355 PRACTICA MEDICALÅ – VOL. 10, NR. 4(42), AN 2015 PRACTICA MEDICALÅ 9 CERCETARE ŞTIINȚIFICĂ Corresponding author: Claudia Dita, MD, PhD student, Bucharest, 258 Fundeni Street, District 2, 022328, Bucharest, Romania E-mail: claudia_dita77@yahoo.com Outcome in pediatric acute lymphoblastic leukemia in children and adolescents using contemporary protocols of chemotherapy – experience of a single Pediatric Hematology-Oncology Center Claudia DITA 1 , Anca COLITA 2,3 , Mirela ASAN 3 , Anca GHEORGHE 4 , Cerasela J ARDAN 2,4 , Mihaela DRAGOMIR 2,5 , Constantin ARION 2,3 1 „Stefan S. Nicolau“ Institute of Virology, Bucharest 2 „Carol Davila“ University of Medicine and Pharmacy, Bucharest 3 Pediatric Clinic, Fundeni Clinical Institute, Bucharest 4 Fundeni Clinical Institute, Bucharest 5 Center of Hematology and Bone Marrow T ransplantation, Fundeni Clinical Institute, Bucharest ABSTRACT The authors studied the outcome of a cohort of pediatric acute lymphoblastic leukemia (ALL) patients (33 children and adolescence) diagnosed and treated conforming to modern Chemotherapy Protocols (ALL IC- BFM 2002, Interfant 06) in a single Center – Pediatric Clinic, Fundeni Clinical Institute, Bucharest, Romania. They analyzed the factors which determine the prognosis and the outcome of these patients in the course of multi-agent systemic chemotherapy to stand at the base of these Protocols: initial age, initial leukocyte count, blasts immunophenotype, cytogenetic and molecular abnormalities, initial response to cortisone, risk groups, time to obtain the complet remission, etc. Among the factors they discussed, a great value was proven to have the minimal residual disease (MRD) determination in certain check points of Protocols and revaluation of patients risk conforming to MRD values. Using the modern Protocols and continuously watching the evolution on therapy enable the authors to obtain results close to those of European and North American Pediatric Hematology Oncology Centers: OS 90.9% by 40 Mo and EFS 72.7% at the end of the same period of time. Keywords: children and adolescents, acute lymphoblastic leukemia, prognosis, minimal residual disease INTRODUCTION It is now widely accepted that pediatric ALL is a biologically heterogeneous disease. (1) This heterogeneity manifests also in what concerns the results of therapy and the outcome. Modern pediatric ALL treatment Protocols employ risk-based therapy to reduce the toxici- ty in patients with low risk ALL (i.e. low risk of treatment failure), and to use aggressive thera- py for those with a high risk of relapse and therefore an unfavorable outcome.