Patients with secondary acute myeloid leukemia undergoing allogeneic stem-cell transplant have inferior outcomes than de novo acute myeloid leukemia regardless minimal residual disease level by flow cytometry.

Abstract

Secondary acute myeloid leukemia (s-AML) patients have a poor prognosis and currently the only curative therapy is allogeneic stem-cell transplant (HSCT). However, we do not yet know whether transplantation is sufficient to reverse the poor prognosis compared to de novo AML patients. We analyzed survival after HSCT comparing a cohort of 58 patients with s-AML versus 52 de novo patients who were transplanted between 2012 and 2020. Patients with s-AML had worse event-free survival (EFS) (p=0.001) and overall survival (OS) (p<0.001) compared to de novo AML due to an increased risk of relapse (p=0.06) and non-relapse mortality (p=0.03). The main difference in survival was observed in patients who achieved complete remission (CR) before HSCT (EFS p=0.002 OS and <0.001), regardless minimal residual disease (MRD) by |multiparametric flow cytometry cohorts. In patients transplanted with active disease (AD), the prognosis was adverse in both s-AML and de novo AML groups (EFS p=0.869 and OS p=0.930). After excluding patients with AD, we stratified the cohort according to conditioning intensity, noticing that s-AML who received MAC had comparable outcomes to de novo AML, but the survival differences remained among reduce intensity conditioning group. In conclusion, transplanted s-AML patients have worse survival among patients in CR before HSCT, regardless of MRD level by flow cytometry compared to de novo AML. MAC patients had similar outcomes irrespective of leukemia ontogeny.