Survival Analysis of Childhood Leukemia in South of Iran, Shiraz

Leukemia is the most prevalent type of cancer in children. The aim of this study was to estimate the 5-year survival rates of Acute Lymphoblastic Leukemia (ALL) and Acute Myeloblastic Leukemia (AML) as well as factors influencing them. This is a nonrandomized retrospective study conducted on 280 patients with ALL and AML. They were all below 15 years old children admitted to Shahid Faghihi hospital, Shiraz, Iran from 2004 to 2008.The survival rates were estimated by applying the Kaplan-Meier method. In addition, the log rank test was used to estimate the statistical significance of differences in the survival probability. Cox regression model was applied to conduct multivariate analysis for adjusting confounding variable. All analyses were performed in SPSS statistical software (version 16). P-values less than 0.05 were considered as statistically significant. The mean (± standard deviation) of the observation period was 28.2±16.1 months. In this period, 60 (24.7%) patients (47 ALL and 15 AML) passed away. The cumulative rate of survival in this study was 53.3±0.1 percent. This probability was 56.6±0.1% and 44.2±0.1% for ALL and AML patients, respectively, which indicates no statistically significant difference between them (P=0.8). According to Cox model, there was a significant relationship among the variables of platelet count and relapse with the survival rate. Platelet count was identified as a positive prognostic factor of the survival rate in ALL patients. However, on the base of our results and other studies, incidence of relapse and the number of relapses are significant factors of survival rates of leukemia.