Patient age and donor HLA matching can stratify allogeneic hematopoietic cell transplantation patients into prognostic groups.

Background: Mixed results surround the accuracy of commonly used prognostic risk scores to predict overall survival (OS) and non‐relapse mortality (NRM) in allogeneic hematopoietic stem cell transplant (allo‐HCT) recipients. We hypothesize that a simple prognostic score performs better than conventional scoring systems. Patients and Methods: OS risk factors, HCT‐CI, age‐HCT‐CI, and augmented‐HCT‐CI were studied in 299 patients who underwent allo‐HCT for myeloid and lymphoid malignancies. A scoring system was developed based on results and validated in a different cohort of 455 patients. Results: Two‐year OS was 51% (95% confidence interval (CI) 0.45–0.56); 2‐year NRM was 34% (95% CI 0.29–0.39). HCT‐CI and associated scores were grouped into 0–2 and ≥3. Age and HLA mismatch status were the only risk factors to affect OS in multivariate analysis (p = 0.02 and 0.05, respectively). HCT‐CI and associated scores were not informative for OS prediction. The weighted scoring system assigned 0 to 2 points for age < 50, 50–64, or ≥65, respectively, and 0–1 points for no HLA mismatch versus any mismatch (except HLA‐DQ). Distinct 2‐year OS (62%, 53%, and 38% [p = <0.001]) and NRM (24%, 34%, and 43% [p = 0.02]) groups were characterized. The scoring system was validated in a second independent cohort with similar results on OS and NRM (p < 0.001). Conclusions: A simple scoring system based on recipient's age and mismatch status accurately predict OS and NRM in two distinct cohorts of allo‐HCT patients. Its simplicity makes it a helpful tool to aid clinicians and patients in clinical decision‐making. [ABSTRACT FROM AUTHOR]