Blood

In this issue of Blood, Gossai et al1 assessed the prognostic significance of central nervous system (CNS) leukemic involvement in 2164 children and young adults, aged 1 to 30 years, who were newly diagnosed with T-cell acute lymphoblastic leukemia (T-ALL) and were1 enrolled in 2 consecutive, phase 3 clinical trials (AALL0434, n = 1550 patients; AALL1231, n = 614 patients), from the Children's Oncology Group (COG). Despite the differences in the 2 trials, the authors found that patients with CNS-1 or CNS-2 status at diagnosis had similar event-free survival (EFS) and overall survival (OS), and these outcomes were significantly better than those of patients with CNS-3 status, all of whom received cranial radiotherapy (CRT).