[Recent advance in treatment of childhood acute lymphoblastic leukemia]

The five-year event-free survival of nearly 80% in childhood acute lymphoblastic leukemia (ALL) achieved in the 1990 s attested to the effectiveness of risk-directed therapy developed through well-designed clinical trials by 4 groups in clinical study, containing CCLSG, TCCSG, KYCCSG and JACLS. Japanese Pediatric Leukemia/Lymphoma Study Group (JPLSG) was organized in 2003 and includes all four clinical study groups in Japan. For the purpose of finding the standard treatment, JPLSG protocols have been started for three distinct and rare types of ALL, including mature B-ALL, infant ALL and Ph+ALL. The 2004 ALL protocol of Childhood Cancer and Leukemia Group in Japan (CCLSG) contained a new 2-step stratification based on initial age/WBC count and minimal residual disease at day 91. The JPLSG/ALL committee was started in 2005 for discussing the ongoing need for cooperative clinical study in Japan and the possibility of nelarabine-containing regimen for T-ALL.