Silvia Regina Brandalise Department of Pediatrics University of Campinas
Caixa Postal 1170 13083-970 Campinas,Sao Paulo Brazil

INTRODUCTION

Modern treatments for acute lymphocytic leukemia in children consistently produced in this last decade approximately 70 to 80% five year disease free survival for all risk groups. Intensified or "augmented" therapies failed to improve those results. Efforts have been done to identify during the first days of therapy, the group of patients known as slow early responders, who carries a significant poor prognosis.
Perhaps for them new strategies based on different pharmacokinetics principles must be done in order to achieve better cure rates.
The prognostic significance of day 4 or day 7 marrow response,as well as, day 8 peripheral blast count reduction is well established by different investigators. However, considering by one side the known difficulties in the routine hematology laboratories to diagnose, after one week of intensive cytoreduction, what is a real lymphoblast and, by the other side, in order to avoid the discomfort involved in a centralized review, we proposed as an alternative to be determined, the WBC counts at day 8 of treatment, as a predictor for therapy failure.