Impact of postremission consolidation chemotherapy on outcome after reduced-intensity conditioning allogeneic stem cell transplantation for patients with acute myeloid leukemia in first complete remission: a report from the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation.

BACKGROUND: The objective of the current study was to investigate the role of postremission consolidation chemotherapy before reduced-intensity conditioning (RIC) allogeneic stem cell transplantation (alloSCT) for patients with acute myeloid leukemia (AML) in first complete remission (CR1).

METHODS: Of the 789 consecutive patients with AML in CR1 who underwent RIC alloSCT from a human leukocyte antigen-matched sibling or matched unrelated donor peripheral stem cell grafts between 2001 and 2010, 591 patients received at least 1 cycle of consolidation chemotherapy and 198 patients did not receive any consolidation chemotherapy before alloSCT. To minimize inherent survival bias in favor of patients who underwent transplant long after achieving CR1, the study focused on 373 patients who underwent transplant within the median time frame between achievement of CR1 and alloSCT (3 months for patients who underwent alloSCT from matched siblings and 4 months for patients who underwent alloSCT from matched unrelated donors). In this subgroup, 151 patients did not receive any consolidation chemotherapy and 222 patients received ≥ 1 consolidation chemotherapy cycle.

RESULTS: With a median follow-up of 36 months (range, 2 months-135 months), the 3-year cumulative recurrence incidence (RI) was not significantly different between the groups (36% ± 4% for the group treated without consolidation chemotherapy vs 38% ± 3% for patients who received consolidation chemotherapy; P = .89). In addition, leukemia-free survival was similar between the groups (45% ± 4% and 47% ± 3%, respectively; P = .41). Dose intensity of cytarabine given during consolidation chemotherapy appeared to have no influence on RI. On multivariate analysis, pretransplant consolidation (≥ 1 cycle vs 0 cycles) was found to have no significant impact on RI (hazards ratio, 1.29; 95% confidence interval, 0.84-1.97 [P = .24]) or leukemia-free survival (hazards ratio, 1.00; 95% confidence interval, 0.71-1.42 [P = .99]).

CONCLUSIONS: The data from the current study suggest no apparent advantage for postremission consolidation chemotherapy before RIC alloSCT, provided a donor is readily available.