Stem cell transplant outcomes worse in pediatric leukemia patients

Mortality after peripheral blood stem cell (PBSC) transplantation is higher than after bone marrow transplantation in children and adolescents with leukemia, according to a report in the November 1st early online publication of Journal of Clinical Oncology.

Previous studies in children have demonstrated faster hematopoietic recovery in recipients of PBSC transplantation, the authors explain, but data on the occurrence of graft-versus-host disease (GVHD) and other outcomes are inconsistent.To further investigate, Dr. Mary Eapen from Medical College of Wisconsin, Milwaukee, and colleagues compared the results of 143 PBSC and 630 bone marrow transplants from HLA-identical sibling donors to children between 8 and 20 years old with acute leukemia.The median time to neutrophil recovery was significantly faster after PBSC (13 days) than after bone marrow transplant (18 days), the authors report, as was median time to platelet recovery (18 versus 26 days, respectively).The cumulative incidences of grades 2 to 4 acute GVHD were similar after PBSC and bone marrow transplants, the results indicate, but the chronic GVHD was significantly more common after PBSC transplant (33%) than after bone marrow transplant (19%).Treatment-related mortality was higher after PBSC transplantation, the researchers note, and the use of growth factor was significantly associated with higher treatment-related mortality after both types of transplants.”While we observed an adverse effect with the use of growth factor for neutrophil recovery, larger studies specifically examining the effect of growth factor use in the early post-transplant period report mixed results,” Dr. Eapen told Reuters Health, and needs further study.Despite similar relapse rates, the probability of overall survival was significantly lower after PBSC transplantation (48%, adjusted 3-year probability of survival) than after bone marrow transplantation (58%), the investigators report. This was largely the result of the difference in the proportion of deaths related to GVHD beyond 100 days post-transplantation — 20% after PBSC and 5% after bone marrow transplant.”Pediatric transplant physicians wishing to use peripheral blood as an alternative to bone marrow for HLA identical sibling transplants should do so in the setting of a well-designed clinical trial so that we can identify patients or clinical settings where peripheral blood offers a benefit over bone marrow grafts,” Dr. Eapen concluded.”Alternative treatment options must be evaluated in a carefully controlled fashion prior to instituting changes in clinical practice,” Dr. Eapen added.(Source: J Clin Oncol 2004;22: Reuters Health: Oncolink: November 2004.)