Abstract
BACKGROUND: The post-remission therapy (PRT) choices for adult t(8;21) acute myeloid leukemia (AML) in first complete remission (CR1) need to be further explored. AIMS: We aimed to investigate the impact of measurable residual disease (MRD) combined with CD19 on PRT choices for adult t(8;21) AML in CR1. METHODS: A total of 150 t(8;21) AML patients were enrolled, including 67 underwent chemotherapy (CMT) and 83 allogeneic hematopoietic stem cell transplantation (allo-SCT) as PRT in CR1. Subgroup analyses were performed according to MRD level after three cycles of chemotherapy combined with CD19 expression. RESULTS: Multivariate analysis indicated MRD(high) after three courses of treatment (HR, 0.14 [95% CI, 0.03-0.66]; p = 0.013) and CD19 negativity (HR, 0.14 [95% CI, 0.02-0.96]; p = 0.045) were risk factors for relapse, while allo-SCT was protective factor for relapse (HR, 0.34 [95% CI, 0.15-0.75]; p = 0.008). Grouped by MRD after three courses of chemotherapy, allo-SCT had lower CIR (p < 0.001) and better OS (p = 0.003) than CMT for MRD(high) patients, CMT showed a higher CIR (35.99% vs. 15.34%, p = 0.100) but comparable OS (p = 0.588) than allo-SCT for MRD(low) patients. Grouped by CD19 expression, allo-SCT demonstrated lower CIR (p < 0.001) and better OS (p = 0.002) than CMT for CD19(-) patients. CMT had a higher CIR (41.37% vs. 10.48%, p = 0.007) but comparable OS (p = 0.147) than allo-SCT for CD19(+) patients. Grouped by MRD combined with CD19, MRD(high) /CD19(+) subsets were identified out of CD19(+) patients benefiting from allo-SCT with lower CIR (p = 0.002) and superior OS (p = 0.020) than CMT. CMT preserved comparable CIR (p = 0.939) and OS (p = 0.658) with allo-SCT for MRD(low) /CD19(+) patients. MRD(low) /CD19(-) subsets were also identified from MRD(low) patients requiring allo-SCT with lower CIR (p < 0.001) and superior OS (p = 0.008) than CMT. Allo-SCT maintained lower CIR (p < 0.001) and superior OS (p = 0.008) than CMT for MRD(high) /CD19(-) patients. CONCLUSIONS: MRD combined with CD19 might optimize PRT choices for adult t(8;21) AML patients in CR1.