CNS prophylaxis in pediatric acute lymphoblastic leukemia

Abstract

A review of clinical trials conducted since 1990 suggests that CRT may be safely omitted in at least some T-ALL patients without a significant decrement in EFS, particularly those with non-high-risk presenting features and favorable early response to therapy. In general, CNS2 status is not associated with an increased risk of relapse when CRT is omitted; however, in most published reports, it is not clear if this is true if only T-ALL patients are considered. Heterogeneity between treatment regimens and the paucity of large randomized trials make it difficult to state definitively that CRT can be safely omitted in T-ALL patients with higher-risk features, such as very high presenting leukocyte counts and/or CNS3 status. In addition, although several studies demonstrated relatively favorable EFS in T-ALL patients treated without CRT, intensified intrathecal and/or systemic chemotherapy is not without adverse effects.4 Based on our review, we conclude that there is insufficient evidence to strongly recommend that CRT be omitted for T-ALL patients with higher-risk features (grade 2B). Additional clinical trials are necessary to determine whether omission of CRT reduces toxicity without compromising efficacy in these high-risk T-ALL patients.