Germline CEBPA mutations in Korean patients with acute myeloid leukemia

Clinical significance of decreased or loss of ABO blood group expression in acute myeloid leukaemia: A single-centre retrospective study

BACKGROUND AND OBJECTIVES

Decreased or loss of ABO blood group antigen expression has been observed in acute myeloid leukaemia (AML) patients. We studied the clinical significance of this group in AML patients.

MATERIALS AND METHODS

This was a retrospective, single-centre cohort study in which the data were retrieved from April 2009 to December 2019. A total of 1592 AML patients with normal ABO blood group antigen (Group I) and 65 patients of decreased or loss of ABO blood group antigen (Group II) group were enrolled. Data were collected at the time of initial admission for pathological diagnosis. To interrogate the underlying mechanism, publicly available The Cancer Genome Atlas AML data were downloaded.

RESULTS

Group II consisted of 3.9% (65/1657) of AML patients. The 90-day survival (D90) probability was higher for Group II with a mean survival of 86.4 days compared to 80.6 days for Group I (p = 0.047). Group II had higher haematocrit (28.6 vs. 27.4%) and lower d-dimer, fibrinogen degradation production and C-reactive protein. Publicly available data revealed that among 11 CpG methylation sites within the ABO gene, 4 sites with elevated methylation level were associated with improved D90 survival probability and demonstrated an inverse correlation with ABO gene expression. Lower expression of the ABO gene showed improved survival trends for D90 (p = 0.058) and 180-day survival (p = 0.072).

CONCLUSION

AML with decreased expression or loss of ABO blood group showed better early survival during D90. Transfusion support for this subgroup of AML patients should be meticulously performed considering serum typing.

Sporadic and Familial Acute Myeloid Leukemia with CEBPA Mutations

PURPOSE OF REVIEW

CCAAT enhancer binding protein A (CEBPA) gene mutation is one of the common genetic alterations in acute myeloid leukemia (AML), which can be associated with sporadic and familial AML.

RECENT FINDINGS

Due to the recent advances in molecular testing and the prognostic role of CEBPA mutation in AML, the definition for AML with CEBPA mutation (AML-CEBPA) has significantly changed. This review provides the rationale for the updates on classifications, and the impacts on laboratory evaluation and clinical management for sporadic and familial AML-CEBPA patients. In addition, minimal residual disease assessment post therapy to stratify disease risk and stem cell transplant in selected AML-CEBPA patients are discussed. Taken together, the recent progresses have shifted the definition, identification, and management of patients with AML-CEBPA.

Hereditary acute myeloid leukemia associated with C-terminal CEBPA germline variants

Acute myeloid leukemia with germline CEBPA mutation is a subtype of acute myeloid leukemia that is associated with a favorable prognosis. Most of the reported cases of acute myeloid leukemia with CEBPA germline variants involve a germline variant in the N-terminus and a somatic variant in the C-terminus. There are only a few reported cases where the CEBPA germline variant has been identified in the C-terminus and the somatic variant in the N-terminus. This case report and review of the literature illustrates that, although acute myeloid leukemia with CEBPA N- or C-terminal germline variants have certain similarities such as atypically young age at diagnosis, frequent relapse, and favourable overall prognosis, there are also significant differences such as lower life-time penetrance of acute myeloid leukemia and shorter time to relapse for germline C-terminal cases. These findings add important information on the natural history and clinical outcomes of acute myeloid leukemia with germline CEBPA C-terminal variants and these findings should be considered in the management of patients and their family members.

