Early postinduction intensification therapy is essential in childhood acute lymphoblastic leukemia

Postinduction intensification therapy (PII) has been key to success in the treatment of many types of childhood cancer and has led to an increase in cure rates during the past 3 decades. This Practice Point commentary discusses the recent findings of the Children's Cancer Group CCG-1961 study, which enrolled 2,078 children and adolescents with acute lymphoblastic leukemia. Patients with rapid marrow response to induction therapy were randomly allocated in a 2 × 2 factorial trial to receive either longer or increased intensity PII. A clear advantage—9% improved event-free survival and 6% improved overall survival at 5 years—was shown for more-intensive but not for longer PII; however, a high incidence of osteonecrosis and an increased rate of infections were observed in rapid early responders. This commentary emphasizes the need to balance the beneficial effects of PII in terms of disease control against the possibility of potentially debilitating late adverse sequelae.