Optimal therapy for adolescents and young adults with acute lymphoblastic leukemia-current perspectives

Adolescents and young adults (AYA) with acute lymphoblastic leukemia (ALL) have worse prognosis than children. Differing biology of ALL may account for some of this disparity in outcome, with AYA patients having far lower incidence of good risk cytogenetic abnormalities, and higher proportion of patients with genetic lesions associated with inferior survival such as Ph-like ALL. Actual chemotherapy may also contribute to differences in outcome. Retrospective studies have shown that AYA patients treated on pediatric-based regimens had higher survival than those treated with adult regimens; the superiority of pediatric protocols has also been proven in several prospective comparative trials. Increase in rate of enrollment of AYA patients in clinical trials may further improve outcome. Cure based on chemotherapy may further limit the role of allogeneic hematopoietic cell transplantation (HCT) in AYA patients. The unique biology of AYA ALL may allow for novel methods of targeted therapy, while immunotherapy, the efficacy of which has been proven for both children and adults, may also play a major role in the treatment of relapsed/refractory ALL.