Philadelphia-Like Acute Lymphoblastic Leukemia in Adults

Transcriptome Analysis in Mexican Adults with Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) represents around 25% of adult acute leukemias. Despite the increasing improvement in the survival rate of ALL patients during the last decade, the heterogeneous clinical and molecular features of this malignancy still represent a major challenge for treatment and achieving better outcomes. To identify aberrantly expressed genes in bone marrow (BM) samples from adults with ALL, transcriptomic analysis was performed using Affymetrix Human Transcriptome Array 2.0 (HTA 2.0). Differentially expressed genes (DEGs) (±2-fold change, p-value < 0.05, and FDR < 0.05) were detected using the Transcriptome Analysis Console. Gene Ontology (GO), Database for Annotation, Visualization, and Integrated Discovery (DAVID), and Ingenuity Pathway Analysis (IPA) were employed to identify gene function and define the enriched pathways of DEGs. The protein-protein interactions (PPIs) of DEGs were constructed. A total of 871 genes were differentially expressed, and DNTT, MYB, EBF1, SOX4, and ERG were the top five up-regulated genes. Meanwhile, the top five down-regulated genes were PTGS2, PPBP, ADGRE3, LUCAT1, and VCAN. An association between ERG, CDK6, and SOX4 expression levels and the probability of relapse and death was observed. Regulation of the immune system, immune response, cellular response to stimulus, as well as apoptosis signaling, inflammation mediated by chemokines and cytokines, and T cell activation were among the most altered biological processes and pathways, respectively. Transcriptome analysis of ALL in adults reveals a group of genes consistently associated with hematological malignancies and underscores their relevance in the development of ALL in adults.

Important factors improving outcome of young adults with acute lymphoblastic leukemia (ALL)

Four categories of important factors improving outcome of young adults and older adolescents with acute lymphoblastic leukemia (ALL) are biologic type, clinical trials, pediatric vs. adult treatment regimen, and psychosocial challenges. Overall, the outcome of ALL in the age group has improved and beginning to catch up with that in children, as exemplified by CALGB 10403, a pediatric treatment regimen. Each is dependent for optimum development, however, on progress in the others. Without adequate psychosocial support and improvement, progress in clinical trials, translational research, and pediatric regimen application is impaired. Without clinical trials, advances in translational research, optimal pediatric regimen application and adequate psychosocial research are restricted. Overall, we have improved the outcome and outlook of ALL in AYAs, as exemplified by CALGB 10403, but we and our current and future patients still have a long way to go.

Optimal treatment for Philadelphia-negative acute lymphoblastic leukemia in first remission in the era of high-intensity chemotherapy

The optimal treatment for Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) in first complete remission (CR1) has not been established in the high-intensity chemotherapy era. The outcomes of patients with Ph-negative ALL who underwent allogeneic hematopoietic stem cell transplantation (HSCT) from a human leukocyte antigen-matched related or unrelated donor in CR1 (HSCT-MRD group and HSCT-MUD group) were obtained from a Japanese registry database. Patients aged 16-24 years and 25-65 years were analyzed separately, and their outcomes were compared to those of patients who continued high-intensity chemotherapy in CR1 in studies (202U group and 202O group) by the Japan Adult Leukemia Study Group (JALSG). In the HSCT-MRD group, patients younger than 25 years had lower overall survival (OS) than the 202U group, presumably due to the higher non-relapse mortality (NRM) in the HSCT-MRD group. Patients 25 years and older had similar OS to the 202O group. The lower relapse rate was counterbalanced by higher NRM in the HSCT-MRD group. In the HSCT-MUD group, patients in both age groups had similar OS to their corresponding groups in the JALSG studies. In conclusion, high-intensity chemotherapy may change the role of HSCT for Ph-negative ALL.

BCR-ABL1-like B-Acute Lymphoblastic Leukemia/Lymphoma: A Comprehensive Review

CONTEXT.—

In the 2016 update of the World Health Organization (WHO) classification of hematopoietic neoplasms, BCR-ABL1-like B-acute lymphoblastic leukemia/lymphoma (B-ALL) is added as a new provisional entity that lacks the BCR-ABL1 translocation but shows a pattern of gene expression very similar to that seen in B-ALL with BCR-ABL1.

OBJECTIVE.—

To review the kinase-activating alterations and the diagnostic approach for BCR-ABL1-like B-ALL.

DATA SOURCES.—

We provide a comprehensive review of BCR-ABL1-like B-ALL based on recent literature and the 2016 update of the World Health Organization classification of hematopoietic neoplasms.

CONCLUSIONS.—

Several types of kinase-activating alterations (fusions or mutations) are identified in BCR-ABL1-like B-ALL. The main categories are alterations in the ABL class family of genes, encompassing ABL1, ABL2, PDGFRB, PDGFRA (rare), and colony-stimulating factor 1 receptor (CSF1R) fusions, or the JAK2 class family of genes, encompassing alterations in JAK2, CRLF2, EPOR, and other genes in this pathway. These alterations determine the sensitivity to tyrosine kinase inhibitors. As a wide variety of genomic alterations are included in this category, the diagnosis of BCR-ABL1-like B-ALL is extremely complex. Stepwise algorithms and comprehensive unbiased testing are the 2 ways to approach the diagnosis of BCR-ABL1-like B-ALL.

