Background: Allogeneic hematopoietic stem cell transplantation (HSCT) is the curative option for treatment of acute myeloid leukemia (AML). Even after HSCT, the relapse rate of AML ranged from 20% to 55%. The prognosis of relapsed AML after HSCT is very poor. But, treatment guideline for relapsed AML after HSCT has not been defined. Thus, we aimed to investigate treatment outcomes and prognostic factors of patients with relapsed AML after allogeneic HSCT.
Patient and Method: Among 624 patients with AML who received HSCT in Asan Medical Center, Korea between 1995 and 2014, 219 patients who had a relapse of AML after HSCT were included in this retrospective study.
Results: Seventy-two patients (32.9%) reattained complete remission (CR). Refractory AML at the time of HSCT (odds ratio [OR], 0.199, P=0.001), high BMI (> 28) (OR, 0.88, P=0.032), graft source from peripheral blood (OR, 0.299, P=0.001) and shorter relapse free interval (< 6 months) (OR, 0.199, P=0.001) were significant negative predictors for CR achievement (Table1). Of included patients, survival after relapse was median 5.2 months (95% CI, 3.96-6.44, months). Leukemia free survival of patients reattaining CR after relapse was median 10.6 months (95% CI, 8.1-13.2 months). Twenty-seven patients received second HSCT following salvage chemotherapy. Patients who had underwent upfront HSCT without chemotherapy for AML and relapse before 6months after HSCT were significantly associated with worse survival after relapse (Hazard ratio [HR], 3.106, P=0.006 and HR, 2.018, P=<0.001, respectively). Donor lymphocyte infusion following salvage chemotherapy and second HSCT had a significant impact on better survival (HR, 0.131, P=0.002 and HR, 0.423, P=0.003, respectively). Male gender (Hazard ratio [HR] 2.465, P=0.012) and extramedullary relapse (HR, 4.215, P=0.001) were negative factors affecting shorter leukemia free survival after relapse.
Conclusion: Donor lymphocyte infusion following salvage chemotherapy and second HSCT can be beneficial option for relapsed AML patients after HSCT. But, novel treatment modalities need to be investigated for improving survivals of relapsed AML patients after HSCT.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.