A meta-analysis combining data from 13 studies including 2,962 adults has shown that allogeneic, but not autologous, hematopoietic cell transplantation (HCT) improves survival in younger adults with acute lymphoblastic leukemia (ALL) in first complete remission. The meta-analysis, which excluded Philadelphia chromosome-positive patients, also found no beneficial effect of autologous HCT compared to chemotherapy. Patients <35 years of age undergoing myeloablative HCT with a matched sibling donor had a survival benefit (Odds ratio [OR] = 0.79; 95% CI, 0.70-0.90, p=0.0003) compared to those without a sibling donor available. Individuals ≥35 years of age did not experience this survival benefit (OR = 1.01; 95% CI, 0.85-1.19, p=0.9), which the authors attributed to the higher absolute risk of non-relapse mortality in older patients.