Approximately 70–80% of adults with acute myelogenous leukemia under age 60 achieve complete remission. High-dose postremission chemotherapy leads to cure in 30–40% of these patients, and high-dose cytarabine has been shown to be superior to therapy with lower doses. Allogeneic bone marrow transplantation (for younger adults with HLA-matched siblings) is curative in approximately 60% of cases. Autologous bone marrow transplantation is a promising new form of therapy that may cure 50–70% of patients in first remission. One recent study demonstrated the superiority of this approach to nonablative chemotherapy. Older adults with acute myelogenous leukemia reportedly achieve complete remission approximately 50% of the time. In selected cases, older patients may be treated with intensive chemotherapy with curative intent.
Ninety percent of adults with acute lymphoblastic leukemia achieve complete remission. Subsequent postremission chemotherapy is curative in 30–50% of adults. Acute lymphoblastic leukemia in children is much more responsive to therapy, with 95% achieving complete remission and 60–70% of these being cured with postremission treatment that is far less toxic than that necessary for adults.
Once leukemia has recurred (“relapsed”) after initial chemotherapy, bone marrow transplantation (BMT) is the only curative option. Allogenic BMT can be used for those under age 55 with histocompatible sibling donors and is successful in 30–40% of cases. Autologous BMT may be curative in 30–50% of cases after a second remission is achieved.