12 Years Experience in Peru with Related Allogeneic Stem Cell Transplantation (allo-sct) in Children with High Risk ALL.

ALL accounts for approximately 70-83% of all childhood leukemia. High risk ALL is a big problem in our country and allogeneic related HSCT has proven to be a curative treatment for high risk patients with ALL.

We analyzed the clinical data of 51 children (27 boys and 24 girls) with ALL undergoing related BMT/PSCT from Edgardo Rebagliati Hospital between 1996 and 2008. Survival probabilities were analyzed by Kaplan and Meier method. Outcome of different subgroups was compared by the log-rank test.

The recipients median age at transplantation was 10.7 years (range, 1 - 18 years). The disease status at conditioning were 1^st CR (n=33), 2^nd CR or more (n=18). The median interval from diagnosis to BMT was 14 months (range, 4 - 93 months). We have used two conditioning regimen: TBI/CTX/VP16 (TBI-1200Gy/CTX-120 mg/kg/ VP16-40mg/kg) in 34 patients (66.7%) or TBI/CTX 16 (31.4%) and 1 patient (2%) standard BuCy conditioning regimen. Graft-versus-host disease (GVHD) prophylaxis was methotrexate and cyclosporin. The median infused CD34 cell number was 6.21×10⁶/kg (range 1.61-14.9×10⁶/kg). The resource of hematopoietic cell was bone marrow 33.3% (17 patients), peripheral blood, 64.7% (33 patients) and both 2% (1 patient). Acute GVHD occurred in 10 (19.6%) patients, and chronic GVHD occurred in 15 (29.4%) patients.

Twelve year overall survival (OS) is 59.8% ± 8.7% (n= 51) and leukemia-free survival probabilities (DFS) were 62.9% ± 8.2%. Patients with 1^st CR and 2^nd CR had a 5 year EFS of 60.1% and 67.3% (log-rank test, P 0.92), respectively.

The mortality non related to transplant was 29.5%; 10 patients (19.6%) due to progressive disease and five patients (9.9%) by sepsis.

Allo-SCT is well tolerated in high risk ALL children with prolonged OS and DFS. Not found statistical significance on OS and DFS between the conditioning regimen used, between status pre-transplant (1^st CR vs 2^nd CR) and we found statistical significance in favor to PB as a source of SC on DFS.

No relevant conflicts of interest to declare.