[Management of genetic predisposition to hematologic malignancies in patients undergoing allogeneic hematopoietic cell transplantation (HCT): Guidelines from the SFGM-TC]

The advent of new technologies has made it possible to identify genetic predispositions to myelodysplastic syndromes (MDS) and acute leukemias (AL) more frequently. The most frequent and best characterized at present are mutations in CEBPA, RUNX1, GATA2, ETV6 and DDX41 and, either in the presence of one of these mutations with a high allelic frequency, or in the case of a personal or family history suggestive of blood abnormalities such as non-immune thrombocytopenia, it is recommended to look for the possibility of a hereditary hematological malignancy (HHM). Indeed, early recognition of these HHMs allows better adaptation of the management of patients and their relatives, as allogeneic hematopoietic stem cell transplantation (HSCT) is very often proposed for these pathologies. According to current data, with the exception of the GATA2 mutation, the constitutional or somatic nature of the mutations does not seem to influence the prognosis of hematological diseases. Therefore, the indication for an allograft will be determined according to the usual criteria. However, when searching for a family donor, it is important to ensure that there is no hereditary disease in the donor. In order to guarantee the possibility of performing the HSC allograft within a short period of time, it may be necessary to initiate a parallel procedure to find an unrelated donor. Given the limited information on the modalities of HSC transplantation in this setting, it is important to assess the benefit/risk of the disease and the procedure to decide on the type of conditioning (myeloablative or reduced intensity). In view of the limited experience with the risk of secondary cancers in the medium and long-term, it may be appropriate to recommend reduced intensity conditioning, as in the case of better characterized syndromic hematological diseases such as Fanconi anemia or telomere diseases. In summary, it seems important to evoke HHM more frequently, particularly in the presence of a family history, certain mutations or persistent blood abnormalities, in order to discuss the specific modalities of HSC allografting, particularly with regard to the search for a donor and the evaluation of certain modalities of the procedure, such as conditioning. It should be noted that the discovery of HHM, especially if the indication of an allogeneic HSC transplant is retained, will raise ethical and psychological considerations not only for the patient, but also for his family. A multidisciplinary approach involving molecular biologists, geneticists, hematologists and psychologists is essential.

Germline mutations among Polish patients with acute myeloid leukemia

BACKGROUND

A small but important proportion of patients (4-10 %) with AML have germline mutations. They can cause the development of AML at an earlier age, confer a higher risk of relapse or predispose to secondary leukemias, including therapy-related leukemias. The analysis of germline mutations in a patient and his/her family is also critical for the selection of suitable family donors if the patient is a candidate for hematopoietic stem cell transplantation (HSCT).

METHODS

103 unrelated consecutive patients with de novo AML were enrolled in the study. Control group consisted of 103 persons from the general population. We performed NGS sequencing of bone marrow cells and buccal swabs DNA of six genes: CEBPA, DDX41, ETV6, TERT, GATA2, and IDH2 to detect germline pathogenic mutations.

RESULTS

In the investigated group, 49 variants were detected in six genes. 26 of them were somatic and 23 germline. Germline variants were detected in all six tested genes. Eight pathogenic germline mutations were detected in 7 AML patients, in three genes: CEBPA, ETV6, and IDH2. One patient had two pathogenic germinal mutations, one in ETV6 and one in CEBPA gene. We identified one novel pathogenic germline mutation in CEBPA gene. The difference in frequency of all pathogenic germline mutations between the tested (7.77 %) and control groups (0.97 %) was statistically significant (p = 0.046). In the tested group, the median age at AML diagnosis was 11 years lower in patients with pathogenic germline mutations than in patients without them (p = 0.028).

CONCLUSIONS

We showed higher frequency of CEBPA, ETV6, and IDH2 germline mutations in AML patients than in control group, which confirms the role of these mutations in the development of AML. We also showed that the median age at the onset of AML in patients with pathogenic germline mutations is significantly lower than in patients without them.

Analytical and Potential Clinical Performance of Oncomine Myeloid Research Assay for Myeloid Neoplasms

INTRODUCTION

Next-generation sequencing (NGS) panels have recently been introduced to efficiently detect genetic variations in hematologic malignancies.

OBJECTIVES

Our aim was to evaluate the performance of the commercialized Oncomine™ myeloid research assay (OMA) for myeloid neoplasms.

METHODS

Certified reference materials and clinical research samples were used, including 60 genomic DNA and 56 RNA samples. NGS was performed using OMA, which enables the interrogation of 40 target genes, 29 gene fusions, and five expression target genes with five expression control genes by the Ion S5 XL Sequencer. The analyzed data were compared with clinical data using karyotyping, reverse transcription polymerase chain reaction (PCR), fluorescence in situ hybridization, Sanger sequencing, customized NGS panel, and fragment analysis.

