Is the outcome of childhood acute myeloid leukemia with t(8;21) inferior in Saudi Arabia? A multicenter SAPHOS leukemia group study

Abstract

Background: Despite the confirmed favorable prognosis of childhood t(8;21) acute myeloid leukemia (AML), recent reports suggest heterogeneity in survival outcomes in this subtype of AML may be influenced by ethnicity. Therefore, we aimed to assess the outcome of childhood t(8;21) AML in an Arab population to evaluate if survival outcomes were inferior and determine the predictive relevance of additional cytogenetic abnormalities. Methods: This multicenter retrospective study analyzed 175 de novo AML children of 14 years of age or younger consecutively diagnosed between January 2005 and December 2012. Survival outcomes were analyzed and patients with t(8;21) were stratified on the basis of karyotype into sole and additional cytogenetic groups. Results: A total of 33 (18.9%) patients had t(8;21) AML. Complete remission (CR) was achieved in 31 (93.9%) patients. The 5-year overall survival, event-free survival, cumulative incidence of relapse (CIR), and remission death rates were 59.9 ± 9.2, 45.6 ± 9.1, 36.4, and 9.1%, respectively. Despite the administration of hematopoietic stem-cell-transplant salvage therapy in first relapse, five out of 11 (45.5%) relapsed patients died of disease. Subanalysis of sole vs. additional cytogenetic abnormalities revealed no significant difference in outcome. Conclusion: In the present study, childhood t(8;21) AML was associated with inferior survival and resistance to salvage therapy compared to reports from international groups. The inferior outcomes were unrelated to additional cytogenetic abnormalities. Further detailed genetic studies are warranted to unmask the biological and clinical differences between racial/ethnic groups. Given the high CR rate of childhood t(8;21) AML, further modification of postremission therapy to improve the CIR rate is needed.