Background Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal haematopoietic neoplasms, characterised by the presence of morphological and functional alterations in different haematopoietic cell lines and anaemia, leucopenia and thrombocytopenia. 5-Azacitidine (AZA) is a hipomethylating agent indicated for the treatment of adult patients, who are not eligible for haematopoietic stem cell transplantation with intermediate-2 and high-risk MDS, according to the International Prognostic Scoring System (IPSS).Its effectiveness was evaluated in 3 studies conducted by the Cancer and Leukaemia Group B.

Purpose This study aims to evaluate the effectiveness of AZA in patients diagnosed with MDS, outside the scope of CT.

Materials and methods Results are taken from a retrospective observational study, including all patients with MDS treated with AZA 75 mg/m2 subcutaneously in our Hospital, during the period November 2007-April 2011. The World Health Organisation (WHO) criteria for diagnosis (bone marrow examination and cytogenetics studies) and classification of MDS were used. Response to treatment was assessed using the International Working Group (IWG 2006) criteria: overall response (complete and partial remission), stable disease, time of transformation to acute myeloid leukaemia (AML), overall survival, cytogenetic response and hematologic improvement.

Results Data collection comprised results from 16 male and 9 female with a median age of 68,72 (±12,52) years. The average time to diagnosis of MDS was 22.56 (± 22.11) days. The number of blasts in bone marrow of patients at the time of diagnosis was on average 11%. An intermediate-2/high IPSS risk was documented in 76% of the patients, an intermediate-1 IPSS risk in 24%. The most frequently used dose was 75 mg/m2 subcutaneously, 12% of the patients required dose adjustment. The mean number of administered cycles was 9 (±6,08). 68% of patients had high transfusion requirement. Overall response was achieved in 29,16% of patients, stable disease in 33,34%, cytogenetic response in 48% and transfusion independence in 25%. The rate and the time of transformation to Acute myeloid leukaemia (AML) was 20,83%. The median overall survival was 32 months (95% CI 10.72-53.29) and the median time to AML transformation in 23 months (95% CI 21.54-24.4).

Conclusions Results demonstrate that 5-azacitidine is an effective drug in the treatment of MDS, outside the scope of CT, which improves overall survival, quality of life and delays AML transformation.