Hematopoietic Stem Cell Transplantation for Acute Lymphoblastic Leukemia: Why Do Adolescents and Young Adults Outcomes Differ from Those of Children? a Study on Behalf of the Francophone Society of Stem Cell Transplantation and Cellular Therapy (SFGM-TC)

• Published in: Blood 2021-11, Vol.138 (Supplement 1), p.2921-2921
• Main Authors: Grain, Audrey, Rialland, Fanny, Chevallier, Patrice, Blin, Nicolas, Dalle, Jean-Hugues, Michel, Gerard, Dhedin, Nathalie, Peffault De Latour, Regis, Pochon, Cecile, yakoub Agha, Ibrahim, Bertrand, Yves, Sirvent, Anne, Jubert, Charlotte, Forcade, Edouard, Berceanu, Anna, Gandemer, Virginie, Schneider, Pascale, Bay, Jacques-Olivier, Rohrlich, Pierre Simon, Brissot, Eolia, Paillard, Catherine, Plantaz, Dominique, Nguyen Quoc, Stephanie, Gonzales, Fanny, Maillard, Natacha, Planche, Lucie, Baruchel, Andre
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2021-146769

Introduction: Adolescents and Young Adults (AYA) represent a specific population in the Acute Lymphoblastic Leukemia (ALL) landscape, often presenting high-risk diseases and increased chemotherapy-related toxicities. Indications of Hematopoietic Stem Cell Transplantation for pediatric patients (HSCT) have been restricted to those with early poor response to chemotherapy. The same trend has led to a decrease of HSCT indications in AYAs, which are nevertheless still more frequent than in younger counterpart. Outcomes of AYAs after HSCT seemed to be worse than the ones of children in two previous studies published in 2013 and 2014. In Minneapolis, the decrease of overall survival in AYA was attributed to an excess of Treatment Related mortality (TRM) (28% versus 14%; p=0.04), but because of small numbers, factors influencing TRM were not identified. Our study aimed to compare, in a large cohort, the outcomes of children and AYA with ALL after HSCT and to determine factors influencing potential differences. Material and Methods: All patients aged between 1 and 25 years, reported in the SFGM-TC (Francophone Society of bone marrow transplantation and cellular therapy) registry, who received a first HSCT in treatment for ALL between 2005 and 2012 were included. The AYA group was defined by age range between 15 and 25 years old, according to European studies and the SFGM-TC. Data about diagnosis and transplantation procedure were prospectively collected in the registry. Before transplant procedure, patients or their parents/guardians provide a signed consent in order to be included in the registry. Results: 891 patients were included, 494 children and 397 AYA. Median time of follow up was 45.6 months (0 to 114). HSCT was performed in first CR for 56.8% of the AYAs, whereas 57.5% of children received HSCT in second CR or more advanced phase (p