Clinical Outcomes of Acute Leukemia in Children Less Than 2 Years: Experience from a Tertiary Center in Thailand

Objective: This study aimed to examine the prognostic factors and treatment outcomes of patients with acute leukemia aged under 2 years. Material and methods: The medical records of acute leukemia patients aged under 2 between January 1979 and December 2021 were retrospectively reviewed. The Kaplan-Meier method was used to calculate the event-free survival (EFS) and overall survival (OS) rates. A univariate Cox proportional hazards regression model was used to identify clinical factors associated with poor EFS and OS. A p-value<0.05 was considered statistically significant.Results: Over the 43-year study period, 137 children with acute leukemia aged under 2 years of age were identified. Of these, 70 (51.1%) had acute lymphoblastic leukemia (ALL) and 67 (48.9%) had acute myeloid leukemia (AML). After induction, 89.1% of ALL patients achieved complete remission, with an induction death rate of 3.2%. The 5-year OS and EFS rates were 46.0% and 41.0%, respectively. After induction, 44.8% of the AML patients achieved complete remission, with an induction death rate of 29.3%. The 5-year OS and EFS rates in this group were 10.0% and 9.0%, respectively. No significant prognostic factors were identified to predict survival outcomes in children with AML under 2 years. Conclusion: Both ALL and AML childhood leukemia patients aged under 2 years had poor survival outcomes.