Analysis of the role of hematopoietic stem-cell transplantation in infants with acute lymphoblastic leukemia in first remission and MLL gene rearrangements: a report from the Children's Oncology Group.
OBJECTIVE
Although the majority of children with acute lymphoblastic leukemia (ALL) are cured with current therapy, the event-free survival (EFS) of infants with ALL, particularly those with mixed lineage leukemia (MLL) gene rearrangements, is only 30% to 40%. Relapse has been the major source of treatment failure for these patients. The parallel Children's Cancer Group (CCG) 1953 and Pediatric Oncology Group (POG) 9407 studies were designed to test the hypothesis that more intensive therapy, including dose intensification of chemotherapy, and hematopoietic stem-cell transplantation (HSCT) would improve the outcome for this group of patients.


METHODS
One hundred eighty-nine infants (CCG 1953, n = 115; POG 9407, n = 74) were enrolled between October 1996 and August 2000. For infants with the MLL gene rearrangement and an appropriate donor, HSCT was the preferred treatment on CCG 1953 and investigator option on POG 9407 after completion of the second phase of therapy. Fifty-three infants underwent HSCT.


RESULTS
The 5-year EFS rate was 48.8% (95% CI, 33.9% to 63.7%) in patients who received HSCT and 48.7% (95% CI, 33.8% to 63.6%) in patients treated with chemotherapy alone (P = .60). Transplantation outcomes were not affected by the preparatory regimen or donor source.


CONCLUSIONS
Our data suggest that routine use of HSCT for infants with MLL-rearranged ALL is not indicated. However, limited by small numbers, this study should not be considered the definitive answer to this question.
Texas Children's Hospital, Houston, TX, USA. zedreyer@txccc.org
ZoAnn E
ZE
Dreyer
Patricia A
PA
Dinndorf
Bruce
B
Camitta
Harland
H
Sather
Mei K
MK
La
Meenakshi
M
Devidas
Joanne M
JM
Hilden
Nyla A
NA
Heerema
Jean E
JE
Sanders
Ron
R
McGlennen
Cheryl L
CL
Willman
Andrew J
AJ
Carroll
Fred
F
Behm
Franklin O
FO
Smith
William G
WG
Woods
Kamar
K
Godder
Gregory H
GH
Reaman
D002869:Chromosome Aberrations; D018572:Disease-Free Survival; D023061:Gene Order; D018380:Hematopoietic Stem Cell Transplantation; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D007223:Infant; D051788:Myeloid-Lymphoid Leukemia Protein / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics* / Q000601:surgery*; D012074:Remission Induction; D016896:Treatment Outcome
C497422:KMT2A protein, human; D051788:Myeloid-Lymphoid Leukemia Protein; D011495:Histone-Lysine N-Methyltransferase