Early postinduction intensification therapy improves survival for children and adolescents with high-risk acute lymphoblastic leukemia: A report from the children's oncology group

Abstract

Longer and more intensive postinduction intensification (PII) improved the outcome of children and adolescents with "higher risk" acute lymphoblastic leukemia (ALL) and a slow marrow response to induction therapy. In the Children's Cancer Group study (CCG-1961), we tested longer versus more intensive PII, using a 2 × 2 factorial design for children with higher risk ALL and a rapid marrow response to induction therapy. Between November 1996 and May 2002, 2078 children and adolescents with newly diagnosed ALL (1 to 9 years old with white blood count 50 000/mm3 or more, or 10 years of age or older with any white blood count) were enrolled. After induction, 1299 patients with marrow blasts less than or equal to 25% on day 7 of induction (rapid early responders) were randomized to standard or longer duration (n = 651 + 648) and standard or increased intensity (n = 649 + 650) PII. Stronger intensity PII improved event-free survival (81% vs 72%, P