Submitted May 15, 2006
Accepted September 22, 2006
Prospective feasibility analysis of reduced intensity
conditioning regimens (RIC) for hematopoetic stem cell
transplantation (HSCT) in elderly patients with acute
myeloid leukemia (AML) and high-risk myelodysplastic
syndrome (MDS)
Elihu Estey*, Marcos de Lima, Raoul Tibes, Sherry Pierce, Hagop Kantarjian, Richard Champlin, and Sergio Giralt
University of Texas M. D. Anderson Cancer Center, Houston, TX
* Corresponding author; email: ehestey{at}mdanderson.org.
To prospectively assess the applicability of reduced intensity transplantation (RIC-HSCT) we wrote a protocol in which all untreated patients age 
50 with AML and unfavorable cytogenetics would be evaluated during induction for a possible RIC-HSCT in first CR (CR1). 99 of 259 patients entered CR. 53 of the 99 were seen by the Transplant Service with the remainder not seen because of illness, lack / unavailability of siblings, refusal, or, primarily, unclear reasons (21 patients). A donor was identified for 26 patients (21 sibling, 5 unrelated) with RIC-HSCT performed in 14 (13 sibling). Results in consulted patients suggested that 
50% of the 85 non-transplanted patients were potential transplant candidates. We attempted to find 1 chemotherapy pair-mate for each transplanted patient based on cytogenetics, age, and a relapse-free survival time (RFS) the time from CR1 to RIC-HSCT in the transplanted patient. 32 of the 39 matches favored (longer RFS) RIC-HSCT and 7 chemotherapy. The probability that the corresponding beta distribution was different than expected, i.e. that RIC-HSCT was superior, was 0.99 (p = 0.004). Results were similar with respect to survival. While RIC-HSCT thus seems of interest, methods are needed to extend its applicability.
