Outcome of childhood T-cell acute lymphoblastic leukemia (T-ALL): Results from DFCI protocol 05-001.

10015 Background: T- ALLaccounts for ~ 15% of pediatric ALL; in general, outcomes have been less favorable than those for B- ALL. Methods: Between 2005-11, 97 evaluable patients (pts) aged 1-18 years (yrs) with newly diagnosed T- ALLwere enrolled on DFCI ALLConsortium Protocol 05-001. Early T-cell precursor (ETP) subtype was retrospectively assessed in 90 pts by flow cytometry. End-Induction minimal residual disease(MRD) was assessed by PCR. All97 pts were initially treated as high-risk regardless of other presenting features; 2 pts were assigned more intensive post-induction therapy based on cytogenetics (MLL-R:1; BCR-ABL:1). Results: Presenting features and outcomes are shown in Table 1. The 4-yr EFS and OS for allT- ALLpts was 83% and 89%, respectively (median follow-up: 4.3 yrs). End-induction MRD was evaluable in 58 (67%) pts achieving CR; high MRD (>0.001) was associated with an inferior DFS (high MRD (N=15): 79%, low MRD (N=43): 95%, p=0.047). ETP subtype was identified in 16 pts (18%). ETP pts ...