Autologous Hematopoietic Stem Cell Transplantation in Acute Lymphoblastic Lymphoma

Abstract

Introduction: Despite high remission rates in acute lymphoblastic leukemia (ALL) patients after induction chemotherapies, post- remission therapies needed to avoiding relapse. Autologous hematopoietic stem cell transplantation (HSCT) role in the treatment of ALL is still controversial. In this retrospective study, we assessed the outcome of auto- HSCT in the treatment of ALL patients treated in this center.

Patients and methods:  From March 1991 to December 2005, 25 ALL patients with no suitable donors underwent auto-HSCT. All patients received Endoxan, Cytarabin and Etoposide according to the center- approved protocol for conditioning regimen. The sources of graft were peripheral blood and bone marrow. The patients hospitalized in same special rooms and circumstances. The Kaplan-Meier method was used for the data analysis.

Results: The median age of patients was 18 years old (range: 8-54). The majority of patients were male. The mean number of WBC count at diagnosis was 48.5×10³/µl. Seventy- two percent of patients received autologous HSCT in CR1. Eighty percent of ALL subtypes were B- lineage. Primary central nervous system involvement at diagnosis time was observed in 16%. The median number of harvested nucleated cells: 4.16×10⁸/kg, MNC: 3.69×10⁸/kg, CD3: 1.52×10⁸/kg and CD34+ cells were 0.07×10⁸/kg of recipient weight. The median time of neutrophil and platelet recovery was 12 (range: 9-37) and 17 (range: 10-74) days, respectively. The median follow-up period for survivors was 12 months (range: 4-110 months). Relapse occurred in 17(68%) of patients. Relapse was the only cause of death in patients. The one-year overall survival (OS) and disease-free survival (DFS) were 46% (SE: 10.2%) and 38% (SE: 9.9%), respectively. Age at transplantation and WBC count at diagnosis time had no significant effect on DFS and OS. Source of stem cells had no significant effect on survival outcome too. Transplantation in first complete remission had the best survival outcome (p =0.01).

Conclusion: The role of autologous HSCT in ALL patients who do not have suitable donors is still inferior to chemotherapy alone. Regarding poor results of the current study, further studies on the role of auto- HSCT in specific subtypes of ALL patients is suggested.