Project description:The molecular landscape of acute lymphoblastic leukemia (ALL) is highly heterogeneous, and genetic lesions are clinically relevant for diagnosis, risk stratification, and treatment guidance. Next-generation sequencing (NGS) has become an essential tool for clinical laboratories, where disease-targeted panels are able to capture the most relevant alterations in a cost-effective and fast way. However, comprehensive ALL panels assessing all relevant alterations are scarce. Here, we design and validate an NGS panel including single-nucleotide variants (SNVs), insertion-deletions (indels), copy number variations (CNVs), fusions, and gene expression (ALLseq). ALLseq sequencing metrics were acceptable for clinical use and showed 100% sensitivity and specificity for virtually all types of alterations. The limit of detection was established at a 2% variant allele frequency for SNVs and indels, and at a 0.5 copy number ratio for CNVs. Overall, ALLseq is able to provide clinically relevant information to more than 83% of pediatric patients, making it an attractive tool for the molecular characterization of ALL in clinical settings.
Project description:Acute lymphoblastic leukemia (ALL) is a blood cancer that primarily affects children but also adults. It is due to the malignant proliferation of lymphoid precursor cells that invade the bone marrow and can spread to extramedullary sites. ALL is divided into B cell (85%) and T cell lineages (10 to 15%); rare cases are associated with the natural killer (NK) cell lineage (<1%). To date, the survival rate in children with ALL is excellent while in adults continues to be poor. Despite the therapeutic progress, there are subsets of patients that still have high relapse rates after chemotherapy or hematopoietic stem cell transplantation (HSCT) and an unsatisfactory cure rate. Hence, the identification of more effective and safer therapy choices represents a primary issue. In this review, we will discuss novel therapeutic options including bispecific antibodies, antibody-drug conjugates, chimeric antigen receptor (CAR)-based therapies, and other promising treatments for both pediatric and adult patients.
Project description:We used next-generation sequencing (NGS) of the immunoglobulin genes to evaluate residual disease in 153 specimens from 32 patients with adult B cell acute lymphoblastic leukemia enrolled in a single multicenter study. The sequencing results were compared with multiparameter flow cytometry (MFC) data in 66 specimens (25 patients) analyzed by both methods. There was a strong concordance (82%) between the methods in the qualitative determination of the presence of disease. However, in 17% of cases, leukemia was detected by sequencing but not by MFC. In 54 bone marrow (BM) and peripheral blood (PB) paired specimens, the burden of leukemia detected by NGS was lower in PB than in BM, although it was still detectable in 68% of the 28 paired specimens with positive BM. Lastly, patients without disease detected by NGS or MFC had a 5-year relapse free survival of > 80%. The results suggest that residual disease detection by immunoglobulin gene sequencing is an extremely sensitive technique and may identify patients that might benefit from transplantation. Moreover, the increased sensitivity of the method may allow frequent peripheral blood testing to supplement marrow sampling to measure disease response.
Project description:Measuring minimal residual disease (MRD) during treatment is valuable to identify acute lymphoblastic leukemia (ALL) patients who require intensified treatment to avert relapse. We performed the next-generation sequencing (NGS)-based immunoglobulin gene (Ig) clonality assay and evaluated its clinical implication in pediatric B-ALL patients to assess MRD. Fifty-five patients who were diagnosed and treated with de novo (n = 44) or relapsed/refractory B-ALL (n = 11) were enrolled. MRD assessment was performed using the LymphoTrack® Dx IGH and IGK assay panels. The percentage of the clonal sequences per total read count was calculated as MRD (% of B cells). The data were normalized as the proportion of total nucleated cells (TNC) by LymphoQuant™ Internal control or the B-cell proportion in each sample estimated by flow cytometry or immunohistochemistry. Clonal Ig rearrangement was identified in all patients. The normalized MRD value was significantly lower than the unnormalized MRD value (p < 0.001). When categorizing patients, 27 of 50 patients (54%) achieved normalized MRD <0.01%, while 6 of them did not achieve MRD <0.01% when applying the unnormalized value. The normalized post-induction MRD value of 0.01% proved to be a significant threshold value for both 3-year event-free survival (100% for MRD <0.01% vs. 60.9% ± 10.2% for MRD ≥0.01%, p = 0.007) and 3-year overall survival (100% for MRD <0.01% vs. 78.3% ± 8.6% for MRD ≥0.01%, p = 0.011). However, unnormalized MRD was not a significant factor for outcome in this cohort. Our study demonstrated that MRD assessment by NGS-based Ig clonality assay could be applied in most pediatric B-ALL patients. Normalized post-induction MRD <0.01% was a significant prognostic indicator.
Project description:The outcomes of pediatric acute lymphoblastic leukemia (ALL) have improved remarkably during the last five decades. Such improvements were made possible by the incorporation of new diagnostic technologies, the effective administration of conventional chemotherapeutic agents, and the provision of better supportive care. With the 5-year survival rates now exceeding 90% in high-income countries, the goal for the next decade is to improve survival further toward 100% and to minimize treatment-related adverse effects. Based on genome-wide analyses, especially RNA-sequencing analyses, ALL can be classified into more than 20 B-lineage subtypes and more than 10 T-lineage subtypes with prognostic and therapeutic implications. Response to treatment is another critical prognostic factor, and detailed analysis of minimal residual disease can detect levels as low as one ALL cell among 1 million total cells. Such detailed analysis can facilitate the rational use of molecular targeted therapy and immunotherapy, which have emerged as new treatment strategies that can replace or reduce the use of conventional chemotherapy.
