Outcome of therapy-related myeloid neoplasms treated with azacitidine

BACKGROUND: Therapy-related myeloid neoplasms (t-MN), including myelodysplastic syndromes and acute myeloid leukemia (t-MDS and t-AML) are associated to clinical and biologic unfavorable prognostic features, including high levels of DNA methylation. METHODS: We retrospectively evaluated 50 t-MN patients (34 MDS and 16 AML) selected among all patients receiving azacitidine (AZA) at 10 Italian Hematology Centers. Patients had developed a t-MN at a median of 6.5 years (range 1.7- 29) after treatment of the primary tumor (hematological neoplasm, 27 patients; solid tumor, 23 patients). RESULTS: The overall response rate was 42% (complete remission: 10 patients, partial remission: 2 and hematological improvement: 8 patients) and was obtained after a median of 3 cycles (range 1-6). Median overall survival (OS) was 21 months (range 1-53.6+) from AZA start. OS was significantly better in patients with less than 20% blasts, in normal karyotype t-AML and when AZA was used as front-line treatment. This was confirmed by the multivariate analysis. CONCLUSIONS: This study reports efficacy of AZA in the largest series of therapy-related MN patients treated with 5-AZA. Our data show that blasts and karyotype maintain their important prognostic role in t-MN also in the azacitidine era.