BACKGROUND/AIM Acute myeloid leukemia (AML) is a biologically heterogeneous disease that can be classified into de novo AML and secondary AML. Secondary AML can be further divided into therapy-related AML (t-AML) or AML evolving from antecedent hematological disorder (AHD-AML). This study evaluated the characteristics and prognosis of secondary AML in a homogeneous East Asian population who are often under-represented.

PATIENTS AND METHODS This was a retrospective, longitudinal cohort study of Korean AML patients over 18 years old treated between January 2000 and December 2013. A total of 437 de novo AML (80.3%), 41 t-AML (7.5%), and 66 AHD-AML (12.1%) were evaluated.

RESULTS First, we found that secondary AML constituted about 19.7% of all AML cases, and t-AML was more prevalent than AHD-AML. Second, we determined AHD-AML as a prognostic factor for inferior survival, independent of other risk factors (HR=2.137, 95%CI=1.534-2.977, p<0.001). The induction response rates correlated well with the overall survival. Furthermore, AHD-AML was associated with worst treatment outcomes and prognosis regardless of cytogenetic risk or age. Interestingly, t-AML was generally associated with better outcomes compared to AHD-AML despite the similarities in treatment schema.

CONCLUSION Secondary AML represents a broad spectrum of diseases and t-AML should be addressed separately from AHD-AML.