Clinical Characteristics and Treatment Strategy of Adolescent Leukemia

Abstract

Clinical characteristics and treatment strategy of Japanese adolescent leukemia were analyzed and compared with those of the United States and Europe. The ratio of acute lymphoblastic leukemia (ALL) /acute myelogenous leukemia was decreased to 1 : 1 in the late adolescent period. Chronic myelogenous leukemia and myelodysplastic syndrome was increased in adolescents. The characteristics of adolescent ALL were found in the frequency of biological features, namely, a decrease of hyperdiploidy (>50 chromosomes) and TEL-AML1 translocation, which were favorable prognostic factors, an increase of Philadelphia chromosomes and hypodiploidy, which were unfavorable factors, an increase of FAB-L2 morphology and T cell phenotypes. In the U.S. and Europe, T cell ALL, formerly an unfavorable prognostic factor, has turned out to be a favorable prognostic factor by the intensive chemotherapy, indicating that treatment is the most important prognostic factor. Age remains an important prognostic factor. A collaborative study by pediatricians and internists should be undertaken to investigate the pathological features and to improve the treatment outcome of Japanese adolescent leukemia.