General Outcome of Four Years Experience in the Treatment of Acute Lymphoblastic Leukemia in the National Hospital Edgardo Rebagliati Martins. Lima- Peru.

To analyze survival outcome and behavioral of the disease in children with acute lymphoblastic leukemia (ALL) in a Social Security Hospital of a Developing country.

We analyze 100 pediatrics patients (less than 14 years old) diagnosed with acute lymphoblastic leukemia (ALL) since 2005 to 2008. Disease-free survival (DFS) was computed according to the Kaplan-Meier method and long rank test, using the SPSS 15.0.

A total of 100 children were evaluated. The major incidence according to age was in the group of children between 1 and 9 years old (76%); there were no difference between gender: 51% females and 49% males. The B type was the most common diagnosed leukemia: The B CALLA positive (CD10, CD19, HLA, DR) was the most frequent inmunophenotype, present in 87 children (87%). T-cell ALL was seen in 7%, bi-phenotype and Pro B in 3%. According to our risk stratification protocol, 34 patients were in the very high risk group (VHR), 47 patients in the high risk (HR) group and 19 patients in the intermediate-low risk (ILR) group. About Kariotype evaluation, the most common presentations were normal and hyperdiploid kariotype (67%). We achieved Complete Remission in 95% of our patients post 4 weeks Induction therapy (“A” Induction period). The Total 4th year disease free survival was 48.9% (36.3% VHR, 50.4% HR and 75.9% ILR); of these 61.8 ± 6.2% had DFS after 2 years of therapy and 55.9±6.9 % after 3 years. The Disease Free Survival was significantly increased on those with the following risk factors at diagnosis: white blood cell count < 100 000/mm3 (P= 0.002), normal or hyperdiploid kariotype (P<0.0001). However age, gender and type of ALL in our small group do not have statistical significance. The groups of patients not responding to prednisone have identical DFS than the Responding patients, but the no responding patients received treatment as an immediately superior group (High or Very High Risk). All the patients that have more than 1% of Minimal Residual Disease after a 4 week Induction therapy and achieved a Complete Remission with other chemotherapy treatment, had a poor DFS of less than 10 months (P = 0.015).

The Total DFS was 48.9%. WBC count below 100,000 mm3; normal and hyperdiploid kariotypes, correlate with best DFS. The MDR >1%, was correlated with poor DFS (less than 10 months). The no responding prednisone group must receive a more intensive chemotherapy (the treatment of the immediately superior risk group). The poor DFS at 4 years explain the reason of our therapeutic decision to perform a sibling stem cell Transplant, in those pediatric patients with HR or VHR Acute Lymphoblastic Leukemia (BMT with a 12 year disease free survival of 59.8%).

No relevant conflicts of interest to declare.