Allogeneic stem cell transplantation for advanced acute promyelocytic leukemia in the ATRA and ATO era

The role of allogeneic stem cell transplant in advanced acute promyelocytic leukemia patients who received standard first and second-line therapy is still unknown. We report the outcome of 31 acute promyelocytic leukemia patients (median age 39) who underwent allogeneic transplant in second-remission (15patients) or beyond (16patients. Sixteen patients were RT-PCR positive and 15 negative for PML/RARA pre-transplant. The 4-year overall-survival was 62 % and 31% for patients transplanted in second-remission and beyond, respectively (p=0.05) and 64% and 27% for patients with RT-PCR-negative and positive pre-transplant, respectively (p=0.03). The 4-year cumulative-incidence of relapse was 32% and 44% for patients transplanted in second-remission and beyond, respectively (p=0.37) and 30% and 47% for patients transplanted with negative and positive RT-PCR, respectively (p=0.30). Transplant-related mortality was 19.6%. In conclusion, allogeneic transplant is effective in advanced acute promyelocytic leukemia in the all-trans-retinoic acid and arsenic trioxide era and should be considered once relapse is diagnosed.