The presence of central nervous system disease at diagnosis in pediatric acute myeloid leukemia does not affect survival: a Children's Oncology Group study

Abstract

Background: The presence of central nervous system (CNS) disease in pediatric acute myeloid leukemia (AML) is often thought to confer a worse prognosis. This study examined the outcome of children with AML who had CNS disease at diagnosis.

Methods: Patients enrolled on Children's Cancer Group protocols 2861, 2891, 2941, and 2961 being treated for de novo AML were classified for the presence of CNS disease at diagnosis as CNS1 (<5 WBC in the CSF without blasts), CNS2 (<5 WBC in the CSF with blasts), or CNS3 (> or =5 WBC in the CSF with blasts). CNS disease at diagnosis was then analyzed regarding patient characteristics and outcome.

Results: There was an incidence of CNS disease (i.e., CNS3 status) of 11% in the 1,459 patients analyzed in this study. The risk factors found are young age, high white cell count, hepatomegaly or splenomegaly at diagnosis, M4 subtype, chromosome 16 abnormalities, and hyperdiploid cytogenetics. There were no significant differences in overall survival, event free survival, or remission rates between the groups; however, a significant difference was seen between the CNS1 and CNS3 groups in disease free survival and isolated CNS relapse risk.

Conclusions: Patients with CNS disease at diagnosis have similar survival to those without CNS disease, although they have an increased incidence of isolated CNS relapse. Patients with CNS disease at diagnosis may warrant more aggressive CNS directed therapy.

Figure 1

Kaplan-Meier figure for overall survival (OS) from study entry for de novo patients by CNS groups. CNS1 five year OS= 50±3%, CNS2 five year OS=59±7%, CNS3 five year OS=50±8%.

Figure 2

Kaplan-Meier figure for event free survival (EFS) from study entry for de novo patients by CNS groups. CNS1 five year EFS=41±3%, CNS2 five year EFS=44±7%, CNS3 five year EFS=34±8%.