Treatment of infant acute lymphoblastic leukemia in Japan

Although current chemotherapeutic regimens cure as many as 70% of children with acute lymphoblastic leukemia (ALL), infants continue to show a poor outcome. Ln this paper, we describe the outcome in 37 ALL infants treated between 1989 and 1995 in Japan. Patients had characteristic findings of infant ALL, including hyperleukocytosis >100 X 10(9)/1 ( 15/37, 41 % ), blast cells with a CD10-negative phenotype (30/37. 81%). and 11q23/MLL involvement (21/37, 57%). Seven were treated according to Aggressive Treatment Research Group protocol. 15 according to the Ministry of Health and Welfare protocol, and 15 according to protocols of other institutions. The 3-year overall event-free survival (EFS) was 33%. The EFS was 13% for infants aged <26 weeks at diagnosis and 43 % for infants aged >26 weeks. Infants who hall blast cells with CD10 negative phenotype with 11q23/MLL involvement were also associated with poor prognosis. However. infants with CD10 positive blasts without 11q23/MLL involvement had a better outcome (EFS 75 %). These results suggest that intensive chemotherapy is effective for patients with good prognostic factors. but for infants with poor prognostic factors a more aggressive approach such as stem cell transplantation might be necessary. (C) 1999 The Japanese Society of Hematology.