Treatment of acute myeloid leukemia in elderly patients: the influence of maintenance therapy (BGM 84 protocol).

Ninety-two elderly patients (ages 50-70) with "de novo" acute myeloid leukemia were given induction chemotherapy consisting of aclacinomycin-A (ACLA) (100 mg/m2/day x 3) and cytosine arabinoside (ARA-C) (100 mg/m2 day, continuous infusion, 7 days). Fifty-one patients (55%) achieved complete remission (CR), 8 patients exhibited drug resistance and 33 patients died during chemotherapy or aplasia. Three patients had severe cardiac toxicity. The only prognostic factor significantly affecting CR was the initial leukocyte count. After consolidation using ACLA (80 mg/m2/day x 2) and ARA-C (100 mg/m2/day x 5), 47 CR patients were randomly assigned to 2 different treatment arms: 23 patients (Group A) received intensive sequential chemotherapy consisting of 4 monthly courses of 8 different drugs while 24 other patients (Group B) were given ACLA and ARA-C at regular intervals, associated with continuous chemotherapy consisting of 6-mercaptopurine, methotrexate and androgens. The probability of disease-free survival at 2 years was significantly higher (33 +/- 22%) for Group B patients than for Group A (13 +/- 16%) (P less than 0.05). We conclude that continuous maintenance chemotherapy may be useful in increasing the number of long-term survivors, at least in the elderly who have not received very intense consolidation chemotherapy following CR.