Effects of Obesity on Stem Cell Transplant Outcomes in Acute Myeloid Leukemia Patients: A Systematic Review and Meta-Analysis
Authors: Saowapa Sakditad , Polpichai Natchaya , Wannaphut Chalothorn , Tanariyakul Manasawee , Bernal Diego Olavarria , Garcia Pleitez Hector , Wattanachayakul Phuuwadith , Suenghataiphorn Thanathip , Kulthamrongsri Narathorn , McCullough Maireigh , Moreira Mariana , Siladech Pharit , Sodsri Tulaton , Tijani Lukman 
Published: December 2024

Background: Acute myeloid leukemia is a type of hematologic malignancy that specifically affects the stem cell progenitors of the myeloid origin. The malignancy is one of the most commonly diagnosed leukemias, with its annual incidence being as high as 25% of all the leukemia cases diagnosed. The overall prognosis of this cancer is generally poor. However, the development of aggressive therapies, such as hematopoietic stem cell transplants, has tremendously improved the prognosis. It is therefore necessary that the different factors that affect the response of these patients to hematopoietic stem cell transplantation (HSCT), such as obesity, be analyzed.
Methodology: A systematic search was conducted on three electronic databases, Google Scholar, Science Direct, and PubMed, for relevant peer-reviewed articles from inception to April 2024. After a detailed review based on predetermined eligibility criteria, only the articles that met the inclusion criteria were used in the data extraction and analysis. We utilized the Review Manager software for all statistical analyses and the Newcastle Ottawa Scale for quality appraisal for all included studies.
Results: The online search yielded 240 studies; however, after careful assessment based on our predetermined eligibility criteria, only five studies were included, and the various data obtained were used in the data analysis. Our analysis showed that obese patients who received HSCT did not have significantly different risk of death compared to the normal weight patients OS RR (1.08; 95% CI [0.98, 1.20] p= 0.13). When subgroup analysis was conducted, the risk of mortality was increased in patients who received allogeneic stem cells RR ( 1.11; 95% CI [1.01, 1.22] p =0.04), and no difference was observed in those who received autologous stem cells RR ( 0.71; 95% CI [0.34, 1.59] p = 0.37). Similarly, obesity did not significantly reduce the risk of leukemia relapse RR (0.89;95% CI [0.78, 1.01] P = 0.08). However, in those that received allogeneic HSCT, the risk of relapse was reduced in obese patients RR (0.86; 95% CI [0.75, 0.99] p= 0.03), and no significant difference was observed in those patients that received autologous stem cells RR (1.19; 95% CI [0.81, 1.75] P=0.38).
Conclusion: Based on our analysis, obesity did not significantly affect the prognosis of AML patients who received HSCT. However, when allogeneic HSCT was considered, obesity increased the risk of mortality and reduced the risk of leukemia relapse. However, since the analysis was based on a limited number of studies, we recommended that further studies be conducted to generate enough empirical evidence on the impact of obesity on the prognosis of AML patients who received HSCT.