Results of Stem Cell Transplantation in Children with CML in Comparison with Treatment with Cytostatics alone or with Interferon alfa. Report of the Polish Children’s Leukemia/ Lymphoma Study Group

Philadelphia positive chronic myeloid leukemia (CML Ph+) is a malignant clonal hematological disease of pluripotent stem cell representing 2–5% of all childhood leukemias [2]. The incidence of CML increases with age and is 1 per 100 000 at the age of 20 [2]. The male to female ratio is 1.8:1 [1]. CML in children remains one of the major problems, because of its progressive clinical course, unless cured by bone marrow transplantation (BMT). Conventional chemotherapy with the use of hydroxyurea (HU) or busulfan (BUS) relieves clinical symptoms and controls the leucocytosis in chronic phase of the disease, but hardly influences overall survival [2]. Interferon alfa (IFN) can lead to very adequate control of leucocytosis and in spite of its possible negative effect on BMT outcome, IFN seems to be an alternative option for those, who do not have a suitable donor for BMT. Moreover, a minority of patients can achieve a major cytogenetic response or elimination of the Philadelphia chromosome or the bcr/abl fusion product. At present, the only known potentially curative therapy is stem cell transplantation (SCT) from either HLA-matched related or unrelated donor [3]. This form of therapy is limited by the availability of a suitable donor [3, 11]. Children can have an 80% or greater chance of long-term survival with a matched related or unrelated donor, provided they are transplanted early in the disease course [4].