Survival differences between adolescents/young adults and children with B precursor acute lymphoblastic leukemia after allogeneic hematopoietic cell transplantation.

Risk-adapted therapy has been the cornerstone of treatment for pediatric B precursor acute lymphoblastic leukemia (B-ALL). Recently, age ≥ 13 years at diagnosis has been identified as a very high-risk feature for chemotherapy treated pediatric patients with B-ALL. Whether age at time of transplantation is associated with poor outcomes in adolescents and young adults (AYA) is unknown. We hypothesized that AYA receiving allogeneic hematopoietic cell transplantation (allo-HCT) would have greater relapse and inferior survival compared with children age <13 years. We reviewed the outcomes in 136 consecutive patients (age 0-30 years) with B-ALL who underwent myeloablative allo-HCT at our institution, including 79 children age <13 years (58%) and 57 AYA age 13-30 years (42%). Overall survival at 5 years was significantly lower in the AYA group (hazard ratio, 1.74; 95% confidence interval [CI], 1.04-2.95; P = .03). In addition, the AYA patients had a greater risk of transplantation-related mortality at 1 year (hazard ratio, 2.23; 95% CI, 1.01-4.90; P = .05), but no difference in relapse (relative risk, 0.85; 95% CI, 0.41-1.76; P = .66). Based on this analysis, AYA patients undergoing allo-HCT for B-ALL have significantly inferior survival and greater transplantation-related mortality compared with children age <13 years, but no difference in relapse, suggesting that allo-HCT may overcome relapse in AYA. Further improvements in peritransplantation care are needed to limit complications in AYA patients.