Nearly 21,000 new cases of acute myeloid leukemia (AML) are diagnosed each year in the United States, about 80% of which occur in individuals aged 60 years and older. The cancer has the highest mortality rate among the different types of leukemia, and, in 2024, it is predicted that about 11,220 deaths will occur from AML. Compared to younger patients with the cancer, older individuals often face more complications and challenges in treatment, greatly impacting their prognosis and reducing life expectancy.
A large retrospective analysis of patients aged 65 years and older diagnosed with AML and treated with an allogeneic hematopoietic stem cell transplant has found significant improvements over 2 decades in posttransplant leukemia-free survival and overall survival, regardless of disease status at transplant. The findings indicate that the opportunity for transplant in older patients with AML should be mandatory and not an option, according to the study authors. The study by Bazarbachi et al was published in Clinical Cancer Research.
Study Methodology
Using data from the European Society for Blood and Marrow Transplantation, researchers identified 7,215 patients diagnosed with AML who received an allogeneic hematopoietic stem cell transplant at age 65 years or older between 2000 and 2021. At the time of their transplants, 64% of the patients were in their first complete remission (CR1), 14% were in their second or subsequent remission (CR2+), and 22% had active disease.
The researchers assessed outcomes in the 3 years immediately following transplant and compared outcomes between patients treated from 2000 to 2009 (n = 728), 2010 to 2014 (n = 1,775), and 2015 to 2021 (n = 4,712). Medium follow-up calculated by the reverse Kaplan-Meier method was 40 months.
Results
The researchers found that the 3-year cumulative relapse incidence gradually and significantly decreased from 37% to 31%, then to 30% (P = .001) over the three time periods, whereas nonrelapse mortality decreased from 31% and 31% to 27% (P = .003). Three-year leukemia-free survival and overall survival gradually and significantly improved from 32% to 38%, and then to 44% (P = .001) and from 37% to 42%, and then to 49% (P = .001), respectively.
In multivariate analysis, significant improvement in the relapse incidence, leukemia-free survival, and overall survival were noted after 2015, whereas nonrelapse mortality was not significantly affected. This improvement was observed regardless of disease status at transplant.
The researchers also found that the incidence of graft-vs-host-disease (GVHD) decreased in the first two time periods (2000–2014 and 2015–2021) from 35% to 31% (P = .002), and that GVHD-free, relapse-free survival improved from 22% to 29%, and then to 34% (P = .001).
Conclusion
“In older patients with AML, we observed an impressive improvement over time in posttransplant outcomes, mostly attributed to decreased relapse incidence rather than decreased nonrelapse mortality, and regardless of disease status at transplant. These large-scale, real-world data can serve as a benchmark for future studies in this setting and indicate that the opportunity for transplant for [older patients] should be mandatory and no longer an option,” concluded the study authors.
Ali Bazarbachi, MD, PhD, of American University of Beirut Medical Center in Lebanon, is the corresponding author of the Clinical Cancer Research paper.
Disclosure: Funding for this study was provided by the European Society for Blood and Marrow Transplantation. For full disclosures of the study authors, visit aacrjournals.org/clincancerres.
