Prognostic Factors for Early Mortality Following Allogeneic Hematopoietic Cell Transplantation in Hematologic Malignancies.

The 100 days following allogeneic hematopoietic stem cell transplantation (allo-HCT) remains a critical period despite advancements in transplant-related care. Post-transplant cyclophosphamide (PTCy) has been implemented as an effective strategy for GVHD prevention across various donor types. This study aimed to evaluate causes of early mortality and prognostic factors for non-relapse mortality (NRM), disease-related mortality (DRM), and overall survival (OS). This was a single institution, retrospective study including adult patients who received their first allo-HCT from 2009 to 2023. Patient- and transplant- related variables were compared between patients who died and those who were alive at 100 days post-allo-HCT. A total of 536 patients were evaluated, including 285 men (53%). Median age at time of allo-HCT was 59 years (range 19-75), and most were White/Caucasian (n = 232; 86%). The predominant diagnosis included acute myeloid leukemia (AML) (n = 195, 36%), myelodysplastic syndrome (MDS) (n = 95, 18%), and myelofibrosis (MF) (n = 57, 11%). Eighty patients (15%) died within 100 days following allo-HCT, with NRM accounting for most early deaths (N = 61; 76%). Primary causes of death were acute GVHD (n = 23), disease relapse/progression (n = 19), and infections (n = 18). On multivariate analysis, earlier transplant year was the only independent predictor of increased 100-day DRM (HR 1.15; P = .049). Male gender (HR 1.78; P = .035), non-acute leukemia diagnoses (HR 2.38; P = .003), and non-PTCy prophylaxis (HR 2.2; P = .032) were independently associated with higher 100-day NRM. PTCy-based GVHD prophylaxis was the only modifiable factor associated with lower early NRM, through reduced GVHD-related deaths without increased infection or DRM.