In patients undergoing rapid lysis of leukemic cells associated with initial therapy, hyperuricemia, hyperphosphatemia, and hyperkalemia can be prevented by close attention to hydration, urine alkalinization, and electrolyte monitoring. Although basic principles in treating ALL and AML are similar, the drug regimens differ. ALL is the most common malignancy in children, with a peak incidence from ages 3 to 5 yr. It also occurs in adolescents and has a second, lower peak in adults. Most investigatory protocols select patients with poor risk factors for more intense therapy because the increased risk and toxicity from treatment is outweighed by the greater risk of treatment failure leading to death.
Several regimens emphasize early introduction of an intensive multidrug regimen.
Remission can be induced with daily oral prednisone and weekly IV vincristine with the addition of an anthracycline or asparaginase. Other drugs and combinations that may be introduced early in treatment are cytarabine and etoposide, and cyclophosphamide. The combinations and their dosages are modified according to the presence of risk factors. Most regimens include maintenance therapy with methotrexate and mercaptopurine. The duration of therapy is usually 2.5 to 3 yr but may be shorter with regimens that are more intensive in earlier phases.