Risk Assessment in Adult T Cell Leukemia/Lymphoma Treated with Allogeneic Hematopoietic Stem Cell Transplantation

Disease status at allogeneic hematopoietic cell transplantation (HCT) is an important pretransplant prognostic factor of HCT in adult T cell leukemia/lymphoma (ATL); however, other prognostic factors, including comorbidities, were not predictive in small cohort analyses. Several scoring systems (HCT-specific comorbidity index [HCT-CI]/modified European Group for Blood and Marrow Transplantation risk score [mEBMT]) have been adopted to predict HCT outcomes in other hematologic malignancies. We retrospectively evaluated HCT-CI and mEBMT to predict nonrelapse mortality (NRM) in 824 ATL patients registered in the Japan Society for Hematopoietic Cell Transplantation TRUMP database, from 2008 until 2013. A higher HCT-CI was associated with greater NRM when comparing HCT-CI 0 versus HCT-CI 1 to 3 and HCT-CI 0 versus HCT-CI ≥ 4. A higher mEBMT score was not associated with higher NRM when comparing mEBMT 0 to 3 with 4 to 6. Because ATL patients are older and consequently at risk of additional complications, we developed an optimized prognostic index for ATL (ATL-HCT-PI) using known risk factors: age, HCT-CI, and donor-recipient sex combination. The ATL-HCT-PI scores effectively predicted the 2-year NRM (22.0%, 27.7%, and 44.4%, respectively). Therefore, the newly developed ATL-HCT-PI, in combination with other risk factors, is more useful for predicting NRM in HCT for ATL patients.