Patients over 50 years: Mercaptopurine (50 mg/m2), PO, days 1 to 7, 28-35 and 56-63;methotrexate (1,5 g/m2) IV/24 hours, day 1, 28 and 56; VM-26 (150 mg/m2)/12 hours, IV days 14 and 42; ARA-C (500 mg/m2)/12 hours, IV days 14-15 and 42-43; intrathecally treatment, days 1, 28 and 56.