Minimal Residual Disease Levels At Time Of CR1and Transplant Predict Outcome In Philadelphia Chromosome-negative Adult ALL

Objective:To evaluate the prognostic effect of minimal residual disease levels at time of CR1and transplant for adult Philadelphia chromosome-negative acute lymphoblastic leukemia (Ph-negative ALL); To discover the subgroup that benefits from allogeneic hematopoietic stem cell transplantation based on the stratification by the MRD levels at CR1.Methods:During January2006to December2011,107adult Ph-negative ALL patients in our center were admitted in this study. Comparing and analyzing the differences of survival between risk groups stratified by traditional prognostic factors or by MRD levels; Then we compare the differences of survival between chemotherapy and transplant arms in the same risk group to discover the subgroup benefits from allogeneic HSCT.Results:The3-year OS and DFS for all patients are44.5±5.0%and40.3±4.8%. The transplant arm has a3-year improved OS and DFS than chemotherapy arm. Stratified by traditional prognostic factors, The survival advantage of HSCT was significant in standard-risk patients, but not in high-risk patients due to a high non-relapse mortality rate. Stratified by MRD levels at time of CR1and transplant with the cut-off of0.02%and0.2%, the survival differences are significant among subgroups. The3-year improved OS with transplant is observed in the MRD at CRl>0.02%subgroup, but not in the MRD at CRl≤0.02%subgroup.Conclusions:MRD levels at time of CR1and transplant can better predict the outcome of adult Ph-negative ALL than the traditional prognostic factors; the subgroup whose MRD at CRl>0.02%benefits from allogeneic HSCT.