Cytogenetic characteristics of and prognosis for acute myeloid leukemia in 107 children

Patients diagnosed with acute myeloid leukemia (AML) in childhood have a poor prognosis. A better understanding of prognostic factors will assist patients and clinicians in making difficult treatment decisions.

To understand further the cytogenetic characteristics of and reassess the prognostic value of cytogenetic abnormalities in childhood AML.

Conventional karyotypes of 107 children with AML were analyzed retrospectively. The cases were divided into 4 groups based on genetic rearrangements; namely patients with: t(15;17)/PML-RARA; t(8;21)/RUNX1-RUNX1T1 or inv(16)(p13;q22) and t(16;16)/CBFB-MYH11; -7 or complex karyotypes; normal karyotypes or other cytogenetic changes. Differences in age, sex, leukocyte count, event-free survival (EFS), and overall survival (OS) were analyzed.

All French-American-British (FAB) subtypes of AML were detected in 107 patients. We successfully cultured 81 of 107 bone marrow specimens, of which 60 cases had abnormal karyotypes. The most common abnormal karyotypes were t(8;21) (17/81 cases), followed by t(15;17) (13/81 cases), -X/Y (10/81 cases). There were no significant differences (P > 0.05) in age, sex, or leukocyte counts between the 4 groups. The differences in 3-year EFS and OS between each pair were significant, except for groups of patients with t(8;21)/RUNX1-RUNX1T1 and patients with normal karyotypes or other cytogenetic changes (P = 0.054).

Chromosomal abnormalities may provide important prognostic factors for AML in children and be helpful for risk stratification and individual treatment.