[A comparative clinico-morphological analysis of acute myelo- and myelomonoblastic leukemias in children and adults].

Previous morphocytochemical, immunological and cytogenetic analyses of blast cells in 174 children and 188 adults admitted to Cancer Research Center have shown that compared to adults in children leukemic precursors belong to earlier stage of differentiation similar to polypotent cell. The analysis covered 2 FAB-variants of ANLL comparable by the number of patients and intensity of the given chemotherapy (M2 and M4 ANLL FAB variants). The study included 65 children (50 with M2 and 15 with M4 FAB variants) and 43 adults (26 with M2 and 17 with M4 FAB variants) given therapy of standard intensity in the regimen 3+7 and 2+5. The children more frequently demonstrated involvement of the liver, spleen and peripheral lymph nodes. The percentage of complete remissions in both groups was not significantly different. 2- and 3-year recurrence-free survival was similar in two age groups with M2 FAB variants of ANLL. However, in M4 variant in adults this survival made up 18% against 0% in children. The differences may arise from lower peroxidase activity in children than in adults. It is suggested that M4 FAB variant in adults may indicate better prognosis than in children. Therefore, therapy in children with M4 FAB ANLL variant should be intensified.