A systematic literature review and meta-analysis of minimal residual disease as a prognostic indicator in adult B-cell acute lymphoblastic leukemia

Minimal (or 'measurable') residual disease in acute lymphoblastic leukemia appears to be a prognostic indicator, with potential value in informing individualized treatment decisions. Complete understanding of the strength of the association between minimal residual disease and long-term outcomes is, however, lacking. A systematic literature review and meta-analysis were performed to elucidate the clinical significance of minimal residual disease with respect to relapse-free survival and overall survival in precursor B-cell acute lymphoblastic leukemia. A total of 23 articles and abstracts, most published between 2012 and 2016, were identified for inclusion in the primary meta-analysis. Typically, patients were in their first complete remission at the time of minimal residual disease assessment; in two studies, all patients were in their second, or later, complete remission. The primary analysis revealed improved relapse-free survival across all studies for patients who achieved minimal residual disease negativity (random effects hazard ratio, 2.34; 95% confidence interval, 1.91-2.86). Improved overall survival for patients who achieved minimal residual disease negativity was also observed (hazard ratio, 2.19; 95% confidence interval, 1.63-2.94). There was no observed difference in the impact of minimal residual disease status in subgroups based on disease stage, minimal residual disease sensitivity threshold level, Philadelphia chromosome status, histological phenotype, risk group, minimal residual disease testing location, minimal residual disease timing after induction, or minimal residual disease detection method. Despite heterogeneity in study design and patient populations between the contributing studies, these data provide a compelling argument for minimal residual disease as a clinical tool for assessing prognosis and guiding treatment decisions in precursor B-cell acute lymphoblastic leukemia.

Updates in the Pathology of Precursor Lymphoid Neoplasms in the Revised Fourth Edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues

PURPOSE OF REVIEW

Acute lymphoblastic leukemias (ALL) are malignant disorders of immature B or T cells that occur characteristically in children, usually under the age of 6 (75%). Approximately 6000 new cases of ALL are diagnosed each year in the USA, 80-85% of which represent B-ALL forms. Most presentations of B-ALL are leukemic, whereas T-ALL presents with a mediastinal mass, with or without leukemic involvement. The revised fourth edition of the World Health Organization (WHO) classification (2017) has introduced some changes in both B and T-ALL. Here, we summarize the categories of lymphoblastic leukemia/lymphomas as defined by the WHO and recent developments in the understanding of this group of hematologic malignancy.

RECENT FINDINGS

Two provisional categories of B-ALL have now been identified including B-ALL, BCR-ABL1-like, and B-ALL with iAMP21. The Philadelphia chromosome-like B-ALL includes forms of the disease that shares the expression profiling of B-ALL with t(9;22) but lack such rearrangement. The second one shows amplification of part of the chromosome 21. Both entities are associated with worse prognosis. Within the T-ALL group, an early precursor T cell form has now been introduced as a provisional category. Such group demonstrates expression of stem cell and myeloid markers in conjunction with the T cell antigens. The current review summarizes the recent updates to the WHO classification.

Use of platelet and erythroid growth factors during induction chemotherapy for acute lymphoblastic leukaemia in a Jehovah's Witness

We present a 21-year-old woman diagnosed with Philadelphia (Ph) chromosome-like CD20 positive B-cell acute lymphoblastic leukaemia (ALL). She was a Jehovah's Witness (JW) and declined all blood product transfusion support. She was initiated on the CALGB 10403 chemotherapy protocol for her ALL. She received darbepoetin alfa and romiplostim as supportive therapies for her disease/chemotherapy-associated anaemia and thrombocytopaenia. A complete remission was achieved with negative minimal residual disease and she remains in remission 18 months after diagnosis. This case report describes the successful treatment of an adult JW with Ph-like CD20 +B cell ALL, in the absence of blood product transfusions, using growth factor support.

Philadelphia-like acute lymphoblastic leukemia: diagnostic dilemma and management perspectives

Acute lymphoblastic leukemia (ALL) is an aggressive hematologic malignancy characterized by suboptimal outcomes in the adult age group. Recently, a new subtype called Philadelphia (Ph)-like ALL has been described. This subgroup is characterized by high cytokine receptor and tyrosine kinase signaling expression, resulting in kinase activation through stimulation of two main pathways, the ABL and JAK/STAT pathways. The diagnostic method or approach for Ph-like ALL is still not standardized and efforts are ongoing to identify an easy and applicable diagnostic method. Accurate and standard testing approaches are much needed and this will facilitate better understanding of this subgroup, including better estimation of the prevalence and incidence in different age groups and the clinical outcomes of such new entity. Here, we review the currently available diagnostic tools, activated pathways, and different therapeutic approaches used to target this subgroup.

