Prognostic Significance of Residual Acute Myeloid Leukemia in Bone Marrow Samples Taken Prior to Allogeneic Hematopoietic Cell Transplantation.

Abstract

We sought to identify features in routine evaluation of pre-hematopoietic cell transplantation (HCT) bone marrow samples from patients with acute myeloid leukemia (AML) that influenced patient outcome. Of 140 patients, evidence of residual leukemia (RL) was identified in 38 (27%) of pre-HCT samples, as defined by 5% or more aspirate blasts, increased blood blasts, clustered or necrotic blasts on biopsy specimens, and/or leukemia-associated karyotypic abnormalities. Morphologic or karyotypic evidence of RL was significantly associated with shorter leukemia-free survival (LFS) compared with cases without identifiable RL (median, 7.1 vs 28.3 months; P  < .0001). Upon multivariable analysis, RL, prior relapse, age, high-risk karyotype, and alternate donor source were each independently associated with shorter LFS. RL in pre-HCT samples was more strongly associated with shorter LFS in patients with intermediate or favorable-risk AML karyotype ( P  = .001) than secondary or adverse karyotype-risk AML ( P  = .04). Rigorous morphologic and karyotypic evaluation of pretransplant marrows is practical and important for posttransplant prognosis.