Comparisons of overall survival (OS) in patients treated with azacitidine according to the presence of a complex karyotype (CK); chromosomal abnormalities [CA] ≥3 (A) and OS according to the presence of a CK (CA≥3) combined with the monosomal karyotype (MK) (B). OS in the group without CK was significantly lower compared to the group with CK in a median follow-up time of 24.2 months (OS, 21.8% in the group with CK, 37.8% in the group without CK, P <0.001) (A). The MK negative status in the group without CK was higher than the other 3 groups (OS of MK +/- in the group without CK, 18.7% vs. 44.8%; MK +/- in the group with CK, 22.2% vs. 21.4%; P <0.001) (B). However, the differences in OS among the other 3 groups were not significant.