Long-term disease-free survival in acute nonlymphocytic leukemia.

Twenty-six of 45 adults (58%) with acute nonlymphocytic leukemia who were treated with intensive induction chemotherapy over 5 yr ago entered complete remission. All patients entering remission were placed on weekly maintenance chemotherapy consisting of cytosine arabinoside and 6-thioguanine. The median duration of complete remission was 17 mo and 7 patients (27%) remained in their initial remission for 62 + to 102 + mo. All but one of the patients in complete remission over 5 yr have had treatment discontinued. Only 1 of 7 patients in remission for more than 5 yr has relapsed. Median survival is 26.5 mo, and 8 patients (31%) currently remain alive without evidence of leukemia 63--105 mo from diagnosis. It is possible to achieve long-term disease-free survival with chemotherapy alone in acute nonlymphocytic leukemia.