Treatment outcome in pediatric patients with T-ALL in Brazil

BACKGROUND: Several studies conducted in high-income countries (HICs) have demonstrated that treatment intensification in pediatric T-cell acute lymphoblastic leukemia (T-ALL) improved survival outcomes. However, studies in low- and middle-income countries (LMICs) remain scarce. In this study, we evaluated survival rates and their associations with clinical factors within the context of the Brazilian Unified Health System. METHODS: Data from 86 patients aged 0-19 years, diagnosed with T-ALL at one of four pediatric oncology reference centers of the Brazilian Unified Health System, were included in the study. Clinical, demographic, and laboratory variables were collected through a retrospective analysis of medical records. RESULTS: Cohort survival rates revealed that the 5-year overall survival probability (pOS) and event-free survival probability (pEFS) for patients with T-ALL were 47% (37.3-59.3) and 43.2% (33.5-55.7), respectively, with infection being the main cause of death (69.4%). In both bivariate and multivariate analyses, the presence of adenomegaly at diagnosis was associated with lower pOS and pEFS. In addition, the GBTLI-HR protocol achieved the highest pOS (70.0%), compared to the 35.0% and 32.0% observed with the ALL IC-BFM 2002-HR and ALL IC-BFM 2009-HR protocols, respectively. This reinforces the need for context-specific adaptations of intensive treatment protocols in LMICs. CONCLUSION: This study offers valuable insights into the clinical and demographic characteristics of patients with T-ALL from Brazil, highlighting substantially higher mortality rates than those reported in HICs, primarily attributed to high infection rates.