Reduced intensity conditioning compared with myeloablative conditioning using unrelated donor transplants in patients with acute myeloid leukemia.
OBJECTIVE
Reduced intensity conditioning regimen (RIC) is increasingly used in hematopoietic stem cell transplantation (HSCT). Unrelated donor (UD) transplants have more complications. We wanted to examine if RIC is a valid treatment option using UD in acute myeloblastic leukemia (AML).


METHODS
Between 1999 and 2005, 401 patients with AML were treated with RIC and 1,154 received myeloablative conditioning (MAC), using UD and reported to the European Group for Blood and Marrow Transplantation Registry. Patients < and > or = 50 years of age were analyzed separately.


RESULTS
Patients receiving RIC were older, received transplants more recently, received peripheral blood stem cells more frequently, and were treated with total-body irradiation less often. In multivariable analysis, in patients younger than 50 years of age, nonrelapse mortality (NRM) was similar using RIC (hazard ratio [HR], 0.85; P = .41), relapse was increased (HR, 1.46; P = .02) and leukemia-free survival (LFS) was the same (HR, 0.88; P = .28), as compared with MAC. In patients > or = 50 years of age, NRM was decreased in the RIC group (HR, 0.64; P = .04), relapse probability was not significantly different (HR, 1.34; P = .16) and LFS was similar (HR, 1.04; P = .79) compared with MAC. CONCLUSION RIC-UD transplants are associated with higher relapse in AML patients younger than 50 years of age and decreased NRM in those > or = 50 years compared with MAC-UD. LFS was similar after both conditioning regimens, regardless of age. Therefore, RIC-UD extend the use of allotransplants for elderly patients and strategies that decrease relapse should be considered mainly in younger patients with AML.
Ringdén
Olle
O
Karolinska University Hospital, Centre for Allogeneic Stem Cell Transplantation, SE-141 86 Stockholm, Sweden. olle.ringden@labmed.ki.se
Labopin
Myriam
M
Ehninger
Gerhard
G
Niederwieser
Dietger
D
Olsson
Richard
R
Basara
Nadezda
N
Finke
Juergen
J
Schwerdtfeger
Rainer
R
Eder
Matthias
M
Bunjes
Donald
D
Gorin
Norbert-Claude
NC
Mohty
Mohamad
M
Rocha
Vanderson
V
D000293:Adolescent; D000328:Adult; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000276:immunology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D014019:Tissue Donors; D019172:Transplantation Conditioning / Q000379:methods*; D055815:Young Adult