RESUMEN
The purpose of this study is to define the role for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in mixed-lineage-leukemia (MLL)-rearranged acute leukemia, which is now poorly understood. A prospective, multi-center cohort study to determine whether allo-HSCT could decrease relapse rates and improve long-term survival of MLL+ leukemia patients was performed. Fifty-six consecutive patients diagnosed with MLL-rearranged acute leukemia undergoing allo-HSCT from two transplant centers in China were enrolled between October 2007 and October 2012. The trial was registered at www.chictr.org as # ChiCTR-ONC-12002739. The incidences of grades II to IV acute graft versus host disease (aGVHD) and of grades III and IV aGVHD were 28.8% (CI, 16.87-40.8%), and 14.2% (CI, 5.4-23.0%), respectively. The cumulative incidences for chronic GVHD (cGVHD) at 2 years after HSCT were 35.2% (CI, 21.2-49.2%). Up to April 30, 2013, 12 patients had relapsed and 11 died from relapse, and 37 patients were still alive without disease recurrence. The relapse and NRM rates at 3 years were 25.3% (CI, 12.7-37.9%) and 18.0% (CI, 2.6-33.4%), respectively. The probalities of overall survival and leukemia free survival were 61.8% (CI, 46.0-77.6%) and 56.3% (CI, 38.1-74.5%) at 3 years, respectively. Patients transplanted during their hematological first complete remission (CR1) had a lower relapse rate (17.9% vs. 48.1%, P = 0.03) compared with patients transplanted beyond CR1. The median overall survival for the 29 patients not receiving allo-HSCT during the study period was 145 days from diagnosis. This study showed that allo-HSCT could be a valuable treatment choice for MLL+ acute leukemia.