Bone marrow recurrence after initial intensive treatment for childhood acute lymphoblastic leukemia

Abstract

Background: The authors studied the clinical outcome of 106 children with acute lymphoblastic leukemia (ALL) who developed a bone marrow recurrence as the first adverse event after contemporary intensified therapy.

Methods: Endpoints were the rates and lengths of second remission, the cumulative incidence of second hematologic recurrence, second event-free survival (EFS), and survival.

Results: Bone marrow recurrences were isolated in 79 patients, and combined with an extramedullary site in 27 patients. The median time to recurrence was 2.6 years (range, 0.3-11.6 years). Seventy-six patients (71.7%) attained a second remission (median length, 0.7 year; range, 0.03-13.3 years). The 5-year survival probability among all patients was 24.2% +/- 4.2% (standard error). On multivariate analysis, time to first disease recurrence and blast cell lineage were found to be independent predictors of a second EFS (P = 0.008 and P = 0.028, respectively). The 5-year EFS estimate in patients with an initial disease remission of >/= 36 months was 42.6% +/- 7.8% but was only 12.5% +/- 3.9% among children with a short duration of disease remission (< 36 months). These estimates were 28.7% +/- 4.9% and 5.0% +/- 3.4%, respectively, for B blast and T blast cell lineages.

Conclusions: Despite acceptable long-term second EFS rates for certain subgroups, overall bone marrow recurrence after intensified first-line therapy for childhood ALL signals a poor outcome.