T-cell acute lymphoblastic leukemia: therapeutic outcomes in adolescents and young adults.

T-cell acute lymphoblastic leukemia (T-ALL) in adolescents and young adults (AYA) poses distinct clinical challenges. This study evaluates the effectiveness and tolerability of a pediatric-inspired regimen in this specific age group, focusing on response rates, survival outcomes, and prognostic indicators. We retrospectively analyzed AYA patients (15-29 years) diagnosed with T-ALL between 2010 and 2020 at Aziza Othmana Hospital, Tunis. All patients received treatment per the EORTC 58,951 protocol. Clinical, cytological, and immunophenotypic data were collected, with special attention to treatment response and minimal residual disease (MRD). Survival outcomes were assessed using Kaplan-Meier estimates, and prognostic factors were examined via uni- and multivariate analyses. Thirty-two patients were included (median age: 20 years; male: female ratio 2.3:1). Complete remission after induction was achieved in 84.4% of cases, with MRD negativity (< 10⁻⁴ at day 35) observed in 42% of patients. At a median follow-up of 62 months, the 5-year overall survival (OS), event-free survival (EFS), and relapse-free survival (RFS) were 62.2%, 62.5%, and 70.8%, respectively. Chemotherapy response at day 19 and MRD negativity were associated with better outcomes, although only relapse occurrence remained independently predictive of OS. Induction mortality reached 9.4%. Relapse occurred in 32.1% of patients, underscoring the need for improved risk stratification. Our findings support the efficacy of pediatric-based protocols in treating AYA with T-ALL. However, high relapse rates and early induction mortality highlight the importance of integrating MRD-guided decisions and enhancing supportive care. Future strategies should incorporate targeted and immune-based therapies to improve long-term outcomes in high-risk subgroups.