Allogeneic hematopoietic cell transplantation compared to chemotherapy consolidation in older acute myeloid leukemia (AML) patients 60-75 years in first complete remission (CR1): an alliance (A151509), SWOG, ECOG-ACRIN, and CIBMTR study

Abstract

The preferred post-remission therapy for older patients with acute myeloid leukemia (AML) in first complete remission (CR1) remains uncertain. In this retrospective, multicenter study, we compared the outcomes for older AML patients (age 60-77 years) receiving allogeneic hematopoietic cell transplantation (alloHCT) (n = 431) with those treated on prospective National Clinical Trials Network induction and nontransplantation chemotherapy (CT) consolidation trials (n = 211). AlloHCT patients were younger (median age: 64.2 versus 67.9 years, p < 0.001), but more frequently had high-risk AML (high WBC, secondary AML, and unfavorable cytogenetics). Overall survival (OS) was worse in alloHCT during the first 9 months after CR1 (HR = 1.52, p = 0.02), but was significantly better thereafter (HR = 0.53, p < 0.0001) relative to CT. Treatment-related mortality (TRM) following HCT was worse in the first 9 months (HR = 2.8, 95% CI: 1.5-5.2, p = 0.0009), while post-HCT relapse was significantly less frequent beyond 9 months (HR = 0.42, 95% CI: 0.29-0.61, p < 0.0001). Despite higher early TRM, alloHCT recipients had superior long-term OS [29% (24-34%) versus CT 13.8% (9-21%) at 5 years]. Although this is a retrospective analysis with potential biases, it indicates that alloHCT led to heightened early risks from TRM, yet reduced relapse and superior long-term survival relative to CT in older AML patients in CR1.

Figure 1:

Overall survival for alloHCT and CT with 5-year point estimate (1A), treatment-related mortality for alloHCT and CT with 5-year point estimate (1B), cumulative incidence of relapse for alloHCT and CT with 5-year point estimate (1C), disease-free survival for alloHCT and CT with 5-year point estimate (1D)

Figure 1:

Overall survival for alloHCT and CT with 5-year point estimate (1A), treatment-related mortality for alloHCT and CT with 5-year point estimate (1B), cumulative incidence of relapse for alloHCT and CT with 5-year point estimate (1C), disease-free survival for alloHCT and CT with 5-year point estimate (1D)

Figure 1:

Overall survival for alloHCT and CT with 5-year point estimate (1A), treatment-related mortality for alloHCT and CT with 5-year point estimate (1B), cumulative incidence of relapse for alloHCT and CT with 5-year point estimate (1C), disease-free survival for alloHCT and CT with 5-year point estimate (1D)

Figure 1:

Overall survival for alloHCT and CT with 5-year point estimate (1A), treatment-related mortality for alloHCT and CT with 5-year point estimate (1B), cumulative incidence of relapse for alloHCT and CT with 5-year point estimate (1C), disease-free survival for alloHCT and CT with 5-year point estimate (1D)

Figure 2:

Disease-free survival by alloHCT or CT stratified by intermediate or poor cytogenetic categories and 5-year point estimates (2A), overall survival by alloHCT or CT stratified by intermediate or poor cytogenetic categories and 5-year point estimates (2B).

Figure 2:

Disease-free survival by alloHCT or CT stratified by intermediate or poor cytogenetic categories and 5-year point estimates (2A), overall survival by alloHCT or CT stratified by intermediate or poor cytogenetic categories and 5-year point estimates (2B).

Figure 3.

The Forest Plot represents the effect of each characteristic (age, Karnofsky Performance Status, and cytogenetic risk group) on overall survival per treatment before and after 9 months.