The best way to cure patients with acute lymphocytic leukemia (ALL) is to give large doses of several chemotherapeutic drugs in a short time. This will kill leukemia cells quickly before they can become resistant to the drugs. The purpose of remission induction chemotherapy is to remove leukemia cells from the bone marrow. Remission is defined as less than 5 percent of leukemia cells remaining in the bone marrow and normal blood counts. More than 95 percent of children and 70 percent to 80 percent of adults with ALL will achieve a complete remission after initial chemotherapy.

Treatment for children and adults is similar, although treatment for children is more intense and uses more types of drugs. Chemotherapy with Oncovin^® (vincristine) and steroids produces complete remission in 50 percent of adults. The addition of an anthracycline drug Cerubidine^® (daunorubicin) or Idamycin^® (idarubicin) increases the complete remission rate to 70 percent to 85 percent. New drugs continue to be added to remission induction therapy, and most current treatments now use five or more different drugs, which may include asparaginase, cyclophosphamide, cytarabine, or others. The use of additional drugs has not been shown to increase the complete remission rate, however some have demonstrated a faster time to achievement of complete remission, which may be associated with prolonged remissions.

Strategies to Improve Remission Induction

Chemotherapy using multiple drugs, improvements in supportive care, and patient and physician participation in clinical studies have all improved the safety and effectiveness of induction therapy. Researchers are investigating the following strategies that may further improve ALL treatment.

• Increased dose intensity - Because higher doses of chemotherapy kill more leukemia cells than lower doses, many doctors believe that increasing the dose or dose intensity of chemotherapy drugs may improve remission and cure rates of patients with ALL. Increasing the dose intensity can be accomplished by increasing the number of doses of drugs in remission induction therapy, increasing the dose intensity of postremission therapy, or by administering very high-dose chemotherapy together with stem cell transplantation as part of the overall treatment strategy.

However, increasing dose intensity increases the risk of side effects. You should discuss benefits versus side effects with your doctor before deciding to take part in a dose-intensive treatment regimen.

• New drug development - All new drugs for the treatment of patients with ALL are tested first in patients with relapsed or refractory disease. When they are found to be effective, they are then evaluated in remission induction regimens. This is more relevant for adults than children because more than 95 percent of children achieve a complete remission with existing treatment regimens.

• Supportive care - Supportive care refers to treatments designed to prevent and control the side effects of cancer and its treatment. Side effects not only cause patients discomfort, but also may prevent the optimal delivery of therapy at its planned dose and schedule. To achieve optimal outcomes from treatment and improve quality of life, it is very important that side effects resulting from cancer and its treatment are appropriately managed. Supportive care measures include red cell and platelet transfusion, antibiotics, and growth factors, such as G-CSF (Neupogen^®) or erythropoietin.