2.8.3Maintenance Treatment

•Risk-adapted maintenance treatment of different duration prevents recurrence of ALL

•Duration of treatment is 1.5–2.5 years with daily 6-mercaptopurine, and once weekly methotrexate, with or without reinduction treatment. Different maintenance schedules and chemotherapy combinations are being tested in cooperative group trials

•The dosage of cytotoxic agents must continuously be adapted to the child’s condition and blood cell counts at weekly to biweekly intervals

•A lifestyle as normal as possible as before the diagnosis has to be followed during maintenance treatment

2.9Prognosis

See also “prognostic factors” page 23

•Approximately 80% of children with ALL survive without relapse with 7–10-year follow-up after diagnosis (long-term remission)

•In about one of five children, a relapse of ALL occurs during maintenance treatment, within the first 6 months after treatment ends or later. The risk of leukemia (recurrence) 5–7 years after diagnosis is as low as in children without leukemia

•A relapse within the first 6 months after treatment stops is associated with a poor prognosis

•A late relapse (more than 6 months after termination of maintenance treatment) usually has a better prognosis, depending on the characteristics of the leukemic cells, on the isolated involvement of CNS only, and on the isolated testicular relapse

2.10Management of Complications and Side Effects

•Prophylactic treatment of tumor lysis syndrome, hyperleukocytosis, and uric acid nephropathy (see Chap. 18)

•Dehydration, infection, anemia, bleeding, and alteration of liver and kidney functions have to be continuously observed and corrected during the different treatment phases

•Anemia:

–Support with transfusion of erythrocytes is indicated when the hemoglobin level is less than 6 g/l and/or when clinical symptoms of anemia occur: 10–15 ml erythrocytes/kg body weight per transfusion

•Bleeding:

–Due to thrombocytopenia (decreased production, suppression by cytotoxic drugs), and/or coagulopathy

–Treatment: platelet transfusion, substitution of coagulation factors, antileukemic treatment