Early use of allogeneic hematopoietic stem cell transplantation for infants with MLL gene-rearrangement-positive acute lymphoblastic leukemia.

Koh, K; Tomizawa, D; Moriya Saito, A; Watanabe, T; Miyamura, T; Hirayama, M; Takahashi, Y; Ogawa, A; Kato, K; Sugita, K; Sato, T; Deguchi, T; Hayashi, Y; Takita, J; Takeshita, Y; Tsurusawa, M; Horibe, K; Mizutani, S; Ishii, E

Sixty-two infants with MLL gene-rearrangement-positive acute lymphoblastic leukemia (MLL-r ALL) were treated with the MLL03 protocol of the Japanese Pediatric Leukemia/Lymphoma Study Group: short-course intensive chemotherapy followed by early allogeneic hematopoietic stem cell transplantation (HSCT) within 4 months of the initial induction. The 4-year event-free survival and overall survival rates were 43.2% (95% confidence interval (CI)=30.7-55.1%) and 67.2% (53.8-77.4%), respectively. A univariate analysis showed younger age (<90 days at diagnosis), central nervous system disease and poor response to initial prednisolone therapy significantly associated with poor prognosis (P<0.05). In a multivariate analysis, younger age at diagnosis tended to be associated with poor outcome (hazard ratio=1.969; 95% CI=0.903-4.291; P=0.088). Although the strategy of early use of HSCT effectively prevented early relapse and was feasible for infants with MLL-r ALL, the fact that substantial number of patients still relapsed even though transplanted in their first remission indicates the limited efficacy of allogeneic HSCT for infants with MLL-r ALL. Considering the risk of severe late effects, indications for HSCT should be restricted to specific subgroups with poor risk factors. An alternative approach incorporating molecular-targeted drugs should be established.

LYMPHOBLASTIC leukemia; LEUKEMIA in children; STEM cell transplantation research; UNIVARIATE analysis; PREDNISOLONE; CENTRAL nervous system diseases

Leukemia (08876924), 2015, Vol 29, Issue 2, p290

0887-6924

Academic Journal

10.1038/leu.2014.172