RESULTS

All targets of reference materials were detected except three (two ASXL1 and one CEBPA) mutations, which we had not expected OMA to detect. In clinical search samples, OMA satisfactorily identified DNA variants, including 90 single nucleotide variants (SNVs), 48 small insertions and deletions (indels), and eight FLT3 internal tandem duplications (ITDs) (Kappa agreement 0.938). The variant allele frequencies of SNVs and indels measured by OMA correlated well with clinical data, whereas those of FLT3-ITDs were significantly lower than with fragment analysis (P = 0.008). Together, OMA showed strong ability to identify RNA gene fusions (Kappa agreement 0.961), except one RUNX1-MECOM. The MECOM gene was highly expressed in all five samples with MECOM-associated rearrangements, including inv(3), t(3;3), and t(3;21).

CONCLUSION

OMA revealed excellent analytical and potential clinical performance and could be a good replacement for conventional molecular tests.

Laboratory evaluation and prognostication among adults and children with CEBPA-mutant acute myeloid leukemia

CEBPA-mutant acute myeloid leukemia (AML) encompasses clinically and biologically distinct subtypes of AML in both adults and children. CEBPA-mutant AML may occur with monoallelic (moCEBPA) or biallelic (biCEBPA) mutations, which can be somatic or germline, with each entity impacting prognosis in unique ways. BiCEBPA AML is broadly associated with a favorable prognosis, but differences in the type and location of CEBPA mutations as well as the presence of additional leukemogenic mutations can lead to heterogeneity in survival. Concurrent FLT3-ITD mutations have a well-documented negative effect on survival in adult biCEBPA AML, whereas support for a negative prognostic effect of mutations in TET2, DNMT3A, WT1, CSF3R, ASXL1, and KIT is mixed. NPM1 and GATA2 mutations may have a positive prognostic impact. MoCEBPA AML has similar survival outcomes compared to AML with wild-type CEBPA, and risk stratification is determined by other cytogenetic and molecular findings. Germline CEBPA mutations may lead to familial biCEBPA AML after acquisition of second somatic CEBPA mutation, with variable penetrance and age. BiCEBPA AML in children is likely a favorable-risk diagnosis as it is in adults, but the role of a single CEBPA mutation and the impact of concurrent leukemogenic mutations are not clear in this population. Laboratory evaluation of the CEBPA gene includes PCR-based fragment-length analysis, Sanger sequencing, and next-generation sequencing. Phenotypic analysis using multiparameter flow cytometry can also provide additional data in evaluating CEBPA, helping to assess for the likelihood of mutation presence.

The clinical characteristics and prognosis of cytogenetically normal AML with single mutations of CEBPA

INTRODUCTION

CEBPA mutation is a common mutation in normal karyotype AML. CEBPAdm AML has been recognized as a separate entity, but there is still controversy to the prognosis of CEBPAsm patients.

METHODS

A total of 151 newly diagnosed cytogenetically normal AML patients treated at the Second Hospital Center of Shanxi Medical University from February 2017 to December 2019 were the subjects of the study. According to the number of mutations in the CEBPA gene, the patients were divided into three groups, CEBPAsm, CEBPAdm, and CEBPAwt patients. The clinical characteristics, gene mutations, response, and prognosis were retrospectively compared among the three groups.

RESULTS

CEBPAsm patients had lower hemoglobin values compared to CEBPAdm (P = .049). There was no statistical difference between the CEBPAsm cases and the CEBPAdm cases in the mutation types and the distribution of mutation regions (P > .050). Compared with CEBPAdm, cases with CEBPAsm were more likely associated with multiple other gene mutations (P = .023). Patients with CEBPAdm had a higher CR, ORR, and OS than those CEBPAwt (P < .050). CEBPAsm patients had a similar OS with CEBPAdm and CEBPAwt patients (P = .281). These CEBPAsm patients with VAF<30% had lower OS than the patients with VAF≥30%. FLT3-ITD mutations could reduce CEBPAsm patients' OS (P = .019).

