Revisiting gene mutations and prognosis of ex-M6a-acute erythroid leukemia with regard to the new WHO classification

N Cervera (1) , N Carbuccia (1) , M Mozziconacci (1) , A Adélaïde (1) , S Garnier (1) , A Guille (1) , A Murati (1) , M Chaffanet (1) , V Vey (1) , D. Birnbaum (1) , V Gelsi-Boyer (1)

1 CRCM - Centre de Recherche en Cancérologie de Marseille

Due to the lack of specific clinical and biological features, M6a-acute erythroid leukemia (M6a-AEL), defined as an erythroid/myeloid type of acute leukemia, is no longer a distinct entity in the last classification of myeloid neoplasms by the World Health Organization (WHO). 1 The diagnosis of M6a-AEL was previously made if a proliferation of erythroid precursors ⩾ 50% with a myeloblast count ⩾ 20% when counted as a percentage of non-erythroid cells, was found in the bone marrow. 2 In 2016, revision of the WHO classification, the denominator used for calculating the blasts percentage was changed from non-erythroid cells to all nucleated cells. Consequently, M6a-AELs are now either myelodysplastic syndromes (MDSs) if the percentage of myelo-blasts is ⩾ 20% of non-erythroid cells but o20% of all nucleated cells or acute myeloid leukemia (AML) if the percentage of myeloblasts is ⩾ 20% of all nucleated cells. As for any other AMLs prior therapy, recurring WHO cytogenetic abnormalities, and criteria for AML with myelodysplasia-related changes (AML-MRC) have to be taken into consideration for classification. By using targeted next-generation sequencing (tNGS) and array-comparative genomic hybridization (aCGH), we previously established a molecular classification of 40 M6a-AELs 3 in five classes (C) based on mutations in NPM1 (C1), transcription factors (C2), splicing factors and/or chromatin modifiers (C3), TP53 (C4) or neither (C5). This classification could help in prognosis stratifica-tion. We have here re-analyzed our M6a-AEL molecular data according to 2016 WHO classification and compared them to a previously published cohort of MDS.

Domaines: Cancer; Hématologie; Génétique humaine

N Cervera, N Carbuccia, M Mozziconacci, A Adélaïde, S Garnier, et al.. Revisiting gene mutations and prognosis of ex-M6a-acute erythroid leukemia with regard to the new WHO classification. Blood Cancer Journal, 2017, 7 (8), pp.e594. ⟨10.1038/bcj.2017.68⟩. ⟨hal-01789525⟩