Should We Move to a Genomic Classification of Neutrophilic Myeloid Neoplasms?

We were very interested to read the letter by Tremblay et al 1 entitled “ CNL and aCML are prognostically distinct: a large National Cancer Database analysis ” and the discussion in relation to our recent article “ CNL and aCML should be considered as a single entity based on molecular pro fi les and outcomes. ” 2 Our study, which focused on a relatively large cohort of atypical chronic myeloid leukemia (aCML, n = 30, now renamed myelodysplastic syndrome [MDS]/myeloproliferative neoplasm [MPN] with neutro-philia in the fi fth World Health Organization [WHO] classi fi cation 3 ) and chronic neutrophilic leukemia (CNL, n = 23), highlighted the similarities with regard to genetic pro fi les, clinical characteristics, and outcomes between these 2 entities. Consequently, we suggested that CNL and aCML may be better classi fi ed as a single entity within the MDS/MPN grouping and further subclassi fi ed for prognosis and potential therapy according to their genetic pro fi le. In their letter, Tremblay et al expressed concern about our proposal based on the morphological differences between these 2 entities (mainly the dysplastic features associated with aCML) but more importantly, on their own observations of differences in overall survival (OS) between aCML and CNL based on National Cancer Database (NCDB) data (aCML, n = 702, OS