| Abstract: | The authors have examined 134 children with acute lymphoblast cell leukemia (ALCL) who were treated at the Research Institute of Pediatric Oncology and Hematology, Russian Cancer Research Center, in January 1990 to November 1999, and followed up till March 1, 1999. The mean duration of follow-ups was 57.46 +/- 2.87 months. The minimum follow-up was 4 months. The immunophenotypical features of stem cell immunological subvariant of ALCL identified from the presence of 10% or 15% of CD34+ lymphoblast cells were similar in the leukemia clone. There is evidence for the isolation of the least mature, stem-cell immunological subvariant of ALCL in children. The immunophenotypic features of stem-cell ALCL in children were as follows: the expression of myeloid antigens (linear and different marker leukemias) and the higher rates of involvement of B-cell leukemias. The clinical and hematological features of stem-cell versus CD34-negative ALCL in children were the low levels of leukocytes (p = 0.009) and blast cells (p = 0.018) in the peripheral blood at diagnosis. At the same time, stem-cell ALCL showed a poorer prognosis. Moreover, blast cell CD34 antigen expression deteriorated prognosis for pre-pre-B (common) immunological variant of ALCL (p = 0.035). Intensified ALCL treatment programmes improved relapseless survival of patients with stem-cell ALCL (p = 0.0042). |