Project description:BackgroundBlinatumomab improved survival outcomes in B-cell acute lymphoblastic leukemia (B-ALL) patients with measurable residual disease (MRD) <10-4 . However, data on blinatumomab clearing MRD with high sensitivity of 10-6 remain scarce. This study evaluates the effectiveness of blinatumomab in eradicating extremely low level (up to <10-6 ) of MRD, as detected by next-generation sequencing (NGS), in children with B-ALL.MethodsPatients (n = 19) whose MRD was undetectable by multiparameter flow cytometry (MFC) (sensitivity of 10-4 ) but detectable by NGS after chemotherapy and followed by blinatumomab consolidation were included retrospectively.ResultsAfter one course of blinatumomab, 13/19 patients (68%) successfully achieved NGS-MRD clearance (undetectable). With a median follow-up of 13.3 months, three of patients who were NGS-MRD positive relapsed within 1.8 months, while another three remained complete remission.ConclusionsOur study was the first to demonstrate that blinatumomab could further eradicate MRD after patients achieve MFC-MRD undetectable in B-ALL patients.
Project description:Aberrant epigenetic modifications are well-recognized drivers for oncogenesis. Pediatric acute lymphoblastic leukemia (ALL) is no exception and serves as a model toward the significant impact these heritable alterations can have in leukemogenesis. In this brief review, we will focus on the main aspects of epigenetics, which control leukemogenesis in pediatric ALL, mainly DNA methylation, histone modification, and microRNA alterations. As we continue to gain better understanding of the driving mechanisms for pediatric ALL at both diagnosis and relapse, therapeutic interventions directed toward these pathways and mechanisms can be harnessed and introduced into clinical trials for pediatric ALL.
Project description:Similar to most cancers, genome-wide DNA methylation profiles are commonly altered in pediatric acute lymphoblastic leukemia (ALL); however, recent observations highlight that a large portion of malignancy-associated DNA methylation alterations are not accompanied by related gene expression changes. By analyzing and integrating the methylome and transcriptome profiles of pediatric B-cell ALL cases and primary tissue controls, we report 325 genes hypermethylated and downregulated and 45 genes hypomethylated and upregulated in pediatric B-cell ALL, irrespective of subtype. Repressed cation channel subunits and cAMP signaling activators and transducers are overrepresented, potentially indicating a reduced cellular potential to receive and propagate apoptotic signals. Furthermore, we report specific DNA methylation alterations with concurrent gene expression changes within individual ALL subtypes. The ETV6-RUNX1 translocation was associated with downregulation of ASNS and upregulation of the EPO-receptor, while Hyperdiploid patients (> 50 chr) displayed upregulation of B-cell lymphoma (BCL) members and repression of PTPRG and FHIT. In combination, these data indicate genetically distinct B-cell ALL subtypes contain cooperative epimutations and genome-wide epigenetic deregulation is common across all B-cell ALL subtypes.
Project description:ImportanceAcute lymphoblastic leukemia (ALL) is the most common form of pediatric cancer, and a leading cause of death in children. Understanding the causes of pediatric ALL is necessary to enable early detection and prevention; congenital cytomegalovirus (cCMV) has recently been identified as a potential moderate-to-strong factor associated with risk for ALL.ObjectiveTo compare the prevalence of cCMV infection between ALL cases and matched controls.Design, setting, and participantsIn this population-based case-control study of ALL cases and matched controls, cases consisted of children aged 0 to 14 years between 1987 and 2014 with an ALL diagnosis identified through the Michigan Cancer Surveillance Program and born in Michigan on or after October 1, 1987. Cancer-free controls were identified by the Michigan BioTrust for Health and matched on age, sex, and mother's race and ethnicity. Data were analyzed from November to May 2022.ExposurescCMV infection measured by quantitative polymerase chain reaction in newborn dried blood spots.Main outcomes and measuresALL diagnosed in children aged 0 to 14 years.ResultsA total of 1189 ALL cases and 4756 matched controls were included in the study. Bloodspots were collected from participants at birth, and 3425 (57.6%) participants were male. cCMV was detected in 6 ALL cases (0.5%) and 21 controls (0.4%). There was no difference in the odds of cCMV infection comparing ALL cases with controls (odds ratio, 1.30; 95% CI, 0.52-3.24). Immunophenotype was available for 536 cases (45.1%) and cytogenetic data for 127 (27%). When stratified by subtype characteristics, hyperdiploid ALL (74 cases) was associated with 6.26 times greater odds of cCMV infection compared with unmatched controls (95% CI, 1.44-27.19).Conclusions and relevanceIn this case-control study of cCMV and pediatric ALL, cCMV was associated with increased risk of hyperdiploid ALL. These findings encourage continued research.