[Treatment strategy for T-cell acute lymphoblastic leukemia in children]

T-cell acute lymphoblastic leukemia (T-ALL) accounted for approximately 10-15% of pediatric ALL and has often been treated within the same framework as B-cell precursor ALL (BCP-ALL). T-ALL has a poorer prognosis than BCP-ALL. However, improvements have been achieved through treatment intensification strategies using dexamethasone, L-asparaginase, and nelarabine, thereby reducing cranial irradiation. Furthermore, T-ALL-specific treatment protocols have been introduced based on these advancements. The JPLSG ALL-T11/JALSG T-ALL-211-U trial in Japan has been conducted from 2011 to 2017 for newly diagnosed patients with T-ALL under the age of 25 years. The trial included minimal residual disease-based treatment stratification and treatment intensification as described above and has shown excellent outcomes. Recently, new therapeutic agents have been actively developed for T-ALL. Thus, targeted therapy development based on new findings is expected in the future.