Survival and risk factors for mortality in pediatric patients with acute myeloid leukemia in a single reference center in low-middle-income country.

ABSTRACT

Despite advances in therapy and care for children with acute myeloid leukemia (AML), survival rates for children in low- and middle-income countries (LMICs) remain poor. We studied risk factors for mortality and survival in children with AML in a LMIC to develop strategies to improve survival for AML children in these countries. This retrospective cohort (2000-2014) analyzed newly diagnosed AML patients (age < 19 years) at a reference center in Brazil. Demographic and clinical variables were reviewed by AML subtype acute promyelocytic leukemia (APL), AML with Down syndrome (AML-DS), and other AML subtypes. Cumulative hazard risk for early death (ED) until 6 weeks of treatment and risk factors for mortality were determined by the multivariate Cox hazard models. Survival was assessed for each AML subtypes. A total of 220 patients were diagnosed APL 50 (22.7%), AML-DS 16 (7.3%), and other AML subtypes 154 (70.0%). The cumulative hazard function values for ED for all patients with AML were 12.5% (95% CI 8.5-18.4%); for each AML patients subtypes APL, 21.7% (95% CI 11.7-40.5%); AML-DS, 6.2% (95% CI 0.9-44.4%); and other AML subtypes, 10.2% (95% CI 6.2-17.0%). White blood cell count (cutoff 10 × 109/L for APL and 100 × 109/L for other AML subtypes) and Afro-descendance were significant risk factors for mortality in APL and other AML subtypes, respectively. Overall survival for patients with APL, AML-DS, and other AML subtypes was 66.8%, 62.5%, and 38.0%, respectively. APL patients had the highest incidence of ED and those with other subtypes had increased relapse risk. We also observed high rates of death in complete remission mainly due to infection. Better risk classification and identification of risk factors for infection may improve the survival of these patients.