Clinical Presentation and Treatment Outcomes of Pediatric Acute Promyelocytic Leukemia: A Study From a Developing Country.

Acute promyelocytic leukemia (APL) is a highly curable form of acute myeloid leukemia (AML) when treated early with all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Resource constraints in low- and middle-income countries (LMICs) may affect results. This study examined the clinical characteristics and outcomes of pediatric patients with APL receiving an ATRA-ATO-based regimen. The retrospective review included 1- to 16-year-olds diagnosed between January 2019 and December 2022. Morphology and PML-RARA detection by fluorescence in situ hybridization (FISH) confirmed the diagnosis. Patients were stratified by initial white cell count (WCC) (low-risk <10×10 9 /L; high-risk ≥10×10 9 /L). Data were retrieved from electronic medical records. Event-free survival (EFS) rates were obtained using the Kaplan-Meier analysis. Fifty patients (mean age: 10.7 y; 56% male) were evaluated. Low-risk was 32%, and high-risk was 68%. Thrombocytopenia and hypofibrinogenemia were common. All patients had PML-RARA FISH-positives, and 100% of evaluated patients attained morphologic and molecular remissions. Eleven (22%) patients died, mostly from hemorrhage. Abandonment and relapses were observed in 10% and 8% of patients, respectively. Two-year EFS was 60% (low-risk 81%; high-risk 50%). The ATRA-ATO regimen showed substantial remission rates, but early deaths remain a concern. Increased survival rates in resource-constrained environments require improved early detection, referral, and supportive care.