Is Allogeneic Stem Cell Transplantation of High-Risk Pediatric Acute Lymphoblastic Leukemia (ALL) Patients More Effective In Preventing Future Relapses of Disease and/ or Mortality In Comparison With Chemotherapeutic Regimens Alone?

OBJECTIVE: The objective of this selective EBM review is to determine whether or not allogeneic SCT of HR pediatric ALL patients is more effective in preventing future relapses of disease and/or mortality in comparison with chemotherapeutic regimens alone. STUDY DESIGN: Review of three English language primary randomized controlled trial studies published between 1996 and the present. DATA SOURCES: Randomized controlled trial studies were found using PubMed. OUTCOMES MEASURED: Each of the three studies evaluated the incidence of recurrent disease and/or mortality in high-risk pediatric ALL patients. These outcomes were analyzed according to the following categories: duration of event-free survival (EFS); duration of disease-free survival (DFS); incidence of relapses; complete remission (CR); death; partial response (PR); resistant disease (RD); and overall survival (OS). RESULTS: Three randomized controlled trials were included in this review. The study by Schrauder et. al., which analyzed the role of SCT in first complete remission for children with very high-risk ALL, showed that the OS for patients who received SCT was higher than that of the patients who received chemotherapy alone (67% vs. 47%). In the study by Ribera et. al. comparing the options of chemotherapy alone versus allogeneic SCT as post-remission therapy, the DFS and OS were both used as indicators of success and showed higher percentages of both in the subgroup that received chemotherapy alone. The final study by Tallen et. al. analyzed a multicenter trial (ALL-REZ BFM 90), which was created with the purpose of improving the prognosis for children with relapsed ALL. The results of this study demonstrated significant differences in the probabilities of EFS and OS amongst the different subgroups analyzed indicating that remission induction regimens must be improved and that allogeneic SCT should be recommended in patients achieving a second complete remission. CONCLUSIONS: Two out of three studies included in this review support the use of allogeneic SCT versus chemotherapeutic regimens alone when treating high-risk pediatric ALL patients. Various factors, such as the achievement of first versus second remission, can also affect the results of studies involving this patient population