Response of therapy-associated acute nonlymphocytic leukemia to intensive induction chemotherapy

Among 31 consecutive patients who developed acute nonlymphocytic leukemia following treatment with chemotherapy or radiation therapy, 17 were treated with intensive chemotherapy aimed at inducing a complete remission. Seven of these 17 patients (41%) obtained a complete remission that ranged in duration from 2 to 11 (median 3) months. Two additional patients who failed to develop normal peripheral blood counts despite postinduction bone marrows that were normocellular and free of leukemia were classified as nonresponders. The median time to complete remission and median duration of leukopenia (WBC less than 1,000/mu 1) were 34 days and 23 days, respectively. Induction chemotherapy was complicated by fever in all patients, documented infection in six patients, and death secondary to sepsis in three. Survival of the 17 patients ranged from less than 1 to 39 (median 4) months. Patients achieving a complete remission had a median survival time of 10 months compared to 2 months for the nonresponders. The other 14 patients received only supportive care and had a median survival of 2 months. These findings indicate that therapy-associated acute nonlymphocytic leukemia (t-ANLL) can frequently respond to chemotherapy and that achieving a complete remission is associated with longer survival. Although these results are encouraging, patients with t-ANLL still have a relatively poor prognosis and efforts directed at improving treatment outcome need to be continued.