Abstract To improve the outcome of pediatric T‐cell acute lymphoblastic leukemia (T‐ALL) patients, the AIEOP‐BFM ALL 2009 trial modified T‐ALL stratification and treatment based on AIEOP‐BFM ALL 2000 and other pediatric ALL groups' results. This report aims to describe the outcome of T‐ALL patients in trial AIEOP‐BFM ALL 2009 and evaluate prognostic features defined within the end of induction (EOI) therapy, for future protocols stratification and interventions. From 06/2010 to 02/2017, 872 T‐ALL patients, aged 1–17, were enrolled. High risk (HR) criteria were prednisone poor response (PPR), Day 15 flow cytometry minimal residual disease (MRD) ≥ 10%, no complete remission at EOI, or polymerase chain reaction (PCR)‐MRD ≥ 5 × 10 −4 at end of consolidation (EOC). Three Cox regression models on event‐free survival (EFS) evaluated prognostic factors. Overall, 5‐year EFS and survival were 79.9% ± 1.4% and 84.9% ± 1.2% with cumulative incidence of relapse (CIR) and death of 13.0% ± 1.2% and 5.9% ± 0.8%. Five‐year EFS and CIR were 86.8% ± 1.6% and 8.7% ± 1.3% in non‐HR patients ( n = 470); 71.9% ± 2.3% and 18.0% ± 1.9% in HR patients ( n = 402). High PCR‐MRD levels at EOI and EOC were prognostic in all models, with EOC‐MRD ≥ 5 × 10 −3 related to a hazard ratio of 6.22 (P < 0.001). When a model considered factors identified at EOI only, central nervous system (CNS)3 (hazard ratio = 2.3, P < 0.001), PPR (hazard ratio = 1.74, P = 0.02), and high EOI‐MRD (hazard ratio 4.71 for ≥5 × 10 −2 vs. negative, P < 0.001) significantly impacted EFS. Results of T‐ALL patients in AIEOP‐BFM ALL 2009 were favorable. While EOC‐MRD remained the strongest prognostic predictor, PPR, CNS3 disease, and EOI‐MRD showed relevant prognostic value, with CNS3 and EOI‐MRD ≥ 5 × 10 −2 being candidate criteria for early stratification and intervention modifications.
Cario et al. (Mon,) studied this question.