Analyzing center specific outcomes in hematopoietic cell transplantation.

Reporting transplant center-specific survival rates after hematopoietic cell transplantation is required in the United States. We describe a method to report 1-year survival outcomes by center, as well as to quantify center performance relative to the transplant center network average, which can be reliably used with censored data and for small center sizes. Each center's observed 1-year survival outcome is compared to a predicted survival outcome adjusted for patient characteristics using a pseudovalue regression technique. A 95% prediction interval for 1-year survival assuming no center effect is computed for each center by bootstrapping the scaled residuals from the regression model, and the observed 1-year survival is compared to this prediction interval to determine center performance. We illustrate the technique using a recent center specific analysis performed by the Center for International Blood and Marrow Transplant Research, and study the performance of this method using simulation.

Twenty years of unrelated donor hematopoietic cell transplantation for adult recipients facilitated by the National Marrow Donor Program.

For more than 20 years the National Marrow Donor Program has facilitated unrelated donor hematopoietic cell transplants for adult recipients. In this time period, the volunteer donor pool has expanded to nearly 12 million adult donors worldwide, improvements have occurred in the understanding and technology of HLA matching, there have been many changes in clinical practice and supportive care, and the more common graft source has shifted from bone marrow (BM) to peripheral blood stem cells (PBSCs). The percentage of older patients who are receiving unrelated donor transplants is increasing; currently over 1 in 10 adult transplant recipients is over the age of 60 years. Chronic myelogenous leukemia (CML) was previously the most common diagnosis for unrelated donor transplantation, but it now comprises less than 10% of transplants for adult recipients. Transplants for acute myelogenous leukemia (AML), acute lymphoblastic leukemia (ALL), non-Hodgkin lymphoma (NHL), and myelodysplastic syndromes (MDS) all outnumber CML. Treatment-related mortality (TRM) has declined significantly over the years, particularly in association with myeloablative transplant preparative regimens. Correspondingly, survival within each disease category has improved. Particularly gratifying are the results in severe aplastic anemia (AA) where 2-year survival has doubled in just 10 years.

Twenty years of unrelated donor bone marrow transplantation for pediatric acute leukemia facilitated by the National Marrow Donor Program.

The National Marrow Donor Program (NMDP) has facilitated unrelated donor hematopoietic cell transplants for more than 20 years. In this time period, there have been many changes in clinical practice, including improvements in HLA typing and supportive care, and changes in the source of stem cells. Availability of banked unrelated donor cord blood (incorporated into the NMDP registry in 2000) as a source of stem cells has become an important option for children with leukemia, offering the advantages of immediate availability for children with high-risk disease, the need for a lesser degree of HLA match, and expanding access for those with infrequent HLA haplotypes. Overall survival (OS) in children with acute leukemia transplanted with unrelated donor bone marrow (BM) is markedly better in more recent years, largely attributable to less treatment-related mortality (TRM). Within this cohort, 2-year survival was markedly better for patients with acute lymphoblastic leukemia (ALL) in first complete response (CR1) (74%) versus second complete response (CR2) (62%) or more advanced disease (33%). Similar findings are observed with patients with AML, suggesting earlier referral to bone marrow transplant (BMT) is optimal for survival. Notably, this improvement over time was not observed in unmodified peripheral blood stem cell (PBSC) recipients, suggesting unmodified PBSC may not be the optimal stem cell source for children.