[Varying course of pancytopenia after busulfan treatment of chronic myelocytic leukemia (CML)].

In 84 patients with chronic myeloid leukaemia receiving a cytostatic monotherapy with busulfan, an aplastic syndrome developed which was confirmed by a biopsy of the pelvis crest and examination of the sternal marrow. The time interval until pancytopenia was detected varied considerably in each case, ranging between 6 and 126 months. There are no correlations to the initial doses of busulfan. 3 patients died of the immediate effects of the bone-marrow damage caused by busulfan. In 4 from 6 of the following pancytopenic patients the leukocyte values lay between 12,800/microliter and 80,400 microliter when busulfan adminstration was interrupted. Thus, it is scarcely possible to give any reliable informations about a leukocyte limit value as a standard for an interruption of therapy in order to prevent bone-marrow aplasia. Taking this into account, the conclusion may be drawn that relatively short control intervals have to be made in this monochemotherapy of CML which often can be used successfully for many years.