Survival for children with relapsed T cell acute lymphoblastic leukemia (T-ALL) is poor when treated with chemotherapy alone, and outcomes after allogeneic hematopoietic cell transplantation (HCT) is not well described. Two hundred twenty-nine children with T-ALL in second complete remission (CR2) received an HCT after myeloablative conditioning between 2000 and 2011 and were reported to the Center for International Blood and Marrow Transplant Research. Median age was 10 years (range, 2 to 18). Donor source was umbilical cord blood (26%), matched sibling bone marrow (38%), or unrelated bone marrow/peripheral blood (36%). Acute (grades II to IV) and chronic graft-versus-host disease occurred in, respectively, 35% (95% confidence interval [CI], 27% to 45%) and 26% (95% CI, 20% to 33%) of patients. Transplant-related mortality at day 100 and 3-year relapse rates were 13% (95% CI, 9% to 18%) and 30% (95% CI, 24% to 37%), respectively. Three-year overall survival and disease-free survival rates were 48% (95% CI, 41% to 55%) and 46% (95% CI, 39% to 52%), respectively. In multivariate analysis, patients with bone marrow relapse, with or without concurrent extramedullary relapse before HCT, were most likely to relapse (hazard ratio, 3.94; P = .005) as compared with isolated extramedullary disease. In conclusion, HCT for pediatric T-ALL in CR2 demonstrates reasonable and durable outcomes, and consideration for HCT is warranted.

This Center for International Blood and Marrow Transplant Research report describes the use of hematopoietic stem cell transplantation (HSCT) in pediatric patients with cancer, 4408 undergoing allogeneic (allo) and3076 undergoing autologous (auto) HSCT in the United States between 2008 and 2014. In both settings, there was a greater proportion of boys (n = 4327; 57%), children < 10 years of age (n = 4412; 59%), whites (n = 5787; 77%), and children with a performance score ≥ 90% at HSCT (n = 6187; 83%). Leukemia was the most common indication for an allo-transplant (n = 4170; 94%), and among these, acute lymphoblastic leukemia in second complete remission (n = 829; 20%) and acute myeloid leukemia in first complete remission (n = 800; 19%) werethe most common. The most frequently used donor relation, stem cell sources, and HLA match were unrelated donor (n = 2933; 67%), bone marrow (n = 2378; 54%), and matched at 8/8 HLA antigens (n = 1098; 37%) respectively. Most allo-transplants used myeloablative conditioning (n = 4070; 92%) and calcineurin inhibitors and methotrexate (n = 2245; 51%) for acute graft-versus-host disease prophylaxis. Neuroblastoma was the most common primary neoplasm for an auto-transplant (n = 1338; 44%). Tandem auto-transplants for neuroblastoma declined after 2012 (40% in 2011, 25% in 2012, and 8% in 2014), whereas tandem auto-transplants increased for brain tumors (57% in 2008 and 77% in 2014). Allo-transplants from relatives other than HLA-identical siblings doubled between 2008 and 2014 (3% in 2008 and 6% in 2014). These trends will be monitored in future reports of transplant practices in the United States.