[High Risk Factors for Transformation into Acute myeloid Leukemia in Patients with Intermediate and High Risk Myelodysplastic syndrome].

Objective: To study the high risk factors for the transformation into acute myeloid leukemia(AML) in patients with intermediate and high risk myelodysplastic syndrome(MDS) treated by decitabine-based regimen.
Methods: The clinical characterstics of 60 intermediate and high risk MDS patients and the factors of its transformed into AML were retrospectively analyzed.
Results: The overall response rate(ORR) of the patients suffered from intermediate and high risk MDS treated by decitabine-based regimen was 65.0％(39/60), among the 60 cases 17 achieved complete remission(CR), 5 achieved morrow complete remission(mCR), 4 achieved partial remission(PR) and 13 achieved hematologic improvement(HI). Twenty-one cases(35.0%) were transformed into AML among 60 cases of intermediate and high risk MDS treated by decitabine-based regimen. The median time of transformation from intermediate and high risk MDS into AML was 10.0 months(1.6-32.0). χ ² or Fisher's exact test showed that 2016 WHO MDS diagnostic subgrouping, myeloid hyperplasia markedly active, delayed interval of decitabine-based treatment associated with the transformation from intermediate to high risk MDS into AML (χ ² =9.878，P=0.031；χ ² =4.319，P=0.038；χ ² =6406，P=0.011); Univariate analysis of Kaplan-Meier test showed that 2016 WHO MDS diagnostic subgroups, bone marrow blast cell ratio, bone marrow dysplasia coefficients, prolonged interval of decitabine-based treatment associated with the transformation from intermediate and high risk MDS into AML (P=0.015，P=0.008，P=0.012，P=0.032); multivariate analysis showed the bone marrow blast cell ratio and the bone marrow dysplasia coefficients were independent risk factors for the transformation from intermediate to high risk MDS into AML (P=0.022，P=0.018).
Conclusion: The bone marrow blast cell ratio and the bone marrow dysplasia coefficients are independent risk factors of transformation into AML in the patients with intermediate and high risk MDS treated by decitabine-based regimen. The regular interval of dicitabine treatment is beneficial to maintain the stability of patients conditions.