Graft-Versus-Host Disease in Adolescents and Young Adults (15-24 Years Old) After Allogeneic Hematopoietic Stem Cell Transplantation for Acute Leukemia in First Complete Remission.

PURPOSE: Adolescents and young adults (AYAs) with cancer are a unique group of patients in terms of disease incidence and biology, outcome, and psychosocial needs. This study aims to correlate the risk of graft-versus-host disease (GvHD) and age in a population of children and young adults with acute leukemia undergoing hematopoietic stem cell transplantation (HSCT) in first complete remission (CR). METHODS: We analyzed the outcome of 153 consecutive children (<15 years), AYAs (15-24 years), and adults (25-35 years) with lymphoblastic or myeloid acute leukemia in first CR who underwent HSCT with matched donors after myeloablative conditioning. GvHD prophylaxis was methotrexate and cyclosporine A (CsA) in all patients. RESULTS: The cumulative incidence of grade II-IV acute GvHD (aGvHD) was significantly higher in AYA patients than in children (subdistribution hazard ratio (SHR), 2.04, p = 0.005) or adults (SHR 1.59, p = 0.048). Both gut and skin aGvHD occurred more frequently in AYA patients. Increasing CsA blood levels with age could not fully account for this difference. No difference in terms of grade III-IV aGvHD was observed. Chronic GvHD was more frequent in AYAs (SHR 2.81, p = 0.007) and adults (SHR 2.31, p = 0.033) than in children. No difference in terms of nonrelated mortality and overall survival was observed among the age subgroups. CONCLUSION: Since GvHD occurrence is strongly correlated to quality of life, specific attention should be paid to AYAs undergoing HSCT. Further studies should investigate the reasons for the excess of GvHD observed in this population.