Defining the Prognostic Implications of Recurring Cytogenetic Aberrations and FLT3-ITD in Acute Myeloid Leukemia Patients Undergoing Allogeneic Stem Cell Transplantation: On Behalf of the ALWP of the EBMT

Introduction Baseline karyotype at diagnosis remains the pivotal determinant of outcome in patients with acute myeloid leukemia (AML). The Medical Research Council (MRC) prognostic model is currently the benchmark for risk assessment in this patient population. However, the prognostic role of the complete spectrum of chromosomal abnormalities in AML patients undergoing allogeneic hematopoietic stem cell transplantation (allo-SCT) is currently unknown. Furthermore, their significance in conjunction with FLT3-ITD status has not been addressed thus far. Methods Using the Acute Leukemia Working Party/European Society for Blood and Marrow Transplantation multicenter database a retrospective analysis was performed to assess the clinical outcomes of AML patients undergoing allo-SCT with respect to specific recurring cytogenetic abnormalities complemented with FLT3-ITD status. We analyzed a cohort consisting of 8558 adult AML patients who underwent allo-SCT in first remission from either a matched sibling or a matched unrelated donor in 2006-2016. Results Patients with inv(3)(q21q26)/t(3;3)(q21;q26), del(5q), monosomy 7, chromosome 17p abnormalities, t(10;11)(p11-14;q13-23), t(6;11)(q27;q23), as well as those patients with a monosomal or complex karyotype experienced significantly inferior leukemia-free survival (LFS) compared to patients with a normal karyotype. Del (9q), trisomy 14, and loss of chromosome X were associated with improved LFS rates. A novel prognostic model delineating 5 distinct groups incorporating cytogenetic complexity and FLT3-ITD status was constructed with significant prognostic implications. Conclusion Our analysis endorses the prognostic significance of the MRC predictive model in patients undergoing allo-SCT in CR1 with some specific modifications. Furthermore, consideration of FLT3-ITD and karyotypic complexity improved the projective capacity of the MRC model in transplanted patients.