Vincristine and prednisolone therapy in blast crisis of chronic myelogenous leukaemia in childhood.

6 cases of chronic myelogenous leukaemia (CML) blast crisis in childhood were treated with vincristine and prednisolone (V-P). In 3 terminal transferase ((TdT)-positive cases, blast cells were lymphoid in appearance. All 3 TdT-positive patients entered a complete remission but developed meningeal leukaemia. The mean duration of survival from the onset of blast crisis was 32 months. In 3 TdT-negative cases, V-P therapy was ineffective. The results of this study suggest that V-P therapy is more effective for CML blast crisis in childhood with TdT positive blast cells and that prophylactic central nervous system treatment is necessary to prevent meningeal leukaemia.