Prognostic Significance of Absolute Lymphocytic Count Recovery in Pediatric Patients with Acute Lymphoblastic Leukemia at South Egypt Cancer Institute

Abstract

Background: Leukemia is the most common cause of disease-related death in childhood despite significant improvement in survival and modern risk stratification. Prognostic significance of absolute lymphocytic count (ALC) recovery was studied in pediatric patients with acute lymphoblastic leukemia (ALL). Methods: One hundred twenty one patients newly diagnosed as ALL ≤ 18 yearstreated at pediatric oncology department, South Egypt Cancer Institute from 2011 to 2015 were enrolled. Age, sex, initial total leucocytic count, immunophenotyping, central nervous system (CNS) involvement, mediastinal mass, bone marrow (BM) response on day fifteen and after finishing induction remission were compared to ALC recovery on day 15 (ALC-15) and day 29 (ALC-29) of induction response. Also, prognostic impact of ALC recovery on event free survival (EFS) and overall survival (OS) was evaluated. Results: ALC didn't show any significant relation to known patients' prognostic factors. Patients with low ALC didn't show significant lower response on day 15 and post induction evaluation from those with high ALC (p = 0.74, 0.6 respectively). ALC-15 ≥ 500 cells/uL showed a prognostic significance as patients with ALC-15 < 500 cells/uL had a poorer outcome (4-EFS 47.8% ± 0.12%) than patients with ALC-15 ≥ 500 cells/uL who carried a better outcome (4-EFS 66.3% ± 0.05%). Neither ALC-500 (day 29) nor ALC-350 (day 15 & day 29) had impact on OS or EFS. In multivariate analysis, ALC-15 < 500 cells/uL still had a poor impact on outcome (OR 2.56, 95% CI 1.27-5.14) with d15-BM response (OR 2.99, 95% CI 1.35-6.61) and age < 10 (OR 1.96, 95% CI 1.01-3.69