Resultados de la implementación del protocolo PETHEMA LPA 99 en el tratamiento de niños con leucemia promielocítica aguda en Bogotá, Colombia

Introduction: In the United States, between 4 and 8% of children with acute myeloid leukemia have acute promyelocytic leukemia (APL), but a higher incidence of this malignancy has been reported in Latin America (20%-28%). The implementation of the PETHEMA LPA 99 protocol, designed for the treatment of APL in adults, has shown an overall survival (OS) >80%. Objective: To describe the results obtained after the implementation of the PETHEMA LPA 99 protocol to treat children with APL at the Fundacion Hospital Pediatrico La Misericordia in Bogota, D.C., Colombia. Materials and methods: Descriptive and retrospective cohort study. The medical records of 30 pediatric patients (<18 years) with APL, who were treated using the PETHEMA LPA 99 protocol between January 2005 and December 2012, were reviewed. Data on the following variables were obtained: early death, death during induction therapy, OS, event-free survival (EFS), and relapse. Results: The male sex was predominant (60%) among the 30 patients included in the study. Regarding risk classification, 13 (43%) were classified as high-risk patients, 12 (40%) as medium-risk, and 5 (17%) as low-risk. Seven individuals died: 2 before receiving cancer treatment, 2 during induction therapy, and 3 after relapse. Relapse was reported in 5 patients. There were no deaths during the consolidation or maintenance phases. OS was 75.4% (95%CI: 55.1-87.5) and EFS was 64.3% (95%CI: 40-80.5). Moreover, OS at 11 years was 80%, 91.7%, and 59.2% for low-risk, intermediate-risk, and high-risk patients, respectively. The median follow-up time was 6.35 years (0-11.43 years). Conclusions: In general, the implementation of the PETHEMA LPA 99 protocol to treat APL in the study population showed very satisfactory results. Therefore, its use in pediatric population is recommended, taking into account the adjustments described in the protocol regarding the characteristics of this age group.