Clinical characteristics and treatment outcomes of pediatric Philadelphia chromosome positive acute lymphoblastic leukemia: a comparative analysis of p190 and p210 subtypes in the TKI era.

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL) is rare in children. We retrospectively analyzed 42 pediatric Ph + ALL patients treated with TKI-based regimens. Patients (28 males, median age 7 years) had median initial WBC 63.32 × 109/L; 29.3% expressed myeloid antigens, 50% had t(9;22) with additional chromosomal abnormalities, 76.2% had IKZF1 deletions. Although the p190 subtype (83.3%) presented with significantly lower white blood cell counts than p210 (48.00 vs. 163.30 × 109/L, p = 0.031), no significant differences were observed in complete remission rate, minimal residual disease negativity, relapse, 3-year overall survival (OS), or event-free survival (EFS) between subtypes. Importantly, dasatinib-based therapy (n = 27) demonstrated superior 3-year OS (100% vs. 66.7%) and EFS (100% vs. 60.0%) compared to imatinib-based therapy (n = 15) (both p < 0.05). Our study indicates that pediatric Ph + ALL has male predominance and frequent genomic aberrations. p190 and p210 have distinct baseline features but comparable outcomes in the TKI era, and dasatinib is a superior first-line TKI.