Abbreviations: AZA, azacitidine; ANC, absolute neutrophil count; Hb, hemoglobin; PLT, platelet; LDH, lactate dehydrogenase; PB, peripheral blood; BM, bone marrow; RAEB, refractory anemia with excess blast; IPSS, International Prognostic Scoring System; ECOG PS, Eastern Cooperative Oncology Group Performance Status; CK, complex karyotype; MK, monosomal karyotype; OS, overall survival; HR, hazard ratio; CI, confidence interval.