A Multicenter Survival Analysis of Adults Type B-Acute Lymphoblastic Leukemia in Ecuador. A Retrospective Study of the Real World.

[OBJECTIVE] To describe clinical characteristics, treatment outcomes, and overall survival (OS) of Ecuadorian adults with B-cell acute lymphoblastic leukemia (B-ALL).

[METHODS] A retrospective multicenter cohort study was conducted in patients > 15 years diagnosed with B-ALL between 2015 and 2022 across eight tertiary centers in Ecuador. Medical records of 734 acute lymphoblastic leukemia cases classified by the 2016 WHO criteria were reviewed; 653 B-ALL patients were included. Multiple frontline chemotherapy regimens were used, and Philadelphia-positive (Ph+) cases were included.

[RESULTS] Among 653 patients, 50.4% were male, with a median age of 31 years (interquartile range, 20-47). Most (93%) received chemotherapy, achieving a complete remission (CR) rate of 53.3% (311/583) and minimal residual disease (MRD) negativity in 49.1% (211/430). Relapse occurred in 62.4% (194/310), and 16 of 164 underwent allogeneic hematopoietic stem cell transplantation (HSCT). Treatment-related mortality was 31.5%, higher in pediatric-inspired protocols (34.4% vs. 21.3%, p < 0.001). Patients < 30 years showed better CR (58.3%, p = 0.026) and longer survival (median OS 15 vs. 8 months, p < 0.001). Median OS for the cohort was 11 months, with a 5-year OS of 22.4%. High-risk patients had inferior OS (11 vs. 14 months, p = 0.036), while no difference was observed between Ph + and Ph- (12 vs. 11 months, p = 0.319).

[CONCLUSION] Adult Ecuadorian patients with B-ALL show lower survival than international cohorts, mainly due to high treatment-related mortality and limited transplantation access. Age was independently associated with response and OS.