Hematopoietic Cell Transplantation in Young Adult Acute Lymphoblastic Leukemia: A United States Population-Level Analysis

In this population-based evaluation of adolescents and young adults (AYA) acute lymphoblastic leukemia (ALL), we describe patterns of care (POC) and outcomes regarding hematopoietic cell transplantation (HCT) in first complete remission (CR1). Data were abstracted from the 2013 United States Surveillance, Epidemiology, and End Results POC study; newly diagnosed AYA ALL were included. Multivariable logistic regression evaluated associations with HCT in CR1; Cox proportional hazards regression evaluated survival associations. Of 399 AYAs with ALL included, 102 (28.5%) underwent HCT in CR1. High-risk cytogenetics (odds ratio [OR] = 4.86, 95% confidence interval [CI] = 3.02-7.83) and hyper-cyclophosphamide, vincristine, adriamycin, and dexamethasone (CVAD) induction (OR = 1.84, 95% CI = 1.07-3.16) were associated with HCT in CR1. Two-year cumulative incidence of relapse, relapse-free survival (RFS), and overall survival (OS) of the entire cohort were 28.3% (95% CI = 23.4-33.4), 69.3% (95% CI = 63.6-74.3%), and 84.1% (95% CI = 79.7-87.5), respectively. Two-year RFS was significantly higher in patients receiving CR1 HCT relative to chemotherapy (83.6%, 95% CI = 72.6-90.5% vs. 64.3%, 95% CI = 57.5-70.3), but no difference was seen in 2-year OS (88.9%, 95% CI = 80.8-93.7 vs. 82.5%, 95% CI = 77.2-86.7). Treatment at a nonteaching hospital was independently associated with inferior OS (hazard ratio = 2.15, 95% CI = 1.23-3.76). Although the ALL landscape is changing, these data provide a snapshot of the use and outcomes of HCT for AYA ALL across the United States.