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 ou tcome. Ln this paper, we describe the outcome in 37 ALL infants treated bet ween 1989 and 1995 in Japan. Patients had characteristic findings of infant ALL, including hyperleukocytosis >100 X 10(9)/1 ( 15/37, 41 % ), blast cel ls 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 e vent-free survival (EFS) was 33%. The EFS was 13% for infants aged <26 week s at diagnosis and 43 % for infants aged >26 weeks. Infants who hall blast cells with CD10 negative phenotype with 11q23/MLL involvement were also ass ociated with poor prognosis. However. infants with CD10 positive blasts wit hout 11q23/MLL involvement had a better outcome (EFS 75 %). These results s uggest that intensive chemotherapy is effective for patients with good prog nostic factors. but for infants with poor prognostic factors a more aggress ive approach such as stem cell transplantation might be necessary. (C) 1999 The Japanese Society of Hematology.