Outcome and prognostic factors for patients who relapse after allogeneic hematopoietic stem cell transplantation

Disease relapse remains a major obstacle to the success of allogeneic hematopoietic stem cell transplantation (HSCT), yet little is known about the relevant prognostic factors after relapse. We studied 1080 patients transplanted between 2004 and 2008, among whom 351 relapsed. The 3-year postrelapse overall survival (prOS) rate was 19%. Risk factors for mortality after relapse included shorter time to relapse, higher disease risk index at HSCT, myeloablative conditioning, high pretransplantation comorbidity index, and graft-versus-host disease (GVHD) occurring before relapse. Important prognostic factors did not vary by disease type. Based on this, we could stratify patients into 3 groups, with 3-year prOS rates of 36%, 14%, and 3% (P < .0001). This score was validated in an historical cohort of 276 patients. Postrelapse donor lymphocyte infusion or repeat HSCT was associated with improved prOS, as was the development of GVHD after relapse. These differences remained significant in models that accounted for other prognostic factors and in landmark analyses of patients who survived at least 2 months from relapse. The results of this study may aid with prognostication and management of patients who relapse after HSCT and motivate the design of clinical trials aimed at relapse prevention or treatment in higher-risk patients.