CONCLUSION

Our data first highlighted the impact of CEBPAsm VAF on OS, and the results showed the lower the VAF was, the shorter the OS tended to. The VAF of CEBPAsm could provide specific significance in some extent for the prognosis of patients.

Novel insights of acute myeloid leukemia with CEBPA deregulation: Heterogeneity dissection and re-stratification

Acute myeloid leukemia with bi-allelic CEBPA mutation was categorized as an independent disease entity with favorable prognosis, however, recent researches have revealed huge heterogeneity within this disease group, and for some patients, relapse remained a major cause of treatment failure. Further risk stratification is essentially needed. Here by reviewing the latest literature, we summarized the characteristics of CEBPA mutation profiles and clinical features, with a special intention of dissecting the heterogeneity within the seemingly homogeneous AML with bi-allelic CEBPA mutations. Specifically, non-classical CEBPA mutation, miscellaneous companion genetic aberrations and the presence of germline CEBPA mutation are three major sources of heterogeneity. Identifying these factors can help us predict patients at a higher risk of relapse, for whom aggressive treatment may be recommended. Novel therapeutic approaches regarding manipulating potentially druggable targets as well as the debate over post remission consolidation regimens has also been discussed.

[Investigation and clinical analysis of a family with germline CEBPA mutations in acute myeloid leukemia]

目的

探讨伴CEBPA基因突变的家族性急性髓系白血病（AML）的临床特征、病因及转归，提高对家族性白血病的认识。

方法

调查一个伴CEBPA基因突变AML家系患者的发病年龄、临床特征、转归及预后并绘制家系谱。对先证者采集骨髓及口腔黏膜细胞，与先证者有血缘关系的亲属，采集外周血，通过基因测序技术检测基因突变。

结果

该家系共有10人诊断为AML，其中男4例，女6例，中位年龄9（3～48）岁。10例患者中，6例死亡，其中4例未进行治疗，1例患者化疗后生存3年复发死亡，1例采取中药及支持治疗生存2年后死亡。4例患者生存，1例接受化疗患者生存达15年，3例患者接受化疗联合造血干细胞移植，至随访截止，生存时间分别为6、9、28个月。对先证者及8名与先证者有血缘关系的亲属进行基因测序，发现5例存在胚系CEBPA TAD p.G36Afs*124突变，其中4例确诊为AML，1例随访至今未发病。

结论

伴CEBPA基因突变的家族性AML多在儿童及青壮年期发病，具有完全或接近完全的外显率，通过积极治疗，大多预后良好。

Secondary leukemia in patients with germline transcription factor mutations (RUNX1, GATA2, CEBPA)

Recognition that germline mutations can predispose individuals to blood cancers, often presenting as secondary leukemias, has largely been driven in the last 20 years by studies of families with inherited mutations in the myeloid transcription factors (TFs) RUNX1, GATA2, and CEBPA. As a result, in 2016, classification of myeloid neoplasms with germline predisposition for each of these and other genes was added to the World Health Organization guidelines. The incidence of germline mutation carriers in the general population or in various clinically presenting patient groups remains poorly defined for reasons including that somatic mutations in these genes are common in blood cancers, and our ability to distinguish germline (inherited or de novo) and somatic mutations is often limited by the laboratory analyses. Knowledge of the regulation of these TFs and their mutant alleles, their interaction with other genes and proteins and the environment, and how these alter the clinical presentation of patients and their leukemias is also incomplete. Outstanding questions that remain for patients with these germline mutations or their treating clinicians include: What is the natural course of the disease? What other symptoms may I develop and when? Can you predict them? Can I prevent them? and What is the best treatment? The resolution of many of the remaining clinical and biological questions and effective evidence-based treatment of patients with these inherited mutations will depend on worldwide partnerships among patients, clinicians, diagnosticians, and researchers to aggregate sufficient longitudinal clinical and laboratory data and integrate these data with model systems.