International Chronic Myeloid Leukemia Pediatric Study

The purpose of the study is to describe and characterize CML in a large pediatric cohort of patients.

International study of CML in children and adolescents 1. Rational and objectives 1.1 Rational: Chronic myeloid leukaemia (CML) is a malignant disease of the hematopoietic system characterized by the presence a reciprocal translocation between chromosome 9 and 22. CML is a very rare disease in children and adolescents, accounting for 2% to 3% of leukemias in this age range, with an annual incidence of 1 case per million children (1,2,3). A recent report of the French National Registry of childhood leukemia and lymphoma revealed an incidence of 0.6 case per million children under 15 years of age between 1990 and 1999 in France. Characteristics of CML seem to differ in this age range compared with adults (5). In Europe, very few children and adolescents with CML is included in national trials nor are they recorded in regional or national registries. A European CML-Registry was established to improve the knowledge concerning this disease but only patients aged 18 years and over are registered. In Europe, a national registry was recently set up in UK to collect prospectively data in patients less than 15 years of age with CML. However, limited information is available concerning the epidemiology and the characteristics of CML in childhood. There are currently two main treatment options in children with CML. The first option is allogeneic hematopoietic transplantation which is a potentially curative therapy in children with a suitable donor. Transplantation with a matched unrelated donor resulted in an overall survival rate of 66% at 3 years in children with CML in first chronic phase (6). A 5-year overall survival rate of 73 % was reported in those transplanted with a matched sibling donor (7). The second option is treatment with imatinib mesylate, an orally administered antityrosine kinase. Imatinib mesylate is well tolerated and cytogenetic and molecular remissions can be achieved in a significant percentage of children with CML (8, 9). However, the ability of imatinib mesylate to cure the disease remains unknown. In adults with CML, Sokal and Hasford reported 2 distinct staging systems able to distinguish patient groups with different survival. These scoring systems were determined in cohorts of patients including adults and children, but the data of the younger patients were not analysed separately. Moreover, the Sokal score was determined in patients treated with busulfan or hydroxyurea and the Hasford score in patients receiving IFN therapy. Identification of prognosis factors and determination of a prognostic scoring system in children and adolescents with CML are essential to optimize individual treatment strategy in this age group. All these points justify the need for an international network to better describe this rare disease in children and adolescents and to optimize individual treatment strategy. 1.2 Objectives. The main objectives of the study are the followings: * To describe the characteristics of CML in a large trial.show_full_description

Inclusion Criteria: * patients less than 18 years of age * diagnosed Philadelphia positive and/or BCR-ABL positive Chronic Myeloid Leukemia (CML) all phases Exclusion Criteria: * patients more than 18 years of age at diagnosis of CML