Survival Benefit of Hematopoietic Stem Cell Transplantation in Infant Acute Lymphoblastic Leukemia, According to Classification of High Risk Group

Lee, Kyoung Ah; Oh, Yoon Su; Kim, Beom Sik; Kim, Hyo Sun; Lyu, Chuhl Joo

Abstract

BACKGROUND
In comparison to older children, acute leukemia in infants has a dismal outcome, despite introduction of intensive multi-agent chemotherapy. Patients with age under 1 year and mixed-lineage leukemia (MLL) gene rearrangements are the most high risk group. In this study, we investigate the outcome of more intensive chemotherapy and the role of hematopoietic stem cell transplantation (HSCT) in high risk group of infant leukemia.
METHODS
This study analyzed on 9 infants with acute lymphoblastic leukemia (ALL) who were diagnosed and treated between 1998 and 2008 at Severance hospital. We classified high risk group with age at diagnosis is under 6 months or white blood cell at diagnosis are over 50,000/microL or presence of MLL gene rearrangements. Patients in high risk group were treated on a protocol of intensive chemotherapy followed by HSCT.
RESULTS
In this study, the 3-years EFS rate for 9 infant ALL patients was 66.7+/-15.7%. Both of 2 patients younger than 6 months of age at diagnosis did not survive. 3yr-EFS rate for the 7 patients categorized in high risk group out of 9 infant ALL patients was 57.1+/-18.7%, and 3 yr EFS of the 6 patients in the high risk group who received HSCT was 60+/-21.9%. We did not experience relapse in 6 patients treated with HSCT.
CONCLUSION
This study showed promising results and lesser risks in high risk group infant ALL treated with intensive chemotherapy and HSCT. We suggest early HSCT with intensive chemotherapy for infant leukemia patients in high risk group.