants associated with complex human traits as well as drug response phenotypes. Our objective in this work was to use available whole-exome sequencing data to perform exome-wide association studies followed by stepwise filtering and validation processes to identify novel variants with a potential to modulate the risk of developing ASNase complications and VIPN. Twelve SNPs were associated with ASNase complications in the discovery cohort including 3 associated with allergy, 3 with pancreatitis and 6 with thrombosis. Of those, rs3809849 in MYBBP1A, rs11556218 in IL16 and rs34708521 in SPEF2 genes were associated with multiple complications and their association with pancreatitis was replicated in an independent validation cohort. As for VCR, three variants were associated with modulating the risk of VIPN: rs2781377 in SYNE2, rs10513762 in MRPL47 and rs3803357 in BAHD1. We also demonstrate a strong combined effect of harbouring multiple risk variants for each of the studied toxicities, and provide internally-validated risk-prediction models based on the weighted genetic risk score method for pancreatitis and VIPN. Furthermore, given the association of the polymorphism in MYBBP1A gene with multiple treatment outcomes, we aimed at understanding how this genetic alteration translates into differences in ASNase treatment response through cell-based functional analysis. Using CRISPR-CAS9 technology we produced gene knockout of PANC1 (pancreatic) cancer cell-lines and tested the difference in viability between the knockouts and wild-type cells following gene deletion and ASNase treatment. Our results suggest a functional role of this gene in modulating the viability, proliferation capacity and the morphology of the knockout cells as well as their sensitivity to ASNase and further advocates the implication of the gene in influencing the outcome of ALL treatment with ASNase. The present work demonstrates that using whole-exome sequencing data in the context of exome-wide association study is a successful “hypothesis-free” strategy for identifying novel genetic markers modulating the effect of childhood ALL treatment and highlights the importance of the synergistic effect of combining risk loci
    • 

    corecore