In a retrospective study of registry data reported in the Journal of Clinical Oncology, Mehta et al identified alternative donor sources for hematopoietic cell transplantation (HCT) that were associated with better graft-vs-host disease (GVHD)-free (GRFS) and chronic GVHD–free (CRFS) relapse-free survival among adult recipients without HLA-matched related or unrelated donors.
Study Details
The study involved Center for International Blood and Marrow Transplant Research registry data from 2,198 patients who underwent umbilical cord blood (n = 838), haploidentical (n =159), 1-antigen mismatched (7/8)-bone marrow (7/8-BM, n = 241), or 7/8-peripheral blood (7/8-PB, n = 960) HCT. All groups were divided by myeloablative conditioning intensity or reduced intensity conditioning, except the haploidentical group (of whom 78% received reduced intensity conditioning). The 7/8-PB group was also divided according to receipt or no receipt of serotherapy. P values for significance were < .0071 in multivariable analysis and < .00025 in direct pairwise comparisons to account for multiple testing.
Key Findings
In multivariable analysis including all groups, the haploidentical group (reference group) had significantly better (all P < .007) GRFS (hazard ratios [HRs) for other groups = 1.44–2.37), CRFS (HRs for other groups = 1.48–2.04), and overall survival (HRs for other groups = 1.52–1.18) vs all other groups, including both the myeloablative conditioning intensity and reduced intensity conditioning subgroups.
Among patients who received myeloablative conditioning intensity, direct pairwise comparisons of other groups (excluding the haploidentical group) showed no significant difference in GRFS or CRFS among the umbilical cord blood, 7/8-BM, and 7/8-PB with serotherapy (n = 256 receiving alemtuzumab or antithymocyte globulin vs n = 368 without serotherapy) groups. The 7/8-PB population without serotherapy had significantly poorer GRFS, higher chronic GVHD, and a trend toward worse CRFS (HR = 1.38, P = .002) vs the 7/8-BM group, and higher chronic GVHD and a trend toward worse CRFS (HR = 1.36, P = .0006) vs the umbilical cord blood group. No differences in overall survival were observed among groups.
Among patients who received reduced intensity conditioning, the haploidentical group had significantly better outcomes compared with all other groups, as shown in the multivariate analysis.
The authors concluded, “Recognizing the limitations of a registry retrospective analysis and the possibility of center selection bias in choosing donors, our data support the use of umbilical cord blood, 7/8-BM, or 7/8-PB (with serotherapy) grafts for patients undergoing myeloablative conditioning intensity HCT and haploidentical grafts for patients undergoing reduced intensity conditioning HCT. The haploidentical group had the best GRFS, CRFS, and overall survival of all groups.”
Rohtesh S. Mehta, MPH, MD, of The University of Texas MD Anderson Cancer Center, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by a Public Health Service Grant/Cooperative Agreement from the National Cancer Institute, National Heart, Lung, and Blood Institute, and National Institute of Allergy and Infectious Diseases and others. For full disclosures of the study authors, visit ascopubs.org.
