Comparison of Risk Scoring Systems in HLA-Matched Related Allogeneic Hematopoietic Stem Cell Transplantation: A Retrospective Cohort Study

Abstract

Objective: Allogeneic hematopoietic stem cell transplantation (AHSCT) is a potentially curative treatment of choice for many hematological diseases. However, there are some transplantation-related risks. Predicting the risk-benefit ratio prior to AHSCT facilitates the choice of conditioning regimens and posttransplant follow-up. Hence, many risk models have been developed. The aim of the present study was to compare 6 different risk models that are clinically used. Materials and Methods: A total of 259 patients were enrolled in this study. The European Society for Blood and Marrow Transplantation (EBMT), Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI), Age-Adjusted Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI-Age), revised Pretransplant Assessment of Mortality (rPAM), Acute Leukemia-EBMT (AL-EBMT), and Disease Risk Index (DRI) risk models were applied retrospectively. Results: The AL-EBMT, HCT-CI, and HCT-CI-Age scoring systems were found to be predictive for 2-year overall survival (OS) and 2-year non-relapse mortality (NRM) (2-year OS: AL-EBMT, reference vs. score 8.5-10, HR: 1.3, p=0.035; AL-EBMT, reference vs. score >10, HR: 3.8, p=0.001; HCT-CI: reference vs. score 1-2, HR: 1.4, p=0.018; HCT-CI: reference vs. score ≥3, HR: 2.5, p<0.001; HCT-CI-Age: reference vs. score 1-2, HR: 1.3, p<0.001; HCT-CI-Age: reference vs. score ≥3, HR: 3.2, p<0.001) (2-year NRM: AL-EBMT: reference vs. score 8.5-10, HR: 1.61, p<0.001; AL-EBMT: reference vs. score >10, HR: 3.3, p<0.001; HCT-CI: reference vs. score 1-2, HR: 1.3, p=0.028; HCT-CI: reference vs. score ≥3, HR: 2.3, p=0.011; HCT-CI-Age: reference vs. score 1-2, HR: 1.3, p=0.01; HCT-CI-Age: reference vs. score ≥3, HR: 2.4, p=0.003). In terms of the Kaplan-Meier estimates of 2-year OS and 2-year NRM, the risk scoring system with the highest predictive power was found to be AL-EBMT (2-year AUC: 0.59 and 0.60, respectively). The other scores were not found to be predictive for 2-year OS and NRM. Conclusion: In the present study at our bone marrow and stem cell transplant center, it has been demonstrated that the HCT-CI, HCT-CI-Age, and AL-EBMT are good predictors of 2-year NRM and OS.