Treatment of resistant disease.

Resistant AML encompasses two groups of patients: those with refractory leukemia and those whose leukemia has relapsed. Refractory leukemia is disease that does not respond to initial induction chemotherapy with cytarabine and an anthracycline. Patients with refractory leukemia are likely to have disease with adverse cytogenetics, a history of antecedent hematologic disturbance, adverse immunophenotypic features, and expression of multiple drug resistance. On the other hand, relapsed leukemia is leukemia that recurs following a CR.The duration of CR greatly affects the patient's prognosis and response to additional treatment. Patients with relapsed leukemia are heterogeneous with variable pretreatment characteristics.