Identification of Molecular and Cytogenetic Risk Factors for Unfavorable Core-binding Factor-positive Adult AML with Post-remission Treatment Outcome Analysis Including Transplantation

Emerging molecular studies have identified a subgroup of patients with unfavorable core-binding factor-positive (CBF)-AML who should be treated by intensified post-remission treatments. We analyzed 264 adults with CBF-AML from 2002 to 2011, and focused on 206 patients who achieved CR after standard '3+7' induction chemotherapy. Patients who achieved CR with an available donor were treated with allogeneic hematopoietic SCT (allo-HSCT, n=115) and the rest were treated with autologous (auto) HSCT (n=72) or chemotherapy alone (n=19). OS was not significantly different between CBFβ/MYH11 (n=62) and RUNX1/RUNX1T1 (n=144), and auto-HSCT showed favorable OS compared with allo-HSCT or chemotherapy alone. Cytogenetic analysis identified that inv(16) without trisomy had a favorable OS and t(8;21) with additional chromosomes had an unfavorable OS, but multivariate analysis revealed those were NS. Patients with c-kit mutation showed inferior OS. For transplanted patients, residual post-transplant CBF-minimal residual disease quantitative PCR with higher WT1 expression at D+60 showed the worst OS with a higher incidence of relapse. Conclusively, we found that unfavorable CBF-AML can be defined with risk stratification using cytogenetic and molecular studies, and a careful risk-adapted treatment approach using frontline transplantation with novel therapies should be evaluated for this particular risk subgroup.