Impact of Pre-transplant Body Mass Index on Outcomes in AML Patients Aged ≥ 50 Years After Allogeneic Hematopoietic Cell Transplantation

Wenwen GuoHaixiao ZhangHongye GaoYawei ZhengMingyang WangWenbin CaoRongli ZhangQiaoling MaYi HeWeihua ZhaiDonglin YangAiming PangSizhou FengMingzhe HanYIGENG CAO^*Erlie Jiang^*

• State Key Laboratory of Experimental Hematology, Peking Union Medical College Hospital (CAMS), Tianjin, China

The prognostic significance of body mass index (BMI) in elderly acute myeloid leukemia (AML) patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) remains controversial. This retrospective study analyzed 142 AML patients aged ≥50 years receiving allo-HCT (2013- 2022), stratified by Chinese BMI criteria: low BMI (<24 kg/m², n = 83) vs. high BMI (≥24 kg/m², n = 59). The median pre-transplant BMI was 23.63 (IQR, 22.07-25.78) kg/m². Multivariate analysis identified BMI <24 kg/m² as an independent risk factor for inferior OS (HR=1.80, p=0.037) and GRFS (HR=2.00, p = 0.003). Although BMI did not correlate with relapse, long-term non-relapse mortality (NRM), or the incidence of acute and chronic graft versus host disease (GVHD), the oneyear NRM was significantly higher in the low BMI group compared to the high BMI group (p = 0.006). Subgroup analysis revealed that high-risk patients [not complete remission (NR) or CR but minimal residual disease (MRD)-positive) with low BMI had markedly reduced 3-year OS (20.87% vs. 57.69%, p=0.006), whereas no difference was observed in low-risk (CR/MRD-negative) patients.Pre-transplant BMI independently predicts inferior survival in older adults with AML undergoing allo-HCT. These findings highlight the need for BMI-guided nutritional interventions, especially for high-risk older patients.