Background/Objectives: Relapse is the greatest obstacle in treating acute myeloid leukemia (AML), occurring in 40–50% of younger patients and most elderly patients. Current immunophenotyping panels for diagnosis and detection of measurable residual disease (MRD) primarily focus on detecting blasts, thereby overlooking AML heterogeneity, which could provide valuable prognostic insights. In this context, we propose repositioning EuroFlow panels within a new set of analyses to assess leukemia stem-like phenotypes for AML prognostic monitoring. Methods: We performed a retrospective study with AML patients at the Hospital de Clínicas de Porto Alegre between 2015 and 2023. Results: Our findings highlight the relevance of leukemia stem cell-like phenotypes, particularly the CD123+, CD34+CD123+, and CD34+CD38− subpopulations, for complementary prognostication of adult and elderly patients. A higher percentage of CD123+ cells was a risk factor for both RFS (p = 0.04) and OS (p = 0.02), whereas an increase in CD34+CD123+ cells was a risk factor for RFS (p = 0.04) only. A higher percentage of CD34+CD38− cells was a risk factor for OS (p = 0.002). From diagnosis to the second monitoring, the CD34+ subpopulation was a more relevant prognostic factor in elderly individuals than in adults. CD34&CD38 most immature subpopulations may increase with poor-prognosis markers in both adults and the elderly. Conclusions: Repositioning immunophenotypic analyses may offer a cost-effective alternative for refined prognostication, particularly in healthcare centers that already have flow cytometry-based AML diagnostics.
Dias et al. (2026) studied this question.