Original StudyThe Effect of Peritransplant Minimal Residual Disease in Adults With Acute Lymphoblastic Leukemia Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

BackgroundAllogeneic HSCT is highly effective for treating ALL. However, many ALL patients relapse after HSCT. There has been a continuing effort to improve identification of patients at high risk of relapse, with the goal of early intervention to improve outcome.Patients and MethodsIn this retrospective analysis, we examined the effect of MRD on the risk of hematologic relapse in 149 adult patients with ALL in morphologic remission undergoing allogeneic HSCT. MRD was assessed at the time of HSCT and after HSCT.ResultsPatients with pretransplant MRD had a trend for shorter progression-free survival (PFS) at 2 years compared with patients without MRD, nearing statistical significance; 28% versus 47%, P = .08, on univariate analysis. This trend remained on multivariate analysis with better PFS in patients without MRD at the time of HSCT, hazard ratio (HR), 0.62 (95% confidence interval, 0.37-1.04); P = .07. Additionally, emergence of MRD after HSCT was a strong predictor for overt hematologic relapse (HR, 4; P < .001) with a median latency interval of 3.8 months.ConclusionThese findings demonstrate the predictive value of monitoring for MRD around the time of transplant in adult patients with ALL.