Matched unrelated donor allogeneic transplantation provides comparable long-term outcome to HLA-identical sibling transplantation in relapsed diffuse large B-cell lymphoma

The objective of this retrospective analysis was to compare outcomes of patients with diffuse large B-cell lymphoma (DLBCL) who received either a matched sibling (sib) or an unrelated donor (URD) allogeneic hematopoietic cell transplantation (allo-HCT). Long-term outcome of 172 DLBCL patients receiving URD-HCT between 2000 and 2007 and reported to the European Group for Blood and Marrow Transplantation, was compared with that of 301 subjects, allografted from sib-HCT. With a median follow-up of 45 months, 3-year PFS approached 35% for both groups; overall survival (OS) was 42% for sib-HCT versus 37% for URD (NS). Multivariate analyses confirmed that donor type was not associated with differences in non-relapse mortality (NRM), relapse rate (RR), PFS or OS. Poor performance status (PS) and refractory disease adversely affected PFS and OS. Prior auto-SCT and multiple previous therapies predicted for shorter PFS. NRM was adversely affected by older age (50 years), poor PS and refractory disease, and RR by time from diagnosis to allo-HCT of <36 months, prior auto-SCT, refractory disease, poor PS and in vivo T-cell depletion with alemtuzumab. This large study shows for the first time that URD-HCT is not inferior to sib-HCT, providing a reasonable therapeutic approach for DLBCL patients, having no HLA-identical sibling available.