Allogeneic hematopoietic cell transplantation for acute leukemia in first relapse or second remission

BACKGROUND The role of pre-transplant salvage chemotherapy has been controversial in relapsed acute leukemia. METHODS We investigated post-transplant outcomes in 65 patients with acute leukemia treated with allogeneic hematopoietic cell transplantation (HCT) during first relapse or second remission. RESULTS The 5-year cumulative incidence of relapse (CIR) was 52.3%. Multivariate analysis for CIR revealed that patients with unfavorable cytogenetics and those not in remission at the time of HCT had a significantly high CIR (P = 0.031 and P = 0.031, respectively). Allogeneic HCT was performed in 14 patients after first relapse without salvage chemotherapy ("untreated relapse" group), 15 patients failed chemotherapy for reinduction of remission before HCT ("refractory relapse" group), and 36 patients attained second remission with salvage chemotherapy before HCT ("second remission" group). The 5-year CIR for patients in the untreated relapse group (57.1%) was higher than that for those in the second remission group (42.3%), but it was lower than that for patients in the refractory relapse group (66.7%). Among patients who underwent allogeneic HCT in relapse, those with bone marrow (BM) blasts ≤30% had a lower 5-year CIR than those in florid relapse (BM blasts >30%) (57.7% vs. 70.6%). CONCLUSION Our results do not support the role of salvage chemotherapy aimed at re-induction of remission before allogeneic HCT in patients with acute leukemia after first relapse. Patients with early relapse do not appear to benefit from salvage chemotherapy before HCT.