Leukemic transformation in patients with myelodysplastic syndromes after treatment with granulocyte colony-stimulating factor.

Myelodysplastic syndromes (MDS) constitute bone marrow malignancies occurring mainly in older individuals and associated with acute myeloid leukemia (AML) transformation in 30 – 40% of cases [1]. In order to assess long-term survival and the AML transformation rate, in 1997 the International MDS Risk Analysis Workshop developed the International Prognostic Scoring System (IPSS), which divides patients with MDS into four risk groups: low, intermediate-1, intermediate-2 and high. Determining the prognosis of MDS is crucial in the eff ort toward defi ning the best treatment for each group [2]. When patients with MDS develop cytopenias and/or blood product transfusion dependency, treatment with growth factors may be initiated according to most treatment guidelines. Th ese include epoetin or darbepoetin and colony-stimulating factors, either alone or in combination, acting in synergy. A number of trials have been published, with erythroid response rates of around 40% in patients with lower-risk disease using International Working Group (IWG) criteria for response [3 – 5]. Some studies have shown a clear synergistic eff ect between the two drugs [6 – 8]. Th e negative impact of treatment with growth factors is widely discussed in the literature relating to solid tumors. Th ere are studies indicating that granulocyte colony-stimulating factor (G-CSF) may increase the risk of AML evolution in aplastic anemia [9] and severe congenital neutropenia [10,11], while other studies suggest a favorable response of patients with MDS to treatment including G-CSF [12]. Th e aim of this retrospective study was to assess the eff ect of treatment with G-CSF on leukemic transformation in 92 consecutive patients with MDS treated in two hematology units in Athens, Greece, between 1996 and 2005. Th e medical records of these patients were retrospectively reviewed. Bone marrow biopsies were reevaluated and diagnosis confi rmed. We used the French – American – British (FAB) classifi cation for MDS instead of the more recent World Health Organization (WHO) classifi cation for practical reasons and due to the presence of patients with chronic myelomonocytic leukemia (CMML). We excluded patients with refractory anemia with excess blasts in transformation (RAEB-T) ( n 16), as well as patients who were considered non-evaluable ( n 5) and