Hematopoietic stem cell transplant in adults with acute lymphoblastic leukemia: the present state

INTRODUCTION

Allogeneic hematopoietic stem cell transplant (allo-HSCT) has an important role in management of acute lymphoblastic leukemia (ALL). Proper patient selection is central to ensure optimal outcomes. Areas covered: This review covers various aspects of HSCT in ALL patients, including indications, donor selection, conditioning regimens, and post-transplant management. Expert commentary: Allo-HSCT is important in post-remission management of ALL but proper risk-stratification is a major challenge. Incorporation of minimal residual disease (MRD) and molecular testing will improve patient allocation. Patients receiving pediatric-inspired induction who achieve molecular remission might not need allo-HSCT in first remission. Allo-HSCT should be considered in patients who don't achieve MDR negativity, didn't receive intensive induction, or have high risk cytogenetic and molecular features. Despite improved responses with tyrosine kinase inhibitors (TKIs) in Philadelphia positive (Ph+) ALL, allo-HSCT remains standard. Matched sibling donors are the optimal graft source, but other sources are valid alternatives. There is no single optimal conditioning regimen and retrospective studies found myeloablative and reduced intensity regimens to be comparable. Following allo-HSCT, there is no role for maintenance therapy in Philadelphia-negative ALL. In Ph+ ALL, maintenance TKIs improve outcomes. The integration of targeted and immunotherapies in the peri-transplant period holds potential for improved outcomes.

B lymphoblastic leukemia/lymphoma: new insights into genetics, molecular aberrations, subclassification and targeted therapy

B lymphoblastic leukemia/lymphoma (B-ALL) is a clonal hematopoietic stem cell neoplasm derived from B-cell progenitors, which mostly occurs in children and adolescents and is regarded as one of top leading causes of death related to malignancies in this population. Despite the majority of patients with B-ALL have fairly good response to conventional chemotherapeutic interventions followed by hematopoietic stem cell transplant for the last decades, a subpopulation of patients show chemo-resistance and a high relapse rate. Adult B-ALL exhibits similar clinical course but worse prognosis in comparison to younger individuals. Ample evidences have shown that the clinical behavior, response rate and clinical outcome of B-ALL rely largely on its genetic and molecular profiles, such as the presence of BCR-ABL1 fusion gene which is an independent negative prognostic predictor. New B-ALL subtypes have been recognized with recurrent genetic abnormalities, including B-ALL with intrachromosomal amplification of chromosome 21 (iAMP21), B-ALL with translocations involving tyrosine kinases or cytokine receptors (“BCR-ABL1-like ALL”). Genome-wide genetic profiling studies on B-ALL have extended our understanding of genomic landscape of B-ALL, and genetic mutations involved in various key pathways have been illustrated. These include CRLF2 and PAX5 alterations, TP53, CREBBP and ERG mutations, characteristic genetic aberrations in BCR-ABL1-like B-ALL and others. The review further provides new insights into clinical implication of the genetic aberrations in regard to targeted therapy development.

BCR-ABL1-like acute lymphoblastic leukaemia: From bench to bedside

Acute lymphoblastic leukaemia (ALL) occurs in approximately 1:1500 children and is less frequently found in adults. The most common immunophenotype of ALL is the B cell lineage and within B cell precursor ALL, specific genetic aberrations define subtypes with distinct biological and clinical characteristics. With more advanced genetic analysis methods such as whole genome and transcriptome sequencing, novel genetic subtypes have recently been discovered. One novel class of genetic aberrations comprises tyrosine kinase-activating lesions, including translocations and rearrangements of tyrosine kinase and cytokine receptor genes. These newly discovered genetic aberrations are harder to detect by standard diagnostic methods such as karyotyping, fluorescent in situ hybridisation (FISH) or polymerase chain reaction (PCR) because they are diverse and often cryptic. These lesions involve one of several tyrosine kinase genes (among others, v-abl Abelson murine leukaemia viral oncogene homologue 1 (ABL1), v-abl Abelson murine leukaemia viral oncogene homologue 2 (ABL2), platelet-derived growth factor receptor beta polypeptide (PDGFRB)), each of which can be fused to up to 15 partner genes. Together, they compose 2-3% of B cell precursor ALL (BCP-ALL), which is similar in size to the well-known fusion gene BCR-ABL1 subtype. These so-called BCR-ABL1-like fusions are mutually exclusive with the sentinel translocations in BCP-ALL (BCR-ABL1, ETV6-RUNX1, TCF3-PBX1, and KMT2A (MLL) rearrangements) and have the promising prospect to be sensitive to tyrosine kinase inhibitors similar to BCR-ABL1. In this review, we discuss the types of tyrosine kinase-activating lesions discovered, and the preclinical and clinical evidence for the use of tyrosine kinase inhibitors in the treatment of this novel subtype of ALL.