Results ofGenoidenticalHemopoietic StemCell Transplantation With Reduced Intensity Conditioning for AcuteMyelocytic Leukemia: Higher Doses of Stem Cells Infused Benefit Patients Receiving Transplants in Second Remission or Beyond—The Acute LeukemiaWorking

Nucleated cell dose is an important and modifiable factor in hematopoietic stem cell transplanta-tion (HSCT), however its association with outcomes in the context of reduced intensity condition-ing regimen (RIC) HSCT for adults with acute myelocytic leukemia (AML) is not known. Patients and Methods From 1998 to 2003, 253 patients with de novo AML, received transplants with RIC and peripheral blood from a genoidentical donor. Median age was 55 years (range, 18 to 72) and the median follow-up was 17 months (range, 2 to 67). One hundred forty one patients received transplants in first remission (CR1), 47 received transplants in second remission (CR2), and 65 patients received transplants in a more advanced phase. Fludarabin-based RIC was used in 91 % of patients and low-dose ( 4 Gy) total-body radiation in 23 % of patients. The median nucleated and CD34 cell dose infused were 9.1 108/kg and 5.8 106/kg, respectively. Results Overall, 2-year leukemia-free survival (LFS) was 41 % 4 % and it was 46 % 5 % for patients receiving a higher cell dose ( 9.1 108/kg) and 37 % 5 % for the remainders (P .03). Higher cell doses exclusively benefited patients who received transplantations in CR2 or beyond, wit