Hematopoietic Stem Cell Transplantation in Acute Promyelocytic Leukemia, Experience in Iran

Background: Acute promyelocytic leukemia is a rare indication for hematopoietic stem cell transplantation. Usually it is indicated as consolidation of salvage regimens following relpase. Here we report our experience with stem cell transplantation in acute promyelocytic leukemia patients. Methods: Between 1989 and 2011, we performed 40 hematopoietic stem cell transplantation in first complete remission or relapsed acute promyelocytic leukemia patients. Median age of patients was 23.5 years. Patients received 11 autologous and 29 allogeneic hematopoietic stem cell transplantation from their HLA fully-matched sibling donors. Different conditioning regimens were applied. A total of 24 patients received hematopoietic stem cell transplantation who were in first complete remission and the remainder with a second or more complete remission. Results: Hematopoietic stem cell engraftment was observed in all cases. There were no deaths prior to 100 days after hematopoietic stem cell transplantation. Acute graft versus host disease was mild to moderate in the majority of patients, whereas it was grade Ill in 4 patients. Chronic graft versus host disease was extensive in 2 cases. With a 4-year median follow up, the relapse rate was 25%. A total of 26 patients are alive. Five year overall survival was 65.5% and 46.8% for allogeneic and autologous hematopoietic stem cell transplantation, respectively. Conclusion: Hematopoietic stem cell transplantation is an acceptable treatment for acute promyelocytic leukemia. Although there is a statistical difference for overall survival between allogeneic or autologous hematopoietic stem cell transplantation, the choice between autologous or allogeneic transplantation needs to have reliable methods for the detection of molecular remission before hematopoietic stem cell transplantation as well as close, reliable follow up of patients with clinical and molecular parameters.