Characteristics and Outcomes of Secondary Acute Myeloid Leukemia and Acute Myeloid Leukemia With Myelodysplasia-Related Changes: Multicenter Study From the Thai Acute Leukemia Study Group

From the Thai acute myeloid leukemia (AML) registry database, secondary AML (sAML) and AML with myelodysplasia-related changes (AML-MRC) account for one-third of newly diagnosed AML. The sAML, AML-MRC, and white blood cell count >100 x10(9)/L were pre-treatment prognostic factors associated with inferior relapse-free survival. Furthermore, AML-MRC with the morphologic criteria of multilineage dysplasia was an adverse prognostic factor for overall survival. Background: Secondary acute myeloid leukemia (sAML) and AML with myelodysplasia-related changes (AML-MRC) both result in dismal outcomes. This retrospective study aimed to determine whether these features are poor prognostic factors independent of older age and adverse cytogenetics, which are commonly associated with a poor prognosis. Methods: The characteristics and real-world outcomes of sAML and AML-MRC from the Thai AML registry database were investigated. Results: From a total of 992 newly diagnosed AML patients, 315 (31.8%) patients were classified into sAML or AML-MRC subtypes. Older age, low white blood cell (WBC) count, low bone marrow blast, and adverse cytogenetic risk were commonly present in sAML and AML-MRC compared to de novo AML. Complete remission after 7 + 3 induction therapy occurred in 42.3% of patients with sAML or AML-MRC and 62.4% of de novo AML (P <.001). The median overall survival (OS) of sAML, AML-MRC, and de novo AML were 6.9, 7.0, and 12.2 months, respectively (P <.001). The independent prognostic factors for inferior OS were older age, intermediate-risk or adverse-risk cytogenetics, WBC count > 100 x10(9) /L, poor performance status, and a subgroup of AML-MRC with the morphologic criteria of multilineage dysplasia (AML-MRC-M). In addition, sAML, AML-MRC, and a WBC count > 100 x10(9)/L were pretreatment prognostic factors associated with poor relapse-free survival (P =.006, P =.017, and P <.001, respectively). Conclusion: Both sAML and AML-MRC are independently associated with poor outcomes in Thai patients. Our study supports AML-MRC-M as an adverse prognostic factor for OS.