Increased survival in childhood acute nonlymphocytic leukemia after treatment with prednisone, cytosine arabinoside, 6-thioguanine, cyclophosphamide, and oncovin (PATCO) combination chemotherapy.

One hundred-sixty-three children with acute nonlymphocytic leukemia (ANLL) were treated with a multiple-drug induction program (PATCO) consisting of prednisone (PDN), cytosine arabinoside ((Ara-C), 6-thioguanine (6-TG), cyclophosphamide (CPM), and Oncovin (VCR). Ninety-six, 59%, obtained a remission. Remission was maintained with daily 6-TG and four-day pulses of Ara-C and CPM with a single dose of VCR every 28 days. The median duration of remission was 11.5 months. Certain prognostic factors affected induction rate and remission duration. Initial white blood count (WBC) was a significant factor in achieving a remission, whereas age, sex, and type of ANLL had no effect. Initial WBC, age, and sex had a significant effect on remission duration, but type of ANLL had no effect. Relapsing patients were treated with daunomycin and 5-azacytidine. The reinduction rate was 53% with a median second remission duration of 190 days. Overall survival for the 163 patients is 55.4% at 12 months, 31.5% at 24 months, 21.4% at 36 months, and 19% at 48 months.