Novel mutations in CEBPA in Korean Patients with acute myeloid leukemia with a normal karyotype

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.

Two Novel CEBPA Mutations in a Turkish Patient with Acute Myeloid Leukemia

Acute myeloid leukemia (AML) was first categorized in 1976 by French, American and British researchers, and divided into eight subgroups (M0 to M7), depending on the cytochemical or histological changes in the leukemic cells. The gene mutations of FLT3-ITD, CEBPA and NPM1 are the most common that cooperate together in the prognosis of AML. The CEBPA gene that is a hematopoietic transcription factor, is located on chromosome 19q13.11, and its prevalence is between 5.0 and 14.0% in AML. The patient was referred to our clinic suffering from menorrhagia, unplanned weight loss in a month and low platelet levels, and was diagnosed with AML on clinical and laboratory examination. Here, we report a patient carrying two novel pathogenic mutations that create a frameshift mutation on the CEBPA gene, c.940_941insCCGTCG TGGAGACGA CGAAGG and c.221_222delAC by Sanger sequencing methodology.

Prognostic implications of CEBPA mutations in pediatric acute myeloid leukemia: a report from the Japanese Pediatric Leukemia/Lymphoma Study Group

CCAAT/enhancer-binding protein alpha (CEBPA) mutations are a favorable prognostic factor in adult acute myeloid leukemia (AML) patients; however, few studies have examined their significance in pediatric AML patients. Here we examined the CEBPA mutation status and clinical outcomes of pediatric AML patients treated in the AML-05 study. We found that 47 (14.9%) of the 315 evaluable patients harbored mutations in CEBPA; 26 cases (8.3%) harbored a single mutation (CEBPA-single) and 21 (6.7%) harbored double or triple mutations (CEBPA-double). After excluding core-binding factor-AML cases, patients harboring CEBPA mutations showed better overall survival (OS; P=0.048), but not event-free survival (EFS; P=0.051), than wild-type patients. Multivariate analysis identified CEBPA-single and CEBPA-double as independent favorable prognostic factors for EFS in the total cohort (hazard ratio (HR): 0.47 and 0.33; P=0.02 and 0.01, respectively). CEBPA-double was also an independent favorable prognostic factor for OS (HR: 0.30; P=0.04). CEBPA-double remained an independent favorable factor for EFS (HR: 0.28; P=0.04) in the normal karyotype cohort. These results suggest that CEBPA mutations, particularly CEBPA-double, are an independent favorable prognostic factor in pediatric AML patients, which will have important implications for risk-stratified therapy.

CEBPA single mutation can be a possible favorable prognostic indicator in NPM1 and FLT3-ITD wild-type acute myeloid leukemia patients with intermediate cytogenetic risk

The aim of this study was to evaluate the prognostic impact of CEBPA single mutation in acute myeloid leukemia (AML) patients with intermediate cytogenetic risk. CEBPA single and double mutations were detected in 11 (9.7%) and 17 (15.1%) of 113 NPM1 wild-type patients, but no CEBPA mutations were detected in a group of 44 NPM1 mutated patients. Among patients with NPM1/FLT3-ITD wild-type, those with CEBPA double mutations (P=0.013 and 0.007 for overall survival and relapse-free survival, respectively) or a single mutation (P=0.039 and 0.020 for overall survival and relapse-free survival, respectively) demonstrated a favorable prognosis compared with CEBPA wild-type patients. Subsequent multivariate analysis confirmed the favorable prognostic impact of CEBPA single and double mutations. Despite the low statistical power of this study due to the small number of patients, our preliminary data suggest that CEBPA single mutation may be associated with favorable clinical outcomes in NPM1/FLT3-ITD wild-type AML patients with intermediate cytogenetic risk.