High vs. low intensity chemotherapy in AML: Survival and transplant outcomes in a brazilian experience

Abstract Although the treatment landscape for acute myeloid leukemia (AML) has evolved with the incorporation of targeted therapies—such as midostaurin for FLT3-mutated disease—patients are still stratified based on eligibility for intensive chemotherapy. High-intensity treatment typically involves an anthracycline plus cytarabine backbone, followed by allogeneic bone marrow transplantation (alloBMT) in first remission for those with high-risk disease, as defined by the European LeukemiaNet (ELN) classification. Low-intensity chemotherapy usually combines a hypomethylating agent with a BCL2 inhibitor. In this retrospective study, we report real-world outcomes of AML treatment based on medical records of a brazilian single center. Methods: We retrospectively analyzed medical records of AML patients at our institution between 2017 and 2024 based on ICD code, excluding cases of acute promyelocytic leukemia and patients under 18 years of age. Patients were categorized based on the intensity of induction therapy: high-intensity (Group 1) or low-intensity (Group 2). Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method and compared using the log-rank test. Years of Life Lost (YLL) were calculated as the difference between the expected life expectancy (based on age and place of residence) and the age at death following diagnosis. Results: A total of 136 patients were included: 74 (54%) in Group 1 and 62 (46%) in Group 2. Male sex predominated in both groups (53% and 56%, respectively). Median age at diagnosis was 49 years (SD = 14) in Group 1 and 74 years (SD = 9) in Group 2. Secondary AML was more frequent in Group 2 (63%) compared to Group 1 (23%). AlloBMT was performed in 72% of Group 1 patients (83% in complete remission) and 24% of Group 2 patients (53% in complete remission). Mortality rates were 30% and 65%, with corresponding YLL of 27 years (SD = 12) and 12 years (SD = 5), respectively. The median follow up was 30 months. In Group 1, 2-year OS was 71% (95% CI, 68%–84%) and 2-year PFS was 47% (95% CI, 36%–62%). In Group 2, 2-year OS was 38% (95% CI, 25%–56%) and 2-year PFS was 34% (95% CI, 22%–52%). Patients who underwent alloBMT had significantly better outcomes in both groups: Group 1: 2-year OS 77% vs. 50% (p = 0.004); 2-year PFS 55% vs. 22% (p = 0.01) Group 2: 2-year OS 65% vs. 30% (p < 0.001); 2-year PFS 49% vs. 30% (p = 0.003) Conclusions: As expected, patients eligible for high-intensity chemotherapy were generally younger and had fewer comorbidities, achieving better outcomes. Nonetheless, this single-center Brazilian study reinforces the favorable impact of alloBMT on AML outcomes, regardless of induction intensity. These findings are particularly relevant in settings with limited access to clinical trials, highlighting the importance of transplant strategies in real-world practice.