Utility of Treatment-Related Mortality (TRM) Score to Predict Outcomes of Adults with Acute Myeloid Leukemia Undergoing Allogeneic Hematopoietic Cell Transplantation

There is long-standing interest in estimating non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (HCT) for AML, but existing tools have limited discriminative capacity. Using single institution data from 861 adults with AML, we retrospectively examined the treatment-related mortality (TRM) score, originally developed to predict early mortality following induction chemotherapy, as a predictor of post-HCT outcome. NRM risks increased stepwise across the 4 TRM score quartiles (at 3 years: 9% [95% confidence interval: 5–13%] in Q1 vs. 28% [22–34%] in Q4). The 3-year risk of relapse was lower in patients with lower TRM score (26% [20–32%] in Q1 vs. 37% [30–43%] in Q4). Consequently, relapse-free survival (RFS) and overall survival (OS) estimates progressively decreased (RFS at 3 years: 66% [59–72%] in Q1 vs. 36% [29–42%] in Q4; OS at 3 years: 72% [66–78%] in Q1 vs. 39% [33–46%] in Q4). With a C-statistic of 0.661 (continuous variable) or 0.642 (categorized by quartile), the TRM score predicted NRM better than the Pretransplantation Assessment of Mortality (PAM) score (0.603) or the HCT-CI/age composite score (0.576). While post-HCT outcome prediction remains challenging, these findings suggest that the TRM score may be useful for risk stratification for adults with AML undergoing allogeneic HCT.