Chronic granulocytic leukemia: cytogenetic conversion of the bone marrow with cycle-specific chemotherapy.

Sixteen patients with Ph1-positive chronic granulocytic leukemic (CGL) were entered on a pulsing chemotherapy program consisting of cytosine arabinoside 100 mg/sq m/day X 5 and thioguanine 100 mq/sq m/day X 5 every 21 days in an attempt to convert the Ph1-positive marrow to a Ph1-negative state and thereby achieve a complete remission. Twelve patients had an adequate trail of drug treatment, and ten of these had adequate chromosome examinations. There were two "conversions," one of which was maintained for 5+ mo, while the other was transient. The program was unacceptable, however, to most patients due to intolerable nausea and vomiting. Thus a prospective chemotherapeutic attempt to convert a Ph1-positive marrow without splenectomy has induced a conversion in two of ten patients. Other regimens which might induce less nausea and vomiting and a higher rate of conversions should be sought in future attempts to alter the invariably fatal outcome of CGL.