Total genomic alteration as measured by SNP-array-based molecular karyotyping is predictive of overall survival in a cohort of MDS or AML patients treated with azacitidine.

Metaphase cytogenetics (MC) has a major role in the risk stratification of patients with myelodysplastic syndromes (MDSs) and can affect the choice of therapies. Azacitidine (AZA) has changed the outcome of patients with MDS or acute myeloid leukemia (AML) unfit for intensive chemotherapy. Identification of patients without the benefit of AZA would allow AZA combination or other drugs in first-line treatments. New whole-genome scanning technologies such as single nucleotide polymorphism microarray (SNP-A)-based molecular karyotyping (MK) improve the risk stratification in MDS and AML. Maintenance of genomic integrity is less than three megabases (Mbs) total disruption of the genome correlated with better overall survival (OS) in patients with lower-risk MDS. In this SNP-A study, we aimed at defining a cutoff value for total genomic copy number (CN) alterations (TGA) influencing the median OS in a cohort of 51 higher-risk MDS/AML patients treated with AZA. We observed that the relative risk of worse OS increased >100 Mb of TGA, as detected by SNP-A-based MK (8 and 15 months respectively, P=0.02). Our data suggest that precise measurement of TGA could provide predictive information in poor and very poor revised International Prognostic Scoring system (IPSS-R) patients treated with AZA.